Diagnostic markers for progressive supranuclear palsy

Abstract

To provide a method for collecting data to evaluate the probability that a subject is afflicted with progressive supranuclear palsy.SOLUTION: The present invention provides a method that includes, in a subject-derived cerebrospinal fluid sample, measuring the amount of a first type of molecules that are bound with an antibody recognizing the KEGILQYCQEVYPELQ epitope in amyloid precursor protein and have an apparent molecular mass of 100 kDa, where the measurement data on the first type of molecules is collected as data with a positive correlation with the probability that a subject is afflicted with progressive supranuclear palsy.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to biomarkers that can be used for the diagnosis of progressive supranuclear palsy.

Background Art

[0002] Progressive supranuclear palsy (PSP) is one of the "Parkinson's syndromes (PS)" including corticobasal degeneration (CBD), multiple system atrophy (MSA), and Parkinson's disease (PD).

[0003] PSP is a progressive neurodegenerative disease of unknown cause, and no fully effective treatment method has been found yet. Pathologically, the formation of aggregates of abnormally phosphorylated tau in the brain is characteristic of PSP, and although it is presumed to be involved in the pathogenesis, the whole picture has not been elucidated.

[0004] According to epidemiological studies in Japan, the prevalence of PSP is estimated to be about 20 per 100,000 people. On the other hand, in the analysis of forensic autopsy cases, PSP pathology was confirmed in 4.6% of autopsy brains of 60 years old or older, and it is推测 that there are more potential PSP cases.

[0005] Typical PSP is characterized by gait disturbance accompanied by easy falls and vertical eye movement disorder. However, no clear biomarker for PSP is known, and clinical diagnosis is made based on clinical symptoms and imaging findings, etc., and the definitive diagnosis is finally made by pathological diagnosis of autopsy brains.

[0006] Advances in clinical research have revealed that, in addition to Richardson's syndrome, which presents a typical clinical picture, PSP can exhibit a wide variety of clinical manifestations, including subtypes with prominent tremors and muscle rigidity similar to Parkinson's disease, subtypes with prominent cerebellar symptoms similar to MSA, subtypes with prominent speech disorders and freezing of gait, and subtypes with clinical features similar to CBD. Thus, PSP presents with a wide range of clinical symptoms, and differentiation and diagnosis from other PS diseases are often difficult, especially in the early stages of the disease. Currently, the only way to assess disease progression or treatment effectiveness is to rely on a scale of clinical signs (Non-Patent Literature 1-5). This difficulty in diagnosis is one of the factors that makes the development of therapeutic drugs and treatments, as well as the conduct of clinical trials, difficult. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Litvan et al., Neurology, 1996, 47(1):1-9. [Non-Patent Document 2] Williams et al., Brain, 2005, 128:1247-1258 [Non-Patent Document 3] Williams et al., Movement Disorders, 2007, 22(15):2235-2241 [Non-Patent Document 4] Kanazawa et al., Mov. Disord., 2009, 24(9):1312-8. [Non-Patent Document 5] Golbe and Ohman-Strickland, Brain, 2007, 130:1552-1565 [Overview of the project] [Problems that the invention aims to solve]

[0008] Therefore, there is a strong need to establish new diagnostic methods to evaluate or determine the likelihood that a subject has PSP. In particular, there is a need for biomarkers that correlate with the presence of PSP. [Means for solving the problem]

[0009] In their research to identify biomarkers characteristic of PSP patients, the inventors identified a specific form of amyloid precursor protein (APP) as a substance that shows PSP-specific changes in the cerebrospinal fluid (CSF) of patients. They found that the levels of these specific forms of APP could show significant differences between CSF samples from PSP patients and CSF samples from non-PSP individuals such as PD patients and healthy individuals, or between CSF samples from PSP patients and CSF samples from Alzheimer's disease (AD) patients.

