JP-2022520587-A5 -

Dates

Publication Date

20221213

Application Date

20200214

Description

Modifications that do not substantially affect the activities of the various embodiments of this disclosure are also understood to be included within the definition of disclosure provided herein. Accordingly, the following examples are intended to illustrate, and not limit, this disclosure. This application provides the invention in the following embodiments. (Aspect 1) A diagnostic method for rheumatoid arthritis (RA): (a) Contacting a biological sample from a person suspected of having RA with peptidylarginine deiminase (PAD) or its antigenic fragment, and (b) The method comprising detecting the presence of anti-PAD IgA in the biological sample, wherein the presence of anti-PAD IgA indicates RA. (Aspect 2) A method for evaluating the severity of disease in individuals suffering from rheumatoid arthritis (RA): (a) Contacting biological samples from subjects suffering from RA with peptidylarginine deiminase (PAD) or its antigenic fragment, and (b) The method comprising detecting the presence of anti-PAD IgA in the biological sample, wherein the presence of anti-PAD IgA indicates the severity of RA. (Aspect 3) The method according to embodiment 1 to 2, wherein the biological sample includes whole blood, plasma, serum, synovial fluid, or sputum. (Aspect 4) The method according to embodiments 1 to 3, wherein the biological sample includes serum or plasma. (Aspect 5) The severity of the aforementioned RA is determined by the methods of embodiments 2 to 4, including the presence of joint erosion. (Aspect 6) The severity of the RA is determined by the methods of embodiments 2 to 5, including severe joint erosion. (Aspect 7) The method according to embodiments 1 to 6, wherein the anti-PAD IgA level correlates with the degree of joint erosion. (Appendix 8) The method of embodiment 7, wherein the degree of joint erosion is reduced mobility. (Aspect 9) The method according to embodiment 8, wherein the reduced mobility includes disability index 3. (Aspect 10) The method according to embodiments 1 to 9, wherein the PAD or its antigenic fragment is selected from the group consisting of PAD2, PAD3, and PAD4. (Phenomenon 11) The method according to embodiment 1 to 10, wherein the PAD or its antigenic fragment comprises PAD4. (Aspect 12) The method according to embodiments 1 to 11, wherein the PAD or its antigenic fragment comprises an amino acid sequence selected from even-numbered sequence numbers in sequence numbers 2 to 92, or an amino acid sequence comprising at least six consecutive amino acids selected from even-numbered sequence numbers in sequence numbers 2 to 92. (Aspect 13) The method according to embodiment 1 to 12, wherein the antigenic fragment comprises 6 to 120, 12 to 100, 18 to 80, 24 to 60, 30 to 50, or 35 to 45 amino acid residues. (Aspect 14) The PAD or its antigenic fragment is obtained by a method comprising isolation from natural resources, chemical synthesis, or recombinant expression, according to the methods of embodiments 1 to 13. (Phenomenon 15) The PAD or its antigenic fragment is obtained by chemical synthesis, according to the methods of Embodiments 1 to 14. (Aspect 16) The detection is carried out by the methods of embodiment 1 to 15, which include an immunoassay. (Aspect 17) The method according to embodiment 16, wherein the immunoassay is selected from the group consisting of fluorescent immunoadsorption assays (FIAs), chemiluminescence immunoassays (CIAs), radioimmunoassays (RIAs), multiplex immunoassays, protein/peptide array immunoassays, solid-phase radioimmunoassays (SPRIA), indirect immunofluorescence assays (IIFs), enzyme-linked immunosorbent assays (ELISAs), and particle-based multi-sample assays (PMATs), or dot blot assays. (Phenomenon 18) The aforementioned detection is (a) Contacting the anti-PAD IgA with a detection probe specific to the anti-PAD IgA, and (b) Detecting the specific binding of the detection probe, Methods according to embodiments 1 to 17, including the methods described above. (Aspect 19) The method according to embodiment 18, wherein the detection probe binds to the anti-PAD IgA. (Aspect 20) The detection probe is coupled to the PAD, according to the method of embodiment 18. (Aspect 21) The method according to embodiments 18 to 20, wherein the detection probe comprises an antibody or a functional fragment thereof. (Aspect 22) The method according to embodiment 21, wherein the antibody or functional fragment thereof comprises anti-IgA. (Aspect 23) The detection probe includes a reporter tag, according to the methods of embodiments 18 to 22. (Aspect 24) The method according to embodiment 23, wherein the reporter tag is a marker. (Aspect 25) The label is selected from the group consisting of fluorophores, enzymes, chemiluminescent components, radioactive components, organic dyes, and small molecules, according to the method of embodiment 24. (Aspect 26) The method according to embodiments 24 and 25, wherein the marker is a fluorescent marker. (Aspect 27) The metho