Histocompatibility antigens in systemic lupus erythematosus.

Histocompatibility (HL-A) antigens were determined in 120 patients with systemic lupus erythematosus (SLE) and 120 matched controls. Increased frequencies of HL-A1 and HL-A8 were found. HL-A1 was more strongly associated with SLE in black patients (71 patients), whereas HL-A8 was more impressively associated with SLE in white patients (49 patients). In addition HL-A1 appeared more frequently in those with early onset of disease in both races; and HL-A1, HL-A8, and the HL-A1,8 phenotype seemed to be associated with severe SLE (renal and central nervous system involvement) in white patients. These data support the proposal that there are genetic influences in the pathogenesis and expression of SLE.