Diseases associated with thyroid autoimmunity: explanations for the expanding spectrum

Association Between Hashimoto's Thyroiditis and Rheumatoid Arthritis: A Bidirectional Mendelian Randomization Study

Background: We aim to investigate the possible causal association between Hashimoto's thyroiditis (HT) and rheumatoid arthritis (RA) using Mendelian randomization (MR) methods. Methods: A bidirectional MR analysis was conducted to evaluate the causal association between HT and RA. We obtained summary statistics data from two extensive genome-wide association studies (GWAS) comprising 15,654 cases of HT and 14,361 cases of RA. The primary effect estimate utilized in this study was the inverse-variance weighted (IVW) method. To ensure the reliability and stability of the results, we employed several additional methods for testing, including MR-Egger, weighted median, simple mode, weighted mode, and MR-PRESSO. Results: Our study revealed compelling evidence of bidirectional causality between HT and RA. When HT was considered as an exposure factor and RA was considered as an outcome factor, this study revealed a positive correlation between HT and RA (IVW: odds ratio [OR] = 2.4546, 95% confidence interval [CI], 1.1473-5.2512; p = 0.0207). Conversely, when we examined RA as the exposure factor and HT as the outcome factor, we still found a positive correlation between them (IVW: OR = 1.2113, 95% CI, 1.1248-1.3044; p = 3.9478 × 10-7). Conclusions: According to our research findings, there exists a bidirectional positive causal relationship between HT and RA among European populations. This implies that individuals with HT have an elevated risk of developing RA, and conversely, individuals with RA have an increased risk of developing HT.

Association between rheumatoid arthritis and autoimmune thyroid disease: evidence from complementary genetic methods

OBJECTIVES

To assess the causal association of Rheumatoid Arthritis (RA) with Autoimmune thyroid disease (AITD).

METHOD

Complementary genetic approaches, including genetic correlation, Mendelian randomization (MR) and colocalization analysis, were conducted to assess the potential causal association between RA and AITD using summary statistics from large-scale genome-wide association studies (GWASs). Various sensitivity analyses had been conducted to assess the robustness and the consistency of the findings.

RESULTS

The linkage disequilibrium score regression revealed a shared genetic structure between RA and AITD, with the significant genetic correlation between RA and autoimmune hyperthyroidism and autoimmune hypothyroidism estimated to be 0.3945 (P = 2.83 × 10-6) and 0.2771 (P = 1.04 × 10-6) respectively. The results of MR analysis showed that RA had a positive causal relationship with autoimmune hypothyroidism and autoimmune hyperthyroidism. The odds ratio (OR) were 1.29 (95% CI, 1.17-1.42; P = 1.08 × 10-7) and 1.47 (95% CI, 1.25-1.72; P = 1.85 × 10-6), respectively. In reverse MR analysis, autoimmune hypothyroidism had a positive causal relationship with RA, OR was 1.51 (95% CI, 1.37-1.66; P = 1.10 × 10-16); autoimmune hyperthyroidism had no causal relationship with RA relationship (P = 0.22). Similar results were found using different MR methods. In addition, colocalization analysis suggested that shared causal variants existed between RA and AITD.

CONCLUSIONS

Our study suggested a potentially causal effect of genetically predicted RA on autoimmune hyperthyroidism and a bidirectional causal relationship between RA and autoimmune hypothyroidism was also observed with complementary genetic approaches, which supports the importance and necessity of thyroid function screening and monitoring in RA patient management in clinical practice.

Shared genetic architecture between hypothyroidism and rheumatoid arthritis: A large-scale cross-trait analysis

BACKGROUND

In recent years, mounting evidence has indicated a co-morbid relationship between hypothyroidism and rheumatoid arthritis (RA), however, the shared genetic factors underlying this association remain unclear. This study aims to investigate the common genetic architecture between hypothyroidism and RA.

