微小変化型ネフローゼ症候群におけるインターロイキン2産生能と反応能

Abstract

The present study was done to investigate the role of cell-mediated immunity in minimal change nephrotic syndrome (MCNS) by measuring interleukin 2 (IL-2) production and the response to IL-2 of peripheral blood lymphocytes (PBL). Moreover, the lymphocyte subpopulations capable of producing IL-2, and expressing IL-2 receptors (IL-2R), were assessed by flow cytometry. Subjects employed in the study were 41 patients with MCNS, 24 with membranous nephropathy (MN), 22 with IgA glomerulonephritis (IgA-GN), and 50 healthy volunteers as controls. Patients with MN and IgA-GN showed normal levels of IL-2 production by PBL. PBL of patients with MCNS, who were in the nephrotic stage prior to initiation of prednisolone (PSL) treatment or who were in remission less than one year, exhibited significantly lower levels of IL-2 production. In contrast, PBL of patients with MCNS, who were in remission more than 1 year or who could remit of PSL regimen, had normal IL-2 production. The IL-2 production by CD4＾+ cells from patients with MCNS at nephrotic stage was normal, but that production by CD8＾+ cells was markedly reduced, returning to normal when the disease was in remission. In patients with MCNS, the IL-2 production correlated positively with both the proportion of CD4＾+ cells and the ratio of CD4＾+/CD8＾+ and inversely with the proportion of CD8＾+ cells. The response to exogenous IL-2 of concanavalin A-induced lymphoblasts from patients with MCNS was significantly lower, although the proportion of IL-2R＾+ cells showed no difference from that of healthy volunteers. These findings suggest that defective IL-2 production and IL-2 response of PBL in patients with MCNS contribute to the pathogenesis of MCNS.