[0010] This disclosure includes at least the following embodiments. [1] A method for collecting data to assess the likelihood that a subject has progressive supranuclear palsy, comprising measuring the amount of a first molecular species having an apparent molecular weight of 100 kDa, which is bound to a cerebrospinal fluid sample derived from the subject by an antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ, wherein the measurement data of the first molecular species is collected as data that positively correlates with the likelihood that the subject has progressive supranuclear palsy. [2] The method according to [1], further comprising measuring the amount of a second molecular species bound by the antibody and having an apparent molecular weight of 74 kDa in a cerebrospinal fluid sample derived from the subject, wherein the measurement data of the second molecular species is collected as data that positively correlates with the likelihood that the subject has Alzheimer's disease rather than progressive supranuclear palsy. [3] The antibody is a monoclonal antibody 22C11, as described in [1] or [2]. [4] A method for collecting data to assess the likelihood that a subject has progressive supranuclear palsy, comprising measuring the amount of a first molecular species of amyloid precursor protein containing the epitope KEGILQYCQEVYPELQ and having an apparent molecular weight of 100 kDa in a cerebrospinal fluid sample derived from the subject, wherein the measurement data of the first molecular species is collected as data positively correlated with the likelihood that the subject has progressive supranuclear palsy. [5] The method according to [4], further comprising measuring the amount of a second molecular species of amyloid precursor protein having an apparent molecular weight of 74 kDa and containing the epitope in a cerebrospinal fluid sample derived from the subject, wherein the measurement data of the second molecular species is collected as data that positively correlates with the likelihood that the subject has Alzheimer's disease rather than progressive supranuclear palsy. [6] The amount of the first and second molecular species is measured by measuring the amount of monoclonal antibody 22C11 bound to the molecular species, as described in [4] or [5]. [7] A method for determining whether a subject has progressive supranuclear palsy or is likely to have it, (1) Obtain a measurement of the amount of a first molecular species having an apparent molecular weight of 100 kDa, which is bound by an antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ, in a cerebrospinal fluid sample derived from the subject, and (2) Comparing the measured amount of the first molecular species with the first reference value. A method for determining that a subject has progressive supranuclear palsy, or is likely to have progressive supranuclear palsy, if the measured amount of the first molecular species is higher than the first reference value. [8] A method for determining whether a subject has progressive supranuclear palsy or is likely to have it, (1) Obtaining a measured value of the amount of a first molecular species having an apparent molecular weight of 100 kDa and bound by an antibody that recognizes the epitope KEGILQYCQEVYPELQ of amyloid precursor protein in a cerebrospinal fluid sample derived from the subject; (2) Comparing the measured value of the amount of the first molecular species with a first reference value; (3) Obtaining a measured value of the amount of a second molecular species having an apparent molecular weight of 74 kDa and bound by the antibody in a cerebrospinal fluid sample derived from the subject; (4) Comparing the measured value of the amount of the second molecular species with a second reference value, and (5) When the measured value of the amount of the first molecular species is higher than the first reference value and the measured value of the amount of the second molecular species is less than or equal to the second reference value, determining that the subject has or is highly likely to have progressive supranuclear palsy. A method comprising the above. [9] In (5) above, when the measured value of the amount of the second molecular species is higher than the second reference value, determining that the subject has or is highly likely to have Alzheimer's disease rather than progressive supranuclear palsy, the method according to [8].

[10] The method according to any one of [7] to [9], wherein the antibody is monoclonal antibody 22C11.

[0011] According to an embodiment of the present disclosure, it has become possible to collect biochemical data useful for the diagnosis of PSP from patient-derived samples. The biomarker according to the embodiment of the present disclosure becomes a new means useful in place of or in addition to existing means in the diagnosis of PSP, and by providing an objective index for the evaluation or determination of disease progression or treatment effect, it can contribute to the improvement of the diagnosis and treatment of PSP.

Brief Description of Drawings

[0012] [Figure 1]FIG. 1 is a graph showing that in shotgun proteomics of cerebrospinal fluid samples, the overall detection amount of peptides derived from amyloid precursor protein was decreased in the PSP group compared to the PD group and the CTL group. Each bar graph corresponds to each individual, and the height of the bar graph indicates the number of detected peptides derived from amyloid precursor protein. [Figure 2] FIG. 2 shows an example of a Western blot of a cerebrospinal fluid sample using monoclonal antibody 22C11. The migration positions of known molecular weight markers are shown on the left side. [Figure 3] FIG. 3 shows the results of measuring the amount of a molecular species having an apparent molecular weight of 100 kDa bound by anti-amyloid precursor protein antibody 22C11 in cerebrospinal fluid samples from different patients. [Figure 4] FIG. 4 shows the results of measuring the amount of a molecular species having an apparent molecular weight of 74 kDa bound by anti-amyloid precursor protein antibody 22C11 in cerebrospinal fluid samples from different patients.