METHODS

Genome-wide association study (GWAS) summary statistics from recently published studies were utilized to examine the genetic correlation, shared genetic loci, and potential causal relationship between hypothyroidism and RA. Statistical methods included linkage disequilibrium score regression (LDSC), high-definition likelihood (HDL), cross-trait meta-analyses, colocalization analysis, multi-marker analysis of genomic annotation (MAGMA), tissue-specific enrichment analysis (TSEA), functional enrichment analysis, and latent causal variable method (LCV).

RESULTS

Our study demonstrated a significant genetic correlation between hypothyroidism and RA(LDSC:rg=0.3803,p=7.23e-11;HDL:rg=0.3849,p=1.02e-21). Through cross-trait meta-analysis, we identified 1035 loci, including 43 novel genetic loci. By integrating colocalization analysis and the MAGMA algorithm, we found a substantial number of genes, such as PTPN22, TYK2, and CTLA-4, shared between the two diseases, which showed significant enrichment across 14 tissues. These genes were primarily associated with the regulation of alpha-beta T cell proliferation, positive regulation of T cell activation, positive regulation of leukocyte cell-cell adhesion, T cell receptor signaling pathway, and JAK-STAT signaling pathway. However, our study did not reveal a significant causal association between the two diseases using the LCV approach.

CONCLUSION

Based on these findings, there is a significant genetic correlation between hypothyroidism and RA, suggesting a shared genetic basis for these conditions.

Thyroid Disease and Systemic Lupus Erythematosus

Background and Objectives: Thyroid disease has been associated with autoimmune disorders. As systemic lupus erythematosus (SLE) is a systemic autoimmune disease with diverse manifestations spanning across all organ systems, the relationship of SLE with thyroid disorders needs investigation. In particular, the relationship of SLE with autoimmune thyroid disease has attracted the interest of the research community. The aim was to evaluate the relationship of SLE with autoimmune thyroid disease. Materials and Methods: A cohort of 45 consecutive patients with a mean age of 47.97 years (range 21-79 years) and 45 age- and sex-matched controls were prospectively studied over a period of 12 months for the presence of thyroid disease and the prevalence of antithyroid antibodies. Results: Four patients (8.9%) were found to suffer from primary hypothyroidism, five (11.11%) from subclinical hypothyroidism and one (2.22%) from hyperthyroidism, whereas one (2.22%) of the controls had primary hypothyroidism and one (2.22%) had hyperthyroidism. Five patients (11.11%) had a thyroid hormone profile that was compatible with the presence of euthyroid sick syndrome. Thyroid peroxidase (TPOab) and thyroglobulin (Tgab) antibodies were detected in 20/45 and 15/45 of the SLE population and in 7/45 and 5/45 of the controls, respectively (p < 0.05, chi-square test). Conclusions: In conclusion, the incidence of clinical thyroid disease is greater amongst SLE patients than in a control population, and in a significant number of these patients, antithyroid antibodies are detectable. Thus, a subset of lupus patients appears to be predisposed to the development of thyroid disease, and this should be considered when evaluating patients with SLE.

Hypoparathyroidism: Genetics and Diagnosis

This narrative report summarizes diagnostic criteria for hypoparathyroidism and describes the clinical presentation and underlying genetic causes of the nonsurgical forms. We conducted a comprehensive literature search from January 2000 to January 2021 and included landmark articles before 2000, presenting a comprehensive update of these topics and suggesting a research agenda to improve diagnosis and, eventually, the prognosis of the disease. Hypoparathyroidism, which is characterized by insufficient secretion of parathyroid hormone (PTH) leading to hypocalcemia, is diagnosed on biochemical grounds. Low albumin-adjusted calcium or ionized calcium with concurrent inappropriately low serum PTH concentration are the hallmarks of the disease. In this review, we discuss the characteristics and pitfalls in measuring calcium and PTH. We also undertook a systematic review addressing the utility of measuring calcium and PTH within 24 hours after total thyroidectomy to predict long-term hypoparathyroidism. A summary of the findings is presented here; results of the detailed systematic review are published separately in this issue of JBMR. Several genetic disorders can present with hypoparathyroidism, either as an isolated disease or as part of a syndrome. A positive family history and, in the case of complex diseases, characteristic comorbidities raise the clinical suspicion of a genetic disorder. In addition to these disorders' phenotypic characteristics, which include autoimmune diseases, we discuss approaches for the genetic diagnosis. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Coexistence of Histologically Proven Chronic Lymphocytic Thyroiditis with Other Thyroid Disorders: A Retrospective Study

