Depression of normal lymphocyte transformation by sera of patients with minimal change nephropathy and other forms of nephrotic syndrome.

Sera from patients with the nephrotic syndrome due to minimal change nephropathy (11 patients), membranous nephropathy (14 patients) and focal glomerulosclerosis (15 patients) inhibited the response of normal lymphocytes to the mitogen Concanavalin A. Although there was a tendency for the sera of patients with minimal change nephropathy to be more inhibitory than sera from the other two forms of nephrotic syndrome, this effect of nephrotic sera on normal lymphocytes is not confined to minimal change nephropathy. Until the exact nature of the inhibitor(s) is established, it is therefore not possible to state that impaired lymphocyte transformation by serum plays a pathogenetic role specifically in minimal change nephropathy. The susceptibility of nephrotic patients to infection may be due in part to the sera of the patients causing reduced lymphocyte function in vivo which leads to a defective immune response.