Relationship of blood transfusion, post-operative infections and immunoreactivity in patients undergoing surgery for gastrointestinal cancer.

BACKGROUND AND OBJECTIVE The immunosuppression induced by perioperative blood transfusion (BT) and its effect on the incidence of post-surgical infectious complications remains controversial. In this study, the relationship between BT and postoperative infections was investigated in 136 gastrointestinal cancer patients submitted to curative surgery. METHODS Clinical and laboratory variables, data on postoperative infections, infection risk factors and types of transfusion were analyzed. Immune function was evaluated in 76 patients and compared before and after surgery. RESULTS The overall postoperative infection rate was 28% for the transfused and 4.6% for the untransfused patients. The univariate analysis of investigated variables indicated that BT, progressive cancer stage, duration of surgery, drains, all had significant association with infection. The multiple logistic regression analysis confirmed BT (p = 0.0028) and advanced cancer stage (p < 0.001) as significant risk factors for the postoperative infections. The results of immunological tests showed no significant differences between transfused and untransfused patient groups, after surgery. Comparing pre- and postoperative data from individual patients, an impairment of natural killer (NK) activity was observed in all patients regardless of their transfusional status; the synthesis of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) was also decreased respectively in the untransfused and in the transfused patients. INTERPRETATION AND CONCLUSIONS These results indicate that other factors, beside BT, can induce immunosuppressive effects in these patients and thus increase their susceptibility to postoperative infections.