MODE FOR CARRYING OUT THE INVENTION

[0013] The present disclosure provides a method for collecting data for evaluating the possibility that a subject is suffering from progressive supranuclear palsy. In some embodiments, the method includes measuring the amount of a first molecular species having an apparent molecular weight of 100 kDa bound by an antibody that recognizes the epitope KEGILQYCQEVYPELQ (SEQ ID NO: 1) of amyloid precursor protein in a cerebrospinal fluid sample derived from the subject.

[0014] The subject in the present disclosure is a human. The method of collecting cerebrospinal fluid samples is well known to those skilled in the art. Typically, cerebrospinal fluid is collected by lumbar puncture.

[0015] An example of a major mRNA sequence of amyloid precursor protein in humans is provided in the NCBI (National Center for Biotechnology Information) Entrez database under reference number NM_000484.2, and is provided in this application as Sequence ID No. 2. The amino acid sequence of the full-length polypeptide encoded by that mRNA is provided as Sequence ID No. 3. The above epitope (Sequence ID No. 1) corresponds to residues 66-81 of Sequence ID No. 3.

[0016] The genes for amyloid precursor proteins are known to undergo different mRNA splicing and post-translational modifications (including phosphorylation and glycosylation) and complex proteolytic processing, resulting in a large number of polypeptides with varying molecular weights and functions. Amyloid-beta, one of these short polypeptides (approximately 40 amino acids; molecular weight approximately 4.5 kDa), is well known to aggregate and accumulate in the brains of Alzheimer's disease patients to form amyloid plaques, and is considered to be the cause of the disease. The term "precursor" in the name amyloid precursor protein indicates that it is a precursor of amyloid plaques. However, in this disclosure, terms such as "amyloid precursor protein" and "amyloid precursor protein isoform" encompass all polypeptides derived from the translation product of the amyloid precursor protein gene, regardless of whether they are precursors, mature products, or final products, and regardless of whether they are full-length polypeptides, cleaved products, or degradation products. Amyloid-beta is located approximately at residues 672-713 of SEQ ID NO: 3 and does not contain the epitope of SEQ ID NO: 1.

[0017] In this disclosure, “apparent molecular weight” means molecular weight determined relatively by comparing the migration distance or migration velocity with multiple known molecular weight markers in gel electrophoresis under reducing and denaturing conditions. Gel electrophoresis is, for example, polyacrylamide gel electrophoresis, most typically SDS-PAGE. Apparent molecular weight is not necessarily the same as absolute molecular weight determined strictly from atomic composition. In this disclosure, the term “molecular species” is used to identify different polypeptide molecules (which may include post-translational modifications) accumulating in a sample with different apparent molecular weights. Terms such as “first,” “second,” etc., are merely terms of convenience to distinguish between different objects (e.g., different molecular species of amyloid precursor protein) and do not imply any order (e.g., order of size or sequence position). Various molecular species include full-length (i.e., uncleaved or degraded) amyloid precursor protein and its various fragments. Western blotting, as is known to those skilled in the art, is, but is not limited to, a method for detecting and quantifying molecular species having a specific apparent molecular weight and binding to a specific antibody or having a specific epitope. For example, Western blotting can be bypassed by fragmenting the gel after electrophoresis according to the apparent molecular weight position and eluting and analyzing the polypeptides contained in the fragments as needed.

