Decreased progression to rheumatoid arthritis or other connective tissue diseases in patients with palindromic rheumatism treated with antimalarials

Objective. To determine whether the use of antimalarials is associated with a reduction in the risk of developing rheumatoid arthritis (RA) or other c onnective tissue diseases in patients with palindromic rheumatism. Methods. We conducted a retrospective cohort study based on a review of med ical records to evaluate the outcome of patients with palindromic rheumatis m referred to an academic center from 1986 to 1996; 113 patients complied w ith the: selection criteria, including diagnostic criteria for palindromic rheumatism and onset of disease since 1980. After adjusting for potential c onfounders, Kaplan-Meier methods and Cox regression models were used to est imate the risk of developing RA or other connective tissue disease in patie nts who had received antimalarials compared to those who had not. Results. Age of disease onset was 40 +/- 12 yrs, and mean disease duration 4.8 +/- 4 yrs; two-thirds of the patients were female, Sixty-two (55%) pati ents received antimalarials, for a mean duration of therapy of 28 mo. Thirt y-three (29%) patients developed RA. 3 developed systemic lupus, and 4 deve loped other connective tissue diseases. Twenty (32%) patients in the antima larial group developed a secondary disease, compared to 20 (39%) who did no t receive therapy. Statistically significant differences were observed comp aring rime to event in both groups. The estimated median time to developmen t of a chronic disease was 162 months in treated and 56 months in untreated patients, After adjusting for other variables in the Cox regression models , significant risk reduction in the development of a secondary disease was observed for antimalarial use (hazard ratio = 0.24; 95% CI 0.09-0.61). For RA, the risk reduction was 0.19 (95% CI 0.07-0.57). We conducted a sensitiv ity analysis around our censoring estimates. The risk reduction remained st atistically significant, with 0.36 for RA and 0.41 for RA or other connecti ve tissue disease, Conclusion. Use of antimalarials in patients with palindromic rheumatism is associated with a reduction in the risk of developing subsequent RA or oth er connective tissue disease.