Recurrent Pregnancy Loss in Women with Hashimoto's Thyroiditis with Concurrent Non-Endocrine Autoimmune Disorders

Autoimmune thyroid disease and ovarian hypofunction: a review of literature

Thyroid hormones(THs) are essential for the proper functioning of the ovaries, and multiple studies have shown that thyroid abnormalities, especially during adolescence and reproductive age, can lead to lifelong ovarian dysfunction. Autoimmune thyroid disease (AITD), one of the most common organ specific autoimmune diseases, is mainly mediated by cellular autoimmune reactions, and has strong inflammatory infiltration and immune active cells, including chemokines and cytokines, which are important components of ovarian aging. This suggests that autoimmune and inflammatory molecular processes may play a role in the emergence of ovarian dysfunction. The purpose of this review is to summarize recent in vivo and in vitro evidence of a complex relationship between AITD and ovarian dysfunction. AITD is closely related to the decline of ovarian function from the perspective of antibody, cytokine, oxidative stress, and genetic factors. Finally, some of the currently known treatments for AITD and hypo ovarian disease are summarized.

Autoimmune Atrophic Gastritis: A Clinical Review

Autoimmune atrophic gastritis (AAG) is a chronic condition characterized by the presence of atrophy in the oxyntic mucosa due to anti-parietal cell antibodies. This review provides a comprehensive and up-to-date overview of autoimmune atrophic gastritis, reporting recent evidence on epidemiology, pathogenesis, diagnosis, clinical presentation, risk of malignancies, and management. The prevalence of AAG has been estimated at between 0.3% and 2.7% in the general population. The diagnosis of AAG is based on a combination of the serologic profile and the histological examination of gastric biopsies. Patients with AAG are often asymptomatic but can also have dyspeptic or reflux symptoms. The atrophy of the oxyntic mucosa leads to iron and vitamin B12 malabsorption, which may result in anemia and neurological affections. Autoimmune atrophic gastritis is associated with an increased risk of type I neuroendocrine tumors (NETs) and gastric cancer, with an incidence rate of 2.8% and 0.5% per person/year, respectively. Management is directed to reinstate vitamins and iron and to prevent malignancies with endoscopic surveillance. In conclusion, atrophic autoimmune gastritis is an infrequent condition, often asymptomatic and misdiagnosed, that requires an early diagnosis for appropriate vitamin supplementation and endoscopic follow-up for the early diagnosis of NETs and gastric cancer.

Autoimmune diseases and adverse pregnancy outcomes: an umbrella review

BACKGROUND

There is a high prevalence of autoimmune conditions in women specially in the reproductive years; thus, the association with adverse pregnancy outcomes has been widely studied. However, few autoimmune conditions/adverse outcomes have been studied more than others, and this umbrella review aims to consolidate existing knowledge in this area with the aim to provide new knowledge and also identify gaps in this research area.

METHODS

Medline, Embase, and Cochrane databases were searched from inception to December 2023. Screening, data extraction, and quality appraisal (AMSTAR 2) were done by two independent reviewers. Data were synthesised narratively and quantitatively. Relative risks (RR)/odds ratio (OR) with 95% confidence intervals were reported.

RESULTS

Thirty-two reviews were included consisting of 709 primary studies. The review reported the association between 12 autoimmune conditions and 16 adverse pregnancy outcomes. Higher risk of miscarriage is reported in women with Sjögren's syndrome RR 8.85 (95% CI 3.10-25.26) and systemic lupus erythematosus (SLE) OR 4.90 (3.10-7.69). Pre-eclampsia was reported higher in women with type 1 diabetes mellitus (T1DM) OR 4.19 (3.08-5.71) and SLE OR 3.20 (2.54-4.20). Women reported higher risk of diabetes during pregnancy with inflammatory bowel disease (IBD) OR 2.96 (1.47-5.98). There was an increased risk of intrauterine growth restriction in women with systemic sclerosis OR 3.20 (2.21-4.53) and coeliac disease OR 1.71 (1.36-2.14). Preterm birth was associated with T1DM OR 4.36 (3.72-5.12) and SLE OR 2.79 (2.07-3.77). Low birth weight babies were reported in women with women with SLE or systemic sclerosis OR 5.95 (4.54-7.80) and OR 3.80 (2.16-6.56), respectively. There was a higher risk of stillbirth in women with T1DM OR 3.97 (3.44-4.58), IBD OR 1.57 (1.03-2.38), and coeliac disease OR 1.57 (1.17-2.10). T1DM in women was associated with 32% lower odds of small for gestational age baby OR 0.68 (0.56-0.83).

