Clinical implications from studies of HLA antigens in idiopathic nephrotic syndrome in children.

HLA class I and II antigen frequencies were determined in two large cohorts of children with idiopathic nephrotic syndrome (NS) from Southwest France (n = 199) and Southwest Germany (n = 152) and compared with unrelated healthy individuals from the same geographical areas. Strength of HLA association was expressed by the relative risk (RR) estimated by Odd's ratio. We examined 105 steroid-resistant and 242 steroid-sensitive NS patients who were subdivided in non-relapsers, infrequent relapsers and frequent relapsers or steroid-dependent patients. In steroid-sensitive patients significant associations were found with HLA-DR7 (RR 5.1 in French, 3.2 in Germans), -DQ2 (RR 4.7/2.3) and with the phenotypic combination HLA-DR3/DR7 (RR 5.6/7.7). Significant negative associations were encountered with HLA-DR2, -DR6 and -DQ1. The associations were stronger in frequent relapsers/steroid-dependent patients than in infrequent relapsers and were not significant in non-relapsers. In steroid-resistant patients the only significant association found was with the combined occurrence of HLA-DR3/DR7. We propose that in childhood NS tissue typing for selected HLA class II antigens is helpful in prediciting the clinical course.