Background  Hashimoto's thyroiditis (HT) is the commonest autoimmune thyroid pathology. It has been reported in increased numbers recently, probably due to the increase in autoimmune diseases across many parts of the world. It is sometimes found associated with other diseases as well as other diseases of the thyroid. There is an unproven association of this condition with thyroid cancer, particularly papillary thyroid carcinoma (PTC).

Methods  This was a retrospective study performed over a period of 5 years. The objectives of this study were to find out the prevalence of histopathologically proven HT in surgically resected thyroid glands for various indications and its association with other thyroid disorders, especially thyroid malignancies. Total 4,630 patients who underwent thyroidectomy during the study period and met the criteria for inclusion were considered for analysis.

Results  Histopathologically proven features of HT were present in 1,295 (28%) of the cases. Among these, 445 (34.36%) had only HT while 850 (65.66%) had HT along with other thyroid diseases. The most common disease associated with HT was multinodular goiter (44.2%), followed by PTC (15.2%). Patients with HT exhibited a higher rate of papillary cancer (16.7%) compared with patients without this pathology (13.8%). Statistically significant association between papillary cancer and HT was found among the female patients.

Conclusion  The prevalence of HT in patients undergoing thyroidectomy is high in the studied population. A statistically significant association exists between papillary thyroid cancer and thyroiditis among female patients. This could form the basis for further research along these lines.

Association between rheumatoid arthritis and thyroid dysfunction: A meta-analysis and systematic review

OBJECTIVE

Rheumatoid arthritis (RA) is an autoimmune disorder. Multiple studies have investigated the risk of thyroid dysfunction in patients with RA but have reached conflicting conclusions. This systematic review aimed to determine whether patients with RA are at higher risk of thyroid dysfunction.

METHODS

We comprehensively reviewed online literature databases, including PubMed, Scopus, Embase, and the Cochrane Library, from their respective inception dates to March 25, 2022. Studies that provided data on at least one case of thyroid dysfunction in RA patients and their controls were included. Based on these data, we calculated pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) for thyroid dysfunction in RA and non-RA patients.

RESULTS

Twenty-nine studies met the inclusion criteria, involving a total of 35,708 patients with RA. The meta-analysis showed that, compared with non-RA patients, RA patients had an increased risk of developing thyroid dysfunction, particularly hypothyroidism (OR 2.25, 95% CI 1.78-2.84). Subgroup analysis suggested that study type and sample source of control group were the source of heterogeneity.

CONCLUSIONS

Patients with RA are at increased risk of developing thyroid dysfunction, especially hypothyroidism. Routine biochemical examination of thyroid function in RA patients should be strengthened. Larger prospective studies are needed to explore the causal relationship between RA and thyroid dysfunction, and to investigate the impact of thyroid dysfunction on RA disease activity, drug efficacy, and medication safety.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42022331142.

The interrelationship between pregnancy, venous thromboembolism, and thyroid disease: a hypothesis-generating review

Pregnancy induces physiological changes that affect the risk of thrombosis and thyroid disease. In this hypothesis-generating review, the physiological changes in the coagulation system and in thyroid function during a normal pregnancy are described, and the incidence of venous thromboembolism (VTE) and thyroid disease in and after a pregnancy are compared and discussed. Furthermore, evidence regarding the association between thyroid disease and VTE in non-pregnant individuals is scrutinized. In conclusion, a normal pregnancy entails hormonal changes, which influence the onset of VTE and thyroid disease. Current evidence suggests an association between thyroid disease and VTE in non-pregnant individuals. This review proposes the hypothesis that maternal thyroid disease associates with VTE in pregnant women and call for future research studies on this subject. If an association exists in pregnant women specifically, such findings may have clinical implications regarding strategies for thyroid function testing and potential thromboprophylaxis in selected individuals.

