The prevalence of HLA alleles in a lupus nephritis population.

Background: Systemic lupus erythematosus (SLE) is a severe autoimmune disease that involves multiple organ systems. Lupus nephritis (LN) is a complication of SLE and is associated with poor survival and high morbidity. Many genomic studies have been performed worldwide, and several histocompatibility leukocyte antigen (HLA) loci are linked to lupus susceptibility.

Objective: The present study evaluated the association of HLA alleles in a lupus patient population, LN group and control group. The second objective evaluated whether HLA allele match or mismatch influenced kidney graft survival in a kidney transplanted lupus population.

Methods: This study was a retrospective study of 2 major groups: general lupus patients (GSLE - n = 108) and a control group (GControl - n = 216). Both groups were also divided into subgroups.

Results: The control group was divided into two subgroups: a healthy control group (HeCTRL) and transplant control group (TxCTRL). The GSLE group was composed of transplanted lupus patients (TxSLE) and non-transplanted lupus patients (nTxSLE). Comparison of the demographics between groups did not reveal differences between ethnicity and gender. A difference in the prevalence of three alleles, B*08, DRB1*08 and DRB1*15, was observed. These alleles were more prevalent in the lupus subgroups compared to the control groups. Five-year survival was not different between patients carrying the allele DRB1*15 in either group (overall p = 0.075; TxSLE p = 0.419; TxCTRL = 0.309). The presence of the match with this allele in the receptor was evaluated and did not demonstrate any difference in graft survival in both groups (p = 0.146) or when analyzed separately in each group (TxCTRL p = 0.739; TxSLE = 0.297).

Conclusion: This study demonstrated that the presence of HLA-DRB1*15 was a strong factor that predisposed patients to the development of SLE and LN, but did not influence kidney graft survival.