CONCLUSIONS

Pregnant women with autoimmune conditions are at a greater risk of developing adverse pregnancy outcomes. Further research is required to develop better preconception to postnatal care for women with autoimmune conditions.

Do elevated thyrotropin levels increase the risk of miscarriages: yes or no?

BACKGROUND

To examine correlation between elevated levels of thyrotropin with the frequency of miscarriages.

METHODS

A cross-sectional study was conducted on the 380 respondents and it investigated TSH (thyrotropin), thyroid peroxidase antibody(anti-TPO) and free thyroxine (FT4) in pregnant women who had a miscarriage (N = 179) and pregnant women with normal pregnancies (N = 201).

RESULTS

The incidence of subclinical hypothyroidism in the miscarriages group was higher than in control group (61.4% vrs 15.79% (p < 0.001). In the miscarriages group with hypothyroidism (first trimester) mean value of TSH was significantly higher 4.31 ± 2.55 mIU/L compared to the control group 1.95 ± 0.86mIU/L (p < 0.001). Logistic multivariate regression revealed that TSH and body mass index (BMI) have a significant influence on the miscarriage; TSH level has a higher odds ratio (OR) 1.47 CI (95% 1.22-1.78) than BMI (OR) 1.14 CI (95% 1.06-1.23)) (p < 0.001). The combination of thyroid autoimmunity and TSH > 2.5mIU/L increase the risk of miscarriage (65.75%) compared to positive anti-TPO antibodies and TSH < 2.5mIU/L(14.15%)(p < 0.001).

CONCLUSIONS

Higher TSH levels correspond with obesity during early pregnancy and may be a sign of maternal thyroid dysfunction. Physiological thyroid function in the first trimester of pregnancy is important for perinatal outcome.

Pathophysiological, immunogenetic, anatomopathological profile of thrombophilia in pregnancy

Thrombophilic states have been associated with early and/or late pregnancy loss and possibly other severe obstetrical complications. Pregnancy-induced hypercoagulability, increased stasis, and the consequences of inherited and acquired thrombophilia are just a few of the factors that contribute to the development of thrombosis in pregnancy. In this review, we illustrate the impact that these factors have on the development of thrombophilia during pregnancy. We also explore how thrombophilia impact pregnancy outcomes. Next, we discuss how human leukocyte antigen G plays a part in thrombophilia during pregnancy by regulating cytokine release to prevent trophoblastic cell invasion and maintain local immunotolerance constant. Human leukocyte antigen class E is briefly explored with thrombophilia in pregnancy. Regarding the anatomopathologic aspect, we describe the different histopathological lesions of the placenta found in women with thrombophilia.

B cells from anti-thyroid antibody positive, infertile women show hyper-reactivity to BCR stimulation

Anti-thyroid antibody (ATA) positivity affects 1 out of 9 women in childbearing age and presents a significant risk for infertility. Emerging evidence indicates that alterations in the B cell receptor induced calcium (Ca2+) signaling could be key in the development of autoimmunity. We aimed to investigate the Ca2+ flux response of B lymphocyte subsets to BCR stimulation in Hashimoto’s thyroiditis and related infertility. We collected peripheral blood samples from ATA+, infertile, euthyroid patients (HIE), hypothyroid, ATA+ patients before (H1) and after levothyroxine treatment (H2), and age-matched healthy controls (HC). All B cell subsets of ATA+, infertile, euthyroid patients showed elevated basal Ca2+ level and hyper-responsivity to BCR ligation compared to the other groups, which could reflect altered systemic immune function. The Ca2+ flux of hypothyroid patients was similar to healthy controls. The levothyroxine-treated patients had decreased prevalence of CD25+ B cells and lower basal Ca2+ level compared to pre-treatment. Our results support the role of altered Ca2+ flux of B cells in the early phase of thyroid autoimmunity and infertility.

