Response of the cellular immune system to cardiopulmonary bypass is independent of the applied pump type and of the use of heparin-coated surfaces.

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+, HLA-DR+, CD45 RO+ and CD71+ leukocyte subpopulations.

CONCLUSIONS

CPB affects the cellular immune system; however, this effect seems to be a physiological reaction, independent of the applied CPB circuit system.