[0018] As described above, the group of polypeptide products that can be generated from the amyloid precursor protein gene is complex and diverse. However, in cerebrospinal fluid samples, several molecular species conjugated by the antibody that recognizes the epitope KEGILQYCQEVYPELQ can be reproducibly detected. Therefore, those skilled in the art can clearly recognize, according to this disclosure, a first molecular species having an apparent molecular weight of 100 kDa, conjugated by the antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ. For example, the first molecular species having an "apparent molecular weight of 100 kDa" as specified in this disclosure can be recognized as a molecular species that migrates faster than a 106 kDa molecular weight marker and slower than a 76 kDa molecular weight marker in gel electrophoresis such as SDS-PAGE. A second molecular species having an "apparent molecular weight of 74 kDa" as identified in this disclosure is also clearly recognizable, and is, for example, a molecular species that electrophores slightly faster than a molecular weight marker of 76 kDa and has an apparent molecular weight greater than 60 kDa.

[0019] To say that an antibody "recognizes" an epitope means, as is usually understood by those skilled in the art, that the specific binding target of the antibody, which is a specific binding molecule, is that epitope. A preferred example of an antibody that recognizes the epitope KEGILQYCQEVYPELQ and specifically binds to it is the monoclonal antibody 22C11 (see, for example, J. Biol. Chem., 1995, 270(9):4205-4208). Monoclonal antibody 22C11 is commercially available from Merck (Millipore), among others. However, the antibodies that can be used in the embodiments of this disclosure are not limited to 22C11. For example, as described in J. Biol. Chem., 2002, 277(23):20979-20990, those skilled in the art can independently produce an antibody that recognizes the epitope (antigen) KEGILQYCQEVYPELQ and specifically binds to it, independently of clone 22C11.

[0020] The amount of a molecular species, or its quantification, can be performed by measuring its abundance relatively or absolutely. The details of measuring the abundance of a molecular species can be appropriately determined by those skilled in the art based on ordinary knowledge. For example, quantification or measurement can be performed by determining the detection amount of a first molecular species, which has an apparent molecular weight of 100 kDa and is bound to an antibody recognizing the epitope KEGILQYCQEVYPELQ, on a Western blot, as a relative value to the detection amount of a reference molecule. The reference molecule is typically the product of a gene whose expression level is considered to be substantially constant, known to those skilled in the art as a housekeeping gene, and may be, for example, a polypeptide of β-actin. The amounts of the amyloid precursor protein molecular species and the reference molecule can be measured on the same Western blot (e.g., by changing the detection label of the antibody) or on separate Western blots (e.g., by electrophoresis of equal volumes of cerebrospinal fluid samples using separate SDS-PAGE).

[0021] Conventionally, it was unknown what specific molecules in what types of biological samples should be measured to be useful for diagnosing progressive supranuclear palsy, and diagnosis had to rely heavily on clinical symptoms, imaging findings, and pathological diagnoses of autopsy brains. Therefore, embodiments of this disclosure provide a novel method for collecting data to assess the likelihood that a subject has progressive supranuclear palsy. More specifically, the first molecular species described above serves as a biomarker, and its measurement or quantitative data is collected as data that positively correlates with the likelihood that a subject has progressive supranuclear palsy.

[0022] "Positive correlation with the likelihood of having progressive supranuclear palsy" means that the level of the biomarker in question is significantly higher in individuals with progressive supranuclear palsy compared to individuals without the condition. Therefore, the higher the level of the biomarker that shows a positive correlation with progressive supranuclear palsy, the more likely that the individual is to have progressive supranuclear palsy.

[0023] In some embodiments, the above method further includes measuring the amount of a second molecular species bound by the antibody and having an apparent molecular weight of 74 kDa in a cerebrospinal fluid sample derived from the same subject. This second molecular species is thought to be an amyloid precursor protein molecular species that contains the same epitope as the first molecular species but has acquired a different apparent molecular weight due to different mRNA splicing and / or post-translational modification and / or proteolysis. Measurement or quantification data of this second molecular species are collected as data that positively correlates with the likelihood that the subject has Alzheimer's disease rather than progressive supranuclear palsy. In other words, the higher the level of this biomarker, the more likely the individual is to have Alzheimer's disease rather than progressive supranuclear palsy. By combining the two biomarkers, the first and second molecular species, more reliable data can be collected to assess the likelihood that a subject has progressive supranuclear palsy.