A Predictive Role of Autoantibodies Against the Epitope aa168–183 of ENO1 in the Occurrence of Miscarriage Related to Thyroid Autoimmunity

Objective

The aim of the research is to study the association between the serum levels of autoantibodies against one important epitope (¹⁶⁸FMILPVGAANFREAMR¹⁸³, designated as P6) of α-enolase (ENO1-P6Abs) and miscarriage among euthyroid females with thyroid autoimmunity (TAI).

Methods

Anti-ENO1-P6 total IgG was investigated in 432 euthyroid women, and its four subclasses were analyzed in 184 euthyroid women. The serum FT4, TSH, TgAb, and TPOAb levels were determined using an electrochemiluminescence immunoassay. The serum ENO1-P6Ab and anti-protein disulfide isomerase A3 autoantibody (PDIA3Ab) levels were determined using an enzyme-linked immunosorbent assay.

Results

The serum levels of anti-ENO1-P6 total IgG, IgG2, IgG3, and IgG4 were significantly higher in euthyroid TAI females than in non-TAI controls. Additionally, anti-ENO1-P6 total IgG and its 4 subtypes were all markedly higher in euthyroid TAI females with pregnancy loss than those without miscarriage. Moreover, logistic regression analysis showed that highly expressed anti-ENO1-P6 total IgG, IgG1, IgG2, and IgG3 subtypes in the serum were all independent risk factors for euthyroid TAI-related miscarriage, and its IgG1 was also for non-TAI-related abortion. According to the trend test, the prevalence of miscarriage was increased in a titer-dependent manner with the raised levels of serum anti-ENO1-P6 total IgG and IgG1, IgG2, and IgG3 subtypes among euthyroid TAI females. The receiver operating characteristic curve analysis of anti-ENO1-P6 total IgG and IgG1, IgG2, and IgG3 subclass expressions in the serum for miscarriage prediction in euthyroid TAI females exhibited that the total areas under the curves were 0.773 ± 0.041, 0.761 ± 0.053, 0.827 ± 0.043, and 0.760 ± 0.050, respectively (all P <0.0001). Their corresponding optimal cut-off OD450 values were 0.68 (total IgG), 0.26 (IgG1), 0.97 (IgG2), and 0.48 (IgG3), with sensitivities of 70.8, 87.5, 83.3, and 85.4%, and specificities of 70.8, 59.1, 77.3, and 56.8%, respectively. There was an additive interaction between serum anti-ENO1-P6 and anti-PDIA3 total IgGs on the development of miscarriage (RERI = 23.6, AP = 0.79, SI = 5.37).

Conclusion

The highly expressed ENO1-P6Abs may be important risk factors for euthyroid TAI-related miscarriage. The serum levels of ENO1-P6Abs may become good predictive markers for pregnancy loss in euthyroid TAI females, especially its IgG2 subclass expression.

The Detrimental Effect of Thyroiditis on Pregnancy Outcome of Patients Affected by Autoimmune Diseases: An Open Question

