Expression of various subtypes of human leukocyte antigen-G in placenta of patients complicated with severe pre-eclampsia

Abstract

To investigate the different expression of various subtypes of human leukocyte antigen-G (HLA-G) in placenta of patients complicated with severe pre-eclampsia. Ten placental samples from early-onset severe pre-eclamptic pregnancies and ten from late-onset severe pre-eclamptic pregnancies were collected as study group; ten placental samples from preterm pregnancies and ten from normal pregnancies were collected as control group. The levels of HLA-G protein in the four groups were measured by western blot and immunohistochemistry. (1) HLA-G1 protein decreased significantly in both the early-onset (2.4 ± 0.6 versus 2.9 ± 1.1, P < 0.05) and the late-onset pre-eclampsia groups (3.5 ± 2.1 versus 4.2 ± 2.4, P < 0.05). (2) HLA-G5 protein increased in the late-onset pre-eclampsia groups (1.8 ± 1.1 versus 1.1 ± 0.9, P < 0.05); the increase in the early-onset pre-eclampsia group is not obvious (1.6 ± 0.9 versus 1.4 ± 0.7, P > 0.05). (3) The level of HLA-G1 protein in placenta from patients complicated with premature labor is lower (2.9 ± 1.1 versus 4.2 ± 2.4, P < 0.05); HLA-G5 protein does not change significantly (1.4 ± 0.7 versus 1.1 ± 0.9, P > 0.05). (4) HLA-G1 and G5 proteins mainly express in the placenta extravillous cytotrophoblast cells. There is also a high level of expression around the blood vessels and in the extraembryonic mesoderm. (1) HLA-G1 decreased significantly in both the early-onset and late-onset pre-eclamptic patients. (2) HLA-G5 increased in both the early-onset and late-onset pre-eclamptic patients, and the increase in the late-onset pre-eclamptic patients is obvious. (3) In late pregnancy, the level of HLA-G1 is lower in patients complicated with premature labor, this may be the result of its earlier pregnancy week; HLA-G5 does not change significantly. (4) HLA-G1 and G5 mainly express in the placenta extravillous cytotrophoblast cells.