Postoperative infections and variations of complement components in cancer patients

Sequential determinations of C4 and factor B serum levels were performed pre- and postoperatively in 56 cancer patients. Patients who underwent radical mastectomy and excision of melanoma had an incidence of surgical infections of 7% and 15%, respectively, and showed a significant postoperative acute-phase increase of C4 and factor B serum levels. A higher incidence of postoperative infections, mostly Gram negative, was recorded in patients who underwent gastric resection (35%) and colorectal resection (73%); these failed to show an early acute-phase response of complement postoperatively. The results of this study confirm the high susceptibility of cancer patients to postoperative infections. Moreover, the lack of postoperative acute-phase increase of C4 and factor B observed in cancer patients who developed postoperative infections suggests an active role of complement in host defense mechanisms against surgical infections.