Investigation of patterns of T helper-1, T helper-2 and T helper-17 associated cytokines in pregnant patients with hashimoto thyroiditis

Introduction: Thyroid autoimmunity is common in women during the reproductive years of their lives. There is a relationship between thyroid autommunity and recurrent pregnancy loss and infertility. In pregnant patients with thyroid autoimmunity T helper-1 (Th1)/T helper-2 (Th2) ratio may shift to Th1 type response and these activated T lymphocytes may lead to implantation failure. Aims of this study are to investigate Th1, Th2 and T helper-17 (Th17) associated cytokines such as IL-2, IL-4, IL-6, IL-10, IL-12 and IL-17 in pregnant patients with Hashimoto Thyroiditis (HT), to evaluate the changes of this cytokines with L-thyroxin (LT4) treatment in pregnant state. We also examine these cytokines in patients with infertility and HT to investigate the possible role of thyroid autoimmunity in infertility.Material and method: Twenty pregnant women whom HT was diagnosed in first timester of pregnancy and were not on LT4 treatment, fifteen pregnant women whom HT was known before pregancy and were on LT4 treatmet already and nineteen pregnant patients without thyroid autoimmunity were included in this study. Thyroid funciton tests, thyroid autoantibodies and cytokine levels of pregnant patients were measured at first and second trimester. Twenty one women with HT and infertility of unknown etiology and eighteen fertile women with HT were also included in this study. Thyroid funciton tests, thyroid autoantibodies and cytokine levels of this patients were measured. Serum-free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), autoantibodies against thyroid peroxidase (anti-TPO), autoantibodies against thyroglobulin (anti-Tg) levels were measured using a chemiluminecent, immunometric method, and cytokine levels were measured using ELISA.Results: In pregnant patients, whom was diagnosed HT in first trimester of pregnacy,serum IL-2 level was significantly higher than control group. [7,29 (0,88-24,05) vs 2,07 (0-9,19), p<0,05]. In this group, serum IL-17 was significantly higher than control group [4,53 (0,94-8,19) vs 1,79 (0,84-5,75), p<0,05]. There was no significant difference between groups for serum IL-4 and IL-10 levels. In second trimester no significant difference was found between groups for all cytokines measured. There was no significant difference between infertile and fertile patients with HT for all cytokines measured.Conclusion: In first trimester we found a significant difference for Th1 and Th17 associated cytokines between HT and control group. There was no difference between groups for these cytokines in second trimester. This action, which correlates with a reduction in thyroid peroxidase antibody titers, may be associated with clinical benefits of LT4 treatment.