A method for assisting diagnosis of rheumatoid arthritis, comprising steps of: measuring at least one chemokine and anti-cyclic citrullinated peptide antibody (anti-CCP antibody) in a blood sample derived from a subject exhibiting joint abnormality and obtaining a concentration of the chemokine and a titre of the anti-CCP antibody in the blood sample; comparing the concentration of the chemokine with a first threshold and comparing the titre of the anti-CCP antibody with a second threshold; and obtaining information for distinguishing rheumatoid arthritis from other autoimmune diseases associated with joint abnormality, wherein: if the concentration of the chemokine is at or higher than the first threshold and the titre of the anti-CCP antibody is at or higher than the second threshold, or the concentration of the chemokine is at or higher than first threshold and the titre of the anti-CCP antibody is less than the second threshold, or the concentration of the chemokine is less than the first threshold and the titre of the anti-CCP antibody is at or higher than the second threshold, information indicating that the subject is likely to have rheumatoid arthritis is obtained and if the concentration of the chemokine is less than the first threshold and the titre of the anti-CCP antibody is less than the second threshold, information indicating that the subject is unlikely to have rheumatoid arthritis is obtained, wherein the chemokine is selected from MIP-1α and MIP-3α. measuring at least one chemokine and anti-cyclic citrullinated peptide antibody (anti-CCP antibody) in a blood sample derived from a subject exhibiting joint abnormality and obtaining a concentration of the chemokine and a titre of the anti-CCP antibody in the blood sample; comparing the concentration of the chemokine with a first threshold and comparing the titre of the anti-CCP antibody with a second threshold; and obtaining information for distinguishing rheumatoid arthritis from other autoimmune diseases associated with joint abnormality, wherein: if the concentration of the chemokine is at or higher than the first threshold and the titre of the anti-CCP antibody is at or higher than the second threshold, or the concentration of the chemokine is at or higher than first threshold and the titre of the anti-CCP antibody is less than the second threshold, or the concentration of the chemokine is less than the first threshold and the titre of the anti-CCP antibody is at or higher than the second threshold, information indicating that the subject is likely to have rheumatoid arthritis is obtained and if the concentration of the chemokine is less than the first threshold and the titre of the anti-CCP antibody is less than the second threshold, information indicating that the subject is unlikely to have rheumatoid arthritis is obtained, wherein the chemokine is selected from MIP-1α and MIP-3α. if the concentration of the chemokine is at or higher than the first threshold and the titre of the anti-CCP antibody is at or higher than the second threshold, or the concentration of the chemokine is at or higher than first threshold and the titre of the anti-CCP antibody is less than the second threshold, or the concentration of the chemokine is less than the first threshold and the titre of the anti-CCP antibody is at or higher than the second threshold, information indicating that the subject is likely to have rheumatoid arthritis is obtained and if the concentration of the chemokine is less than the first threshold and the titre of the anti-CCP antibody is less than the second threshold, information indicating that the subject is unlikely to have rheumatoid arthritis is obtained, wherein the chemokine is selected from MIP-1α and MIP-3α.