BIOMARKER FOR COGNITIVE DYSFUNCTION DISEASES, AND METHOD FOR DETECTION OF COGNITIVE DYSFUNCTION DISEASES USING THE BIOMARKER

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of copending application Ser. No. 13/995,682, filed on Sep. 3, 2013, which was filed as PCT International Application No. PCT/JP2011/007150 on Dec. 21, 2011, which claims the benefit under 35 U.S.C. §119(a) to Patent Application No. 2010-285726, filed in JAPAN on Dec. 22, 2010, all of which are hereby expressly incorporated by reference into the present application.

FIELD OF THE INVENTION

The present invention relates to novel biomarkers for mild cognitive impairment or cognitive impairment including Alzheimer disease, and methods for detecting cognitive impairment using such biomarkers.

BACKGROUND OF THE INVENTION

The commonly used means to differentiate between normal and non-normal states of a human subject using his or her biological materials are mainly those which have been used in the field of diagnostics. Most frequently used are those methods which target biomarkers in blood. It has been practiced in this field to comparatively measure the amount of a specific protein or a peptide that is less than 10,000 in molecular weight or, in the case of enzyme protein, enzyme activities in samples from normal (healthy) subjects and those from diseased individuals to help diagnosis. Here, prior to testing real samples, measurements are done on a fixed number each of samples from healthy controls and patients with certain disease with respect to the amount (s) or activity (activities) of single or multiple specific proteins or peptides and the ranges of abnormal and normal values are respectively determined. The sample to be evaluated is then analyzed by the same method and the resultant value is judged with respect to whether it is in normal or abnormal range.

In the actual measurements, the amount(s) of specified protein(s) or peptide(s) in test samples, as such or after dilution, are determined by the use of enzyme-linked immmunosorbent assay (ELISA) which uses a primary, or secondary, antibody labeled with an enzyme reacting with a substrate that yields a color upon reaction, chemiluminescent immunoassay (CLIA), radioimmunoassay (RIA) which uses a primary, or secondary, antibody labeled with a radioisotope, and, if the protein is an enzyme, the measurement of the activity of the enzyme by adding its substrate and determining the intensity of produced color, etc. These antibody-based methods are called as enzyme-, fluorescence- or radioisotope-labeled methods, respectively. In addition, there is a method where an enzyme reaction product derived from the corresponding substrate is determined by high performance liquid chromatography (HPLC). In further addition, there is a method where HPLC is combined with mass spectrometer, called LC-MS/MS, and there is a method called selected reaction monitoring (SRM)/multiple reaction monitoring (MRM) that utilizes LC-MS/MS. In another method to determine the concentration in a sample, it is appropriately pretreated, and separation of proteins or peptides is attained by 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and target protein or peptide is determined by silver staining, Coomassie blue staining or immunological staining (Western blotting) that uses an antibody to target protein or peptide. In still further addition, there is a method which utilizes mass spectrometry to determine the amount of target protein or peptide in samples fractionated by column chromatography. Instead of column chromatography, protein chips and magnetic beads may also be utilized for purpose of pretreatment.

Furthermore, these inventors have developed an immunoMS method, where target protein or peptide is captured by beads (including magnetic ones) with linked antibody to the protein or peptide, eluted from the beads, and determined by mass spectrometry. Further, intact proteins have been reported to be analyzed by mass spectrometry using above-mentioned methods after digestion with trypsin etc. (Patent Document 1). Here, intact target proteins are selected either by fractionation or by adsorption to an adsorbant specific to them and then determined by mass spectrometry.

Number of patients suffered from cognitive impairment like Alzheimer disease is increasing rapidly along with increasing of old-age population in Japan. It is estimated that number of patients is 1.3 million in 1995 and it will be 1.9 million in 2005 and will reach to about 3.0 million in 2020. It is reported that 60-90% of cognitive impairment is Alzheimer disease. As manifestation of Alzheimer disease is not only loss of memory but several disturbance in daily life, increase of patients of this disease is becoming an important social issue to be solved. In Japan, Donepezil-hydrochloride, anti-acetylcholine esterase inhibitor has been available for medical treatment for Alzheimer disease since 1999, and it let progress of cognitive impairment in these patients be ‘slow-down’ efficiently, if the patient is diagnosed at early stage. Thus, in medication of Alzheimer disease, most important issue is ‘early diagnosis’ to treat the patients effectively by drug available at present and new coming drug.

Followings are major criteria for diagnosis of Alzheimer disease described in DSM-IV, which is published by American Psychiatric Association.

• • A. The development of multiple cognitive deficits manifested by both
  • (1) memory impairment (impaired ability to learn new information or to recall previously learned information)
  • (2) one (or more) of the following cognitive disturbances:
    • a) aphasia (language disturbance)
    • b) apraxia (impaired ability to carry out motor activities despite intact motor function)
    • c) agnosia (failure to recognize or identify objects despite intact sensory function)
    • d) disturbance in executive functioning (i.e., planning, organizing, sequencing, abstracting)
  • B. The cognitive deficits in Criteria A1 and A2 each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning. (Non-patent reference 1)

There are several types of neurological disorders related to Alzheimer disease (AD). As cognitive dysfunction appears gradually in dementia including AD, there is a disease status of pre-stage of dementia. This stage is called as mild cognitive impairment (MCI). In United States, 10% MCI develops to AD within 1 year, and 50% of MCI develops to AD within 4 years. MCI is defined as a condition characterized by newly acquired cognitive decline to an extent that is beyond that expected for age or educational background, yet not causing significant functional impairment, and not showing disturbance in daily life. Frontotemporal dementia (frontotemporal lobar degeneration) (FTD) shows loss of personal awareness, loss of social awareness, hyperorality, and stereotyped, perseverative behavior. These clinical characteristics are different from AD. FTD includes Pick's disease, which is characterized by microscopically Pick bodies usually found in limbic, paralimbic, and ventral temporal lobe cortex. Dementia with Lewy bodies (DLB) is characterized by progressive disease and psychiatric symptoms include anxiety, depression, hallucinations (usually visual) and delusions (false beliefs). DLB is thought to be the second most common subtype and 10-30% of dementia is DLB. The symptoms of DLB are caused by the build-up of Lewy bodies. FTD and DLB belong to demented neurological disease as they also lose of memory, their ability to solve problems and maintain emotional control. (Non-patent reference 1)

In description in present patent, cognitive impairment includes AD, MCI and the demented neurological disease.

The screening tests for dementia widely used are the Hasegawa Dementia Scale-revised (HDS-R) and Mini-Mental State Examination (MMSE). In these screening tests, inspector asks several questions and evaluates level of cognitive impairment of each subject by scores. HDS-R is revised version of HDS published in 1991. In FDS-R, test consists of 9 questions to analyses orientation, remembrance, calculation, retain and recall ability, and common sense. Full score is 30 and a person whose score is less than 23 is suspected as dementia. MMSE has been developed in United States to screen and diagnose dementia, and analyses global cognitive function, with items assessing orientation, word recall, attention and calculation, language abilities, and visuospatial (drawing) ability. This test consists of 11 questions, and full score is 30 and a person who has score less than 23 is suspected as dementia. The results of HDS-R and MMSE coincide with each other. Both are used for screening, not for diagnosis and not for staging of disease progression. (Non-patent reference 1)

Neuroimaging test for dementia are Computed tomography (CT) and Magnetic resonance imaging (MRI) which evaluate morphological changes like brain atrophy and ventricular dilation and single-photon emission computed tomography (SPECT) which analyses regional cerebral blood flow and PET which shows brain metabolism by measurement of consumption of oxygen and sugar. SPECT and PET, nuclear imaging technologies, can identify neuronal dysfunction at preclinical stage. However, these neuroimaging cannot be widely used in hospitals because they need special facilities to perform nuclear imaging, and neuroimaging may not be objective test as imaging diagnosis is completely depend on the skill of physician who analyses the mages.

Thus, methods for screening and diagnosis of dementia including AD that are available at present is dependent on tests lacking objectivity and is dependent on expensive instruments, and so it is very difficult to use these tests for screening of early stage-cognitive impairment. If we get blood (serum/plasma) biomarker for cognitive impairment, which enables us objective test using specimens we can easily obtain, we can identify cognitive impairment at early stage (preclinical stage) by blood test using such biomarker. Present patent provides novel biomarkers and a novel and potent diagnostic method for cognitive impairment by using such biomarkers and biomarkers described here.

CITATION LIST

Patent Document

• Patent Document 1, JP-A-2004-333274
• Patent Document 2, JP-A-2006-308533

Non-Patent Document

• Non-Patent Document 1, “The better understanding of Alzheimer's disease.,” edited by Imaharu Nakano and Hldehiro Mizusawa., Nagai Shoten Co., Ltd., 2004 (in Japanese)
• Non-Patent Document 2, Benkirane, N. et al., J. Biol. Chem. Vol. 268, 26279-26285, 1993

SUMMARY OF THE INVENTION

Technical Problem

The present invention aims to present methods to detect mild cognitive impairment or cognitive impairment including Alzheimer disease by using a protein or its partial peptide that differs in presence or absence, or in quantity between non-cognitive impairment subjects (including healthy people, the human subjects that may be affected with any disease and unaffected with psychiatry disease including cognitive impairment. These human subjects are allowed to match the age and gender of patient with cognitive impairment. And, these human subjects are called non-demented control, hereinafter abbreviated to NDC.) and patients with cognitive impairment and further aims to present biomarkers comprising said proteins and said partial peptides to be used to detect mild cognitive impairment or cognitive impairment including Alzheimer disease.

Solution to Problem

These inventors investigated to find out means to detect cognitive impairment and found a peptide capable of detecting mild cognitive impairment or cognitive impairment including Alzheimer disease in the serum. Said peptides found in the present invention are those with significance as a biomarker to detecting in the case of serum not only other biological materials such as blood, plasma, cerebrospinal fluid, and urine. Simultaneously, protein or peptide is the origin of these peptides (hereinafter referred to as intact proteins or peptides) also has significance as biomarkers.

Specifically, these inventors found that a biomarker comprising at least one protein or peptide selected from the group consisting of Complement C3 consisting of amino acid sequence expressed by SEQ ID NO: 1, Transcription factor AP-2 gamma consisting of amino acid sequence expressed by SEQ ID NO: 3, Synapsin-3 consisting of amino acid sequence expressed by SEQ ID NO: 5, Oxytocin receptor consisting of amino acid sequence expressed by SEQ ID NO: 7, Inter-alpha-trypsin inhibitor heavy chain H5-like protein consisting of amino acid sequence expressed by SEQ ID NO: 9, E3 ubiquitin-protein ligase HERC2 consisting of amino acid sequence expressed by SEQ ID NO: 11, Prothrombin consisting of amino acid sequence expressed by SEQ ID NO: 13, Transthyretin consisting of amino acid sequence expressed by SEQ ID NO: 15, Tumor necrosis factor receptor superfamily member 16 consisting of amino acid sequence expressed by SEQ ID NO: 17, Complement C4-A consisting of amino acid sequence expressed by SEQ ID NO: 19, Complement C4-B consisting of amino acid sequence expressed by SEQ ID NO: 21, Fibrinogen alpha chain (isoform 1) consisting of amino acid sequence expressed by—SEQ ID NO: 23, and Fibrinogen alpha chain (isoform 2) consisting of amino acid sequence expressed by SEQ ID NO: 25; or a biomarker comprising protein fragment or peptide of not less than 5 amino acid residues arising from at least one protein or peptide selected from the group consisting of them, could be used as biomarkers to detect cognitive impairment.

Furthermore, these inventors found that a biomarker comprising from the group consisting of Complement C3-derived peptide CO3 consisting of amino acid sequence expressed by SEQ ID NO: 2, Transcription factor AP-2 gamma-derived peptide AP2C consisting of amino acid sequence expressed by SEQ ID NO: 4, Synapsin-3-derived peptide SYN3 consisting of amino acid sequence expressed by SEQ ID NO: 6, Oxytocin receptor-derived peptide OXYR consisting of amino acid sequence expressed by SEQ ID NO: 8, Inter-alpha-trypsin inhibitor heavy chain H5-like protein-derived peptide ITH5L consisting of amino acid sequence expressed by SEQ ID NO: 10, E3 ubiquitin-protein ligase HERC2-derived peptide HERC2 consisting of amino acid sequence expressed by SEQ ID NO: 12, Prothrombin-derived peptide THRB consisting of amino acid sequence expressed by SEQ ID NO: 14, Transthyretin-derived peptide TTHY consisting of amino acid sequence expressed by SEQ ID NO: 16, Tumor necrosis factor receptor superfamily member 16-derived peptide TNR16 consisting of amino acid sequence expressed by SEQ ID NO: 18, Complement C4-derived peptide CO4-1 consisting of amino acid sequence expressed by SEQ ID NO: 20, Complement C4-derived peptide CO4-2 consisting of amino acid sequence expressed by SEQ ID NO: 22, Fibrinogen alpha chain-derived peptide FIBA-1 consisting of amino acid sequence expressed by SEQ ID NO: 24, Fibrinogen alpha chain-derived peptide FIBA-2 consisting of amino acid sequence expressed by SEQ ID NO: 26, and Fibrinogen alpha chain-derived peptide FIBA-3 consisting of amino acid sequence expressed by SEQ ID NO: 27 could be used as biomarkers to detect cognitive impairment.

These inventors brought the present invention to perfection by further succeeding in determining simultaneously these many proteins and its partial peptides by using two-dimensional high performance liquid chromatography-MALDI TOF-MS method (mass spectrometry) and immunoMS method.

The features of the present invention are shown below.

