Ethnic differences in risk for pediatric rheumatic illness in a culturally diverse population.

Objective: To analyze the differences of occurrence of pediatric rheumatic disease among various ethnic groups in a culturally diverse isolated geographic area.

Methods: A retrospective study of pediatric rheumatic diseases in a multiethnic area during a 6 year period.

Results: A group of 922 patients was categorized based on predominant ethnicity, and their risk of having acute rheumatic fever (ARF), juvenile rheumatoid arthritis (JRA), and systemic lupus erythematosus (SLE) was studied. Odds ratios (OR) were computed for each illness with Caucasians as the reference group. Results indicated that Polynesians were overrepresented among patients with ARF, having elevated OR that were significantly different from Caucasians (22.5-120.7, p < 0.0001). For SLE, the highest OR were obtained for Samoans, Filipinos, and Japanese. In contrast, for JRA, Filipinos and Japanese had OR less than one, and no Samoans were diagnosed with JRA, possibly indicating a protective effect against developing JRA.

Conclusion: This unique retrospective study examined the ethnic variations of expression of certain rheumatic diseases in an isolated region. Results reveal that certain ethnic groups are at risk for ARF and SLE, but are protected against JRA. These findings suggest investigating possible immunogenetic similarities and differences in these illnesses.