Few data are available evaluating obstetrical outcome when thyroiditis coexist with autoimmune diseases. Objectives of our study were: 1) To assess the prevalence of thyroiditis in pregnant women with autoimmune diseases; 2) To evaluate the effects on pregnancy outcome when different autoimmune diseases are associated with thyroiditis. Two groups of pregnant women were analysed: a study group of pregnant women with autoimmune diseases (n = 268) versus a control group of pregnant women (n = 1,150). In both groups the research for thyroid antibodies, anti-thyroid peroxidase antibodies and anti-thyroglobulin antibodies, was performed. The positivity had a prevalence of 17.54% in women with autoimmune diseases (n = 47) versus 5.57% in the control group (n = 64) (p-value < 0.00001). Only major rheumatic diseases (MRD) were analysed for pregnancy outcome (week of delivery, birth weight and birth weight percentile): systemic lupus erythematosus (SLE) n = 36, antiphospholipid syndrome (APS) n = 44 and connective tissue diseases (CTD) n = 23. MRD were divided according to positive or negative results for thyroid antibodies. Thyroiditis in CDT patients showed a detrimental effect on pregnancy outcome, in terms of earlier week of delivery: 37.86 ± 0.90 (mean ± SD) in CTD with thyroiditis versus 38.56 ± 0.73 (mean ± SD) in CTD without thyroiditis (p-value = 0.03) and lower birth weight: 2,790.71 g ± 257.17 SD in CTD with thyroiditis versus 3,019.33 g ± 305.48 g in CTD without thyroiditis (p-value < 0.05). In SLE and APS thyroiditis did not appear to influence pregnancy outcome. However, we suggest investigating anti-thyroid antibodies in all autoimmune diseases with special attention to pregnant women with thyroiditis and CTD.

Pregnancy Outcome in Women With APECED (APS-1): A Multicenter Study on 43 Females With 83 Pregnancies

CONTEXT

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED; also known as autoimmune polyendocrine syndrome type 1) has a severe, unpredictable course. Autoimmunity and disease components may affect fertility and predispose to maternal and fetal complications, but pregnancy outcomes remain unknown.

OBJECTIVE

To assess fetal and maternal outcomes and course of clinical APECED manifestations during pregnancy in women with APECED.

DESIGN AND SETTING

A multicenter registry-based study including 5 national patient cohorts.

PATIENTS

321 females with APECED.

MAIN OUTCOME MEASURE

Number of pregnancies, miscarriages, and deliveries.

RESULTS

Forty-three patients had altogether 83 pregnancies at median age of 27 years (range, 17-39). Sixty (72%) pregnancies led to a delivery, including 2 stillbirths (2.4%) and 5 (6.0%) preterm livebirths. Miscarriages, induced abortions, and ectopic pregnancies were observed in 14 (17%), 8 (10%), and 1 (1.2%) pregnancies, respectively. Ovum donation resulted in 5 (6.0%) pregnancies. High maternal age, premature ovarian insufficiency, primary adrenal insufficiency, or hypoparathyroidism did not associate with miscarriages. Women with livebirth had, on average, 4 APECED manifestations (range 0-10); 78% had hypoparathyroidism, and 36% had primary adrenal insufficiency. APECED manifestations remained mostly stable during pregnancy, but in 1 case, development of primary adrenal insufficiency led to adrenal crisis and stillbirth. Birth weights were normal in >80% and apart from 1 neonatal death of a preterm baby, no serious perinatal complications occurred.

CONCLUSIONS

Outcome of pregnancy in women with APECED was generally favorable. However, APECED warrants careful maternal multidisciplinary follow-up from preconceptual care until puerperium.

The expression of anti-protein disulfide isomerase A3 autoantibody is associated with the increased risk of miscarriage in euthyroid women with thyroid autoimmunity

Miscarriage frequently occurs in euthyroid women with thyroid autoimmunity (TAI), but its mechanisms remain unclear. Our previous study has found that the serum level of anti-protein disulfide isomerase A3 autoantibody (PDIA3Ab) was significantly increased in mice with TAI. This study was aimed to explore whether there could be an association between the expression of PDIA3Ab and the occurrence of miscarriage in euthyroid TAI women. It was found that the serum level of PDIA3Ab was significantly increased in euthyroid TAI women as compared with that of non-TAI controls. Especially, serum PDIA3Ab level was markedly higher in euthyroid TAI women with miscarriage than the ones without miscarriage. Furthermore, binary logistic regression analysis showed that the serum PDIA3Ab level was an independent risk factor for spontaneous abortion in euthyroid TAI women with an odds ratio of 13.457 (95% CI, 2.965-61.078). The receiver operating characteristic (ROC) analysis of serum PDIA3Ab expression for predicting the miscarriage in euthyroid TAI women showed that the area under the curve was 0.707 ± 0.05 (P < 0.001). The optimal cut-off OD450 value of serum PDIA3Ab was 0.7129 with a sensitivity of 52.5% and specificity of 86.3% in euthyroid TAI women. Trend test showed that the prevalence of spontaneous abortion was markedly increased with the rise of serum PDIA3Ab level among TAI women in a titer-dependent manner. In conclusion, serum PDIA3Ab expression may imply an increased risk of spontaneous abortion in euthyroid TAI women, and it can be used as a new predictive bio-marker.