Coeliac disease is a risk factor for the development of seronegative arthritis in patients with autoimmune thyroid disease

OBJECTIVE

Hashimoto's thyroiditis is known to cluster with other systemic autoimmune disorders. Rheumatic manifestations, such as a seronegative non-erosive polyarthritis have been described. The aim of this study was to evaluate the characteristics and the prevalence of rheumatic features in thyroiditis patients, and to ascertain whether the association with systemic autoimmune disorders improved the arthritis manifestations.

METHODS

In total, 180 thyroiditis patients were enrolled. Major clinical and demographic characteristics have been recorded. Patients underwent a rheumatological clinical assessment and extra-articular manifestations allowing for a differential diagnosis with systemic autoimmune diseases and spondyloarthropathy. Presence of systemic autoimmune diseases was recorded.

RESULTS

A total of 8.33% of thyroiditis patients shown a peripheral inflammatory arthritis (P = 0.002). Female gender (P = 0.042) and thyroid peroxidase (TPOAbs) positivity (P = 0.001) were more frequent. In total, 37 patients had systemic autoimmune diseases (P = 0.0003). A significant high prevalence of coeliac disease and Addison disease was found (P = 0.034 and P = 0.049, respectively). In patients with coeliac disease, the articular manifestations were more frequent (21.21%) (P = 0.001) and the risk to develop joint involvement was 2.96.

CONCLUSION

Although we found an articular involvement in about one-third of thyroiditis patients, the prevalence of inflammatory arthropathy was only 8.33%. The prevalence of other coexisting autoimmune disorders was 34.26% with a significant prevalence of coeliac disease (7.41%). Thyroiditis patients with coeliac disease have an articular involvement more frequently than those without. In these patients, we have found a high risk of developing arthritis than patients with only thyroiditis, suggesting cumulative autoimmune effects in the developing articular involvement.

Prevalence of other autoimmune diseases in polyglandular autoimmune syndromes type II and III

PURPOSE

Polyglandular autoimmune syndromes (PAS) are complex, heterogeneous disorders in which various autoimmune diseases can occur, affecting both endocrine and non-endocrine organs. In this meta-analysis, the prevalence of associated autoimmune disorders was investigated in PAS II and III.

METHODS

A comprehensive search in MEDLINE and Embase databases identified 479 studies with the keywords of PAS II and PAS III. 18 records containing a total of 1312 patients fulfilled our inclusion criteria (original studies reporting at least 10 cases and containing the combination of other autoimmune disorders) and were selected for further analysis. A meta-analysis of prevalence was performed using the random-effects model with the calculation of 95% confidence intervals (CI). Results of each meta-analysis were displayed graphically using forest plots.

RESULTS

Distinction between PAS II and PAS III was made in 842 cases, of which 177 and 665 were PAS II and III (21.1 vs 78.9%), respectively. The prevalence of Hashimoto's thyroiditis was significantly higher than that of Graves's disease (39% [95% CI 17-65%] vs. 4% [95% CI 0-10%], respectively; p = 0.001). In PAS II, Addison's disease (AD) coexisted with AITDs, T1DM or the combination of these conditions in 65, 18 and 10% of cases, respectively. In addition, one other endocrine and five non-endocrine organ-specific autoimmune disorders were reported. In PAS III, two other autoimmune endocrinopathies, six non-endocrine organ-specific, and four systemic autoimmune disorders were found in combination with AITDs.

CONCLUSIONS

AITDs, T1DM and AD are the most common combinations in PAS, thus screening for these conditions seems to be reasonable.

Alemtuzumab-related thyroid disease in people with multiple sclerosis is associated with age and brainstem phenotype at disease onset

Background

Autoimmune thyroid disease (AITD) occurs in 40%–50% of alemtuzumab-treated persons with multiple sclerosis (pwMS), most of whom will develop Graves’ Disease (GD).

