FACS analysis of peritoneal lymphocytes in ovarian cancer and control patients

In this study different lymphocyte populations in the malignant ascites of 10 patients with ovarian carcinoma and in the peritoneal fluid of 8 control patients (tubal ligation and benign conditions) were analyzed. A panel of monoclonal antibodies against the CD markers of lymphocytes was used to stain different populations and the cells were analyzed on a FACS II (fluorescence-activated cell sorter). The mean percentage of B lymphocytes in the peritoneal cavity of the OVCA patients was 0.18 +/- 0.5% and in the control patients 0.05 +/- 0.07%. There was no significant difference between the two groups. In the OVCA group and in the controls the percentage of T lymphocytes (CD5+) was 23.5% and 17.1% respectively with no significant difference between the groups. These results indicate that B lymphocytes are not present in the human peritoneal cavity. The small numbers of B cells found in this study could be due to contamination with peripheral blood. The human peritoneal cavity contains a cell population which differs from that present in peripheral blood. Significant numbers of B lymphocytes have been reported in the peritoneal cavity of mice. The difference between the lymphocyte population of the human peritoneal cavity and that of rodents implies that data on characterization and function of B lymphocytes in the mouse peritoneal cavity would not be applicable to humans.