HLA-DR antigens in Blacks with rheumatoid arthritis and systemic lupus erythematosus.

HLA-DR locus antigens were studied in a large population of Black Americans with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). An association was found with DR4 in RA (p less than 0.001) and DR3 in SLE (p less than 0.01). Our findings are similar to those reported in Caucasians. No significant correlations between clinical manifestations and DR locus antigens were apparent in either disease. Our results support the association of D locus antigens with disease susceptibility more than with clinical severity.