The effect of thyroid autoimmunity on T-cell responses in early pregnancy

Th1 or Th2 cytokines are correlated with Tregs and T cell subsets and pregnancy outcomes in patients with autoimmune thyroid disease during early, middle, late pregnancy, and postpartum period

Autoimmune thyroid disease (AITD) is a T lymphocytes-mediated autoimmune disorder affecting pregnant women. The current study sought to determine the correlations between T helper-1 (Th1)/T helper-2 (Th2) cytokines and regulatory T cells (Tregs) and T cell subsets and pregnancy outcomes in AITD patients during early pregnancy (T1), middle pregnancy (T2), late pregnancy (T3), and postpartum period (PP). A total of 60 patients with Graves' disease, 60 patients with Hashimoto's thyroiditis, and 30 healthy pregnant women were initially enrolled in the study. Thyroid hormones and antibodies, Th1 or Th2 cytokines, transforming growth factor-β, Tregs, CD4+ T helper cells (CD4+), CD8+ T helper cells (CD8+) levels were determined by means of Maglumi2000 automatic chemiluminescence instrument, enzyme-linked immunosorbent assay, and flow cytometry. Our findings demonstrated higher IFN-γ and IL-2 levels, along with lower IL-4, IL-10, TGF-β, Treg, and CD4+/CD8+ levels in AITD patients during T1, T2, T3, and PP. Furthermore, the TGF-β, Treg, and CD4+/CD8+ levels were lower in the IFN-γ/IL-2 high expression group but higher in the IL-4/IL-10 high expression group. The IFN-γ and IL-2 levels were higher, while IL-4 and IL-10 level were lower in AITD patients with adverse pregnancy outcomes. Lastly, Th1 cytokines were higher and Th2 cytokines were lower in AITD patients and elicited correlation with Tregs and CD4+/CD8+ levels. Collectively, our findings highlighted that up-regulation of Th1 cytokines may increase the percentage of adverse pregnancy outcomes in AITD patients.

Thyroid Autoimmunity in Female Infertility and Assisted Reproductive Technology Outcome

The regulation of the female reproductive system is one of the most relevant actions of thyroid hormones. Adequate thyroid hormones production is essential for normal menstrual function and fertility as well as for the successful maintenance of pregnancy. The relationship between reproductive failure and thyroid disorders is particularly relevant and attracts attention worldwide. Thyroid autoimmunity (TAI), defined by the presence of circulating antithyroid antibodies targeting thyroid peroxidase (TPOAb) and thyroglobulin (TgAb), is prevalent among women of reproductive age and is the most frequent cause of thyroid dysfunction. Several studies addressed the association between TAI, thyroid function, and fertility as well as pregnancy outcome after spontaneous or assisted conception. Infertility, miscarriages, and fetal-maternal complications are described in overt autoimmune hypothyroidism. More debatable is the role of mild thyroid dysfunction, mainly subclinical hypothyroidism (SCH), and TAI in the absence of thyroid dysfunction in infertility and reproductive outcome. Assisted reproductive technology (ART) has become an integral element of care for infertility. Women with TAI undergoing ART are of particular interest since they carry a higher risk of developing hypothyroidism after the ovarian stimulation but whether TAI, in absence of thyroid dysfunction, adversely affects ART outcome is still controversial. Likewise, the role of levothyroxine (LT4) in improving fertility and the success of ART in euthyroid women with TAI is unclear. This review discusses the role of TAI, in the absence of thyroid dysfunction, in infertility and in ART outcome.

Prunella vulgaris can improve the pregnancy outcomes of experimental autoimmune thyroiditis rats by inhibiting Th1/Th17 immune responses

Autoimmune thyroiditis (AIT), one of the most common autoimmune diseases among women of reproductive age, is closely associated with reproductive failure and other obstetric complications. However, effective clinical strategies for the management of pregnant women with AIT are limited. It has been shown that Prunella vulgaris (PV), a traditional herbal medicine, can ameliorate AIT and other common thyroid disorders. Therefore, using an experimental autoimmune thyroiditis (EAT) rat model, we investigated the potential effects of PV on AIT-related pregnancy outcomes. According to the administered dose of PV, EAT rats were randomly divided into the untreated EAT and PV-treated EAT groups. We found that thyroid peroxidase antibody and thyroglobulin antibody serum levels and the inflammatory infiltration of the thyroid were reduced in all PV-treated groups. Increased splenic Tgfb1 mRNA levels and Treg cell proportions were associated with decreased Th1/Th17 cell proportions, and Ifng mRNA levels were reduced in rats that received low and medium doses of PV. Moreover, in the low-dose PV group, fetal development retardation and placental injuries were reversed. Overall, our findings indicated that PV could alleviate AIT and improve pregnancy outcomes in EAT rats by downregulating Th1/Th17 immune responses and inducing Treg cell proliferation.