[1] A biomarker for detection of cognitive impairment comprising protein fragment or peptide of not less than 5 amino acid residues arising from at least one protein or peptide selected from the group consisting of Complement C3 consisting of amino acid sequence expressed by SEQ ID NO: 1, Transcription factor AP-2 gamma consisting of amino acid sequence expressed by SEQ ID NO: 3, Synapsin-3 consisting of amino acid sequence expressed by SEQ ID NO: 5, Oxytocin receptor consisting of amino acid sequence expressed by SEQ ID NO: 7, Inter-alpha-trypsin inhibitor heavy chain H5-like protein consisting of amino acid sequence expressed by SEQ ID NO: 9, E3 ubiquitin-protein ligase HERC2 consisting of amino acid sequence expressed by SEQ ID NO: 11, Prothrombin consisting of amino acid sequence expressed by SEQ ID NO: 13, Transthyretin consisting of amino acid sequence expressed by SEQ ID NO: 15, Tumor necrosis factor receptor superfamily member 16 consisting of amino acid sequence expressed by SEQ ID NO: 17, Complement C4-A consisting of amino acid sequence expressed by SEQ ID NO: 19, Complement C4-B consisting of amino acid sequence expressed by SEQ ID NO: 21, Fibrinogen alpha chain (isoform 1) consisting of amino acid sequence expressed by SEQ ID NO: 23, and Fibrinogen alpha chain (isoform 2) consisting of amino acid sequence expressed by SEQ ID NO: 25, or a biomarker for detection of cognitive impairment comprising at least one protein or peptide selected from the group consisting of them.

[2] A biomarker for detection of cognitive impairment comprising the peptide selected from the group consisting of Complement C3-derived peptide CO3 consisting of amino acid sequence expressed by SEQ ID NO: 2, Transcription factor AP-2 gamma-derived peptide AP2C consisting of amino acid sequence expressed by SEQ ID NO: 4, Synapsin-3-derived peptide SYN3 consisting of amino acid sequence expressed by—SEQ ID NO: 6, Oxytocin receptor-derived peptide OXYR consisting of amino acid sequence expressed by SEQ ID NO: 8, Inter-alpha-trypsin inhibitor heavy chain H5-like protein-derived peptide ITH5L consisting of amino acid sequence expressed by SEQ ID NO: 10, E3 ubiquitin-protein ligase HERC2-derived peptide HERC2 consisting of amino acid sequence expressed by SEQ ID NO: 12, Prothrombin-derived peptide THRB consisting of amino acid sequence expressed by SEQ ID NO: 14, Transthyretin-derived peptide TTHY consisting of amino acid sequence expressed by SEQ ID NO: 16, Tumor necrosis factor receptor superfamily member 16-derived peptide TNR16 consisting of amino acid sequence expressed by SEQ ID NO: 18, Complement C4-derived peptide CO4-1 consisting of amino acid sequence expressed by SEQ ID NO: 20, Complement C4-derived peptide CO4-2 consisting of amino acid sequence expressed by SEQ ID NO: 22, Fibrinogen alpha chain-derived peptide FIBA-1 consisting of amino acid sequence expressed by SEQ ID NO: 24, Fibrinogen alpha chain-derived peptide FIBA-2 consisting of amino acid sequence expressed by SEQ ID NO: 26, and Fibrinogen alpha chain-derived peptide FIBA-3 consisting of amino acid sequence expressed by SEQ ID NO: 27, or a biomarker for detection of cognitive impairment comprising at least one protein or peptide selected from the group consisting of them.

[3] A biomarker of cognitive impairment comprising the peptides selected from the group consisting of amino acid sequence expressed by SEQ ID NOS: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, and 27 that is appeared or increased in biological material of patients of cognitive impairment as compared to biological material of subjects not suffering from psychiatry disease.

[4] A biomarker of Alzheimer disease comprising the peptides selected from the group consisting of amino acid sequence expressed by SEQ ID NOS: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, and 27 that is appeared or increased in biological material of patients of Alzheimer disease as compared to biological material of subjects not suffering from psychiatry disease.

[5] A biomarker of mild cognitive impairment comprising the peptides selected from the group consisting of amino acid sequence expressed by SEQ ID NOS: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, and 27 that is appeared or increased in biological material of patients of mild cognitive impairment as compared to biological material of subjects not suffering from psychiatry disease.

[6] Method for detection of cognitive impairment involving determination in biological material of at least one biomarker for cognitive impairment described in any of [1] to [5].

[7] Method for detection of psychiatry disease described in [6] wherein detection is made either by immunoblot procedure, Western blotting, enzyme-, fluorescence-, or radioisotope-labeled antibody method, mass spectrometry, immunoMS method or surface plasmon resonance method.

[8] A kit for detection of cognitive impairment to determine at least one biomarker described in any of [1] to [5].

[9] A kit for detection of psychiatry disease containing antibody or aptamer to at least one biomarker described in any of [1] to [5].

Advantageous Effect of the Invention

According to the present invention, it is possible to diagnose the subject such as suffering from mild cognitive impairment or cognitive impairment including Alzheimer's disease, when to increase or appear compared to the biological sample of subjects not suffering from psychiatry disease by determining amount of at least one biomarker comprising protein fragment or peptide of not less than 5 amino acid residues arising from at least one protein or peptide selected from the group consisting of Complement C3 consisting of amino acid sequence expressed by SEQ ID NO: 1, Transcription factor AP-2 gamma consisting of amino acid sequence expressed by SEQ ID NO: 3, Synapsin-3 consisting of amino acid sequence expressed by SEQ ID NO: 5, Oxytocin receptor consisting of amino acid sequence expressed by SEQ ID NO: 7, Inter-alpha-trypsin inhibitor heavy chain H5-like protein consisting of amino acid sequence expressed by SEQ ID NO: 9, E3 ubiquitin-protein ligase HERC2 consisting of amino acid sequence expressed by SEQ ID NO: 11, Prothrombin consisting of amino acid sequence expressed by SEQ ID NO: 13, Transthyretin consisting of amino acid sequence expressed by SEQ ID NO: 15, Tumor necrosis factor receptor superfamily member 16 consisting of amino acid sequence expressed by SEQ ID NO: 17, Complement C4-A consisting of amino acid sequence expressed by SEQ ID NO: 19, Complement C4-B consisting of amino acid sequence expressed by SEQ ID NO: 21, Fibrinogen alpha chain (isoform 1) consisting of amino acid sequence expressed by SEQ ID NO: 23, and Fibrinogen alpha chain (isoform 2) consisting of amino acid sequence expressed by SEQ ID NO: 25.

In addition, according to the present invention, it is possible to diagnose the subject such as suffering from mild cognitive impairment or cognitive impairment including Alzheimer's disease, when to increase or appear compared to the biological sample of subjects not suffering from psychiatry disease by determining kind or amount at least one peptide selected from the group consisting of Complement C3-derived peptide CO3 consisting of amino acid sequence expressed by SEQ ID NO: 2, Transcription factor AP-2 gamma-derived peptide AP2C consisting of amino acid sequence expressed by SEQ ID NO: 4, Synapsin-3-derived peptide SYN3 consisting of amino acid sequence expressed by SEQ ID NO: 6, Oxytocin receptor-derived peptide OXYR consisting of amino acid sequence expressed by SEQ ID NO: 8, Inter-alpha-trypsin inhibitor heavy chain H5-like protein-derived peptide ITH5L consisting of amino acid sequence expressed by SEQ ID NO: 10, E3 ubiquitin-protein ligase HERC2-derived peptide HERC2 consisting of amino acid sequence expressed by SEQ ID NO: 12, Prothrombin-derived peptide THRB consisting of amino acid sequence expressed by SEQ ID NO: 14, Transthyretin-derived peptide TTHY consisting of amino acid sequence expressed by SEQ ID NO: 16, Tumor necrosis factor receptor superfamily member 16-derived peptide TNR16 consisting of amino acid sequence expressed by SEQ ID NO: 18, Complement C4-derived peptide CO4-1 consisting of amino acid sequence expressed by SEQ ID NO: 20, Complement C4-derived peptide CO4-2 consisting of amino acid sequence expressed by SEQ ID NO: 22, Fibrinogen alpha chain-derived peptide FIBA-1 consisting of amino acid sequence expressed by SEQ ID NO: 24, Fibrinogen alpha chain-derived peptide FIBA-2 consisting of amino acid sequence expressed by SEQ ID NO: 26, and Fibrinogen alpha chain-derived peptide FIBA-3 consisting of amino acid sequence expressed by SEQ ID NO: 27.

The present invention provides a diagnostic system that is high in both accuracy and specificity. The present invention enables highly accurate diagnosis of cognitive impairment in which there have been no specific test methods for such biological materials as blood. Furthermore, the biomarkers disclosed in the present invention are highly useful in judgment of drug efficacy.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates the cluster map of Marker A. The dots within the rectangle indicated by (A) are m/z and retention time of the mass peak of Marker A detected from the serum of the individual subject using reverse phase chromatography. The dots in a cluster can be regarded as the same retention time and the same m/z in the error range, and the dots in a cluster are defined to be derived from the same peptide.

FIG. 2 illustrates the results of differential analysis in the case of Marker A. As shown in the amino acid sequences resulting of MS/MS analysis in FIG. 4, Marker A is Complement C3-derived peptides CO3. FIG. 2 shows the comparison between NDC and cognitive impairment (AD, MCI, DLB and FTD) related to CO3.

FIG. 3 illustrates the ROC curves of CO3 expressed by SEQ ID NO: 2. Definition of the ROC curve, see the section on the results of Example. FIG. 3A) shows the ROC curve of the comparison of AD vs. NDC. FIG. 3B) shows the ROC curve of the comparison of MCI vs. NDC.

FIG. 4 illustrates the MS/MS spectrum of CO3 by TOF/TOF mass spectrometer. In FIG. 4 top, it was shown the amino acid sequence of CO3, and it was shown y-ions and b-ions that appear in the MS/MS spectrum.

FIG. 5 illustrates the results of differential analysis of AP2C expressed by SEQ ID NO: 4. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 6 illustrates the results of differential analysis of SYN3 expressed by SEQ ID NO: 6. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 7 illustrates the results of differential analysis of OXYR expressed by SEQ ID NO: 8. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 8 illustrates the results of differential analysis of ITH5L expressed by SEQ ID NO: 10. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 9 illustrates the results of differential analysis of HERC2 expressed by SEQ ID NO: 12. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 10 illustrates the results of differential analysis of THRB expressed by SEQ ID NO: 14. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 11 illustrates the results of differential analysis of TTHY expressed by SEQ ID NO: 16. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 12 illustrates the results of differential analysis of TNR16 expressed by SEQ ID NO: 18. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 13 illustrates the results of differential analysis of CO4-1 expressed by SEQ ID NO: 20. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 14 illustrates the results of differential analysis of CO4-2 expressed by SEQ ID NO: 22. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 15 illustrates the results of differential analysis of FIBA-1 expressed by SEQ ID NO: 24. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 16 illustrates the results of differential analysis of FIBA-2 expressed by SEQ ID NO: 26. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

FIG. 17 illustrates the results of differential analysis of FIBA-3 expressed by SEQ ID NO: 27. This figure shows a comparison between cognitive impairment patients (AD, MCI, DLB, FTD) and subjects not suffering from psychiatry disease (NDC).

DESCRIPTION OF EMBODIMENTS

The present invention is a method for determining the kind and the amount of intact protein and/or its partial peptide when test subject is suffering from cognitive impairment as well as for diagnosing whether test subject is suffering from cognitive impairment. A peptide is generally said to be a chemical entity, made by polymerizing a number of amino acids, of less than 10,000 in molecular weight or by polymerizing several to less than about 50 amino acid residues. While in the present invention a partial peptide of an intact protein can be used as a biomarker for detection of cognitive impairment, such partial peptide is defined as a peptide of less than 10,000 in molecular weight consisting of a part of the amino acid sequence of the intact protein. Such peptide may arise as a partial peptide during the expression by transcription followed by synthesis by translation before maturing into an intact protein or as a peptide produced by enzyme digestion in the body after the intact protein has been synthesized. It is possible that, when the body is in abnormal state suffering from such disease as cognitive impairment, the mechanism for protein synthesis and regulation is de-regulated. In other words, the present invention is also a method for determining if test subject is in normal state or is suffering from cognitive impairment by using the degree of protein synthesis and/or protein digestion as an indicator. The detection of cognitive impairment in the present invention means evaluation and differentiation, i.e., diagnosis of test subject as to whether the subject is suffering from cognitive impairment. The present invention can also include the evaluation of patient's risk of suffering from more serious cognitive impairment.

Specifically, in the method of the present invention, the examples of intact protein that can be used as a cognitive impairment include Complement C3 consisting of amino acid sequence expressed by SEQ ID NO: 1, Transcription factor AP-2 gamma consisting of amino acid sequence expressed by SEQ ID NO: 3, Synapsin-3 consisting of amino acid sequence expressed by SEQ ID NO: 5, Oxytocin receptor consisting of amino acid sequence expressed by SEQ ID NO: 7, Inter-alpha-trypsin inhibitor heavy chain H5-like protein consisting of amino acid sequence expressed by SEQ ID NO: 9, E3 ubiquitin-protein ligase HERC2 consisting of amino acid sequence expressed by SEQ ID NO: 11, Prothrombin consisting of amino acid sequence expressed by SEQ ID NO: 13, Transthyretin consisting of amino acid sequence expressed by SEQ ID NO: 15, Tumor necrosis factor receptor superfamily member 16 consisting of amino acid sequence expressed by SEQ ID NO: 17, Complement C4-A consisting of amino acid sequence expressed by SEQ ID NO: 19, Complement C4-B consisting of amino acid sequence expressed by SEQ ID NO: 21, Fibrinogen alpha chain (isoform 1) consisting of amino acid sequence expressed by SEQ ID NO: 23, and Fibrinogen alpha chain (isoform 2) consisting of amino acid sequence expressed by SEQ ID NO: 25, and further, the peptide fragments that comprise of partial peptides of not less than 5 amino acid residues of these intact proteins can be used as same purpose.

