OBJECTIVETo explore the effect of cardiopulmonary bypass (CPB) on the profile of protein expression in peripheral blood mononuclear cells (PBMCs).

METHODSEleven patients undergoing cardiac surgery under cardiopulmonary bypass were enrolled in the study. Peripheral blood samples were collected before CPB (T0), 1 h after CPB (T1) and at the end of operation (T2), and PBMCs were obtained by gradient centrifugation. The profile of protein expression was analyzed using 2-D gel electrophoresis (2-DE) and mass spectrometry. The candidate proteins were further identified by Western blotting.

RESULTCompared to protein profile at T0, 12 protein spots were identified to be up-regulated in PBMCs at T1 (P <0.05), among which S100A9 reached the peak level at T1 and decreased after operation,but not returned to its initial level.

CONCLUSIONResults indicate that 12 proteins are likely to be involved in CPB, however, their roles need to be elucidated.