[Relationship between the expression of human leukocyte antigen G and preeclampsia]

To detect the expression of human leukocyte antigen-G (HLA-G) in tissues from pregnant women with preeclampsia and discuss the relationship between HLA-G and preeclampsia.

Pregnant women with preeclampsia in Maternal and Child Health Hospital of Shaanxi Province from March 2009 to December 2009 were included. Eight were included into mild preeclampsia groups and 22 were included into severe preeclampsia group. And 30 age-matched normal pregnancies were referred as the control group. All women in the three groups received cesarean section. The soluble HLA-G (sHLA-G) levels in peripheral blood, umbilical blood and amniotic fluid were examined by ELISA; the expressions of HLA-G protein in placenta, fetal membrane and umbilical cord were examined by western blot.

(1) The sHLA-G levels in peripheral blood, umbilical blood and amniotic fluid in each group. The sHLA-G levels in peripheral blood in mild and severe preeclampsia group were (50 ± 14) and (30 ± 6) µg/L respectively, and the sHLA-G levels in umbilical blood were (34 ± 10) and (26 ± 8) µg/L respectively. All were significantly lower than those in the control group (P < 0.01), which were (100 ± 16) and (70 ± 9) µg/L respectively. There was also statistical difference between mild and severe preeclampsia group (P < 0.01). Although the sHLA-G level in umbilical blood of severe preeclampsia group was lower than that in mild preeclampsia group, there was no statistical difference (P > 0.05). The sHLA-G levels in amniotic fluid in mild and severe preeclampsia groups were (26 ± 7) and (25 ± 5) µg/L respectively, which were lower than that in the control group (27 ± 6) µg/L, but the differences were not significant (P > 0.05). There was no statistical difference between mild and severe preeclampsia groups (P > 0.05). (2) The expression levels of HLA-G protein in placenta, fetal membrane and umbilical cord in each group. The expression levels of HLA-G in placenta and fetal membrane in the control group were 1.59 ± 0.36 and 0.42 ± 0.09 respectively. The expression of HLA-G in placenta was significantly higher than that in fetal membrane (P < 0.05). The expression level of HLA-G in umbilical cord in the control group was 0.24 ± 0.17, statistically different from those in placenta and fetal membrane, respectively (P < 0.01). The expression levels of HLA-G in placenta in mild and severe preeclampsia groups were 0.78 ± 0.21 and 0.29 ± 0.17 respectively, significantly different from the control group (P < 0.01). There was no expression of HLA-G in fetal membrane and umbilical cord in mild and severe preeclampsia groups.

The expressions of HLA-G in the peripheral blood, umbilical blood and placenta in women with preeclampsia are significantly lower than those in normal pregnant women. The abnormal expression of HLA-G might be associated with the pathogenesis of preeclampsia.