Recent insights into the impact of immune dysfunction on reproduction in autoimmune thyroiditis

Autoimmune thyroiditis (AIT) is a common organ-specific autoimmune disease with a high incidence among women of childbearing age. Recent studies have reported that women with AIT are more susceptible to infertility, miscarriage and preterm birth. It has been investigated that abnormal changes in maternal immune system and maternal-fetal interface can dampen the immune tolerance between mother and fetus, which underlie the pathogenesis of adverse pregnancy outcomes. Hence, we summarize the immunological changes related to adverse reproductive outcomes in AIT and highlight the respective contributions of both humoral and cellular immune dysfunctions to pregnancy failures. Moreover, the direct impacts of AIT on maternal-fetal immune activation and biological influences to trophoblasts are discussed as well. All these associations require confirmation in larger studies, and the pathogenic mechanisms need to be better understood, which might provide useful information for clinical diagnosis and therapy of AIT.

The Impact of Thyroid Disorders on Clinical Pregnancy Outcomes in a Real-World Study Setting

Background: Subclinical hypothyroidism (SCH) and thyroid autoimmunity (TAI) have been associated with poor clinical pregnancy outcomes. However, these outcomes also depend on a number of demographic and obstetric variables. Therefore, the aim of this study was to investigate the impact of thyroid disorders on these outcomes, after adjustment for associated demographic and obstetrical parameters. Methods: This is cross-sectional study including 1521 pregnant women who underwent work-up and follow-up in the Centre Hospitalier Universitaire (CHU) Saint-Pierre, Brussels, and had ongoing pregnancies. Thyroid function (thyrotropin [TSH], free thyroxine [fT4]) and TAI (thyroid peroxidase antibodies) was determined at median (Q1-Q3) 13 (11-17) weeks. Baseline parameters and the prevalence of poor clinical pregnancy outcomes were compared between controls (no TAI and TSH <2.51 mIU/L) and three study groups (isolated TAI [TSH <2.51 mIU/L], SCH1 [TSH 2.51-3.7 mIU/L], SCH2 [TSH >3.7 mIU/L]). The impact of the different thyroid groups and demographic/obstetric independent variables on six poor clinical pregnancy outcomes (preeclampsia, intrauterine growth restriction [IUGR], preterm birth, neonatal intensive care unit [NICU] admission, low birth weight, and macrosomia) was investigated in a logistic regression model. Treatment with thyroid hormone before and during pregnancy and assisted and multiple pregnancies were exclusion criteria. Results: In total, 79 preeclampsias (5.2%), 40 IUGRs (2.6%), 79 preterm births (5.2%), 10 admissions to NICU (0.66%), 74 low birth weights (4.9%), and 94 babies with macrosomia (6.2%) were documented. TAI was independently associated with NICU admission (adjusted odds ratio [aOR] 16.92 confidence interval [CI 3.36-85.29]; p < 0.001) and TSH, as a continuous variable in the whole range, with preeclampsia (aOR 1.97 [CI 1.18-3.31]; p = 0.010). Trends were present for an association between SCH2 and preeclampsia (aOR 16.73 [CI 1.43-196.42]; p = 0.025), and for SCH1with NICU admission and low birth weight (aOR 19.36 [CI 1.18-316.97]; p = 0.038 and 21.38 [CI 1.29-353.39]; p = 0.032, respectively). Conclusions: Pregnant women with TAI had a significantly higher risk of an admission of the baby to the NICU, and SCH tended to be associated with a higher risk of preeclampsia and low birth weight. Other poor clinical pregnancy outcomes were not associated with thyroid disorders, but with demographic and obstetric parameters.

