Production of interleukin 2 (IL-2) and responsiveness to IL-2 of peripheral blood lymphocytes in minimal change nephrotic syndrome.

We investigated the role cell-mediated immunity in minimal change nephrotic syndrome (MCNS) by measuring interleukin 2 (IL-2) production and the responsiveness to IL-2 of peripheral blood lymphocytes (PBL). PBL from patients with MCNS, who were in the nephrotic stage prior to initiation of prednisolone (PSL) treatment or who were in remission for less than 1 yr, exhibited significantly lower levels of IL-2 production. In contrast, PBL from patients with MCNS, who were in remission for more than 1 yr or who could remit from the PSL regimen, showed normal IL-2 production. IL-2 production by CD4+ cells from patients with MCNS in the nephrotic stage was normal, but that by CD8+ cells was markedly reduced, however returned to normal when the disease was in remission. The responsiveness to exogenous IL-2 of concanavalin A-induced lymphoblasts from patients with MCNS was significantly lower, although the proportion of Tac antigen-positive cells did not differ from that of healthy volunteers. These findings suggest that defective IL-2 production and IL-2 responsiveness of PBL in patients with MCNS contribute to the pathogenesis of MCNS.