Variations in T-helper 17 and Regulatory T Cells during The Menstrual Cycle in Peripheral Blood of Women with Recurrent Spontaneous Abortion

Abstract

Background: Disorders in immune system regulation may result in pregnancy abnormalities
\nsuch as recurrent spontaneous abortion (RSA). This study aims to determine
\nthe ratio of regulatory T (Treg) and T helper (Th) 17 cells in unexplained RSA (URSA)
\nwomen during proliferative and secretory phases of their menstrual cycles compared to
\nhealthy non-pregnant women.
\nMaterials and Methods: In this case control study, 25 women with URSA and 35 healthy,
\nnon-pregnant women were enrolled. The percentage of Th17 and Treg cells in participants
\nperipheral blood were determined by flow cytometry.
\nResults: The percentage of Th17 cells and their related cytokines in serum (IL-17A)
\nwere higher in the proliferative and secretory phases of the menstrual cycles of URSA
\nwomen compared to the control women. However, a lower percentage of Treg cells and
\ntheir related cytokines in serum, transforming growth factor (TGF) β1 and interleukin
\n(IL)-10 were detected in the proliferative but not the secretory phase of the URSA group.
\nThe ratio of Th17/CD4+ Treg was higher in the URSA group than the control group. We
\nobserved an increased ratio of Th17/CD4+ Treg during the proliferative and secretory
\nphases in URSA women.
\nConclusion: The imbalance between Th17 and Treg cells during the proliferative
\nphase of menstrual cycles in the URSA group may be considered a cause for spontaneous
\nabortion.