Histocompatibility antigen combinations in rheumatoid arthritis.

The frequencies of HLA-A, -B, -C, DR and MT lymphocyte alloantigens in clinical and serologic subsets of rheumatoid arthritis (RA) were determined in 65 Caucasian patients with definite or classical disease and compared to frequencies observed in normal individuals. The elevation in frequency of several antigens controlled by different genes in the major histocompatibility complex (MHC) suggested that combinations of antigens may be associated with RA. Significant associations were found for HLA-A1-DR4 and A1-MT2 (p less than 0.001), Bw40-DR4 (p less than 0.002) and Cw3-DR4 (p less than 0.001). The results indicate that combinations of genes in the MHC are influential in predisposing to RA.