In pregnant women, acute primary infections with T.gondii can induce congenital infections in the unborn fetus, leading to either spontaneous abortion or mild to devastating congenital defects. Analysis of apoptosis mechanism that lead to abortion may provide a new insight into toxoplasmosis pathogenesis at least in abortion. We supposed that the apoptosis of placental could be as a result of immune responses ,
which could be mediated by Th-1 response , and most probably via enhance expression of Fas-FasL. IL-8 could play a role in the mechanism of placental tissue damage by enhancing recruitment of inflammatory
cells to the site of infection could be another mechanism of induction of abortion during toxoplasma infection.
A total of eighty six women with spontaneous abortion and five women with induced abortion for medical causes were enrolled in this study. Venous blood was collected from all patients for the detection of specific anti-Toxoplasma IgM in the serum using the ELISA test. At the same time, trophoblastic tissue during curettage was collected for immunohistochemical analysis for the detection of T.gondii antigen and
evaluation of Fas, FasL and IL8 expression. ELISA test for the detection of specific IgM in serum and
immunohistochemistry method for the detection of antigen in tissue were used as diagnostic methods for T.gondii. Twenty five women were found to have Toxoplasma infection by immunohistochemistry (IHC) method, while twenty two women were found to have Toxoplasma infection by ELISA method (at the same time had T.gondii infection by IHC). From the remaining negative cases by IHC of eighty six, twenty five women were selected as a patient control group to be comparable with the positive group. The results indicated a high frequency of the T. gondii infection among women with abortion, 22 of 86 women (26%) have IgM Abs against T. gondii by ELISA test. While the results of the IHC revealed that 25 of 86 women (29%) have Toxoplasma antigen within the trophoblastic tissue. The frequency of the number of miscarriages was studied. It was found that within the positive group the highest percent of patients was
among those who had no previous miscarriages, and the same result was found within the negative group, while the entire five control group had no previous miscarriage. The distribution of abortion among trimesters was studied.The majority of abortion cases fall in the first trimester within the positive and negative groups. The expression of Fas, FasL and IL8 were detected by in situ hybridization (ISH) technique in trophoblastic tissue. The results of in situ hybridization revealed a significant increase in the level of Fas,
FasL and IL8 in positive and negative groups of patients with spontaneous abortion in comparison with induced abortion group. There is high positive correlation between Fas, FasL and IL8 expression in trophoblastic tissue. In conclusion, the data of this study strengthen the possibility that the apoptosis of placental tissue could be as a result of immune responses, which could be mediated by Th-1 response, and most probably via enhance expression of Fas-FasL. Also triggering of Fas and FasL up-regulate expression of certain pro-inflammatory cytokines, IL8 in this study, providing a link between apoptosis and inflammation.