Impaired NK-cell-mediated cytotoxic activity and cytokine production in patients with endometriosis: A possible role for PCBs and DDE

Endometriosis is a gynaecological disorder characterized by the presence and growth of endometrial tissue in ectopic sites. In this study we examined the immunological functions of patients with endometriosis and serum level of PCBs and p,p′-DDE to verify the impact of these environmental contaminants on the dysregulation of immune functions. We found that proliferative responses and immunoglobulin production were not dysregulated in patients with endometriosis while NK cell activity was significantly down-regulated in these patients. Moreover, a significant down-regulation of IL-1β and IL-12 production was found in patients with respect to controls. Serum levels of PCBs and p,p′-DDE were found to be significantly higher in women with endometriosis than in the control group, with respect to the sum of the congeners most prominent in human tissues. In particular, total PCBs concentration in patients with endometriosis and controls was respectively 330 and 160 ng/g fat with respect to the most abundant congeners, while p,p′-DDE concentration was of 770 and 310 ng/g fat. Moreover, we found that normal human PBMC pulsed with PCBs, p,p′-DDE and their combination showed a significant down-regulation of NK cell cytotoxic activity and IL-1β and IL-12 production. These findings suggest that changes in specific immune parameters correlate with elevated serum PCBs and DDE levels and endometriosis.