[Familial studies of systemic lupus erythematosus. HLA markers and complotypes]

Particular susceptibility to systemic lupus erythematosis (SLE) could be due to a certain alleles of class I, II or III of the major histocompatibility complex (MHC). The existence of total hereditary deficiencies of factor 2 or 4 of the complement in this syndrome suggests the presence of silent alleles which could conceivably play a determining role in the appearance of SLE. In this study, the HLA haplotypes and complotypes (C2, C4, Bf) were determined in 20 individuals suffering from SLE, and compared with 108 healthy, genotyped individuals. The results obtained showed a significant increase in the frequency of C4 BQ0 in patients compared with that found in controls (chi 2 = 12.27, p less than 0.001, Relative Risk = 3.78), and confirm the HLA association, DR3/SLE (chi 2 = 5.45, p less than 0.02, RR = 2.53).