[The expression of human leukocyte antigen G and E on human first trimester placenta and its relationship with recurrent spontaneous abortion].

OBJECTIVE

To investigate the distribution of human leukocyte antigen (HLA)-G and E on human first trimester placenta and its relationship with unexplained recurrent spontaneous abortion (RSA).

METHODS

Fifteen women with normal first trimester pregnancy and fifteen patients with RSA were included in this study. In situ hybridization and immunohistochemical staining were employed to detect the mRNA and protein of HLA-G, E in first trimester placenta.

RESULTS

The HLA-G, E mRNA were detected in all trophoblasts, including syncytiotrophoblast, villous and extravillous cytotrophoblast. HLA-G protein was only found at extravillous trophoblast by mAb 4H84 specific to HLA-G. The same expression sites were observed for both HLA- E protein and its mRNA. The expression of HLA-G, E mRNA in the RSA group were much lower than those in the control group. The HLA-G, E protein were also expressed at low level in RSA group.

CONCLUSION

The inconsistency of the distribution of HLA-G mRNA and protein was probably due to the monoclone antibody 4H84. There is strong correlation between lack of the mRNA and protein expression of HLA-G, E found in the trophoblasts at the fetal-maternal interface and RSA.