Etiopathological role of treg cells in first trimester pregnancy loses: An immunohistochemical study

Aim: Habitual abortion is a worldwide health problem that affects 1-5% of all pregnant women. Although assisted reproductive techniques have become an almost routine obstetric procedure and its success has increased, a significant number of cases result in spontaneous abortion. Although the etiopathogenesis of the abortion has not been clarified clearly, the data shows that spontaneous abortion is associated with impaired maternal immune tolerance. T regulatory (Treg) cells have a significant role in immune tolerance mechanisms. The aim of the present study was to address the etiopathogenetic importance of Treg cells specifically in both habitual and post-IVF spontaneous abortions. Material and Methods: This study included 24 cases in each four groups of missed abortion, habitual abortion, spontaneous abortion after IVF, and unwanted pregnancy (control group). The immunostaining intensity and distribution of CD25 positive Treg cells in the curettage materials were scored separately, and the Q score was calculated by combining both scores. Results: The CD25 Q score of Treg cells showed a significant difference between four groups (one-way ANOVA testi, p=0,003). Post-hoc test (Bonferroni t test) showed that Q score did not show any difference between the missed abortion and control group, whereas it significantly decreased in habitual abortion and IVF abortion cases compared to the control group (p=0,003 ve p=0,02, respectively). Conclusion: Based on our findings, we conclude that Treg cell loss may play a significant role in the etiopathogenesis of habitual and post-IVF abortion cases. However, molecular studies at the level of expression analysis are needed for a definite conclusion related to this hypothesis. Key Words: abortion, habitual abortion, in vitro fertilizaton, miscarriage, spontan abortion, Treg cells