HLA-A, B, DR and Bf allotypes in patients with idiopathic membranous nephropathy (IMN)

Fifty-five adult biopsy-proven patients with idiopathic membranous nephropathy were examined for HLA-A, B and DR antigens, and for the Bf allotypes. The phenotype frequencies of HLA-DR3 (52 vs. 23%) and HLA-B8 (46 vs. 24%) showed a significant increase in the IMN patient group compared to those of controls from the same region. The supraphenotype in which the combination of DR3-B8 alleles in Bf SS homozygotes occurred was significantly more common in the patient group than in the controls. A subset of six individuals carrying antigens DR3, B8, and common Bf*S alleles was identified, and the clinical course of those patients was found to be significantly worse compared to the rest of the patients. The present results do not support the existing suggestion that the clinical course of these diseases in Caucasians is determined by antigens B18 and the rare Bf allele (Bf*F1). It seems likely that IMN is not a single disease but a renal lesion that can result from several combinations of genetic predisposition and environmental stimuli.