Suppression of T cell proliferation induced by concanavalin A in hemophilia patients

Concanavalin A (Con-A)-induced suppression of T cell proliferation was studied in 48 patients with severe hemophilia. Two groups of patients were defined according to the proliferative response when increasing numbers of Con A-induced cells were added to a constant number of phytohemagglutinin (PHA)-stimulated autologous T cells: In group A (60%) and in normal controls, higher suppression was achieved when more Con A-induced cells were added; in Group B, increasing numbers of Con A-induced cells produced no suppression of stimulated PHA-triggered proliferation. This effect could be corrected in Group B by inducing suppression in the presence of inhibitors of the oxidative metabolism of arachidonic acid. No correlation was found between the suppression profile and HIV-1 or HBV serology. Clinical evolution, as judged by signs and symptoms of AIDS related complex tended to be better in Group B than in Group A patients. It is suggested that decreased Con A-induced suppression in Group B may represent part of a normal regulatory process that involves products of arachidonic acid oxidative metabolism.