ObjectiveTo evaluate the effects of leukocyte filtration (LF) on blood components and cytokines of residual pump blood after cardiopulmonary bypass (CPB). MethodsForty patients who underwent selective cardiac surgery with CPB in Fu wai Hospital from December 2012 to February 2013 were included in this study. There were 34 male and 6 female patients with their age of 16-72 years. All the patients were randomly divided into an experimental group and a control group. In the experimental group, patients received residual pump blood transfusion which had been processed with LF and stored in sterile blood collection bags. In the control group, patients received residual pump blood transfusion which was stored in sterile blood collection bags without LF process after CPB. Blood samples were taken before CPB (T1) at the end of CPB (T2) and 4 hours (T3) after CPB to examine blood components and concentrations of IL-6, IL-10 and TNF-α. ResultsWhite blood cell count and neutrophil count of the experimental group were significantly lower than those of the control group at T2 and T3 (P<0.05). There was no statistical difference in red blood cell count, hemoglobin,hematocrit or free hemoglobin at respective time points between the 2 groups (P>0.05). There was no statistical difference in plasma IL-6,IL-10 or TNF-α concentrations at different time points within either group (P>0.05) or at respective time points between the 2 groups (P>0.05). ConclusionLF can reduce white blood cell count and neutrophil count of residual pump blood,but does not significantly change other blood components and plasma concentrations of IL-6,IL-10 or TNF-α after CPB.