RACIAL-DIFFERENCES IN THE DISTRIBUTION OF SYSTEMIC SCLEROSIS-RELATED SERUM ANTINUCLEAR ANTIBODIES

Objective. To determine racial differences in the frequencies of syste mic sclerosis (SSc)-related serum antinuclear antibodies (ANA). Method s. We tested serum samples from 275 Japanese, 416 North American Cauca sian, and 24 North American black SSc patients for 8 SSc-related serum ANA, using indirect immunofluorescence, double immunodiffusion, and r adioimmunoprecipitation assays. Results. In comparing the 3 racial gro ups, we found that anti-U1 RNP, anti-RNA polymerase I, II, and III, an d anti-U3 RNP antibodies were the most frequently detected antibodies in Japanese, Caucasian, and black patients, respectively. Anti-PM-Sd a ntibody was found exclusively in Caucasians. Conclusion. The productio n of SSc-related serum ANA is related to immunogenetic background.