Problem: thyroid autoimmunity (TAI), which is T helper (Th)1-cell-mediated autoimmunity to thyrocytes, is associated with increased risk of miscarriages and highly prevalent in women with infertility. We aim at investigating the prevalence of TAI in women with recurrent spontaneous abortions (RSA) or unexplained infertility (UI) and its relationship with cellular and humoral immune abnormalities.
Method of study: prevalence of antiphospholipid antibodies, anti-nuclear antibody, other non-organ-specific antibodies (NOSAs; anti-dsDNA, anti-ssDNA, anti-histone, anti-Scl70), peripheral blood natural killer (NK) cell levels (%) and cytotoxicity, and CD3(+) /CD4(+) Th1/Th2 cell ratios were compared in women with and without TAI. Thyroid functional tests (TFT) were analyzed in both groups before and after pregnancy.
Results: tumor necrosis factor-α/IL-10 expressing CD3(+) /CD4(+) cell ratios (P < 0.05), CD56(+) NK cell levels (P < 0.05), the prevalence of anticardiolipin antibodies (P < 0.05) and other NOSAs (P < 0.005) were significantly higher in women with TAI when compared to women without TAI. Changes in thyroid-stimulating hormone levels between before and after pregnancy in women with TAI were significantly higher when compared to those of women without TAI (P < 0.05).
Conclusion: TAI is associated with impaired cellular and humoral immune responses in women with RSA or UI. In women with TAI, serial TFT is recommended when pregnancy is established.