[Expression of thrombomodulin in maternal plasma and placental tissue in early onset severe preeclampsia].

OBJECTIVE: To explore the thrombomodulin (TM) expression levels changes in plasma and placenta in patients with early onset severe preeclampsia. METHODS: Sixty cases of severe preeclampsia women who delivered in the affiliated Xuzhou Maternity and Child Health Care Hospital of Xuzhou Medical College were enrolled in the study from June 2012 to February 2014, including 30 patients with early onset severe preeclampsia (early onset group), and 30 patients with late onset severe preeclampsia (late onset group). Healthy pregnant women were divided into two control groups according to gestational weeks at delivery: early control group (n = 23, at 28-33⁺⁶ weeks), and late control group (n = 30, delivered after 34 weeks). ELISA was used to detect the levels of TM in plasma. Immunohistochemistry SP was applied to detect the TM protein expression on placenta. TM mRNA was determined by reverse transcription polymerase chain reaction (RT)-PCR technique. RESULTS: (1) TM level in plasma in early onset group and late onset group were (90.8 ± 6.9) and (87.5 ± 7.0) µg/L, and TM level in plasma in early control group and late control group were (37.7 ± 2.3) and (37.7 ± 2.5) µg/L. Plasma TM level in early onset group was higher than that in late onset group, early control group and late control group. The TM level had no statistically significant compare of early-onset group to late onset group. (P > 0.05). The plasma TM level in early onset group was significantly higher than that in early control group (P < 0.05), and the plasma TM level in late onset group was significantly higher than that in late control group (P < 0.05). (2) TM expressed mainly in the membrane and cytoplasm of placental syncytiotrophoblasts and endothelial cells. The expression of TM protein in early onset group was 47% (14/30), significantly lower than that in late onset group, early control group and late control group (P < 0.05), in which the positive rate were 90% (27/30), 91% (21/23) and 93% (28/30) respectively (P < 0.05). There was no difference between late onset group and late control group (P > 0.05). There was no difference between early control group and late control group (P > 0.05). (3) TM mRNA expression in early onset group, late onset group, early control group and late control group were 0.14 ± 0.06, 0.89 ± 0.23, 0.88 ± 0.22 and 0.93 ± 0.19, respectively. The expression of TM mRNA in early onset group was significantly lower than that in late onset group, early control group and late control group (P < 0.05), and the difference between early control group and late control group was not statistically significant (P > 0.05). There was no difference between late onset group and late control group (P > 0.05). There was no difference between early control group and late control group (P > 0.05). CONCLUSIONS: Decreased expression of TM in placenta may be associated with the pathogenesis of early onset severe preeclampsia, there may be different pathogenesis in early onset and late onset severe preeclampsia.