Low Serum IL-17A in Pregnancy During Second Trimester Is Associated With an Increased Risk of Subclinical Hypothyroidism

Problem: Interleukin-17A (IL-17A) has a role in sustaining normal pregnancy. IL-17A is also associated with thyroid autoimmunity during pregnancy. This study sought to investigate whether IL-17A is a risk factor for thyroid dysfunction during pregnancy in women negative for thyroid autoantibodies. Methods of Study: The study comprised 216 pregnant women with negative thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) during the second trimester who provided blood samples for serum IL-17A, thyroid autoantibodies and thyroid function tests. To further evaluate the ratio of CD4+IL-17A+ Th17 cells, we collected peripheral blood from 26 women with thyroid-stimulating hormone (TSH) levels ≤ 2.5 mIU/L and 26 pregnancy-week matched women with TSH levels >2.5 mIU/L, along with samples from 20 women with TSH levels ≤ 4 mIU/L and 20 pregnancy-week matched women with TSH levels >4 mIU/L. Results: The serum IL-17A levels and ratios of CD4+IL-17A+ cells were significantly lower in women with TSH > 2.5 mIU/L than in those with TSH ≤ 2.5 mIU/L (both P < 0.01). Similar lower differences were noted in women with TSH > 4 mIU/L than in those with TSH ≤ 4 mIU/L (both P < 0.01). Moreover, serum TSH correlated negatively with IL-17A levels (β = -0.195, P = 0.004), but positively with the week of gestation (β = 0.284, P < 0.001). Logistic regression indicated that a lower serum IL-17A level was a risk factor for TSH > 2.5 mIU/L [OR = 0.453 (0.298-0.689), P = 0.000] and TSH > 4.0 mIU/L [OR = 0.588 (0.385-0.899), P = 0.013]. Conclusion: A low serum IL-17A level during the second trimester is associated with an increased risk of TSH > 2.5 mIU/L and subclinical hypothyroidism.

The exploration of Hashimoto's Thyroiditis related miscarriage for better treatment modalities

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disease (ATD) worldwide and is strongly associated with miscarriage and even recurrent miscarriage (RM). Moreover, with a deepening understanding, emerging evidence has shown that immune dysfunctions caused by HT conditions, including imbalanced subsets of CD4+ T-helper cells, B regulatory (Breg) cells, high expression levels of CD56dim natural killer (NK) cells, and cytokines, possibly play an important role in impairing maternal tolerance to the fetus. In recent years, unprecedented progress has been made in recognizing the specific changes in immune cells and molecules in patients with HT, which will be helpful in exploring the mechanism of HT-related miscarriage. Based on these findings, research investigating some potentially more effective treatments, such as selenium (Se), vitamin D3, and intravenous immunoglobulin (IVIG), has been well developed over the past few years. In this review, we highlight some of the latest advances in the possible immunological pathogenesis of HT-related miscarriage and focus on the efficacies of treatments that have been widely introduced to clinical trials or practice described in the most recent literature.

[Pathogenetic features of immunological disorders in women with thyroid peroxidase antibodies presence and their effect on infertility treatment by in vitro fertilization (IVF)]

Autoimmune thyroiditis (AIT) is the most common thyroid disease among women of fertile age. An increase of thyropercosidase antibodies (TPO-Ab) occupies one of the leading positions among other autoantibodies in patients with idiopathic infertility. Stimulation of superovulation in assisted reproductive technology (ART) programs leads to thyroid overstimulation, relative hypothyroxinemia and an increase of thyroid stimulating hormone (TSH) level in women with positive TPO-Ab carrier state, leading to a decrease in the reserve capacity of the thyroid affected by the autoimmune process. There is a large number of studies concerning the effect of autoimmune thyroid diseases on the infertility treatment outcomes in ART programs, but the results are contradictory. One of the hypotheses is that TPO-Ab affect the embryo implantation process in the uterus, based on an imbalance of cytokine production by T-helper type 1, 2, and 17, which are not easy to correct by classical hormone replacement therapy with levothyroxine. Nowadays, the immunological mechanisms of these disorders are not well investigated.