[0024] The epitope KEGILQYCQEVYPELQ (SEQ ID NO: 1) is an epitope specific to amyloid precursor proteins. The molecular species bound by an antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ can be rephrased as a molecular species (e.g., a fragment) of amyloid precursor protein containing the epitope. In other words, the present disclosure provides a method for collecting data to assess the likelihood that a subject has progressive supranuclear palsy, comprising measuring the amount of a first molecular species of amyloid precursor protein containing the epitope KEGILQYCQEVYPELQ and having an apparent molecular weight of 100 kDa in a cerebrospinal fluid sample derived from the subject, wherein the measurement data of this first molecular species is collected as data positively correlated with the likelihood that the subject has progressive supranuclear palsy.

[0025] This embodiment may further include measuring the amount of a second molecular species of amyloid precursor protein containing the epitope and having an apparent molecular weight of 74 kDa in cerebrospinal fluid samples derived from the same subject. The measurement data of this second molecular species is collected as data that positively correlates with the likelihood that the subject has Alzheimer's disease rather than progressive supranuclear palsy.

[0026] The molecular species of amyloid precursor protein containing the above epitope can be quantified by measuring the amount of an antibody that recognizes this epitope, such as the monoclonal antibody 22C11, bound to the target molecular species. Typically, this measurement is performed on a Western blot.

[0027] In another aspect, the Disclosure provides a method for determining whether a subject has or is likely to have progressive supranuclear palsy, the method comprising: (1) Obtain a measurement of the amount of a first molecular species having an apparent molecular weight of 100 kDa, which is bound by an antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ, in a cerebrospinal fluid sample derived from the subject. (2) Compare the measured amount of the first molecular species with the first reference value. (3) Obtain a measurement of the amount of a second molecular species that is bound by the antibody and has an apparent molecular weight of 74 kDa in a cerebrospinal fluid sample derived from the above subject. (4) Compare the measured amount of the second molecular species with the second reference value, and (5) If the measured amount of the first molecular species is higher than the first reference value, and the measured amount of the second molecular species is less than or equal to the second reference value, the subject is determined to have progressive supranuclear palsy or is highly likely to have it.

[0028] It is a logical necessity that stage (2) is performed after stage (1), stage (4) is performed after stage (3), and stage (5) is performed after stages (2) and (4). However, in this method, for example, it is arbitrary which of stage (1) and stage (3) is performed first, and they may be performed simultaneously. Similarly, it is arbitrary which of stage (2) and stage (4) is performed first, and they may be performed simultaneously.

[0029] In this embodiment as well, monoclonal antibody 22C11 can be suitably used, but as explained above, the antibody that can be used is not necessarily limited to monoclonal antibody 22C11.

[0030] The first and second reference values ​​can be predetermined by those skilled in the art. As will be understood by those skilled in the art, the first and second reference values ​​may be based, for example, on measurements of the first and second molecular species in cerebrospinal fluid (CSF) samples from multiple individuals who have been determined, by clinical or definitive diagnosis, to be free from or without progressive supranuclear palsy and Alzheimer's disease, or who have been determined to be free from or without progressive supranuclear palsy and Alzheimer's disease. In one example, the first reference value may be selected from a value that is at least twice the average of the measurements of the first molecular species in CSF samples from multiple individuals who do not have progressive supranuclear palsy and Alzheimer's disease. In another example, the first reference value may be selected from a value within the range of the 60th to 80th percentile of the measurements of the first molecular species in CSF samples from multiple individuals who have progressive supranuclear palsy. In one example, the second reference value may be selected from a value that is at least twice the average of the measurements of the second molecular species in CSF samples from multiple individuals who do not have progressive supranuclear palsy and Alzheimer's disease. In another example, the value could be selected from the 60th to 80th percentile range of the measurement values ​​for the second molecular isomorphism in cerebrospinal fluid samples from multiple individuals with Alzheimer's disease.

[0031] However, it should be understood that, in general, the threshold levels for biomarkers can be made looser or stricter depending on the purpose of each individual study (for example, whether it is for initial screening to select a broad group of potential patients, or for detailed diagnosis of individual patients, etc.), and that the threshold values ​​in this disclosure can also be predetermined by a person skilled in the art based on ordinary skill, depending on the individual application, and can be varied as appropriate.