Still further, an example of biomarkers for cognitive impairment of the present invention includes the partial peptides consisting of amino acid sequence expressed by SEQ ID NO: 2 of Complement C3-derived peptide CO3, SEQ ID NO: 4 of Transcription factor AP-2 gamma-derived peptide AP2C, SEQ ID NO: 6 of Synapsin-3-derived peptide SYN3, SEQ ID NO: 8 of Oxytocin receptor-derived peptide OXYR, SEQ ID NO: 10 of Inter-alpha-trypsin inhibitor heavy chain H5-like protein-derived peptide ITH5L, SEQ ID NO: 12 of E3 ubiquitin-protein ligase HERC2-derived peptide HERC2, SEQ ID NO: 14 of Prothrombin-derived peptide THRB, SEQ ID NO: 16 of Transthyretin-derived peptide TTHY, SEQ ID NO: 18 of Tumor necrosis factor receptor superfamily member 16-derived peptide TNR16, SEQ ID NO: 20 of Complement C4-derived peptide CO4-1, SEQ ID NO: 22 of Complement C4-derived peptide CO4-2, SEQ ID NO: 24 of Fibrinogen alpha chain-derived peptide FIBA-1, SEQ ID NO: 26 of Fibrinogen alpha chain-derived peptide FIBA-2, and SEQ ID NO: 27 of Fibrinogen alpha chain-derived peptide FIBA-3. In the present invention, proteins and peptides consisting of amino acid sequences derived from SEQ ID NOS: 1 through 27 by deletion, exchange, and/or addition of one or a few amino acids can be used as biomarkers and are included in the present invention. “One or a few” herein means “one or three,” “one or two,” or “one.” Furthermore, the partial peptides that can be used as biomarkers in the present invention include those peptide fragments consisting of not less than 5 amino acid residues arising respectively from SEQ ID NOS: 1 through 27. The basis for the limitation of peptide fragments consisting of not less than 5 amino acid residues is in the description below in Non-patent Document 2. The document reported that an antibody obtained by using the peptide IRGERA as immunogen, which was the C-terminus (130-135) of histone H3, recognized the peptide IKGERA derived by exchange of K for R and the peptide CGGGERA which was derived by deletion of IR followed by addition of CGG. This demonstrates that the immunogenicity (antigenicity) is recognized by a peptide of not less than 4 amino acid residues. In order to expand this finding to other peptides than the C-terminus of histone H3, the number of amino acid residue is defined as not less than 5 instead of 4 in the present invention. To make such a low molecular weight peptide as the subject of the present invention is important when the method of detection and differentiation uses immunological means including immunoblot, ELISA and immunoMS.

It is to be noted that there are cases where a sugar chain or sugar chains have been added to an intact protein or its partial peptide to form glycated entities. Proteins and partial peptides in glycated form can also be used as biomarkers for detection of cognitive impairment.

It is also to be noted that, in the present invention, biomarker can be quantified or its presence or absence can be determined qualitatively.

Two-dimensional electrophoresis (2-DE) or 2-dimensional chromatography (2-DC) can be used in the present invention to separate biomarkers in biological materials including serum. Known chromatographic methods can be selected from ion-exchange chromatography, reverse-phase chromatography and gel-filtration chromatography. It is also possible to make quantification with the SRM/MRM method in LC-MS/MS technology. Furthermore, the immunoMS method which these inventors have developed, where target protein or peptide is captured by beads (including magnetic ones) with antibody linked to the protein or peptide, eluted from the beads, and determined by mass spectrometry enables convenient determination of presence or absence or the amount of target protein, protein fragment or peptide without the use of 2-DE or chromatography.

It is possible with the use of the method disclosed in the present invention to evaluate at the stage of mild of cognitive dysfunction in test subject and therefore it can be useful in prophylactic medicine. Further, when psychotherapy and/or drug therapy is given to patients with cognitive impairment, it is reflected in the amount of proteins and partial peptides in biological materials such as serum if the progression of the disorder has been inhibited. Therefore, by measuring these proteins and partial peptides, it is possible to evaluate and determine therapeutic effect.

The kind and amount of a protein in biological materials can be determined by various methods. If target protein (including protein fragment and partial peptide) has been characterized and when an antibody (primary antibody) to it has already been obtained, the following methods can be used:

1. Immunoblot

This is one of the simplest methods. Test serum in a fixed amount (about 1 microliter) after stepwise dilution is dropped onto an appropriate membrane such as of nitrocellulose and dried in air. The membrane is treated with a blocking solution containing a protein such as BSA, washed, reacted with primary antibody, and washed. Thereafter, the membrane is reacted with labeled secondary antibody to detect the primary antibody. The membrane is washed and the label is visualized to measure its density.

2. Western Blotting

After separation with one-dimensional or two-dimensional electrophoresis involving isoelectric focusing or SDS-PAGE, proteins are transferred onto such an appropriate membrane as of PVDF and their amounts are determined, as in above-mentioned immunoblot, using primary antibody and labeled secondary antibody.

3. ELISA

Antibody to protein or its partial peptide is fixed to such a plate as a chemically modified microtiter plate. Appropriate amounts of samples after stepwise dilution are applied to the plate and incubated. Proteins and peptides not captured are removed by washing. Next, the plate is incubated with secondary antibody labeled with fluorescent or chemiluminescent substance or enzyme. After addition of respective substrate, fluorescence, chemiluminescence or visible light due to enzyme reaction is measured for evaluation and judgment.

Additional examples of methods are illustrated below (see Patent Document 2) but the invention is not limited by these examples.

4. Methods that Use Microarray (Microchip)

A microarray is a general term for devices where solidified materials with affinity for target substances are arrayed on solid support (plate). In the present invention, antibodies or aptamer to proteins and partial peptides are arrayed. A sample of biological material is placed on the microarray for fixation of target proteins or partial peptides and the microarray is then incubated with secondary antibody labeled with fluorescent or chemiluminescent substance or enzyme. After addition of respective substrate, fluorescence, chemiluminescence or visible light due to enzyme reaction is measured.

5. Mass Spectrometry

In mass spectrometry, for example, antibody to a specified protein or partial peptide is attached to chemically modified microbeads or plate (protein chip). The microbeads could be magnetic beads. There are no requirements for the material of the plate. The antibody to be used could be (1) an antibody which recognizes the full length form of the specified protein only, (2) an antibody which recognizes a partial peptide only, (3) all of antibodies which recognizes both the specified protein and its partial peptide, or a combination of (1) and (2), (1) and (3), or (2) and (3). Samples after stepwise dilution with original solvent or buffer are added to the microbeads or plate carrying antibody or antibodies and incubated. Those proteins and partial peptides not captured are removed by washing. The protein or partial peptide captured by microbeads or plate is eluted, and analyzed by mass spectrometry with MALDI-TOF-MS, SELDI-TOF-MS, etc. Measurements are made with respect to the mass and intensity of the peak due to the protein, protein fragment or partial peptide. Prior to the measurements a fixed amount of substance serving as the internal standard is added to the original biological material and the intensity of its peak is also measured. The concentration of the target in the original biological material can be calculated from the ratio of peak intensity of the target to the peak intensity of the internal standard. This is called immunoMS method. Further, it is possible to make quantification, after the sample is diluted with original solvent or buffer, or after part of proteins are removed, by separation with HPLC followed by mass spectrometry with electrospray ionization (ESI) method. Therein the SRM/MRM method can be utilized for absolute quantification with the use of an isotope-labeled internal standard peptide.

Furthermore, in addition to the above-mentioned methods, it is possible to analyze proteins and partial peptides by using 2-DE, surface plasmon resonance, etc.

The present invention includes the method to detect cognitive impairment from the presence or absence or amount of the above-mentioned biomarker after applying biological material obtained from test subject to 2-DE or surface plasmon resonance.

EXAMPLES

Discovery of a marker peptide for detection of cognitive impairment using two-dimensional liquid chromatography-mass spectrometry (2D-LC-MALDI TOF-MS).

(1) Serum Samples.

Followings, the characters before the parenthesis are an abbreviation.

A sera obtained from 40 AD (Alzheimer's disease), 35MCI (mild cognitive impairment), 13 DLB (Dementia with Lewy bodies), 7 FTD (frontotemporal lobar degeneration), and 21 NDC (subjects not suffering from psychiatry disease) were used.

(2) Methods

After 475 μl of 0.1% trifluoroacetic acid (TFA) were added in each of 25 μl of sera, samples were boiled for 15 min at 100 degrees. Subsequently, in order to recover peptides of molecular weight of 10,000 or less, ultrafiltration were performed by using YM-10 filter unit (Millipore Corp.). Then the analysis using 2D-LC-MALDI TOF-MS were performed as follows. In other words, recovering samples were fractionated to 382 fractions per sample by using two-dimensional HPLC (SCX cation exchange column at one-dimension and C18 reverse-phase column at two-dimension). The samples were fractionated into two fractions by SCX cation exchange column, namely, SCX 1 fraction is through fraction, SCX 2 fraction is the fraction that eluted with 100% salt solution. Two fractions that were fractionated by SCX, respectively, were fractionated 191 fractions by C18 reverse phase column chromatography. It was eluted with 6 seconds in one fraction, and the retention times were calculated by multiplying the number of minus 1 from number of eluted fractions to 6 seconds. All fractionated samples were spotted on MALDI target plate (MTP AnchorChip™ 600/384 plate, BRUKER DALTONICS) for MALDI TOF/TOF mass spectrometer (ultraflex TOF/TOF, BRUKER DALTONICS) using a spotting robot (AccuSpot, SHIMADZU) that is connected online, and matrix solution (alpha-cyano-hydroxycinnamic acid, CHCA) were mixed and crystallized. After mounting MALDI target plate into ultraflex TOF/TOF, the mass and the peak area of the mass were measured automatically in reflectron mode by irradiating to crystallized sample by laser. Peak area was normalized with 250 fmole of per each well of bradykinin 1-7 fragment that was added into matrix solution in advance. In other words, the area value was calculated dividing the peak area of specific mass in sample by the peak area obtained from bradykinin1-7 fragment. This area value is corresponding in 25 μl of sample serum. Detection of difference in abundance of peptides in serum between groups (called differential analysis) was performed using multi-group statistical analysis software Parnassum™ (MCBI) developed by us. Peptide that was observed to difference in abundance was directly determined amino acid sequence in MS/MS analysis by ultraflex TOF/TOF, and intact proteins or peptides of their origin were identified.

(3) Results

The following shows the result of differential analysis by Parnassum software for data of serum individual subjects obtained using 2D-LC MALDI TOF-MS. FIG. 1 shows the result that was obtained from sample that was applied to 2D-LC-MALDI TOF-MS. Sample was fractionated into 2 fractions by SCX cation exchange column in the first dimension, then first fractions from SCX column (SCX 1) were fractionated into 191 fractions by C18 reverse-phase column. Mass spectra of 191 fractions were obtained by MALDI TOF-MS measuring. As the horizontal axis is the m/z and the vertical axis is the fractions of reverse-phase column chromatography, FIG. 1 was visualized by Parnassum software developed by present inventors. The dots in FIG. 1 shows respectively TOF-MS peak derived from the individual subject. The sections that dots are gathered can be regarded as the same retention time and the same m/z in the error range, and the dots in the sections are defined to be derived from the same peptide. These sections are referred to as clusters. Section (A) of FIG. 1 shows cluster of Marker A.

FIG. 2 shows the results of differential analysis in the case of Marker A. As shown in FIG. 4, Marker A is Complement C3-derived peptides CO3. FIG. 2 shows the comparison between subjects not suffering from psychiatry disease (NDC) and cognitive impairment (AD, MCI, DLB and FTD) related to CO3. In the results of t-test, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC (p<0.05).

From the results of FIG. 2, in order to evaluate the extent to which the Marker A is useful as biomarker, the analysis by receiver operating characteristic (ROC) curve was performed. A) and B) in FIG. 3 shows respectively the ROC curve of the comparison of AD vs. NDC and MCI vs. NDC. If the area value (hereinafter referred to as the AUC value) of under the ROC curve is close to 1, the usefulness as biomarker of Marker A will be higher. In A) and B) of FIG. 3, the typical values of sensitivity and specificity are the values of the point (open square in the figure) of the coordinate on ROC curve that the distance is minimized when a straight line was drawn to ROC curve from the point of 100% on y-axis. The value of cut-off giving this point becomes a useful threshold to distinguish between the different groups, and the values of sensitivity and specificity at that time (i.e., above the typical values) becomes an indicator of the usefulness of biomarkers together with AUC values. In A) of FIG. 3, as typical values in AD vs. NDC, the sensitivity was 73.0%, the specificity was 100%, and the AUC value was 0.88. In B) of FIG. 3, as typical values in MCI vs. NDC, the sensitivity was 70.6%, the specificity was 89.5%, and the AUC value was 0.83.

Thus, it was revealed that Marker A was useful to distinguish AD and MCI with NDC. In particular, since MCI is the state of previous stage of AD, Marker A is considered to be an extremely useful marker to detect MCI for early diagnosis of potential subjects to migrate to AD.

