The association of the HLA class II antigens with clinical and autoantibody expression in Malaysian Chinese patients with systemic lupus erythematosus.

The frequency of the HLA class II antigens/alleles (HLA-DR, DQ and DP) were studied in 70 Malaysian Chinese patients with systemic lupus erythematosus (SLE) to examine the contribution of these genes to disease susceptibility, their clinical expression and Immunological responses. This was done using modified PCR-RFLP technique. These samples were then compared with 66 ethnically matched controls. We found a strong association of the DQA10102 (p corr = 0.032, rr = 3.39), DQB10501 (p corr = 0.003, rr = 4.55), 0601 (p corr = 0.006, rr = 4.22) and DPB1 0901(p corr = 0.02, rr = 4.58) with SLE. Clinically, we found a strong association of DR2 and DQA10301 with renal involvement and DQA10102 with alopecia. Immunologically, statistical analysis (Chi-square test ) showed a strong association of DQA10102 with anti-Ro/La antibodies while DQA10301 was observed to be strongly associated with antibodies to ds DNA. DQA1*0102 was found more frequently in those with a later disease onset (30 years of age or above). From these data we suggest that the HLA class II genes play a role in conferring disease susceptibility and clinical and immunological expression.