IL-2, IL-10, IL-12 and IL-23 mRNA expression in the decidual tissue in patients with missed and spontaneous abortions in early pregnancy
Background: Miscarriages are one of the most common complications of the first term of pregnancy. The rate of early miscarriages is about 15% of all diagnosed cases. Meanwhile, immune causes of miscarriages are not well understood. The aim of the study: To study the expression of IL-2, IL-10, IL-12 and IL-23 mRNAs, participating in differentiation of Th1, Treg and Th17, in the decidua of patients with sporadic missed and spontaneous abortions at 6-10 weeks of gestation. Materials and methods: 34 patients with missed abortions, 34 patients with spontaneous abortions and 57 patents with progressive pregnancy (control group), admitted for medical abortion, were examined at 6-10 weeks of gestation. Patients with severe extragenital diseases, antiphospholipid syndrome, endocrine disorders, anatomic abnormalities of the uterus, сhromosomal abnormalities of embryo and fetus were excluded from the research. The decidual tissue was obtained by uterine abrasion. IL-2, IL-10, IL-12 and IL-23 mRNA expression was detected by reverse-transcription qPCR. Statistical analysis was performed by Mann-Whitney test using Statistica 13.2 (Statsoft, USA). Results: The expression of IL-12 mRNA was significantly higher in the decidua of patients with spontaneous abortions compared with the control group. The expression of IL-12 in patients with missed abortions didn’t have significant differences with the control group. IL-12 provides differentiation of Th1-lymphocytes and stimulates NK-cells. The levels of IL-2, IL-10 and IL-23 in the decidua of patients with missed and spontaneous abortions had no significant differences compared with the control group. IL-2 provides differentiation of Treg. IL-10 is anti-inflammatory cytokine, secreted predominantly by Th2 and Treg, and inhibiting Th17 differentiation. IL-23 provides differentiation of Th17. Conclusion: Thus, patients with spontaneous abortions have higher expression of IL-12 mRNA, providing differentiation of Th1 lymphocytes, in the decidual tissue compared with the control group. As patients with missed and spontaneous abortions don’t have significant differences with the control group in mRNA expression of IL-2, IL-10 and IL-23, regulating Treg/Th17 balance, further investigations should be performed for estimating the role of these cytokines in pathogenesis of miscarriages.