Quantitative and functional alterations of plasmacytoid dendritic cells contribute to immune tolerance in ovarian cancer.

In ovarian cancer, the immune system fails to eradicate established tumors partly due to the induction of immune tolerance within tumor microenvironment. In this study, we investigated the contribution of plasmacytoid dendritic cells (pDC) in the establishment of immune tolerance in a cohort of 44 ovarian cancer patients. In the tumor and malignant ascites, CD4(+)CD123(+)BDCA2(+) pDC were the most abundant dendritic cell subset; however, they were profoundly depleted in peripheral blood. The presence of pDC in primary ovarian cancer, but not ascites, was an independent prognostic factor associated with early relapse. Following chemotherapy, we observed a partial restoration of blood pDC levels in patients in complete remission. These findings show preferential recruitment of pDC into tumors where they express a partially mature phenotype that may reflect an in situ activation. Importantly, compared with pDC found in ascites or blood, tumor-associated pDC (TApDC) produced less IFN-α, TNF-α, IL-6, macrophage inflammatory protein-1ß, and RANTES in response to toll-like receptor stimulation, and alterations in pDC functions were mainly mediated through tumor-derived TNF-α and TGF-ß. Unlike ascites-derived pDC, TApDC induced IL-10 production from allogeneic naive CD4(+) T lymphocytes, suggesting the existence of a paracrine immunosuppressive loop. Taken together, our findings indicate that both local and systemic dysfunction of pDC play a critical role in the progression of ovarian cancer via induction of immune tolerance.

[Invasive hydatiform mole in a postmenopausal woman]. / Môle hydatiforme invasive chez une patiente ménopausée.

Gestational trophoblastic disease occurs rarely in postmenopausal women. We report the case of a 51 year-old postmenopausal woman with an invasive complete mole. Invasive mole should be distinguished from choriocarcinoma, by a thorough sampling showing infiltrative molar villi associated with a prominent trophoblastic proliferation. Gestational trophoblastic diseases in postmenopausal women can represent malignant changes of trophoblastic remnants of a prior pregnancy after a period of latency or correspond to a possible current pregnancy as demonstrated by an ovarian corpus luteum of pregnancy in our patient. The unusual finding in our case is that the gestational trophoblastic disease follows a pregnancy occurring after a biologically confirmed menopause.