THE EFFECTS OF ETHNICITY ON DISEASE PATTERNS IN 472 ORIENTALS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective. To determine the effects of ethnicity on disease manifestat ions in Oriental patients with systemic lupus erythematosus (SLE) and to describe the risk of developing renal or central nervous system (CN S) involvement with time. Methods. A retrospective study of 472 patien ts with SLE seen at the only Rheumatology Unit in Singapore. The effec t of ethnicity on selected disease manifestations at diagnosis was ass essed after adjusting for demographic variables using multiple logisti c regression. The probability of developing selected disease manifesta tions with time was determined using the Kaplan-Meier product limit me thod. Results. At diagnosis, Malays had a higher risk of renal or CNS involvement than Chinese (OR 2.26, 95% CI 1.21 to 4.21, and OR 3.07, 9 5% CI 1.01 to 9.34, respectively), and Indians a lower risk of malar r ash and a higher risk of oral ulcers than Chinese (OR 0.30, 95% CI 0.1 3 to 0.68, and OR 2.90, 95% CI 1.45 to 7.34, respectively). The preval ence of renal or CNS involvement in the entire cohort increased with t ime, reaching 75.6% (95% CI66.1% to 85.0%) and 16.7% (95% CI 11.7% to 21.6%), respectively, after 18 years of disease. Conclusion. Ethnicity influenced disease manifestations at diagnosis in this cohort of Orie ntal patients with SLE. Renal or CNS involvement developed in previous ly unaffected patients up to 18 years after diagnosis, highlighting th e need for continued vigilance in patients with lupus.