Bactericidal and opsonic activity of cirrhotic ascites and nonascitic peritoneal fluid.

BA and OA of sera and uninfected ascitic fluid from patients with alcoholic cirrhosis were assayed against gram-negative enteric bacilli. This was compared with BA and OA in normal serum and in peritoneal fluid obtained at laparoscopy or laparotomy from noncirrhotic patients. Cirrhotic sera showed significantly reduced BA and OA against one of the organisms tested, Serratia marcescens. It had reduced OA but normal BA against E. coli. Ascitic fluid was markedly deficient in BA and OA against all strains tested when compared to both cirrhotic sera and nonascitic peritoneal fluid. Immunoglobulin and complement concentrations in cirrhotic ascites were reduced. Ascites did not inhibit the BA or OA of normal serum. However, replacement experiments suggested that the diminished activity of ascites was largely the result of its reduced complement concentration. The demonstrated deficit in both BA and OA of ascites may be a factor in the frequency of spontaneous enteric bacillary peritonitis in the cirrhotic patient.