HLA CLASS-II ANTIGENS ASSOCIATED WITH SYSTEMIC LUPUS-ERYTHEMATOSUS INBLACK SOUTH-AFRICANS

Objective-To assess the associations of HLA class II antigens with sys temic lupus erythematosus (SLE) in black South Africans. Methods-HLA-D RB1 genotype frequencies assigned by polymerase chain reaction (PCR) a mplification and sequence specific oligonucleotide probes were compare d between 49 black SLE patients hom Baragwanath Hospital and 87 ethnic ally matched controls. HLA-DQA1 and -DQB1 genotypes were also assigned in 45 of the SLE patients and 74 controls by PCR using sequence speci fic primers. Results-HLA-DRB102 was increased in the patients compare d with controls (odds ratio = 3.67; 95% confidence interval = 1.49 to 9.02; p < 0.005). HLA-DQB10201 was not associated with development of the disease itself, but was associated with the presence of Ro antibo dies (p = 0.01). HLA-DRB103 was less strongly linked to DQB1*02 in th is population than in white populations and was not associated with SL E. Conclusions-In black South Africans there is evidence for a locus o n DR2 haplotypes contributing to SLE, Another gene, possibly HLA-DQB1 02, not linked to DR2 is involved in the subset of patients exhibiting Ro antibodies.