Analysis of HLA-G expression in preeclampsia and intrauterine growth restriction

Suh, Min Jung; Moon, Jeong Min; Hur, Soo Young; Kim, Sa Jin

Abstract

OBJECTIVE
To determine whether soluble HLA-G protein levels in plasma and/or HLA-G protein in placental tissues differ between women with gestational complications (preeclampsia and/or intrauterine growth restriction, IUGR) and women with normal pregnancies.
METHODS
A sandwich enzyme-linked immunosorbent assay was used to investigate the HLA-G expression level in 11 cases of preeclampsia, 8 cases of preeclampsia with IUGR, 18 cases of IUGR, and 10 normal control subjects.
RESULTS
Plasma HLA-G levels were decreased significantly in the preeclampsia group (median, 0.072 microgram/mL), the preeclampsia with IUGR group (median, 0.086 microgram/mL), and the IUGR group (median, 0.081 microgram/mL), in comparison with normal pregnant women (median, 0.360 microgram/mL) (P=0.002, P=0.049, and P=0.003, respectively). Also, Placental HLA-G levels were decreased significantly in the preeclampsia group (median, 0.016 microgram/mg), the preeclampsia with IUGR group (median, 0.015 microgram/mg), and the IUGR group (median, 0.021 microgram/mg), in comparison with normal pregnant women (median, 0.091 microgram/mg) (P<0.001, P=0.002, and P=0.001, respectively). There was a significant correlation between plasma and placental HLA-G levels (r=0.807, P<0.001).
CONCLUSION
Our results indicate that the attenuated expression of placental HLA-G and reduced release of this protein into the maternal circulation in gestational complications, such as preeclampsia and IUGR may alter the maternal-fetal immune relationship, and thus could be at play in the pathophysiology of these diseases. This suggests that assessment of levels of HLA-G proteins may be useful in predicting development of preeclampsia and IUGR.