Evaluation of T lymphocyte subpopulations in children with nephrotic syndrome.

We have evaluated lymphocyte subsets both quantitatively and functionally in children with nephrotic syndrome. Ten children had minimal change nephrotic syndrome (MCNS), seven had focal segmental glomerular sclerosis (FSGS) and four had recovered from MCNS. Two patients with FSGS had decreased OKT4+ cells and a decreased T4/T8 ratio. Patients with active MCNS synthesized significantly less IgM in vitro than did normal subjects (P less than 0.005). In vitro IgG synthesis was significantly decreased in patients with active nephrotic syndrome whether it was due to MCNS or FSGS. Co-culture studies involving lymphocyte subsets suggested that both patients with decreased percentages of T4+ cells had decreased T helper cell activity as well. The results of this study support previous speculation about abnormal immune function in some patients with nephrotic syndrome.