FIG. 4, for Marker A, illustrates the results of MS/MS spectrum using ultraflex TOF/TOF. The signals that show y-ions and b-ions have enough appeared, and the amino acid sequence could be readily identified. Mascot search was performed on this result and the protein of origin or the peptide (hereinafter referred to as intact proteins or peptides) is Complement C3, and the detected peptide was found that the sequence is APVIHQEMIGGLRN (SEQ ID NO: 2). CO3 of entry name of Swiss-Prot against Complement C3 will use as an abbreviation of the peptide name. Followings, for peptides other than CO3, entry name will use as peptide name, similarly.

Including the Marker A, the peptides that have difference in abundance between the groups in serum were measured MS/MS spectra using ultraflex TOF/TOF, and in addition to determining the amino acid sequence, the results identified intact proteins or peptides were shown below. For peptides other than Marker A, the signals that show y-ions and b-ions has enough appeared, and the amino acid sequence could be readily identified. The following amino acid sequence that shows a set of two sequences, the first sequence shows the amino acid sequence of intact proteins, and the second sequence shows the amino acid sequence of peptide detected by 2D-LC MALDI TOF-MS. The peptide comprising of the underlined portion in the first sequence correspond to the sequence of peptide detected by 2D-LC MALDI TOF-MS. The amino acid sequence starting at 0001 in the sequence shows the sequence of the N-terminus side.

(1) Complement C3-Derived Peptide CO3

CO3 shown as SEQ ID NO: 2 had formed a cluster by clustering using Parnassum software.

As shown in FIG. 2, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC (t-test, p<0.05). Thus, it was revealed that CO3 shown as SEQ ID NO: 2 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See FIG. 3A), 3B) and Table 1).

Intact Protein/Peptide

(SEQ ID NO: 1)

0001	SPMYSIITPN ILRLESEETM VLEAHDAQGD VPVTVTVHDF PGKKLVLSSE
0051	KTVLTPATNH MGNVTFTIPA NREFKSEKGR NKFVTVQATF GTQVVEKVVL
0101	VSLQSGYLFI QTDKTIYTPG STVLYRIFTV NHKLLPVGRT VMVNIENPEG
0151	IPVKQDSLSS QNQLGVLPLS WDIPELVNMG QWKIRAYYEN SPQQVFSTEF
0201	EVKEYVLPSF EVIVEPTEKF YYIYNEKGLE VTITARFLYG KKVEGTAFVI
0251	FGIQDGEQRI SLPESLKRIP IEDGSGEVVL SRKVLLDGVQ NPRAEDLVGK
0301	SLYVSATVIL HSGSDMVQAE RSGIPIVTSP YQIHFTKTPK YFKPGMPFDL
0351	MVFVTNPDGS PAYRVPVAVQ GEDTVQSLTQ GDGVAKLSIN THPSQKPLSI
0401	TVRTKKQELS EAEQATRTMQ ALPYSTVGNS NNYLHLSVLR TELRPGETLN
0451	VNFLLRMDRA HEAKIRYYTY LIMNKGRLLK AGRQVREPGQ DLVVLPLSIT
0501	TDFIPSFRLV AYYTLIGASG QREVVADSVW VDVKDSCVGS LVVKSGQSED
0551	RQPVPGQQMT LKIEGDHGAR VVLVAVDKGV FVLNKKNKLT QSKIWDVVEK
0601	ADIGCTPGSG KDYAGVFSDA GLTFTSSSGQ QTAQRAELQC PQPAARRRRS
0651	VQLTEKRMDK VGKYPKELRK CCEDGMRENP MRFSCQRRTR FISLGEACKK
0701	VFLDCCNYIT ELRRQHARAS HLGLARSNLD EDIIAEENIV SRSEFPESWL
0751	WNVEDLKEPP KNGISTKLMN IFLKDSITTW EILAVSMSDK KGICVADPFE
0801	VTVMQDFFID LRLPYSVVRN EQVEIRAVLY NYRQNQELKV RVELLHNPAF
0851	CSLATTKRRH QQTVTIPPKS SLSVPYVIVP LKTGLQEVEV KAAVYHHFIS
0901	DGVRKSLKVV PEGIRMNKTV AVRTLDPERL GREGVQKEDI PPADLSDQVP
0951	DTESETRILL QGTPVAQMTE DAVDAERLKH LIVTPSGCGE QNMIGMTPTV
1001	IAVHYLDETE QWEKFGLEKR QGALELIKKG YTQQLAFRQP SSAFAAFVKR
1051	APSTWLTAYV VKVFSLAVNL IAIDSQVLCG AVKWLILEKQ KPDGVFQEDA
1101	PVIHQEMIGG LRNNNEKDMA LTAFVLISLQ EAKDICEEQV NSLPGSITKA
1151	GDFLEANYMN LQRSYTVAIA GYALAQMGRL KGPLLNKFLT TAKDKNRWED
1201	PGKQLYNVEA TSYALLALLQ LKDFDFVPPV VRWLNEQRYY GGGYGSTQAT
1251	FMVFQALAQY QKDAPDHQEL NLDVSLQLPS RSSKITHRIH WESASLLRSE
1301	ETKENEGFTV TAEGKGQGTL SVVTMYHAKA KDQLTCNKFD LKVTIKPAPE
1351	TEKRPQDAKN TMILEICTRY RGDQDATMSI LDISMMTGFA PDTDDLKQLA
1401	NGVDRYISKY ELDKAFSDRN TLIIYLDKVS HSEDDCLAFK VHQYFNVELI
1451	QPGAVKVYAY YNLEESCTRF YHPEKEDGKL NKLCRDELCR CAEENCFIQK
1501	SDDKVTLEER LDKACEPGVD YVYKTRLVKV QLSNDFDEYI MAIEQTIKSG
1551	SDEVQVGQQR TFISPIKCRE ALKLEEKKHY LMWGLSSDFW GEKPNLSYII
1601	GKDTWVEHWP EEDECQDEEN QKQCQDLGAF TESMVVFGCP N

Complement C3-Derived Peptide CO3

	(SEQ ID NO: 2)
	APVIHQEMIGGLRN

(2) Transcription Factor AP-2 Gamma-Derived Peptide AP2C

For AP2C shown as SEQ ID NO: 4, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 5)

Thus, it was revealed that AP2C shown as SEQ ID NO: 4 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1) Intact protein/peptide

(SEQ ID NO: 3)

0001	MLWKITDNVK YEEDCEDRHD GSSNGNPRVP HLSSAGQHLY SPAPPLSHTG
0051	VAEYQPPPYF PPPYQQLAYS QSADPYSHLG EAYAAAINPL HQPAPTGSQQ
0101	QAWPGRQSQE GAGLPSHHGR PAGLLPHLSG LEAGAVSARR DAYRRSDLLL
0151	PHAHALDAAG LAENLGLHDM PHQMDEVQNV DDQHLLLHDQ TVIRKGPISM
0201	TKNPLNLPCQ KELVGAVMNP TEVFCSVPGR LSLLSSTSKY KVTVAEVQRR
0251	LSPPECLNAS LLGGVLRRAK SKNGGRSLRE KLDKIGLNLP AGRRKAAHVT
0301	LLTSLVEGEA VHLARDFAYV CEAEFPSKPV AEYLTRPHLG GRNEMAARKN
0351	MLLAAQQLCK EFTELLSQDR TPHGTSRLAP VLETNIQNCL SHFSLITHGF
0401	GSQAICAAVS ALQNYIKEAL IVIDKSYMNP GDQSPADSNK TLEKMEKHRK

Transcription Factor AP-2 Gamma-Derived Peptide AP2C

	(SEQ ID NO: 4)
	PGRQSQEGAGLPSHHG

(3) Synapsin-3-Derived Peptide SYN3

For SYN3 shown as SEQ ID NO: 6, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 6)

Thus, it was revealed that SYN3 shown as SEQ ID NO: 6 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 5)

0001	MNFLRRRLSD SSFMANLPNG YMTDLQRPDS STSSPASPAM ERRHPQPLAA
0051	SFSSPGSSLF SSLSSAMKQA PQATSGLMEP PGPSTPIVQR PRILLVIDDA
0101	HTDWSKYFHG KKVNGEIEIR VEQAEFSELN LAAYVTGGCM VDMQVVRNGT
0151	KVVSRSFKPD FILVRQHAYS MALGEDYRSL VIGLQYGGLP AVNSLYSVYN
0201	FCSKPWVFSQ LIKIFHSLGP EKFPLVEQTF FPNHKPMVTA PHFPVVVKLG
0251	HAHAGMGKIK VENQLDFQDI TSVVAMAKTY ATTEAFIDSK YDIRIQKIGS
0301	NYKAYMRTSI SGNWKANTGS AMLEQVAMTE RYRLWVDSCS EMFGGLDICA
0351	VKAVHSKDGR DYIIEVMDSS MPLIGEHVEE DRQLMADLVV SKMSQLPMPG
0401	GTAPSPLRPW APQIKSAKSP GQAQLGPQLG QPQPRPPPQG GPRQAQSPQP
0451	QRSGSPSQQR LSPQGQQPLS PQSGSPQQQR SPGSPQLSRA SSGSSPNQAS
0501	KPGATLASQP RPPVQGRSTS QQGEESKKPA PPHPHLNKSQ SLTNSLSTSD
0551	TSQRGTPSED EAKAETIRNL RKSFASLFSD

Synapsin-3-Derived Peptide SYN3

	(SEQ ID NO: 6)
	EMFGGLDICAVKAVHSK

(4) Oxytocin Receptor-Derived Peptide OXYR

For OXYR shown as SEQ ID NO: 8, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 7) Thus, it was revealed that OXYR shown as SEQ ID NO: 8 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 7)

0001	MEGALAANWS AEAANASAAP PGAEGNRTAG PPRRNEALAR VEVAVLCLIL
0051	LLALSGNACV LLALRTTRQK HSRLFFFMKH LSIADLVVAV FQVLPQLLWD
0101	ITFRFYGPDL LCRLVKYLQV VGMFASTYLL LLMSLDRCLA ICQPLRSLRR
0151	RTDRLAVLAT WLGCLVASAP QVHIFSLREV ADGVFDCWAV FIQPWGPKAY
0201	ITWITLAVYI VPVIVLAACY GLISFKIWQN LRLKTAAAAA AEAPEGAAAG
0251	DGGRVALARV SSVKLISKAK IRTVKMTFII VLAFIVCWTP FFFVQMWSVW
0301	DANAPKEASA FIIVMLLASL NSCCNPWIYM LFTGHLFHEL VQRFLCCSAS
0351	YLKGRRLGET SASKKSNSSS FVLSHRSSSQ RSCSQPSTA

Oxytocin Receptor-Derived Peptide OXYR

	(SEQ ID NO: 8)
	AAPPGAEGNRT

(5) Inter-Alpha-Trypsin Inhibitor Heavy Chain H5-Like Protein-Derived Peptide ITH5L

For ITH5L shown as SEQ ID NO: 10, area values of cognitive impairment (AD, MCI and DLB) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 8)

Thus, it was revealed that ITH5L shown as SEQ ID NO: 10 was useful to distinguish patient of cognitive impairment (AD, MCI and DLB) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 9)

0001	GPPVPASSST KLLMTSYSMR STVVSRYAHT LVTSVLFNPH AEAREAIFDL
0051	DLPHLAFISN FTMTINNKVY IAEVKEKHQA KKIYEEAHQQ GKTAAHVGIR
0101	DRESEKFRIS TSLAAGTEVT FSLAYEELLQ RHQGQYQLVV SLRPGQLVKR
0151	LSIEVTVSER TGISYVHIPP LRTGRLRTNA HASEVDSPPS TRIERGETCV
0201	RITYCPTLQD QSSISGSGIM ADFLVQYDVV MEDIIGDVQI YDDYFIHYFA
0251	PRGLPPMEKN VVFVIDVSSS MFGTKMEQTK TAMNVILSDL QANDYFNIIS
0301	FSDTVNVWKA GGSIQATIQN VHSAKDYLHC MEADGWTDVN SALLAAASVL
0351	NHSNQEPGRG PSVGRIPLII FLTDGEPTAG VTTPSVILSN VRQALGHRVS
0401	LFSLAFGDDA DFTLLRRLSL ENRGIARRIY EDTDAALQLK GLYEEISMPL
0451	LADVRLNYLG GLVGASPWAV FPNYFGGSEL VVAGQVQPGK QELGIHLAAR
0501	GPKDQLLVAH HSEGATNNSQ KAFGCPGEPA PNVAHFIRRL WAYVTIGELL
0551	DAHFQARDTT TRHLLAAKVL NLSLEYNFVT PLTSLVMVQP KQASEETRRQ
0601	TSTSAGPDTI MPSSSSRHGL GVSTAQPALV PKVISPKSRP VKPKFYLSST
0651	TTASTKKMLS SKELEPLGES PHTLSMPTYP KAKIPAQQDS GTLAQPTLRT
0701	KPTILVPSNS GTLLPLKPGS LSHQNPDILP TNSRTQVPPV KPGIPASPKA
0751	DTVKCVTPLH SKPGAPSHPQ LGALTSQAPK GLPQSRPGVS TLQVPKYPLH
0801	TRPRVPAPKT RNNMPHLGPG ILLSKTPKIL LSLKPSAPPH QISTSISLSK
0851	PETPNPHMPQ TPLPPRPDRP RPPLPESLST FPNTISSSTG PSSTTTTSVL
0901	GEPLPMPFTP TLPPGRFWHQ YDLLPGPQRT RQVLGPSRPG VPTMSLLNSS
0951	RPTPEGSPPN LPILLPSSIL PEAISLLLLP EELELLSESM VESKFVESLN
1001	PPAFYTFLTP DEDGSPNWDG NSEEILGGAG GSMESQGSSV GLAKGTLPSI
1051	FTFSSSVDGD PHFVIQIPHS EEKICFTLNG HPGDLLQLIE DPKAGLHVSG
1101	KLLGAPPRPG HKDQTRTYFQ IITVTTDKPR AYTITISRSS ISLRGEGTLR
1151	LSWDQPALLK RPQLELYVAA AARLTLRLGP YLEFLVLRHR YRHPSTLQLP
1201	HLGFYVANGS GLSPSARGLI GQFQHADIRL VTGPMGPCLR RHHGPDVPVI
1251	LGKRLLKDSP RLLPRWASCW LVKRSHVELL LGHPYLSYVL

