Response of the Cellular Immune System to Cardiopulmonary Bypass Is Independent of the Applied Pump Type and of the Use of Heparin-Coated Surfaces

Abstract

Background: Cardiopulmonary bypass (CPB) is associated with an activation of leukocytes. The extent of this activation was thought to depend on the applied CPB-circuit set-up. The present study comparatively evaluated the effect of roller pump, centrifugal pump, and uncoated and heparin-coated surfaces. Methods: 73 patients were included, randomly assigned to 3 groups. In group A a roller pump was used, in group B a centrifugal pump, and in group C a centrifugal pump together with Carmeda^™ heparin-coated surfaces. The quantitative (cell count) and the qualitative changes of leukocyte populations (subpopulations and expression of the CD126^-, HLA-DR^-, CD45 RO^-, CD71 antigens) was comparatively analysed before, during, and following CPB. Results: Groups A and B did not differ in leukocyte counts and the differences between groups B and C were restricted to Single time points. Neither groups A and B, nor groups B and C differed significantly in the relative distribution of lymphocyte subpopulations or in the percentage of CD126⁺, HLADR⁺, CD45 RO⁺ and CD71⁺ leukocyte subpopulations. Condusions: CPB affects the cellular immune system; however, this effect seems to be a physiological reaction, independent of the applied CPB circuit system.

Key words

Cardiopulmonary bypass - Centrifugal pump - Heparin-coated surfaces - Leukocytes - Flow cytometry