Effect of Hyperthyroidism Control During Pregnancy on Maternal and Fetal Outcome: A Systematic Review and Meta-Analysis

CONTEXT

Although the overt hyperthyroidism treatment during pregnancy is mandatory, unfortunately, few studies have evaluated the impact of treatment on reducing maternal and fetal outcomes.

OBJECTIVE

This study aimed to demonstrate whether treatment to control hyperthyroidism manifested during pregnancy can potentially reduce maternal-fetal effects compared with euthyroid pregnancies through a systematic review with meta-analysis.

DATA SOURCE

MEDLINE (PubMed), Embase, Cochrane Library Central, LILACS/BIREME until May 2021.

STUDY SELECTION

Studies that compared, during the gestational period, treated women with hyperthyroidism versus euthyroid women. The following outcomes of this comparison were: pre-eclampsia, abruptio placentae, fetal growth retardation, gestational diabetes, postpartum hemorrhage, low birth weight, stillbirth, spontaneous abortions, premature birth.

DATA EXTRACTION

Two independent reviewers extracted data and performed quality assessments. Dichotomous data were analyzed by calculating risk differences (DR) with fixed and random effect models according to the level of heterogeneity.

DATA SYNTHESIS

Seven cohort studies were included. The results of the meta-analysis indicated that there was a lower incidence of preeclampsia (p=0.01), low birth weight (p=0.03), spontaneous abortion (p<0.00001) and preterm birth (p=0.001) favouring the euthyroid pregnant group when compared to those who treated hyperthyroidism during pregnancy. However, no statistically significant differences were observed in the outcomes: abruptio placentae, fetal growth retardation, gestational diabetes mellitus, postpartum hemorrhage, and stillbirth.

CONCLUSIONS

Our findings demonstrated that treating overt hyperthyroidism in pregnancy is mandatory and appears to reduce some potential maternal-fetal complications, despite there still being a residual risk of negative outcomes.

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.

Subclinical thyroid diseases and isolated hypothyroxinemia during pregnancy

Thyroid diseases in pregnancy are common. While data on management of overt diseases are clear, there is no consensus regarding subclinical thyroid disease. Many studies have tried to clarify the impact of subclinical thyroid disease on pregnancy outcomes without reaching universal conclusions. As several studies are present in literature, but no univocal indication is present to manage each condition, the present review tries to summarize the recent indications for such disease. The most updated guidelines are 2017 American thyroid association for thyroid disease during pregnancy, which at present represent the most accurate and reliable guide. Subclinical hyperthyroidism during pregnancy has not been associated with adverse outcomes and only needs follow up. Subclinical hypothyroidism is associated with adverse obstetric and offspring outcomes. At present thyroxine treatment is recommended in selected cases, as beneficial effects are not clear for all these patients. Data regarding the association between isolated hypothyroxinemia and adverse maternofetal outcome are controversial but treatment is not indicated. Autoimmune thyroid disease represents the main thyroid risk factor for adverse pregnancy outcomes. If patients have normal TSH values, treatment is not indicated. A possible thyroxine treatment can be evaluated on a case-by-case basis in euthyroid patients with history of abortion/infertility. In the last years, risks of subclinical thyroid dysfunction on the outcome of gestation and new-born have been scaled back. Further prospective studies are necessary to better understand thyroid dysfunction in pregnancy to perfectly target treatment in appropriate settings.

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.