Objective

To explore contributory factors for alemtuzumab-related AITD in pwMS.

Methods

A retrospective patient chart review was performed.

Results

Sixteen out of 52 (30.8%) pwMS developed AITD. GD occurred in 56.3% (n = 9), the majority (n = 7, 77.8%) symptomatic. All but one (85.7%) pwMS with symptomatic GD developed atypical, large and rapid fluctuations in thyroid hormone levels unexplained by effect of anti-thyroid medication alone. All symptomatic GD cases were age ≤32 years when starting alemtuzumab (ɸ = 0.60, p = 0.03). PwMS who started alemtuzumab at a younger age developed thyroid disease earlier (r = 0.51, p = 0.04). PwMS with clinical and radiological evidence of brainstem involvement at onset of multiple sclerosis were 11 times more likely to develop symptomatic GD compared with those with other phenotypes (p < 0.01).

Conclusion

Alemtuzumab-induced reconstitution GD may result from early and increased cross-reactivity between antigens common to the brainstem and thyroid, or presence of shared Human Leukocyte Antigen (HLA) alleles that determine brainstem and thyroid involvement. We suggest cautious use of alemtuzumab in younger (≤32 years) pwMS with early brainstem involvement, especially those actively planning pregnancy, where alternative therapies are readily available.

Maternal Autoimmune Disorders and Risk of Kawasaki Disease in Offspring

We assessed the association between maternal autoimmune disorders and offspring risk of Kawasaki disease in a longitudinal cohort of 792 108 newborns. We found that maternal autoimmune disorders, especially autoimmune thyroiditis, may be risk factors for Kawasaki disease in children, particularly young children.

Autoimmune thyroid disorders and rheumatoid arthritis: A bidirectional interplay

Rheumatoid arthritis (RA) and autoimmune thyroid disease (AITD) can occur in the same patient in the autoimmune polyglandular syndrome 2. The association of the two conditions has been recognized long-time ago and the prevalence of AITD in patients with RA and vice versa is well assessed. Geographical variation of AITD and related autoantibodies in RA patients is partly due to ethnic and environmental differences of the studied populations. The impacts of thyroid disorders on RA outcome and vice versa are still controversy. In both AITD and RA genetic susceptibility and environmental factors play a synergic role in the development of the diseases. In this review we aimed at investigating the association of AITD and thyroid autoantibodies with RA, the common pathogenic pathways, the correlation with RA disease activity, and influence of the treatment.

To Treat or Not to Treat Subclinical Hypothyroidism, What Is the Evidence?

OBJECTIVE

levothyroxine prescriptions have increased remarkably during the last decade, and it is most likely to be prescribed in subclinical hypothyroidism. The aim of this review was to present data on when levothyroxine treatment should be initiated, and the effects of treatment in subclinical hypothyroidism on symptoms such as weight, quality of life, vitality, cognition, and cardiovascular disease. We also discuss evidence for different thyroid-hormone medications. In addition, the option to withhold medication when there is uncertain diagnosis or lack of clinical improvement is discussed.

METHODS

a literature search in PubMed on the term "treatment of subclinical hypothyroidism" in combination with "quality of life", "weight", "cognition", and "cerebrovascular disease".

RESULTS

current research supports that levothyroxine should be initiated in patients with a thyroid stimulating hormone (TSH) >10 mIU/L. Treatment for hypothyroidism is becoming more frequent. Symptoms related to vitality, weight, and quality of life in subclinical disease often persist with levothyroxine treatment, and other causes should be explored. Patients with cardiovascular-risk factors may benefit from treatment, especially younger patients. Caution is necessary when treating elderly subjects with levothyroxine.

CONCLUSION

lifelong treatment with levothyroxine should normally only be considered in manifest hypothyroidism. However, in subclinical hypothyroidism with a TSH >10 mIU/L, therapy is indicated. In milder subclinical forms, a wait-and-see strategy is advocated to see if normalization occurs. Subgroups with cardiovascular risk and subclinical hypothyroidism may benefit from levothyroxine therapy.

