Inhibitory factors of lymphocyte transformation in sera from patients with minimal change nephrotic syndrome

This study was undertaken to establish the specificity and relation to disease activity of serum inhibitors of lymphocyte function in minimal change nephrotic syndrome (MCNS). Sera from 21 children with MCNS were evaluated for their effect on blast transformation of normal human lymphocytes after stimulation with E-PHA, ConA, PWM or allogeneic cell surface antigens (mixed lymphocyte cultures;MLC). Sera from patients in relapse on no medication (n = 12), in relapse on steroids (n = 5), and in remission on steroids (n = 7) were significantly more inhibitory than sera from patients in late remission off steroids (n = 14 both in mitogen induced blast transformation and in MLC. Sera from eight children with other forms of nephrotic syndrome exhibited the same degree of inhibition of E-PHA, ConA, and PWM induced mitogenesis but significantly less inhibition of MLC when compared to 12 MCNS patients in untreated relapse. Thus serum inhibition of mitogen induced blast transformation is not specific for MCNS but occurs in other forms of nephrotic syndrome as well. Conversely, sera from MCNS patients does selectively inhibit MLC. Finally, the inhibitory activity of MCNS sera for both mitogen and cell surface antigen stimulation correlates with the course of the disease.