Natural killer cells in the pathogenesis of preeclampsia: a double-edged sword.

OBJECTIVE: To investigate the relationship between natural killer (NK) cells, extravillous trophoblast cells (EVTs) and vessel remodeling in early human pregnancy, and the association between NK cells and preeclampsia (PE) in late human pregnancy. METHODS: Human decidual tissues from women with normal pregnancies were collected and examined for the relationship of NK cells with uterine vessel remodeling using immunohistochemistry. Percentages of peripheral blood NK (pNK) and decidual NK (dNK) cells and the levels of intracellular interferon (IFN)-γ, perforin and granzyme B in normal pregnancies, late-onset and early-onset PE were analyzed using flow cytometry. Cytolytic functions of dNK cells from normal and PE pregnancies were examined. Effects of conditioned medium (CM) of dNK cells from normal and PE pregnancies on first trimester trophoblast invasion and migration were tested. RESULTS: In early pregnancy samples (9-13 weeks of gestation), we noted moderate vessel remodeling with abundant perivascular NK cells but a limited number of surrounding EVTs. The numbers of both human pNK cells and dNK cells and intracellular interferon (IFN)-γ, perforin and granzyme B production were significantly higher in PE compared with normal pregnancies at the time of delivery for both early- and late-onset disease. dNK cells from PE pregnancies not only killed first trimester trophoblasts but also inhibited their invasion and migration when compared to normal controls. CONCLUSION: Our results suggest that NK cells, in conjunction with EVTs, may play an important role in controlling uterine SA remodeling at the early stages of vessel remodeling, but they contribute to the pathogenesis of PE in late pregnancy.

Acute mesenteric venous thrombosis in a pregnant woman at 35 weeks of gestation: a case report and review of the literature.

BACKGROUND: Mesenteric venous thrombosis (MVT) is an infrequent thrombotic event that can cause devastating intestinal hemorrhagic ischemia. The mortality rate among patients with acute MVT ranges from 20 to 50%. Occurrence of MVT in pregnancy is quite rare. In this case report, we describe a pregnant woman who presented with acute MVT at 35 weeks of gestation. CASE PRESENTATION: Our case was a 26-year-old primigravid woman at 35 weeks gestation. She presented to Guangzhou First People's Hospital with complaints of abdominal pain, nausea and vomiting. The second day after admission, she complained of more intense abdominal pain, anorexia, vomiting and abdominal distention that were out of proportion to physical signs. An emergency exploratory laparotomy was performed. The entire ileum, part of the jejunum and part of the ascending colon were gangrenous, and thromboembolism was discovered in the corresponding mesenteric veins. The necrotic intestine was resected and an end-to-end jejunum-colon anastomosis was performed. A cesarean section was performed to remove the placenta and fetus, which had expired. Histopathological analysis revealed extensive edema, hemorrhage, inflammatory infiltration and necrosis in the resected bowel, and widespread thrombosis in mesenteric venous lumens. CONCLUSION: The diagnosis of MVT during pregnancy is very difficult due to its low incidence, and non-characteristic symptoms, signs and laboratory results. MVT may be the underlying cause of severe abdominal pain during pregnancy and should be included in the differential diagnosis of pregnant patients with an acute abdomen.