Association of Other Autoimmune Diseases With Thyroid Eye Disease

BACKGROUND

Thyroid eye disease (TED) is a potentially disfiguring and sight-threatening autoimmune (AI) orbitopathy, affecting up to 400,000 people in the UK. There are no accurate early predictors of TED severity. Although polyautoimmunity has been shown to affect AI disease severity, its influence on TED severity has never been investigated. The prevalence of polyautoimmunity among TED patients is also unclear, with discordant results reported in the literature. This study evaluates the prevalence of non-thyroid/"other" AI (OAI) conditions in an ethnically diverse TED cohort and assesses how polyautoimmunity affects TED severity and activity.

METHODS

A retrospective study of patients presenting to multidisciplinary TED clinics across three North-West London hospitals between 2011 and 2019. Data collected included: 1) demographics; 2) OAI conditions and management; 3) endocrine management of thyroid dysfunction; 4) details of TED and clinical activity score at presentation.

RESULTS

Two hundred and sixty-seven patients with a median age of 46 (35-54) years were included, 79.4% were female and 55% were Black, Asian and minority ethnic (BAME). Thirty-seven patients (13.9%) had OAI conditions, with rheumatoid arthritis (3.7%), vitiligo (3.0%) and psoriasis (3.0%) among the most prevalent. Of patients with OAI conditions, 43.2% (16/37) required immunosuppression prior to TED onset. Non-immunosuppressed patients with OAI conditions had a significantly higher clinical activity score at presentation than TED-only and previously immunosuppressed patients (p=0.02). No significant differences were observed in thyroid receptor antibody titers between these groups.

CONCLUSIONS

This study finds a 13.9% prevalence of OAI conditions among TED patients. Patients with OAI conditions overall have a tendency for more severe and significantly more clinically active TED than those without OAI conditions. Larger, prospective studies are warranted to further evaluate polyautoimmunity as an early predictor of TED severity.

Iron Deficiency, a Risk Factor of Thyroid Disorders in Reproductive-Age and Pregnant Women: A Systematic Review and Meta-Analysis

BACKGROUND

Iron deficiency (ID) is concerned as the most common nutritional deficiency worldwide. The effects of ID on thyroid function and autoimmunity in pregnant women and reproductive-age women are controversial. The aim of the current study was to summarize the evidences and evaluate the relationship between ID and thyroid disorders.

METHODS

In this systematic review and meta-analysis, studies published on the Cochrane, Embase, Medline, and PubMed databases by October 2020 were searched. A total of 636 studies which discussed the correlation between ID and thyroid disorders were eligible in the initial search. Pooled mean differences (MD) and 95% confidence intervals (CI) were calculated for the assessment of thyrotropin (TSH) and free thyroxine (FT4) levels. Combined odd ratios (OR) and 95% CI were calculated for the assessment of the prevalence of overt and subclinical hypothyroidism, positive thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb).

RESULTS

For women of reproductive age, ID could significantly increase the risk of positive TPOAb (OR: 1.89; 95% CI: 1.17, 3.06: P = 0.01) and both positive TPOAb and TgAb (OR: 1.48; 95% CI: 1.03, 2.11: P = 0.03). The meta-analysis of pregnant women showed that pregnant women with ID had increased serum TSH levels (MD: 0.12; 95% CI: 0.07, 0.17; P < 0.00001) and decreased FT4 levels (MD: -0.73; 95% CI: -1.04, -0.41; P < 0.00001). Meanwhile, the prevalence of overt (OR: 1.60; 95% CI: 1.17, 2.19; P = 0.004) and subclinical (OR: 1.37; 95% CI: 1.13, 1.66; P = 0.001) hypothyroidism in pregnant women with ID was significantly increased.

CONCLUSIONS

ID may adversely affect thyroid function and autoimmunity of pregnant and reproductive-age women and it is very necessary for monitoring iron nutritional status and early treatment of ID for them.

Prevalence of latent and overt polyautoimmunity in autoimmune thyroid disease: A systematic review and meta-analysis

BACKGROUND

Thyroid autoimmunity is the most frequent condition involved in polyautoimmunity (PolyA). However, the frequency of latent and overt PolyA in patients with autoimmune thyroid disease (AITD) as the index condition is unknown. Therefore, the purpose of this study was to determine the prevalence of these types of PolyA in patients with AITD as the index condition.