Inter-Alpha-Trypsin Inhibitor Heavy Chain H5-Like Protein-Derived Peptide ITH5L

	(SEQ ID NO: 10)
	RVSLFSLAFGDDAD

(6) E3 Ubiquitin-Protein Ligase HERC2-Derived Peptide HERC2

For HERC2 shown as SEQ ID NO: 12, area values of cognitive impairment (AD, MCI and DLB) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 9)

Thus, it was revealed that HERC2 shown as SEQ ID NO: 12 was useful to distinguish patient of cognitive impairment (AD, MCI and DLB) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 11)

0001	MPSESFCLAA QARLDSKWLK TDIQLAFTRD GLCGLWNEMV KDGEIVYTGT
0051	ESTQNGELPP RKDDSVEPSG TKKEDLNDKE KKDEEETPAP IYRAKSILDS
0101	WVWGKQPDVN ELKECLSVLV KEQQALAVQS ATTTLSALRL KQRLVILERY
0151	FIALNRTVFQ ENVKVKWKSS GISLPPVDKK SSRPAGKGVE GLARVGSRAA
0201	LSFAFAFLRR AWRSGEDADL CSELLQESLD ALRALPEASL FDESTVSSVW
0251	LEVVERATRF LRSVVTGDVH GTPATKGPGS IPLQDQHLAL AILLELAVQR
0301	GTLSQMLSAI LLLLQLWDSG AQETDNERSA QGTSAPLLPL LQRFQSIICR
0351	KDAPHSEGDM HLLSGPLSPN ESFLRYLTLP QDNELAIDLR QTAVVVMAHL
0401	DRLATPCMPP LCSSPTSHKG SLQEVIGWGL IGWKYYANVI GPIQCEGLAN
0451	LGVTQIACAE KRFLILSRNG RVYTQAYNSD TLAPQLVQGL ASRNIVKIAA
0501	HSDGHHYLAL AATGEVYSWG CGDGGRLGHG DTVPLEEPKV ISAFSGKQAG
0551	KHVVHIACGS TYSAAITAEG ELYTWGRGNY GRLGHGSSED EAIPMLVAGL
0601	KGLKVIDVAC GSGDAQTLAV TENGQVWSWG DGDYGKLGRG GSDGCKTPKL
0651	IEKLQDLDVV KVRCGSQFSI ALTKDGQVYS WGKGDNQRLG HGTEEHVRYP
0701	KLLEGLQGKK VIDVAAGSTH CLALTEDSEV HSWGSNDQCQ HFDTLRVTKP
0751	EPAALPGLDT KHIVGIACGP AQSFAWSSCS EWSIGLRVPF VVDICSMTFE
0801	QLDLLLRQVS EGMDGSADWP PPQEKECVAV ATLNLLRLQL HAAISHQVDP
0851	EFLGLGLGSI LLNSLKQTVV TLASSAGVLS TVQSAAQAVL QSGWSVLLPT
0901	AEERARALSA LLPCAVSGNE VNISPGRRFM IDLLVGSLMA DGGLESALHA
0951	AITAEIQDIE AKKEAQKEKE IDEQEANAST FHRSRTPLDK DLINTGICES
1001	SGKQCLPLVQ LIQQLLRNIA SQTVARLKDV ARRISSCLDF EQHSRERSAS
1051	LDLLLRFQRL LISKLYPGES IGQTSDISSP ELMGVGSLLK KYTALLCTHI
1101	GDILPVAASI ASTSWRHFAE VAYIVEGDFT GVLLPELVVS IVLLLSKNAG
1151	LMQEAGAVPL LGGLLEHLDR FNHLAPGKER DDHEELAWPG IMESFFTGQN
1201	CRNNEEVTLI RKADLENHNK DGGFWTVIDG KVYDIKDFQT QSLTGNSILA
1251	QFAGEDPVVA LEAALQFEDT RESMHAFCVG QYLEPDQEIV TIPDLGSLSS
1301	PLIDTERNLG LLLGLHASYL AMSTPLSPVE IECAKWLQSS IFSGGLQTSQ
1351	IHYSYNEEKD EDHCSSPGGT PASKSRLCSH RRALGDHSQA FLQAIADNNI
1401	QDHNVKDFLC QIERYCRQCH LTTPIMFPPE HPVEEVGRLL LCCLLKHEDL
1451	GHVALSLVHA GALGIEQVKH RTLPKSVVDV CRVVYQAKCS LIKTHQEQGR
1501	SYKEVCAPVI ERLRFLFNEL RPAVCNDLSI MSKFKLLSSL PRWRRIAQKI
1551	IRERRKKRVP KKPESTDDEE KIGNEESDLE EACILPHSPI NVDKRPIAIK
1601	SPKDKWQPLL STVTGVHKYK WLKQNVQGLY PQSPLLSTIA EFALKEEPVD
1651	VEKMRKCLLK QLERAEVRLE GIDTILKLAS KNFLLPSVQY AMFCGWQRLI
1701	PEGIDIGEPL TDCLKDVDLI PPFNRMLLEV TFGKLYAWAV QNIRNVLMDA
1751	SAKFKELGIQ PVPLQTITNE NPSGPSLGTI PQARFLLVML SMLTLQHGAN
1801	NLDLLLNSGM LALTQTALRL IGPSCDNVEE DMNASAQGAS ATVLEETRKE
1851	TAPVQLPVSG PELAAMMKIG TRVMRGVDWK WGDQDGPPPG LGRVIGELGE
1901	DGWIRVQWDT GSTNSYRMGK EGKYDLKLAE LPAAAQPSAE DSDTEDDSEA
1951	EQTERNIHPT AMMFTSTINL LQTLCLSAGV HAEIMQSEAT KTLCGLLRML
2001	VESGTTDKTS SPNRLVYREQ HRSWCTLGFV RSIALTPQVC GALSSPQWIT
2051	LLMKVVEGHA PFTATSLQRQ ILAVHLLQAV LPSWDKTERA RDMKCLVEKL
2101	FDFLGSLLTT CSSDVPLLRE STLRRRRVRP QASLTATHSS TLAEEVVALL
2151	RTLHSLTQWN GLINKYINSQ LRSITHSFVG RPSEGAQLED YFPDSENPEV
2201	GGLMAVLAVI GGIDGRLRLG GQVMHDEFGE GTVTRITPKG KITVQFSDMR
2251	TCRVCPLNQL KPLPAVAFNV NNLPFTEPML SVWAQLVNLA GSKLEKHKIK
2301	KSTKQAFAGQ VDLDLLRCQQ LKLYILKAGR ALLSHQDKLR QILSQPAVQE
2351	TGTVHTDDGA VVSPDLGDMS PEGPQPPMIL LQQLLASATQ PSPVKAIFDK
2401	QELEAAALAV CQCLAVESTH PSSPGFEDCS SSEATTPVAV QHIRPARVKR
2451	RKQSPVPALP IVVQLMEMGF SRRNIEFALK SLTGASGNAS SLPGVEALVG
2501	WLLDHSDIQV TELSDADTVS DEYSDEEVVE DVDDAAYSMS TGAVVTESQT
2551	YKKRADFLSN DDYAVYVREN IQVGMMVRCC RAYEEVCEGD VGKVIKLDRD
2601	GLHDLNVQCD WQQKGGTYWV RYIHVELIGY PPPSSSSHIK IGDKVRVKAS
2651	VTTPKYKWGS VTHQSVGVVK AFSANGKDII VDFPQQSHWT GLLSEMELVP
2701	SIHPGVTCDG CQMFPINGSR FKCRNCDDFD FCETCFKTKK HNTRHTFGRI
2751	NEPGQSAVFC GRSGKQLKRC HSSQPGMLLD SWSRMVKSLN VSSSVNQASR
2801	LIDGSEPCWQ SSGSQGKHWI RLEIFPDVLV HRLKMIVDPA DSSYMPSLVV
2851	VSGGNSLNNL IELKTININP SDTTVPLLND CTEYHRYIEI AIKQCRSSGI
2901	DCKIHGLILL GRIRAEEEDL AAVPFLASDN EEEEDEKGNS GSLIRKKAAG
2951	LESAATIRTK VFVWGLNDKD QLGGLKGSKI KVPSFSETLS ALNVVQVAGG
3001	SKSLFAVTVE GKVYACGEAT NGRLGLGISS GTVPIPRQIT ALSSYVVKKV
3051	AVHSGGRHAT ALTVDGKVFS WGEGDDGKLG HFSRMNCDKP RLIEALKTKR
3101	IRDIACGSSH SAALTSSGEL YTWGLGEYGR LGHGDNTTQL KPKMVKVLLG
3151	HRVIQVACGS RDAQTLALTD EGLVFSWGDG DFGKLGRGGS EGCNIPQNIE
3201	RLNGQGVCQI ECGAQFSLAL TKSGVVWTWG KGDYFRLGHG SDVHVRKPQV
3251	VEGLRGKKIV HVAVGALHCL AVTDSGQVYA WGDNDHGQQG NGTTTVNRKP
3301	TLVQGLEGQK ITRVACGSSH SVAWTTVDVA TPSVHEPVLF QTARDPLGAS
3351	YLGVPSDADS SAASNKISGA SNSKPNRPSL AKILLSLDGN LAKQQALSHI
3401	LTALQIMYAR DAVVGALMPA AMIAPVECPS FSSAAPSDAS AMASPMNGEE
3451	CMLAVDIEDR LSPNPWQEKR EIVSSEDAVT PSAVTPSAPS ASARPFIPVT
3501	DDLGAASIIA ETMTKTKEDV ESQNKAAGPE PQALDEFTSL LIADDTRVVV
3551	DLLKLSVCSR AGDRGRDVLS AVLSGMGTAY PQVADMLLEL CVTELEDVAT
3601	DSQSGRLSSQ PVVVESSHPY TDDTSTSGTV KIPGAEGLRV EFDRQCSTER
3651	RHDPLTVMDG VNRIVSVRSG REWSDWSSEL RIPGDELKWK FISDGSVNGW
3701	GWRFTVYPIM PAAGPKELLS DRCVLSCPSM DLVTCLLDFR LNLASNRSIV
3751	PRLAASLAAC AQLSALAASH RMWALQRLRK LLTTEFGQSI NINRLLGEND
3801	GETRALSFTG SALAALVKGL PEALQRQFEY EDPIVRGGKQ LLHSPFFKVL
3851	VALACDLELD TLPCCAETHK WAWFRRYCMA SRVAVALDKR TPLPRLFLDE
3901	VAKKIRELMA DSENMDVLHE SHDIFKREQD EQLVQWMNRR PDDWTLSAGG
3951	SGTIYGWGHN HRGQLGGIEG AKVKVPTPCE ALATLRPVQL IGGEQTLFAV
4001	TADGKLYATG YGAGGRLGIG GTESVSTPTL LESIQHVFIK KVAVNSGGKH
4051	CLALSSEGEV YSWGEAEDGK LGHGNRSPCD RPRVIESLRG IEVVDVAAGG
4101	AHSACVTAAG DLYTWGKGRY GRLGHSDSED QLKPKLVEAL QGHRVVDIAC
4151	GSGDAQTLCL TDDDTVWSWG DGDYGKLGRG GSDGCKVPMK IDSLTGLGVV
4201	KVECGSQFSV ALTKSGAVYT WGKGDYHRLG HGSDDHVRRP RQVQGLQGKK
4251	VIAIATGSLH CVCCTEDGEV YTWGDNDEGQ LGDGTTNAIQ RPRLVAALQG
4301	KKVNRVACGS AHTLAWSTSK PASAGKLPAQ VPMEYNHLQE IPIIALRNRL
4351	LLLHHLSELF CPCIPMFDLE GSLDETGLGP SVGFDTLRGI LISQGKEAAF
4401	RKVVQATMVR DRQHGPVVEL NRIQVKRSRS KGGLAGPDGT KSVFGQMCAK
4451	MSSFGPDSLL LPHRVWKVKF VGESVDDCGG GYSESIAEIC EELQNGLTPL
4501	LIVTPNGRDE SGANRDCYLL SPAARAPVHS SMFRFLGVLL GIAIRTGSPL
4551	SLNLAEPVWK QLAGMSLTIA DLSEVDKDFI PGLMYIRDNE ATSEEFEAMS
4601	LPFTVPSASG QDIQLSSKHT HITLDNRAEY VRLAINYRLH EFDEQVAAVR
4651	EGMARVVPVP LLSLFTGYEL ETMVCGSPDI PLHLLKSVAT YKGIEPSASL
4701	IQWFWEVMES FSNTERSLFL RFVWGRTRLP RTIADFRGRD FVIQVLDKYN
4751	PPDHFLPESY TCFFLLKLPR YSCKQVLEEK LKYAIHFCKS IDTDDYARIA
4801	LTGEPAADDS SDDSDNEDVD SFASDSTQDY LTGH

E3 Ubiquitin-Protein Ligase HERC2-Derived Peptide HERC2

	(SEQ ID NO: 12)
	KLAELPAAAQPSAEDSD

(7) Prothrombin-Derived Peptide THRB

For THRB shown as SEQ ID NO: 14, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 10)

