SERUM INHIBITOR OF BLASTOGENESIS IN IDIOPATHIC NEPHROTIC SYNDROME TRANSFERRED BY LYMPHOCYTES

Suppression of concanavalin A- and phytohemagglutinin-induced lymphoblastogenesis was observed when serum from patients with hypoalbuminemia constituted 20% by volume of the culture medium. There was no evidence for a lymphocytotoxin or for absence of a factor essential for blastogenesis. Transfer experiments using serum from patients with idiopathic nephrotic syndrome (INS) indicated the presence of a heat-stable inhibitor with marked affinity for lymphocytes. A factor in normal serum appeared to block attachment of the inhibitor but was less firmly cell bound. Paradoxically, lymphocytes isolated from patients with INS with circulating inhibitor responded normally to mitogens, probably because receptors on lymphocytes for the inhibitor were masked by the normal serum factor. Washing entailed in harvesting the cells would make them susceptible to the inhibitor. © 1979.