Expression of ki-67, bcl-2 and bax in the first trimester abortion materials

Objective: The aim of this study was to investigate possible similar or different mechanisms in recurrent and spontaneous abortion by evaluating immunohistochemical correlation between proliferation marker Ki-67, and apoptosis markers bcl-2 and bax in the fetal trophoblasts and maternal deciduas from abortion material. Material and Method: Eighty samples of curettage materials from 65 abortion patients histopathologically diagnosed “decidua showing Arias-stella reaction and chorionic villi” or only “decidua showing Arias-stella reaction” were included in the study. Hematoxylin&Eosin stained sections from all cases were re-evaluated and further stained immunohistochemically using antibodies against Ki-67, bcl-2 and bax. Results: Proliferation rate evaluated by Ki-67 expression both in the cytotrophoblastic cells and decidua was found to be significantly lower in spontaneous and recurrent abortions compared to evacuation abortion. The extent of bcl-2 expression in syncytiotrophoblastic cells covering villous stroma was also decreased in spontaneous abortion. There were no significant differences between spontaneous and recurrent abortions in terms of bcl-2 expression in syncytiotrophoblasts and Ki-67 proliferation index in cytotrophoblastic cells or decidua. bax staining showed minimal decidual expression in a few spontaneous and recurrent abortions. Conclusion: We concluded that proliferation rate was decreased in fetal villous cytotrophoblasts and maternal deciduas in spontaneous and recurrent abortions. We also proposed that loss of bcl-2 expression in syncytiotrophoblasts may cause abortion in a subset of cases. However, the data from spontaneous and recurrent abortions did not not support the presence of different mechanisms in both groups.