Non-specific rheumatic manifestations in patients with Hashimoto's thyroiditis: a pilot cross-sectional study

PURPOSE

Hashimoto's thyroiditis (HT) is often associated with rheumatic disorders (arthritis, etc.), but many HT patients report non-specific rheumatic signs and symptoms in the absence of clinically evident rheumatic diseases. Aim of this study was to evaluate the prevalence of non-specific rheumatic manifestations (RMs) in HT subjects without classified autoimmune comorbidities.

METHODS

500 HT patients (467 F, 33 M; median age 41 years, range 14-69) and 310 age- and sex-matched controls, consecutively referred to the Endocrine Unit of Messina University Hospital, were evaluated for non-specific RMs. None took L-thyroxine.

EXCLUSION CRITERIA

autoimmune comorbidities, infectious, and/or inflammatory diseases, history of neoplasia, BMI > 30 kg/m².

RESULTS

In our HT cohort, 100 patients (20%) complained of one or more RMs, vs 21 controls (6.8%; P < 0.001). There were minimal differences between the manifestations recorded in the two groups, the most common being polyarthralgias and myalgias/fibromyalgia, but non-specific RMs occurred threefold more in HT patients. Comparing HT patients with RMs (96 F and 4 M) with those affected by HT alone, female sex was prevalent (F:M ratio 24:1 vs 5:1) with higher age at diagnosis (median 43 vs 37 years; P < 0.001). HT patients with RMs (62%) were mostly euthyroid (median TSH 2.0 µIU/L) and only 7% overtly hypothyroid, discouraging a possible causal relationship between thyroid dysfunction per se and RMs.

CONCLUSIONS

A significant percentage of HT patients complains of non-specific rheumatic signs and symptoms, in the absence of other diagnosed systemic comorbidities and regardless of thyroid functional status, deserving careful evaluation and prolonged follow-up.

Brown Adipose Tissue Response to Cold Stimulation Is Reduced in Girls With Autoimmune Hypothyroidism

Objective

The interaction between thyroid status and brown adipose tissue (BAT) activation is complex. We assessed the effect of autoimmune hypothyroidism (ATD) in female children on BAT activation, measured using infrared thermography.

Design

Twenty-six female participants (14 with ATD and 12 healthy controls) between 5 and 17 years of age attended a single study session. Thermal images were taken of the supraclavicular region before, and after, the introduction of a cool stimulus.

Results

Participants with ATD had lower resting (hypothyroid, 34.9 ± 0.7°C; control, 35.4 ± 0.5°C; P = 0.03) and stimulated (hypothyroid, 35.0 ± 0.6°C; control, 35.5 ± 0.5°C; P = 0.04) supraclavicular temperatures compared with controls, but there was no difference between groups in the temperature increase with stimulation. BAT activation, calculated as the relative temperature change comparing the supraclavicular temperature to a sternal reference region, was reduced in participants with ATD (hypothyroid, 0.1 ± 0.1°C; control, 0.2 ± 0.2°C; P = 0.04). Children with ATD were frequently biochemically euthyroid due to replacement therapy, but, despite this, increased relative supraclavicular temperature was closely associated with increased TSH (r = 0.7, P = 0.01) concentrations.

Conclusions

Girls with ATD had an attenuated thermogenic response to cold stimulation compared with healthy controls, but, contrary to expectation, those with suboptimal biochemical control (with higher TSH) showed increased BAT activation. This suggests that the underlying disease process may have a negative effect on BAT response, but high levels of TSH can mitigate, and even stimulate, BAT activity. In summary, thyroid status is a complex determinant of BAT activity in girls with ATD.