METHODS

This study adhered to the relevant sections of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. Searches through MEDLINE, Embase and LILACS were done to find articles in Spanish and English. Relevant vocabulary terms and key terms related to AITD and other autoimmune diseases were used. Two investigators independently screened the eligible studies, extracted data and assessed the quality and risk of bias. Fixed and random effect models were used accordingly. Cluster analysis was used to determine similarities among diseases in the articles included (based on Jaccard index).

RESULTS

A total of 56 articles fulfilled the inclusion criteria. Of these, 25 were case-controls, 17 were cohorts, and 14 were cross-sectional studies. These studies included a total of 47 509 patients. Female was the predominant gender and included 38 950 patients (81.23%, 95% CI: 80.85-81.60). Graves' disease (GD) was the most common type of thyroid autoimmunity (69.16%, 95% CI: 68.23-70.07). Globally, overt PolyA was found in 13.46% of the patients with AITD. This type of PolyA was represented mainly by type 1 diabetes and autoimmune gastritis. Latent PolyA was presented in 17.45% of the patients, and anti-proinsulin, anti-parietal cells and dsDNA antibodies were the most common. HT had the highest frequency of overt PolyA in Europe (15.60%, 95% CI: 14.72-16.53), whereas latent PolyA was most common in patients with GD in Asia (21.03%, 95% CI: 17.76-24.71). Overt and latent PolyA were associated with gastrointestinal and endocrinological ADs in most of cases and clustered with rheumatological, dermatological and neurological ADs.

CONCLUSIONS

Latent and overt PolyA are common in patients with AITD. These results provide insightful information for early diagnosis and management of concurrent ADs in patients with AITD. Aggregation of ADs in different clusters may help to define different phenotypes associated with thyroid autoimmunity that are critically relevant in clinical settings.

T Helper (Th) Cell Profiles in Pregnancy and Recurrent Pregnancy Losses: Th1/Th2/Th9/Th17/Th22/Tfh Cells

During pregnancy, various immune effectors and molecules participating in the immune-microenvironment establish specific maternal tolerance toward the semi-allogeneic fetus. Activated maternal immune effectors by the trophoblast antigens, such as T helper (Th), T cytotoxic (Tc), T regulatory (Treg), and B cells, are involved in the regulation of adaptive immunity. Recognition of active signal through the T cell receptors stimulate the differentiation of naive CD3⁺CD4⁺ T cells into specific T cell subsets, such as Th1, Th2, Th9, Th17, Th22, and follicular Th cells (Tfh). Each of these subsets has a significant and distinct role in human pregnancy. Th1 immunity, characterized by immune-inflammatory responses, becomes dominant during the peri-implantation period, and the “controlled” Th1 immunity benefits the invading trophoblasts rather than harm. Quickly after the placental implantation, the early inflammatory Th1 immunity is shifted to the Th2 anti-inflammatory immune responses. The predominant Th2 immunity, which overrules the Th1 immunity at the placental implantation site, protects a fetus by balancing Th1 immunity and accommodate fetal and placental development. Moreover, Treg and Th9 cells regulate local inflammatory immune responses, potentially detrimental to the fetus. Th17 cells induce protective immunity against extracellular microbes during pregnancy. However, excessive Th17 immunity may induce uncontrolled neutrophil infiltration at the maternal-fetal interface. Other Th cell subsets such as Tfh cells, also contribute to pregnancy by setting up favorable humoral immunity during pregnancy. However, dysregulation of Th cell immunity during pregnancy may result in obstetrical complications, such as recurrent pregnancy losses (RPL) and preeclampsia (PE). With this review, we intend to deliver a comprehensive overview of CD4⁺ Th cell subsets, including Th1, Th2, Th9, Th17, Th22, and Tfh cells, in human pregnancy by reviewing their roles in normal and pathological pregnancies.

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.