Lymphocyte cytotoxicity in the peritoneal cavity and blood of patients with ovarian cancer.

After an intensive course of combination chemotherapy, 16 patients with minimal residual ovarian cancer that was documented at second-look laparotomy, had an indwelling Tenckhoff catheter placed and underwent multiple peritoneal saline lavages. Lymphocyte-enriched populations from the peritoneal cavity and peripheral blood were obtained by density gradient centrifugation and examined for cell-surface phenotype and a variety of immune functions, including natural killer cytotoxicity and antibody-dependent cell-mediated cytotoxicity. Phenotypic characterization revealed that peritoneal lymphocytes consisted primarily of T cells and cells bearing receptors for the crystallizable fragment of immunoglobulin G (IgG) (crystallizable fragment-receptor), and contained a very low number of B cells. Peritoneal natural killer lymphocyte cytotoxicity and antibody-dependent cell-mediated cytotoxicity were very low in all but two patients. Incubation of peritoneal lymphocytes with Corynebacterium parvum and interferon in vitro did not result in augmented cytotoxicity against susceptible targets. Supernatants from cultured peritoneal cells of all patients markedly inhibited natural cytotoxic activity of normal donor blood lymphocytes. These results suggest that lymphocytes collected from the peritoneal cavity of patients with minimal residual ovarian cancer are deficient in natural and antibody-dependent cytotoxic effector function. This deficiency may influence the host's ability to control the spread and proliferation of tumor cells in the peritoneal cavity.