The role of Th17 cells in the pathophysiology of pregnancy and perinatal mood and anxiety disorders

T cells play a key role in adaptive immune responses, and shifts among T cell classes occur in normal pregnancy. There is evidence for the role of T_H17 cells and dysregulation of the T_H17/T_reg cell balance in morbidities and autoimmune diseases during pregnancy. Because T_H17 responses may play a role in depression and anxiety outside of pregnancy, we hypothesize that T_H17 responses and the balance of T_H17/T_reg activity may also contribute to the development of depression and anxiety during pregnancy. To explore this hypothesis, this review has three main aims: 1) to evaluate systematically the role of T_H17 cells and cytokines during pregnancy; 2) to compare changes in the ratio of T_H17/T_reg cells during pregnancy morbidities with the changes that occur in depression and anxiety outside of pregnancy; and 3) to provide a basis for further research on T_H17 cells in perinatal mood and anxiety disorders, with an eye toward the development of novel therapeutics. We also review the limited literature concerning perinatal mood and anxiety disorders, and hypothesize about the potential role of T_H17 cells in these illnesses. Understanding the pathophysiology of perinatal mood and anxiety disorders will aid development of novel therapeutics that address immunological mechanisms, in addition to the serotonin system, which are targetable molecules in treating depression and anxiety during pregnancy.

The expression of cytokines IFN-γ, IL-4, IL-17A, and TGF-β1 in peripheral blood and follicular fluid of patients testing positive for anti-thyroid autoantibodies and its influence on in vitro fertilization and embryo transfer pregnancy outcomes

The aim of this work was to study the expression of the cytokines IFN-γ, IL-4, IL-17 A, and TGF-β1 in peripheral blood and follicular fluid (FF) of patients positive for antithyroid autoantibodies (ATA⁺) with normal thyroid gland function and the influence of these autoantibodies on in vitro fertilization and embryo transfer (IVF-ET) pregnancy outcomes. Nineteen patients were in the ATA⁺ group, and 27 patients tested negative for anti-thyroid autoantibody (ATA^-). Blood samples were drawn from the two groups of patients on the oocyte retrieval day and the 5th and 14th days of transplantation; in addition, FF was extracted on the oocyte retrieval day from both groups of patients and tested through enzyme-linked immunosorbent assay (ELISA) for IFN-γ, IL-4, IL-17 A, and TGF-β1. For the ATA⁺ group, the concentration of IFN-γ increased whereas the concentration of TGF-β1 decreased in peripheral blood on the oocyte retrieval day (p < .05); the concentration of IL-4 decreased in peripheral blood on the 5th and 14th days of transplantation for the ATA⁺ group (p < .05); further, the concentration of IL-17 A increased whereas that of TGF-β1 decreased in FF (p < .05). The ratio of IL-17 A/TGF-β1 in the ATA⁺ group significantly increased in FF and peripheral blood on the oocyte retrieval day and the 14th day of transplantation (p < .05). The ratio of IL-17 A/TGF-β1 in FF of the pregnant patients was significantly lower than in the non-pregnant patients (p < .05). The findings suggested that the ratio between pro-inflammatory and anti-inflammatory cytokines was adversely affected; therefore, adverse pregnancy outcomes of patients with ATA⁺ undergoing IVF-ET treatment may be attributed to immunological mechanisms.

Does severe vitamin D deficiency impact obstetric outcomes in pregnant women with thyroid autoimmunity?

