To evaluate whether the number of susceptible factors influences disease progression in Japanese patients diagnosed with early rheumatoid arthritis (RA).
Fifty-eight Japanese outpatients (46 female, 12 male; mean age 48.9 yrs) with early RA of less than one year after onset were enrolled in the study. The criteria for early RA (Japanese Ministry of Welfare) were used. DNA was extracted from fingernail clippings and the gene frequencies of HLA-DRB1 alleles were investigated. The degrees of progression of (1) clinical symptoms, (2) laboratory findings, (3) radiographic changes, and (4) magnetic resonance imaging score were analyzed by a comparison of the above at time of diagnosis and at final examination (an average of 14 months after the time of diagnosis).
The frequencies of the susceptible factors (S: 0101, 0401, 0404, 0405, 1001, and 1402) were 17, 3.4, 0.9, 29, 0, and 0%, respectively. The progression of inflammatory autoimmune activity, erosion incidence, and synovial proliferation severity in the S/S group was significantly more rapid than that in the other groups. In the disease activity at each time, the difference between the S/S group and the S/N group was significant, as was that between the S/S group and the N/N group, but the difference between the S/N group and the N/N group was not significant.
Haplotyping of HLA-DRB1 using the patient's nail clippings may be useful as a prognostic marker for disease progression in early RA.