Thus, it was revealed that THRB shown as SEQ ID NO: 14 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 13)

0001	ANTFLEEVRK GNLERECVEE TCSYEEAFEA LESSTATDVF WAKYTACETA
0051	RTPRDKLAAC LEGNCAEGLG TNYRGHVNIT RSGIECQLWR SRYPHKPEIN
0101	STTHPGADLQ ENFCRNPDSS TTGPWCYTTD PTVRRQECSI PVCGQDQVTV
0151	AMTPRSEGSS VNLSPPLEQC VPDRGQQYQG RLAVTTHGLP CLAWASAQAK
0201	ALSKHQDFNS AVQLVENFCR NPDGDEEGVW CYVAGKPGDF GYCDLNYCEE
0251	AVEEETGDGL DEDSDRAIEG RTATSEYQTF FNPRTFGSGE ADCGLRPLFE
0301	KKSLEDKTER ELLESYIDGR IVEGSDAEIG MSPWQVMLFR KSPQELLCGA
0351	SLISDRWVLT AAHCLLYPPW DKNFTENDLL VRIGKHSRTR YERNIEKISM
0401	LEKIYIHPRY NWRENLDRDI ALMKLKKPVA FSDYIHPVCL PDRETAASLL
0451	QAGYKGRVTG WGNLKETWTA NVGKGQPSVL QVVNLPIVER PVCKDSTRIR
0501	ITDNMFCAGY KPDEGKRGDA CEGDSGGPFV MKSPFNNRWY QMGIVSWGEG
0551	CDRDGKYGFY THVFRLKKWI QKVIDQFGE

Prothrombin-Derived Peptide THRB

	(SEQ ID NO: 14)
	TATSEYQTFFNPRTFGSGEAD

(8) Transthyretin-Derived Peptide TTHY

For TTHY shown as SEQ ID NO: 16, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 11)

Thus, it was revealed that TTHY shown as SEQ ID NO: 16 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 15)

0001	GPTGTGESKC PLMVKVLDAV RGSPAINVAV HVFRKAADDT WEPFASGKTS
0051	ESGELHGLTT EEEFVEGIYK VEIDTKSYWK ALGISPFHEH AEVVFTANDS
0101	GPRRYTIAAL LSPYSYSTTA VVTNPKE

Transthyretin-Derived Peptide TTHY

	(SEQ ID NO: 16)
	AVRGSPAINVAVHVFRKAAD

(9) Tumor Necrosis Factor Receptor Superfamily Member 16-Derived Peptide TNR16

For TNR16 shown as SEQ ID NO: 18, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 12)

Thus, it was revealed that TNR16 shown as SEQ ID NO: 18 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 17)

0001	KEACPTGLYT HSGECCKACN LGEGVAQPCG ANQTVCEPCL DSVTFSDVVS
0051	ATEPCKPCTE CVGLQSMSAP CVEADDAVCR CAYGYYQDET TGRCEACRVC
0101	EAGSGLVFSC QDKQNTVCEE CPDGTYSDEA NHVDPCLPCT VCEDTERQLR
0151	ECTRWADAEC EEIPGRWITR STPPEGSDST APSTQEPEAP PEQDLIASTV
0201	AGVVTTVMGS SQPVVTRGTT DNLIPVYCSI LAAVVVGLVA YIAFKRWNSC
0251	KQNKQGANSR PVNQTPPPEG EKLHSDSGIS VDSQSLHDQQ PHTQTASGQA
0301	LKGDGGLYSS LPPAKREEVE KLLNGSAGDT WRHLAGELGY QPEHIDSFTH
0351	EACPVRALLA SWATQDSATL DALLAALRRI QRADLVESLC SESTATSPV

Tumor Necrosis Factor Receptor Superfamily Member 16-Derived Peptide TNR16

	(SEQ ID NO: 18)
	QTASGQALKGDGGLYS

(10) Complement C4-A-Derived Peptide CO4-1

For CO4-1 shown as SEQ ID NO: 20, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 13)

Thus, it was revealed that CO4-1 shown as SEQ ID NO: 20 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

After Biosynthesis, Complement C4-A protein is divided into C4 beta chain, Complement C4-A alpha chain and Complement C4 gamma chain by processing.

SEQ ID NO: 19 is amino acid sequence of intact Complement C4-A protein containing all of these processed peptides.

Intact Protein/Peptide

(SEQ ID NO: 19)

0001	KPRLLLFSPS VVHLGVPLSV GVQLQDVPRG QVVKGSVFLR NPSRNNVPCS
0051	PKVDFTLSSE RDFALLSLQV PLKDAKSCGL HQLLRGPEVQ LVAHSPWLKD
0101	SLSRTTNIQG INLLFSSRRG HLFLQTDQPI YNPGQRVRYR VFALDQKMRP
0151	STDTITVMVE NSHGLRVRKK EVYMPSSIFQ DDFVIPDISE PGTWKISARF
0201	SDGLESNSST QFEVKKYVLP NFEVKITPGK PYILTVPGHL DEMQLDIQAR
0251	YIYGKPVQGV AYVRFGLLDE DGKKTFFRGL ESQTKLVNGQ SHISLSKAEF
0301	QDALEKLNMG ITDLQGLRLY VAAAIIESPG GEMEEAELTS WYFVSSPFSL
0351	DLSKTKRHLV PGAPFLLQAL VREMSGSPAS GIPVKVSATV SSPGSVPEVQ
0401	DIQQNTDGSG QVSIPIIIPQ TISELQLSVS AGSPHPAIAR LTVAAPPSGG
0451	PGFLSIERPD SRPPRVGDTL NLNLRAVGSG ATFSHYYYMI LSRGQIVFMN
0501	REPKRTLTSV SVFVDHHLAP SFYFVAFYYH GDHPVANSLR VDVQAGACEG
0551	KLELSVDGAK QYRNGESVKL HLETDSLALV ALGALDTALY AAGSKSHKPL
0601	NMGKVFEAMN SYDLGCGPGG GDSALQVFQA AGLAFSDGDQ WTLSRKRLSC
0651	PKEKTTRKKR NVNFQKAINE KLGQYASPTA KRCCQDGVTR LPMMRSCEQR
0701	AARVQQPDCR EPFLSCCQFA ESLRKKSRDK GQAGLQRALE ILQEEDLIDE
0751	DDIPVRSFFP ENWLWRVETV DRFQILTLWL PDSLTTWEIH GLSLSKTKGL
0801	CVATPVQLRV FREFHLHLRL PMSVRRFEQL ELRPVLYNYL DKNLTVSVHV
0851	SPVEGLCLAG GGGLAQQVLV PAGSARPVAF SVVPTAAAAV SLKVVARGSF
0901	EFPVGDAVSK VLQIEKEGAI HREELVYELN PLDHRGRTLE IPGNSDPNMI
0951	PDGDFNSYVR VTASDPLDTL GSEGALSPGG VASLLRLPRG CGEQTMIYLA
1001	PTLAASRYLD KTEQWSTLPP ETKDHAVDLI QKGYMRIQQF RKADGSYAAW
1051	LSRDSSTWLT AFVLKVLSLA QEQVGGSPEK LQETSNWLLS QQQADGSFQD
1101	PCPVLDRSMQ GGLVGNDETV ALTAFVTIAL HHGLAVFQDE GAEPLKQRVE
1151	ASISKANSFL GEKASAGLLG AHAAAITAYA LSLTKAPVDL LGVAHNNLMA
1201	MAQETGDNLY WGSVTGSQSN AVSPTPAPRN PSDPMPQAPA LWIETTAYAL
1251	LHLLLHEGKA EMADQASAWL TRQGSFQGGF RSTQDTVIAL DALSAYWIAS
1301	HTTEERGLNV TLSSTGRNGF KSHALQLNNR QIRGLEEELQ FSLGSKINVK
1351	VGGNSKGTLK VLRTYNVLDM KNTTCQDLQI EVTVKGHVEY TMEANEDYED
1401	YEYDELPAKD DPDAPLQPVT PLQLFEGRRN RRRREAPKVV EEQESRVHYT
1451	VCIWRNGKVG LSGMAIADVT LLSGFHALRA DLEKLTSLSD RYVSHFETEG
1501	PHVLLYFDSV PTSRECVGFE AVQEVPVGLV QPASATLYDY YNPERRCSVF
1551	YGAPSKSRLL ATLCSAEVCQ CAEGKCPRQR RALERGLQDE DGYRMKFACY
1601	YPRVEYGFQV KVLREDSRAA FRLFETKITQ VLHFTKDVKA AANQMRNFLV
1651	RASCRLRLEP GKEYLIMGLD GATYDLEGHP QYLLDSNSWI EEMPSERLCR
1701	STRQRAACAQ LNDFLQEYGT QGCQV

Complement C4-Derived Peptide CO4-1

	(SEQ ID NO: 20)
	NGFKSHALQLNNRQIR

(11) Complement C4-B-Derived Peptide CO4-1

From the results of MS/MS analysis and MASCOT database search, A sequence of CO4-1 peptide as shown SEQ ID NO: 20 is an amino acid sequence present in the part of topological region that is common to Complement C4-A protein (SEQ ID NO: 19) and Complement C4-B protein. After Biosynthesis, Complement C4-B protein is divided into C4 beta chain, Complement C4-B alpha chain and Complement C4 gamma chain by processing.

SEQ ID NO: 21 is amino acid sequence of intact Complement C4-B protein containing all of these processed peptides.

Intact Protein/Peptide

(SEQ ID NO: 21)

0001	KPRLLLFSPS VVHLGVPLSV GVQLQDVPRG QVVKGSVFLR NPSRNNVPCS
0051	PKVDFTLSSE RDFALLSLQV PLKDAKSCGL HQLLRGPEVQ LVAHSPWLKD
0101	SLSRTTNIQG INLLFSSRRG HLFLQTDQPI YNPGQRVRYR VFALDQKMRP
0151	STDTITVMVE NSHGLRVRKK EVYMPSSIFQ DDFVIPDISE PGTWKISARF
0201	SDGLESNSST QFEVKKYVLP NFEVKITPGK PYILTVPGHL DEMQLDIQAR
0251	YIYGKPVQGV AYVRFGLLDE DGKKTFFRGL ESQTKLVNGQ SHISLSKAEF
0301	QDALEKLNMG ITDLQGLRLY VAAAIIESPG GEMEEAELTS WYFVSSPFSL
0351	DLSKTKRHLV PGAPFLLQAL VREMSGSPAS GIPVKVSATV SSPGSVPEVQ
0401	DIQQNTDGSG QVSIPIIIPQ TISELQLSVS AGSPHPAIAR LTVAAPPSGG
0451	PGFLSIERPD SRPPRVGDTL NLNLRAVGSG ATFSHYYYMI LSRGQIVFMN
0501	REPKRTLTSV SVFVDHHLAP SFYFVAFYYH GDHPVANSLR VDVQAGACEG
0551	KLELSVDGAK QYRNGESVKL HLETDSLALV ALGALDTALY AAGSKSHKPL
0601	NMGKVFEAMN SYDLGCGPGG GDSALQVFQA AGLAFSDGDQ WTLSRKRLSC
0651	PKEKTTRKKR NVNFQKATNE KLGQYASPTA KRCCQDGVTR LPMMRSCEQR
0701	AARVQQPDCR EPFLSCCQFA ESLRKKSRDK GQAGLQRALE ILQEEDLIDE
0751	DDIPVRSFFP ENWLWRVETV DRFQILTLWL PDSLTTWEIH GLSLSKTKGL
0801	CVATPVQLRV FREFHLHLRL PMSVRRFEQL ELRPVLYNYL DKNLTVSVHV
0851	SPVEGLCLAG GGGLAQQVLV PAGSARPVAF SVVPTAAAAV SLKVVARGSF
0901	EFPVGDAVSK VLQIEKEGAI HREELVYELN PLDHRGRTLE IPGNSDPNMI
0951	PDGDFNSYVR VTASDPLDTL GSEGALSPGG VASLLRLPRG CGEQTMIYLA
1001	PTLAASRYLD KTEQWSTLPP ETKDHAVDLI QKGYMRIQQF RKADGSYAAW
1051	LSRDSSTWLT AFVLKVLSLA QEQVGGSPEK LQETSNWLLS QQQADGSFQD
1101	LSPVIHRSMQ GGLVGNDETV ALTAFVTIAL HHGLAVFQDE GAEPLKQRVE
1151	ASISKANSFL GEKASAGLLG AHAAAITAYA LSLTKAPVDL LGVAHNNLMA
1201	MAQETGDNLY WGSVTGSQSN AVSPTPAPRN PSDPMPQAPA LWIETTAYAL
1251	LHLLLHEGKA EMADQASAWL TRQGSFQGGF RSTQDTVIAL DALSAYWIAS
1301	HTTEERGLNV TLSSTGRNGF KSHALQLNNR QIRGLEEELQ FSLGSKINVK
1351	VGGNSKGTLK VLRTYNVLDM KNTTCQDLQI EVTVKGHVEY TMEANEDYED
1401	YEYDELPAKD DPDAPLQPVT PLQLFEGRRN RRRREAPKVV EEQESRVHYT
1451	VCIWRNGKVG LSGMAIADVT LLSGFHALRA DLEKLTSLSD RYVSHFETEG
1501	PHVLLYFDSV PTSRECVGFE AVQEVPVGLV QPASATLYDY YNPERRCSVF
1551	YGAPSKSRLL ATLCSAEVCQ CAEGKCPRQR RALERGLQDE DGYRMKFACY
1601	YPRVEYGFQV KVLREDSRAA FRLFETKITQ VLHFTKDVKA AANQMRNFLV
1651	RASCRLRLEP GKEYLIMGLD GATYDLEGHP QYLLDSNSWI EEMPSERLCR
1701	STRQRAACAQ LNDFLQEYGT QGCQV

Just in case, following shows the sequence of CO4-1.