Purpose: Vitamin D plays an important role in the modulation of the immune system and anti-autoimmune activities. Autoimmune thyroid diseases related to endocrine disorders are associated with poor obstetric outcomes in pregnancy. Herein, we aimed to investigate the contribution of vitamin D hypovitaminosis to poor pregnancy outcomes in pregnant women with the positive autoimmune antibody.Materials and methods: This was a prospective case-control study that enrolled pregnant women at their first trimester. The pregnant women were divided based on thyroid antibody (TA) status (TA-positive pregnant group (TAs (+)) and negative group (TAs (-)). Vitamin D status was categorized as sufficient, insufficient, and deficient (severe and moderate).Results: A total of 283 pregnant women were enrolled in this study. A total of 219 pregnant women were assigned to the TAs (-) group and 64 to the TAs (+) group. The rate of vitamin D insufficiency was 8.7, and 7.8% in the pregnant with TAs (-), and the pregnant with TAs (+) groups, respectively. Vitamin D deficiency was highly prevalent in all groups. Specifically, the prevalence rate was 91 and 92% in the pregnant with TAs (-) and the pregnant with TAs (+) groups, respectively. Admission to the neonatal intensive care unit (NICU) was more prevalent in the pregnant with TAs (+) group than in the pregnant with TAs (-) group (40.6 versus 25%; p = .0187; effect size (ES) = 0.134). The rate of gestational diabetes mellitus (GDM) was significantly higher in the pregnant women with TAs (+) group than that in the pregnant women with TAs (-) group (12.5 versus 4.1%; p = .03; ES =0.13). The rate of NICU admission and GDM was significantly higher in the severe vitamin D-deficient pregnant group with TAs (+) than that in the severe vitamin D-deficient pregnant group with TAs (-) (47 versus 23%; p = .007; ES =0.207 and 19.4% versus 4.1%; p = .006; ES =0.214, respectively).Conclusions: Severe vitamin D deficiency may contribute to increase the prevalence of GDM and need for NICU admission in pregnant women with positive TA.

Preconceptional antithyroid peroxidase antibodies, but not thyroid-stimulating hormone, are associated with decreased live birth rates in infertile women

OBJECTIVE

To study whether preconceptual thyroid-stimulating hormone (TSH) and antithyroid peroxidase (TPO) antibodies are associated with poor reproductive outcomes in infertile women.

DESIGN

Secondary analysis of data from two multicenter, randomized, controlled trials conducted by the Reproductive Medicine Network of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Multivariable logistic regression analyses were performed to assess the association between preconceptual TSH levels and anti-TPO antibodies.

SETTING

Not applicable.

PATIENT(S)

Serum samples from 1,468 infertile women were utilized.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Cumulative conception, clinical pregnancy, miscarriage, and live birth rates were calculated.

RESULT(S)

Conception, clinical pregnancy, miscarriage, and live birth rates did not differ between patients with TSH ≥2.5 mIU/L vs. TSH < 2.5 mIU/L. Women with anti-TPO antibodies had similar conception rates (33.3% vs. 36.3%) but higher miscarriage rates (43.9% vs. 25.3%) and lower live birth rates (17.1% vs. 25.4%) than those without anti-TPO antibodies. Adjusted, multivariable logistic regression models confirmed elevated odds of miscarriage (odds ratio 2.17, 95% confidence interval 1.12-4.22) and lower odds of live birth (oddr ratio 0.58, 95% confidence interval 0.35-0.96) in patients with anti-TPO antibodies.

CONCLUSION(S)

In infertile women, preconceptional TSH ≥2.5 mIU/L is not associated with adverse reproductive outcomes; however, anti-TPO antibodies are associated with increased risk of miscarriage and decreased probability of live birth.

CLINICAL TRIAL REGISTRATION NUMBER

PPCOS II NCT00719186; AMIGOS NCT01044862.

Thyroid Autoimmunity is Associated with Decreased Cytotoxicity T Cells in Women with Repeated Implantation Failure

Thyroid autoimmunity (TAI), which is defined as the presence of autoantibodies against thyroid peroxidase (TPO) and/or thyroglobulin (TG), is related to repeated implantation failure (RIF). It is reported that TAI was involved in reproductive failure not only through leading thyroid function abnormality, but it can also be accompanied with immune imbalance. Therefore, this study was designed to investigate the association of thyroid function, immune status and TAI in women with RIF. Blood samples were drawn from 72 women with RIF to evaluate the prevalence of TAI, the thyroid function, the absolute numbers and percentages of lymphocytes. The prevalence of thyroid function abnormality in RIF women with TAI was not significantly different from that in RIF women without TAI (c(2) = 0.484, p > 0.05). The absolute number and percentage of T cells, T helper (Th) cells, B cells and natural killer (NK) cells were not significantly different in RIF women with TAI compared to those without TAI (all p > 0.05). The percentage of T cytotoxicity (Tc) cells was significantly decreased in RIF women with TAI compared to those without TAI (p < 0.05). Meanwhile, Th/Tc ratio was significantly increased (p < 0.05). These results indicated that the decreased Tc percentage and increased Th/Tc ratio may be another influential factor of adverse pregnancy outcomes in RIF women with TAI.