Thermal injury-associated immunosuppression: occurrence and in vitro blocking effect of post recovery serum

Sera from 38 of 72 burn patients have been found to be significantly suppressive to the PHA-induced blastogenesis of normal human lymphocytes in culture. In many of these patients, we have observed that suppression levels decline with recovery. In a study of eight of these patients, we have found that the addition of post recovery serum to cultures of normal lymphoyctes blocked the suppressive effect of autologous serum obtained earlier. Blocking appears to be achieved through the formation of antibodies since: a) IgG levels are greatly elevated in serum samples having blocking activity, b) the time of appearance of blocking substances in the serum is compatible with the generation of antibody, and c) blocking activity is contained in the protein-A isolated IgG fraction of such post recovery serum.