Complement C4-Derived Peptide CO4-1

	(SEQ ID NO: 20)
	NGFKSHALQLNNRQIR

(12) Complement C4-A-Derived Peptide CO4-2

For CO4-2 shown as SEQ ID NO: 22, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 14)

Thus, it was revealed that CO4-2 shown as SEQ ID NO: 22 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1) After Biosynthesis, Complement C4-A protein is divided into C4 beta chain, Complement C4-A alpha chain and Complement C4 gamma chain by processing.

SEQ ID NO: 19 is amino acid sequence of intact Complement C4-A protein containing all of these processed peptides.

Intact Protein/Peptide

(SEQ ID NO: 19)

0001	KPRLLLFSPS VVHLGVPLSV GVQLQDVPRG QVVKGSVFLR NPSRNNVPCS
0051	PKVDFTLSSE RDFALLSLQV PLKDAKSCGL HQLLRGPEVQ LVAHSPWLKD
0101	SLSRTTNIQG INLLFSSRRG HLFLQTDQPI YNPGQRVRYR VFALDQKMRP
0151	STDTITVMVE NSHGLRVRKK EVYMPSSIFQ DDFVIPDISE PGTWKISARF
0201	SDGLESNSST QFEVKKYVLP NFEVKITPGK PYILTVPGHL DEMQLDIQAR
0251	YIYGKPVQGV AYVRFGLLDE DGKKTFFRGL ESQTKLVNGQ SHISLSKAEF
0301	QDALEKLNMG ITDLQGLRLY VAAAIIESPG GEMEEAELTS WYFVSSPFSL
0351	DLSKTKRHLV PGAPFLLQAL VREMSGSPAS GIPVKVSATV SSPGSVPEVQ
0401	DIQQNTDGSG QVSIPIIIPQ TISELQLSVS AGSPHPAIAR LTVAAPPSGG
0451	PGFLSIERPD SRPPRVGDTL NLNLRAVGSG ATFSHYYYMI LSRGQIVFMN
0501	REPKRTLTSV SVFVDHHLAP SFYFVAFYYH GDHPVANSLR VDVQAGACEG
0551	KLELSVDGAK QYRNGESVKL HLETDSLALV ALGALDTALY AAGSKSHKPL
0601	NMGKVFEAMN SYDLGCGPGG GDSALQVFQA AGLAFSDGDQ WTLSRKRLSC
0651	PKEKTTRKKR NVNFQKAINE KLGQYASPTA KRCCQDGVTR LPMMRSCEQR
0701	AARVQQPDCR EPFLSCCQFA ESLRKKSRDK GQAGLQRALE ILQEEDLIDE
0751	DDIPVRSFFP ENWLWRVETV DRFQILTLWL PDSLTTWEIH GLSLSKTKGL
0801	CVATPVQLRV FREFHLHLRL PMSVRRFEQL ELRPVLYNYL DKNLTVSVHV
0851	SPVEGLCLAG GGGLAQQVLV PAGSARPVAF SVVPTAAAAV SLKVVARGSF
0901	EFPVGDAVSK VLQIEKEGAI HREELVYELN PLDHRGRTLE IPGNSDPNMI
0951	PDGDFNSYVR VTASDPLDTL GSEGALSPGG VASLLRLPRG CGEQTMIYLA
1001	PTLAASRYLD KTEQWSTLPP ETKDHAVDLI QKGYMRIQQF RKADGSYAAW
1051	LSRDSSTWLT AFVLKVLSLA QEQVGGSPEK LQETSNWLLS QQQADGSFQD
1101	PCPVLDRSMQ GGLVGNDETV ALTAFVTIAL HHGLAVFQDE GAEPLKQRVE
1151	ASISKANSFL GEKASAGLLG AHAAAITAYA LSLTKAPVDL LGVAHNNLMA
1201	MAQETGDNLY WGSVTGSQSN AVSPTPAPRN PSDPMPQAPA LWIETTAYAL
1251	LHLLLHEGKA EMADQASAWL TRQGSFQGGF RSTQDTVIAL DALSAYWIAS
1301	HTTEERGLNV TLSSTGRNGF KSHALQLNNR QIRGLEEELQ FSLGSKINVK
1351	VGGNSKGTLK VLRTYNVLDM KNTTCQDLQI EVTVKGHVEY TMEANEDYED
1401	YEYDELPAKD DPDAPLQPVT PLQLFEGRRN RRRREAPKVV EEQESRVHYT
1451	VCIWRNGKVG LSGMAIADVT LLSGFHALRA DLEKLTSLSD RYVSHFETEG
1501	PHVLLYFDSV PTSRECVGFE AVQEVPVGLV QPASATLYDY YNPERRCSVF
1551	YGAPSKSRLL ATLCSAEVCQ CAEGKCPRQR RALERGLQDE DGYRMKFACY
1601	YPRVEYGFQV KVLREDSRAA FRLFETKITQ VLHFTKDVKA AANQMRNFLV
1651	RASCRLRLEP GKEYLIMGLD GATYDLEGHP QYLLDSNSWI EEMPSERLCR
1701	STRQRAACAQ LNDFLQEYGT QGCQV

Complement C4-Derived Peptide CO4-2

	(SEQ ID NO: 22)
	APLQPVTPLQLFEGRRN

(13) Complement C4-B-Derived Peptide CO4-2

From the results of MS/MS analysis and MASCOT database search, A sequence of CO4-2 peptide as shown SEQ ID NO: 22 is an amino acid sequence present in the part of topological region that is common to Complement C4-A protein (SEQ ID NO: 19) and Complement C4-B protein. After Biosynthesis, Complement C4-B protein is divided into C4 beta chain, Complement C4-B alpha chain and Complement C4 gamma chain by processing. SEQ ID NO: 21 is amino acid sequence of intact Complement C4-B protein containing all of these processed peptides.

Intact Protein/Peptide

(SEQ ID NO: 21)

0001	KPRLLLFSPS VVHLGVPLSV GVQLQDVPRG QVVKGSVFLR NPSRNNVPCS
0051	PKVDFTLSSE RDFALLSLQV PLKDAKSCGL HQLLRGPEVQ LVAHSPWLKD
0101	SLSRTTNIQG INLLFSSRRG HLFLQTDQPI YNPGQRVRYR VFALDQKMRP
0151	STDTITVMVE NSHGLRVRKK EVYMPSSIFQ DDFVIPDISE PGTWKISARF
0201	SDGLESNSST QFEVKKYVLP NFEVKITPGK PYILTVPGHL DEMQLDIQAR
0251	YIYGKPVQGV AYVRFGLLDE DGKKTFFRGL ESQTKLVNGQ SHISLSKAEF
0301	QDALEKLNMG ITDLQGLRLY VAAAIIESPG GEMEEAELTS WYFVSSPFSL
0351	DLSKTKRHLV PGAPFLLQAL VREMSGSPAS GIPVKVSATV SSPGSVPEVQ
0401	DIQQNTDGSG QVSIPIIIPQ TISELQLSVS AGSPHPAIAR LTVAAPPSGG
0451	PGFLSIERPD SRPPRVGDTL NLNLRAVGSG ATFSHYYYMI LSRGQIVFMN
0501	REPKRTLTSV SVFVDHHLAP SFYFVAFYYH GDHPVANSLR VDVQAGACEG
0551	KLELSVDGAK QYRNGESVKL HLETDSLALV ALGALDTALY AAGSKSHKPL
0601	NMGKVFEAMN SYDLGCGPGG GDSALQVFQA AGLAFSDGDQ WTLSRKRLSC
0651	PKEKTTRKKR NVNFQKAINE KLGQYASPTA KRCCQDGVTR LPMMRSCEQR
0701	AARVQQPDCR EPFLSCCQFA ESLRKKSRDK GQAGLQRALE ILQEEDLIDE
0751	DDIPVRSFFP ENWLWRVETV DRFQILTLWL PDSLTTWEIH GLSLSKTKGL
0801	CVATPVQLRV FREFHLHLRL PMSVRRFEQL ELRPVLYNYL DKNLTVSVHV
0851	SPVEGLCLAG GGGLAQQVLV PAGSARPVAF SVVPTAAAAV SLKVVARGSF
0901	EFPVGDAVSK VLQIEKEGAI HREELVYELN PLDHRGRTLE IPGNSDPNMI
0951	PDGDFNSYVR VTASDPLDTL GSEGALSPGG VASLLRLPRG CGEQTMIYLA
1001	PTLAASRYLD KTEQWSTLPP ETKDHAVDLI QKGYMRIQQF RKADGSYAAW
1051	LSRDSSTWLT AFVLKVLSLA QEQVGGSPEK LQETSNWLLS QQQADGSFQD
1101	LSPVIHRSMQ GGLVGNDETV ALTAFVTIAL HHGLAVFQDE GAEPLKQRVE
1151	ASISKANSFL GEKASAGLLG AHAAAITAYA LSLTKAPVDL LGVAHNNLMA
1201	MAQETGDNLY WGSVTGSQSN AVSPTPAPRN PSDPMPQAPA LWIETTAYAL
1251	LHLLLHEGKA EMADQASAWL TRQGSFQGGF RSTQDTVIAL DALSAYWIAS
1301	HTTEERGLNV TLSSTGRNGF KSHALQLNNR QIRGLEEELQ FSLGSKINVK
1351	VGGNSKGTLK VLRTYNVLDM KNITCQDLQI EVTVKGHVEY TMEANEDYED
1401	YEYDELPAKD DPDAPLQPVT PLQLFEGRRN RRRREAPKVV EEQESRVHYT
1451	VCIWRNGKVG LSGMAIADVT LLSGFHALRA DLEKLTSLSD RYVSHFETEG
1501	PHVLLYFDSV PTSRECVGFE AVQEVPVGLV QPASATLYDY YNPERRCSVF
1551	YGAPSKSRLL ATLCSAEVCQ CAEGKCPRQR RALERGLQDE DGYRMKFACY
1601	YPRVEYGFQV KVLREDSRAA FRLFETKITQ VLHFTKDVKA AANQMRNFLV
1651	RASCRLRLEP GKEYLIMGLD GATYDLEGHP QYLLDSNSWI EEMPSERLCR
1701	STRQRAACAQ LNDFLQEYGT QGCQV

Just in case, following shows the sequence of CO4-2.

Complement C4-Derived Peptide CO4-2

	(SEQ ID NO: 22)
	APLQPVTPLQLFEGRRN

(14) Fibrinogen Alpha Chain (Isoform 1)-Derived Peptide FIBA-1

For FIBA-1 shown as SEQ ID NO: 24, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 15)

Thus, it was revealed that FIBA-1 shown as SEQ ID NO: 24 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 23)

0001	GPRVVERHQS ACKDSDWPFC SDEDWNYKCP SGCRMKGLID EVNQDFTNRI
0051	NKLKNSLFEY QKNNKDSHSL TTNIMEILRG DFSSANNRDN TYNRVSEDLR
0101	SRIEVLKRKV IEKVQHIQLL QKNVRAQLVD MKRLEVDIDI KIRSCRGSCS
0151	RALAREVDLK DYEDQQKQLE QVIAKDLLPS RDRQHLPLIK MKPVPDLVPG
0201	NFKSQLQKVP PEWKALTDMP QMRMELERPG GNEITRGGST SYGTGSETES
0251	PRNPSSAGSW NSGSSGPGST GNRNPGSSGT GGTATWKPGS SGPGSTGSWN
0301	SGSSGTGSTG NQNPGSPRPG STGTWNPGSS ERGSAGHWTS ESSVSGSTGQ
0351	WHSESGSFRP DSPGSGNARP NNPDWGTFEE VSGNVSPGTR REYHTEKLVT
0401	SKGDKELRTG KEKVTSGSTT TTRRSCSKTV TKTVIGPDGH KEVTKEVVTS
0451	EDGSDCPEAM DLGTLSGIGT LDGFRHRHPD EAAFFDTAST GKTFPGFFSP
0501	MLGEFVSETE SRGSESGIFT NTKESSSHHP GIAEFPSRGK SSSYSKQFTS
0551	STSYNRGDST FESKSYKMAD EAGSEADHEG THSTKRGHAK SRPVRDCDDV
0601	LQTHPSGTQS GIFNIKLPGS SKIFSVYCDQ ETSLGGWLLI QQRMDGSLNF
0651	NRTWQDYKRG FGSLNDEGEG EFWLGNDYLH LLTQRGSVLR VELEDWAGNE
0701	AYAEYHFRVG SEAEGYALQV SSYEGTAGDA LIEGSVEEGA EYTSHNNMQF
0751	STFDRDADQW EENCAEVYGG GWWYNNCQAA NLNGIYYPGG SYDPRNNSPY
0801	EIENGVVWVS FRGADYSLRA VRMKIRPLVT Q

Fibrinogen Alpha Chain-Derived Peptide FIBA-1

	(SEQ ID NO: 24)
	SSSYSKQFTSSTSYNRGDSTFES

(15) Fibrinogen Alpha Chain (Isoform 2)-Derived Peptide FIBA-1

From the results of MS/MS analysis and MASCOT database search, A sequence of FIBA-1 peptide as shown SEQ ID NO: 24 is an amino acid sequence present in the part of topological region that is common to Fibrinogen alpha chain (isoform 1) (SEQ ID NO: 23) and Fibrinogen alpha chain (isoform 2). Followings, as SEQ ID NO: 25, an amino acid sequence of intact protein of Fibrinogen alpha chain (isoform 2) were shown.

