Host Defense Mechanisms of the Peritoneal Cavity and Continuous Ambulatory Peritoneal Dialysis

Clinical and experimental data reviewed in this paper illustrate the perturbations of normal bio logical functions, which may accompany a major technological advance. There is a marked reduction in opsonic molecules, particularly IgG and C3, that occur after the instillation of large volumes of dialysate into the abdominal cavity. This greatly alters the normal balance in the peritoneal milieu and significantly impairs the normal function of phagocytic cells in the abdominal cavity. The “immunocompromised environment” produced is reflected in the high incidence of peritonitis in CAPD patients. Gram-positive organisms, particularly S. epidermidis , predominate. The higher incidence of gram-positive organisms in CAPD peritonitis probably reflects the more frequent exposure to gram-positive organisms during CAPD. These clinical data coupled with our experimental results suggest that the instillation of IgG locally in the abdominal cavity might enhance host defenses against peritonitis. This approach to prevention would represent a modern application of a treatment that was used extensively in the era before antibiotic therapy.