BENEFICIAL EFFECT OF AUTOLOGOUS BLOOD-TRANSFUSION ON INFECTIOUS COMPLICATIONS AFTER COLORECTAL-CANCER SURGERY

Homologous blood transfusion has been associated with an increased ris k of postoperative infectious complications. To test the clinical cons equences of this apparently immunosuppressive effect of homologous blo od in a controlled trial, we designed a study in which the control gro up deposited autologous blood before their operations for use should t ransfusion be needed. We enrolled 120 patients with apparently curable colorectal cancer who were able to predeposit autologous blood (haemo globin > 12.5 g/dL). 58 patients were assigned to receive homologous b lood if blood transfusions were needed during operation, and the other 62 to receive their own predeposited blood followed, if necessary, by homologous blood. Despite the similarity between the groups in factor s known to affect the risk of postoperative infections, there was a si gnificant difference in postoperative infection rate between the homol ogous and autologous blood groups (17 [27%] vs 7 [12%], p < 0.05; unad justed odds ratio 2.75 [95% CI 1.07-7.11). The rates of non-infectious complications were similar. Probably because their preoperative blood depositing caused the autologous blood patients to have lower haemogl obin concentrations, they were more likely to require transfusion than were the homologous blood group (53 [91%] vs 37 [60%], p < 0.001; rel ative risk 1.53 [1.24-1.89]).20 (35%) required homologous as well as a utologous blood. To adjust for the many infection-related factors, we did multivariate regression analysis; tumour location, preoperative AS A index, and study group assignment were the only significant risk fac tors. The odds ratio for postoperative infections adjusted for these f actors was 2.84 (1.02-7.98, homologous vs autologous). Testing of dela yed-type hypersensitivity responses before and after surgery showed de creases in both mean diameter and number of positive reactions in reci pients of homologous blood and slight increases in those who received autologous blood. This study shows the clinical potential of blood-tra nsfusion-mediated immunomodulation, which may be important also in tum our immunology.