Major histocompatibility complex antigens and immune mechanisms in steroid-responsive nephrotic syndrome.

Although the pathogenesis of steroid-responsive nephrotic syndrome (SRNS) is obscure, involvement of an immune mechanism is often suggested. Further evidence of an immune basis for this disorder is an increased frequency of specific major histocompatibility complex (MHC) antigens. In the first part of this study, the phenotypic frequency of HLA-A, -B, -C, -DR antigens were investigated in 30 children with SRNS and in 630 controls. In the second part, total T (CD3+ cells) and B lymphocytes (CD19+ cells) and the lymphocyte subsets (CD4+, CD8+ cells and their ratio) were studied in the same patients and in 30 healthy children. The investigations of all patients were performed during the acute stage and 14 of 30 during remission stage. Human leukocyte antigens (HLA) were determined by standard microlymphocytotoxicity assay and lymphocytes were analyzed by flow cytometry. Human leukocyte antigens A3, DR4, DR7 and the haplotype HLA-A2/B12 showed the strongest association with SRNS. In the studies for cellular immune disorder, CD3+ and CD8+ cells were found to be decreased significantly in the acute stage before beginning steroid therapy. No significant difference in lymphocyte subsets was observed in the remission stage without steroid or immunosuppressive therapy.