Intact Protein/Peptide

(SEQ ID NO: 25)

0001	GPRVVERHQS ACKDSDWPFC SDEDWNYKCP SGCRMKGLID EVNQDFTNRI
0051	NKLKNSLFEY QKNNKDSHSL TTNIMEILRG DFSSANNRDN TYNRVSEDLR
0101	SRIEVLKRKV IEKVQHIQLL QKNVRAQLVD MKRLEVDIDI KIRSCRGSCS
0151	RALAREVDLK DYEDQQKQLE QVIAKDLLPS RDRQHLPLIK MKPVPDLVPG
0201	NFKSQLQKVP PEWKALTDMP QMRMELERPG GNEITRGGST SYGTGSETES
0251	PRNPSSAGSW NSGSSGPGST GNRNPGSSGT GGTATWKPGS SGPGSTGSWN
0301	SGSSGTGSTG NQNPGSPRPG STGTWNPGSS ERGSAGHWTS ESSVSGSTGQ
0351	WHSESGSFRP DSPGSGNARP NNPDWGTFEE VSGNVSPGTR REYHTEKLVT
0401	SKGDKELRTG KEKVTSGSTT TTRRSCSKTV TKTVIGPDGH KEVTKEVVTS
0451	EDGSDCPEAM DLGTLSGIGT LDGFRHRHPD EAAFFDTAST GKTFPGFFSP
0501	MLGEFVSETE SRGSESGIFT NTKESSSHHP GIAEFPSRGK SSSYSKQFTS
0551	STSYNRGDST FESKSYKMAD EAGSEADHEG THSTKRGHAK SRPVRGIHTS
0601	PLGKPSLSP

Just in case, following shows the sequence of FIBA-1.

Fibrinogen Alpha Chain-Derived Peptide FIBA-1

	(SEQ ID NO: 24)
	SSSYSKQFTSSTSYNRGDSTFES

(16) Fibrinogen Alpha Chain (Isoform 1)-Derived Peptide FIBA-2

For FIBA-2 shown as SEQ ID NO: 26, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 16)

Thus, it was revealed that FIBA-2 shown as SEQ ID NO: 26 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 23)

0001	GPRVVERHQS ACKDSDWPFC SDEDWNYKCP SGCRMKGLID EVNQDFTNRI
0051	NKLKNSLFEY QKNNKDSHSL TTNIMEILRG DFSSANNRDN TYNRVSEDLR
0101	SRIEVLKRKV IEKVQHIQLL QKNVRAQLVD MKRLEVDIDI KIRSCRGSCS
0151	RALAREVDLK DYEDQQKQLE QVIAKDLLPS RDRQHLPLIK MKPVPDLVPG
0201	NFKSQLQKVP PEWKALTDMP QMRMELERPG GNEITRGGST SYGTGSETES
0251	PRNPSSAGSW NSGSSGPGST GNRNPGSSGT GGTATWKPGS SGPGSTGSWN
0301	SGSSGTGSTG NQNPGSPRPG STGTWNPGSS ERGSAGHWTS ESSVSGSTGQ
0351	WHSESGSFRP DSPGSGNARP NNPDWGTFEE VSGNVSPGTR REYHTEKLVT
0401	SKGDKELRTG KEKVTSGSTT TTRRSCSKTV TKTVIGPDGH KEVTKEVVTS
0451	EDGSDCPEAM DLGTLSGIGT LDGFRHRHPD EAAFFDTAST GKTFPGFFSP
0501	MLGEFVSETE SRGSESGIFT NTKESSSHHP GIAEFPSRGK SSSYSKQFTS
0551	STSYNRGDST FESKSYKMAD EAGSEADHEG THSTKRGHAK SRPVRDCDDV
0601	LQTHPSGTQS GIFNIKLPGS SKIFSVYCDQ ETSLGGWLLI QQRMDGSLNF
0651	NRTWQDYKRG FGSLNDEGEG EFWLGNDYLH LLTQRGSVLR VELEDWAGNE
0701	AYAEYHFRVG SEAEGYALQV SSYEGTAGDA LIEGSVEEGA EYTSHNNMQF
0751	STFDRDADQW EENCAEVYGG GWWYNNCQAA NLNGIYYPGG SYDPRNNSPY
0801	EIENGVVWVS FRGADYSLRA VRMKIRPLVT Q

Fibrinogen Alpha Chain-Derived Peptide FIBA-2

	(SEQ ID NO: 26)
	SSSYSKQFTSSTSYNRGDSTFESKS

(17) Fibrinogen Alpha Chain (Isoform 2)-Derived Peptide FIBA-2

From the results of MS/MS analysis and MASCOT database search, A sequence of FIBA-2 peptide as shown SEQ ID NO: 26 is an amino acid sequence present in the part of topological region that is common to Fibrinogen alpha chain (isoform 1) (SEQ ID NO: 23) and Fibrinogen alpha chain (isoform 2). Followings, as SEQ ID NO: 25, an amino acid sequence of intact protein of Fibrinogen alpha chain (isoform 2) were shown.

Intact Protein/Peptide

(SEQ ID NO: 25)

0001	GPRVVERHQS ACKDSDWPFC SDEDWNYKCP SGCRMKGLID EVNQDFTNRI
0051	NKLKNSLFEY QKNNKDSHSL TTNIMEILRG DFSSANNRDN TYNRVSEDLR
0101	SRIEVLKRKV IEKVQHIQLL QKNVRAQLVD MKRLEVDIDI KIRSCRGSCS
0151	RALAREVDLK DYEDQQKQLE QVIAKDLLPS RDRQHLPLIK MKPVPDLVPG
0201	NFKSQLQKVP PEWKALTDMP QMRMELERPG GNEITRGGST SYGTGSETES
0251	PRNPSSAGSW NSGSSGPGST GNRNPGSSGT GGTATWKPGS SGPGSTGSWN
0301	SGSSGTGSTG NQNPGSPRPG STGTWNPGSS ERGSAGHWTS ESSVSGSTGQ
0351	WHSESGSFRP DSPGSGNARP NNPDWGTFEE VSGNVSPGTR REYHTEKLVT
0401	SKGDKELRTG KEKVTSGSTT TTRRSCSKTV TKTVIGPDGH KEVTKEVVTS
0451	EDGSDCPEAM DLGTLSGIGT LDGFRHRHPD EAAFFDTAST GKTFPGFFSP
0501	MLGEFVSETE SRGSESGIFT NTKESSSHHP GIAEFPSRGK SSSYSKQFTS
0551	STSYNRGDST FESKSYKMAD EAGSEADHEG THSTKRGHAK SRPVRGIHTS
0601	PLGKPSLSP

Just in case, following shows the sequence of FIBA-2.

Fibrinogen Alpha Chain-Derived Peptide FIBA-2

	(SEQ ID NO: 26)
	SSSYSKQFTSSTSYNRGDSTFESKS

(18) Fibrinogen Alpha Chain (Isoform 1)-Derived Peptide FIBA-3

For FIBA-3 shown as SEQ ID NO: 27, area values of cognitive impairment (AD, MCI, DLB and FTD) were significantly higher than NDC. (t-test, p<0.05) (see FIG. 17)

Thus, it was revealed that FIBA-3 shown as SEQ ID NO: 27 was useful to distinguish patient of cognitive impairment (AD, MCI, DLB and FTD) with subjects not suffering from psychiatry disease (NDC). According to the analysis by receiver operating characteristic (ROC) curve, CO3 was clearly useful to distinguish AD and MCI with NDC. (See Table 1)

Intact Protein/Peptide

(SEQ ID NO: 23)

0001	GPRVVERHQS ACKDSDWPFC SDEDWNYKCP SGCRMKGLID EVNQDFTNRI
0051	NKLKNSLFEY QKNNKDSHSL TTNIMEILRG DFSSANNRDN TYNRVSEDLR
0101	SRIEVLKRKV IEKVQHIQLL QKNVRAQLVD MKRLEVDIDI KIRSCRGSCS
0151	RALAREVDLK DYEDQQKQLE QVIAKDLLPS RDRQHLPLIK MKPVPDLVPG
0201	NFKSQLQKVP PEWKALTDMP QMRMELERPG GNEITRGGST SYGTGSETES
0251	PRNPSSAGSW NSGSSGPGST GNRNPGSSGT GGTATWKPGS SGPGSTGSWN
0301	SGSSGTGSTG NQNPGSPRPG STGTWNPGSS ERGSAGHWTS ESSVSGSTGQ
0351	WHSESGSFRP DSPGSGNARP NNPDWGTFEE VSGNVSPGTR REYHTEKLVT
0401	SKGDKELRTG KEKVTSGSTT TTRRSCSKTV TKTVIGPDGH KEVTKEVVTS
0451	EDGSDCPEAM DLGTLSGIGT LDGFRHRHPD EAAFFDTAST GKTFPGFFSP
0501	MLGEFVSETE SRGSESGIFT NTKESSSHHP GIAEFPSRGK SSSYSKQFTS
0551	STSYNRGDST FESKSYKMAD EAGSEADHEG THSTKRGHAK SRPVRDCDDV
0601	LQTHPSGTQS GIFNIKLPGS SKIFSVYCDQ ETSLGGWLLI QQRMDGSLNF
0651	NRTWQDYKRG FGSLNDEGEG EFWLGNDYLH LLTQRGSVLR VELEDWAGNE
0701	AYAEYHFRVG SEAEGYALQV SSYEGTAGDA LIEGSVEEGA EYTSHNNMQF
0751	STFDRDADQW EENCAEVYGG GWWYNNCQAA NLNGIYYPGG SYDPRNNSPY
0801	EIENGVVWVS FRGADYSLRA VRMKIRPLVT Q

Fibrinogen Alpha Chain-Derived Peptide FIBA-3

	(SEQ ID NO: 27)
	SSSYSKQFTSSTSYNRGDSTFESKSY

(19) Fibrinogen Alpha Chain (Isoform 2)-Derived Peptide FIBA-3

From the results of MS/MS analysis and MASCOT database search, A sequence of FIBA-3 peptide as shown SEQ ID NO: 27 is an amino acid sequence present in the part of topological region that is common to Fibrinogen alpha chain (isoform 1) (SEQ ID NO: 23) and Fibrinogen alpha chain (isoform 2). Followings, as SEQ ID NO: 25, an amino acid sequence of intact protein of Fibrinogen alpha chain (isoform 2) were shown.

Intact Protein/Peptide

(SEQ ID NO: 25)

0001	GPRVVERHQS ACKDSDWPFC SDEDWNYKCP SGCRMKGLID EVNQDFTNRI
0051	NKLKNSLFEY QKNNKDSHSL TTNIMEILRG DFSSANNRDN TYNRVSEDLR
0101	SRIEVLKRKV IEKVQHIQLL QKNVRAQLVD MKRLEVDIDI KIRSCRGSCS
0151	RALAREVDLK DYEDQQKQLE QVIAKDLLPS RDRQHLPLIK MKPVPDLVPG
0201	NFKSQLQKVP PEWKALTDMP QMRMELERPG GNEITRGGST SYGTGSETES
0251	PRNPSSAGSW NSGSSGPGST GNRNPGSSGT GGTATWKPGS SGPGSTGSWN
0301	SGSSGTGSTG NQNPGSPRPG STGTWNPGSS ERGSAGHWTS ESSVSGSTGQ
0351	WHSESGSFRP DSPGSGNARP NNPDWGTFEE VSGNVSPGTR REYHTEKLVT
0401	SKGDKELRTG KEKVTSGSTT TTRRSCSKTV TKTVIGPDGH KEVTKEVVTS
0451	EDGSDCPEAM DLGTLSGIGT LDGFRHRHPD EAAFFDTAST GKTFPGFFSP
0501	MLGEFVSETE SRGSESGIFT NTKESSSHHP GIAEFPSRGK SSSYSKQFTS
0551	STSYNRGDST FESKSYKMAD EAGSEADHEG THSTKRGHAK SRPVRGIHTS
0601	PLGKPSLSP

Just in case, following shows the sequence of FIBA-3.

Fibrinogen Alpha Chain-Derived Peptide FIBA-3

	(SEQ ID NO: 27)
	SSSYSKQFTSSTSYNRGDSTFESKSY

TABLE 1
Marker Peptide	AD vs. NDC	MCI vs. NDC

Sequence No.	Sequence name	AUC value	AUC value

2	CO3	0.88	0.83
4	AP2C	0.78	0.70
6	SYN3	0.77	0.77
8	OXYR	0.81	0.77
10	ITH5L	0.79	0.70
12	HERC2	0.76	0.73
14	THRB	0.85	0.79
16	TTHY	0.73	0.69
18	TNR16	0.75	0.74
20	CO4-1	0.73	0.67
22	CO4-2	0.76	0.74
24	FIBA-1	0.77	0.64
26	FIBA-2	0.74	0.61
27	FIBA-3	0.80	0.64

Table 1 shows AUC values obtained by the analysis by receiver operating characteristic (ROC) curve in the detection of cognitive impairment of each marker peptides.

Using these marker peptides in singly or in combination, using or without using liquid chromatography and/or any other suitable separation methods, directly measuring the abundance in serum using other methods such as mass spectrometry or immunological methods or enzymatic methods, on the diagnosis, it is possible to distinguish between non-psychiatry disease subjects including normal healthy subjects and subjects of cognitive impairment like AD, MCI, DLB and FTD.

INDUSTRIAL APPLICABILITY

By using the biomarkers disclosed in the present invention, mild cognitive impairment and cognitive impairment including Alzheimer disease can be detected. This invention is applicable to the field of medical diagnostics including diagnostic reagent.

SEQUENCE LIST

10P01009_Sequence.txt