A STUDY OF THE EFFECTS OF EXTRACORPOREAL-CIRCULATION ON THE IMMUNOLOGICAL SYSTEM OF HUMANS

Objectives: The objectives of this study were to quantify the immunosu ppressive effects of cardiopulmonary bypass (CPB) and to identify mech anisms responsible for the postoperative immunosuppression of patients undergoing cardiac surgery. Design: A prospective study from 20 conse cutive patients. Setting: The same team operated on all patients in a major teaching hospital. and the immunologic tests were performed in t he hospital's hematology laboratory. Participants: Twenty patients wer e studied who had consented to participate in the study. Interventions : All patients underwent valve replacement under general anesthesia. M easurements and Main Results: The changes in the white blood cell coun t (WBC), in the B, T, T-4, T-8 lymphocytes, the concentrations of C-re active protein (CRP), a(1)-antitrypsin (A(1)AT), a(2)-macroglobulin (A (2)MG), C-3, C-4, immunoglobulin A (IgA), IgM, IgG, kappa (K), and lam bda (L) chains were studied. The postoperative immune response was exp ressed with (1) increased mean axillary temperature (37.5 degrees +/- 0.62 degrees) in the first postoperative 24 hours; (2) increase of WBC (p < 0.001) and T-8 (P < 0.01); (3) reduction of C-3 (p = 0.01) and A (2)MG (p < 0.01); (4) reduction of IgA (p < 0.001) and IgG, K, L chain s (p < 0.01); and (5) reduction of T (p < 0.01) and T-4 (p < 0.01). In the first 24 hours postoperatively, B cells were increased (81%) toge ther with CRP (p < 0.01) and A(1)AT. Conclusions:The observed immune a lterations were mostly of no immunologic origin and were related to he modilution and inflammation together with an immunosuppressive effect of trauma and stress. Copyright (C) 1996 by W.B. Saunders Company