[0032] In one embodiment, the method includes determining in step (5) that if the measured amount of the second molecular species is higher than the second reference value, the subject has or is likely to have Alzheimer's disease rather than progressive supranuclear palsy.

[0033] Since Alzheimer's disease is a separate disease that does not belong to the Parkinsonian syndromes, the need or priority of differentiating progressive supranuclear palsy from Alzheimer's disease may be judged to be relatively low in situations where progressive supranuclear palsy is clinically suspected (for example, when the subject exhibits gait disturbance and / or vertical eye movement disorder). Therefore, in another embodiment, steps (3) and (4) above may be omitted, and in a step after (2), if the measured amount of the first molecular isoform is higher than the first reference value, it may be determined that the subject has or is likely to have progressive supranuclear palsy.

[0034] If a subject is not determined to have progressive supranuclear palsy (PSP) or is not likely to have it, they may be determined not to have PSP or to be unlikely to have it (or to be unlikely to have it). Similarly, if a subject is not determined to have Alzheimer's disease or is not likely to have it, they may be determined not to have Alzheimer's disease or to be unlikely to have it. [Examples]

[0035] The following describes specific embodiments with reference to examples, but these are illustrative examples, and the invention of this disclosure is not limited to these examples.

[0036] In this exploratory study, cerebrospinal fluid (CSF) samples were collected from four PSP patients, four Parkinson's disease (PD) patients, and four healthy control groups (CTLs) under identical conditions using surface-enhanced laser desorption / ionization time-of-flight mass spectrometry (SELDI-TOF MS). The PSP patients were diagnosed based on the criteria described in Non-Patent Documents 1-4. Two of these patients received pathological diagnoses. The PD patients were diagnosed based on the criteria described in Postuma et al., Mov. Disord., 2015, 30(12):1591-601.

[0037] Shotgun proteomics using SELDI-TOF MS identified amyloid precursor protein as one of the proteins showing a specific change in detection levels in PSP patients. Specifically, an overall trend was observed where the detection levels of amyloid precursor protein peptides were lower in the PSP group compared to the PD group and the CTL group (Figure 1).

[0038] Therefore, we conducted a verification study to investigate the possibility that amyloid precursor proteins or their molecular species could serve as biomarkers for PSP. In this example, cerebrospinal fluid was collected from the individuals listed in the table below. PSP, PD, and CTL are as described above. CBS refers to patients with corticobasal syndrome, and AD refers to patients with Alzheimer's disease. Although Alzheimer's disease is not a disease belonging to the Parkinsonian syndromes, the AD group was included in this study in light of the established knowledge that molecular species of amyloid precursor proteins play a major role in Alzheimer's disease.

[0039] [Table 1]

[0040] Cerebrospinal fluid was electrophoresed using a standard 10% SDS-PAGE method, and Western blot analysis was performed using monoclonal antibody 22C11 (catalog number MAB348-100UL) purchased from Merck. Clone 22C11 is an antibody that recognizes the epitope KEGILQYCQEVYPELQ, corresponding to amino acids 66-81 of the amyloid precursor protein sequence shown in the NCBI Entrez database reference number NM_000484.2. Antibody-bound molecular species were detected and quantified using ECL Prime Western blotting detection reagent (Amersham). Several reproducible bands (molecular species) were detected, as illustrated in Figure 2. Hereinafter, in this example, "molecular species" refers to the molecular species of amyloid precursor protein specifically bound by the 22C11 antibody on the cerebrospinal fluid Western blot.

[0041] Individual amyloid precursor protein molecular species were quantified by normalizing the detected amount, i.e., band intensity, as a relative amount to the detected amount of β-actin in the same cerebrospinal fluid sample. Band intensity was measured using Image-J software. Multiple regression analysis, corrected for age and sex, was performed using PSP as the reference, with a significance level of less than 5%.

[0042] Paradoxically, considering the shotgun proteomics results (Figure 1) showing generally lower levels of amyloid precursor protein-derived peptides in PSP patients, the amount of molecular species with an apparent molecular weight of 100 kDa was found to be statistically significantly higher in the PSP group compared to the CTL group and the PD group (Figure 3). In Figures 3 and 4, each point represents an individual, and the amount of molecular species measured as a relative amount to β-actin. The "whiskers" on the graphs represent the standard deviation for each group, and the midpoint of the whiskers represents the mean. In addition to 100 kDa, molecular species with apparent molecular weights of 110 kDa, 74 kDa, 60 kDa, 54 kDa, 28 kDa, 24 kDa, 20 kDa, and 12 kDa were similarly quantified (data not shown), but only the 100 kDa molecular species showed a statistically significant change in the PSP group compared to the CTL group or the PD group.

[0043] On the other hand, the amount of molecular species with an apparent molecular weight of 74 kDa was observed to be specifically elevated in the AD group, and this was statistically significant compared to the PSP group, which was at substantially the same level as the CTL group (Figure 4). Several individuals in the AD group showed a particularly elevated amount of molecular species with an apparent molecular weight of 100 kDa (Figure 3), and these multiple AD individuals overlapped with multiple AD individuals that showed an elevated amount of molecular species with an apparent molecular weight of 74 kDa (Figure 4).

[0044] These results illustrate that a molecular species with an apparent molecular weight of 100 kDa, bound by an antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ in cerebrospinal fluid, may be useful as a diagnostic marker for progressive supranuclear palsy, and that measurement data of this molecular species in cerebrospinal fluid can be collected as data that positively correlates with the likelihood that a subject has progressive supranuclear palsy. On the other hand, a molecular species with an apparent molecular weight of 74 kDa does not increase in the PSP group but may specifically increase in the AD group, and therefore can be collected as data that positively correlates with the likelihood that a subject has Alzheimer's disease rather than progressive supranuclear palsy.

Claims

1. A method for collecting data to assess the likelihood that a subject has progressive supranuclear palsy, comprising measuring the amount of a first molecular species having an apparent molecular weight of 100 kDa, which is bound to a cerebrospinal fluid sample derived from the subject by an antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ, wherein the measurement data of the first molecular species is collected as data that positively correlates with the likelihood that the subject has progressive supranuclear palsy.

2. The method according to claim 1, further comprising measuring the amount of a second molecular species bound by the antibody and having an apparent molecular weight of 74 kDa in a cerebrospinal fluid sample derived from the subject, wherein the measurement data of the second molecular species is collected as data positively correlated with the likelihood that the subject has Alzheimer's disease rather than progressive supranuclear palsy.

3. The method according to claim 1 or 2, wherein the antibody is a monoclonal antibody 22C11.

4. A method for collecting data to assess the likelihood that a subject has progressive supranuclear palsy, comprising measuring the amount of a first molecular species of amyloid precursor protein containing the epitope KEGILQYCQEVYPELQ and having an apparent molecular weight of 100 kDa in a cerebrospinal fluid sample derived from the subject, wherein the measurement data of the first molecular species is collected as data positively correlated with the likelihood that the subject has progressive supranuclear palsy.

5. The method according to claim 4, further comprising measuring the amount of a second molecular species of amyloid precursor protein containing the epitope and having an apparent molecular weight of 74 kDa in a cerebrospinal fluid sample derived from the subject, wherein the measurement data of the second molecular species is collected as data that positively correlates with the likelihood that the subject has Alzheimer's disease rather than progressive supranuclear palsy.

6. The method according to claim 4 or 5, wherein the amount of the first and second molecular species is measured by measuring the amount of monoclonal antibody 22C11 bound to the molecular species.

7. In a cerebrospinal fluid sample derived from a subject, the amount of a first molecular species having an apparent molecular weight of 100 kDa, which is bound by an antibody that recognizes the amyloid precursor protein epitope KEGILQYCQEVYPELQ, is measured. A method for testing the likelihood that a subject has progressive supranuclear palsy by comparing the measured amount of the first molecular species with a predetermined first reference value, wherein if the measured amount is higher than the first reference value, the subject is likely to have progressive supranuclear palsy, and if the measured amount of the first molecular species is lower than the first reference value, the subject is unlikely to have progressive supranuclear palsy.

8. The method according to claim 7, wherein the antibody is a monoclonal antibody 22C11.

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