The antigenic link between thyroid autoimmunity and breast cancer

The association between breast cancer and benign thyroid disorders, in particular thyroid autoimmunity, has been debated for decades. Autoantibodies to thyroid peroxidase, the hallmark of thyroid autoimmunity, have a higher prevalence among patients with breast cancer compared with the general population. Furthermore a correlation between their positivity and a better prognosis of breast cancer was found in several independent small-scale studies, even if such observation was not confirmed in a subsequent retrospective study conducted on the largest patient cohort to date. The thyroid and mammary glands present several biological similarities, therefore the hypothesis of an immune response to shared thyroid/breast antigens could in part explain the association between thyroid autoimmunity and breast cancer. The sodium iodide symporter is expressed in both glands, however it seems unlikely to be the key common antigen, considering that autoantibodies targeting it are rare. Instead thyroid peroxidase, one of the major thyroid autoantigens, is also expressed in breast tissue and therefore represents the main antigenic link between thyroid autoimmunity and breast cancer. Furthermore lactoperoxidase, an enzyme of the same family that shares structural similarities with thyroid peroxidase, is expressed in neoplastic breast cells and is responsible for the cross-reactivity with some autoantibodies to thyroid peroxidase. Novel strategies for the diagnosis and treatment of breast cancer might take advantage of the antigenic link between thyroid and breast tissues.

Phenotypic Expression of Autoimmunity in Children With Autoimmune Thyroid Disorders

Autoimmune thyroid diseases (AITDs), including Hashimoto's thyroiditis (HT) and Graves' disease (GD), tend to aggregate with other non-thyroidal autoimmune diseases (NTADs). Aim of this Mini-review is to report the most recent insights concerning the clustering of NTADs in pediatric patients with either HT or GD, the pathophysiology of AITDs and the metamorphic thyroid autoimmunity. A systematic literature research of the last 15 years, according to EQUATOR statement, was carried out through MEDLINE via PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) Embase, CINAHL, Cochrane Library, based on the following keywords: (autoimmune thyroid disease OR Hashimoto thyroiditis OR Grave's disease) AND (autoimmune comorbidities OR extra-thyroidal autoimmune disorders) AND (children OR adolescents OR pediatrics) AND (celiac disease OR type 1 diabetes mellitus OR arthropathies OR cutaneous diseases) AND (Turner syndrome OR Down syndrome). One-hundred and twenty-eight manuscripts were extrapolated but only seventeen were eligible. On the basis of the available reports it may be inferred that clustering of NTADs can be significantly modified by both patients' age at AITDs presentation and association with Down's syndrome (DS). Particularly, the association of AITDs with celiac disease and type 1 diabetes was most commonly reported in children than in adults. A sequential shifting from HT to GD has been described in children with AITDs, and it seems to be more frequent in children with DS than in those without DS. Coexistence of autoimmune diseases might be the result of a complex interaction among genetics, environment and epigenetic modifications that are able to affect gene expression, immune system response and, finally, the pathogenesis of autoimmune diseases.

Extrahepatic Autoimmune Diseases are Prevalent in Autoimmune Hepatitis Patients and Their First-Degree Relatives: Survey Study

Background

Concurrent autoimmune illnesses contribute to increased medical burden and reduced quality of life in patients with autoimmune hepatitis (AIH). The frequency of coexisting autoimmune conditions among North American patients with AIH and their families remains incomplete. Challenges associated with disease capture in the electronic medical record, high study costs, and geographic spread of patients are formidable barriers to understanding the extent of concurrent autoimmune conditions in these groups.

Objective

This objective of this study was to examine the frequency of extrahepatic autoimmune diseases (EHAD) among AIH cases and healthy controls as well as their first-degree relatives using social networking sites (SNS).

Methods

We developed a 53-question survey detailing the history of autoimmune diseases. A survey link was posted at routine intervals within specific Web-based cohorts on SNS. Healthy controls, without self-reported autoimmune liver disease, were recruited from Amazon’s Mechanical Turk. Continuous variables were summarized using medians and P values obtained with the Wilcoxon rank-sum test. Categorical variables were compared using the chi-square test.

Results

Compared with controls (n=1162), cases (n=306) were more likely to be older (median age: 49 vs 33 years), female (284/306, 92.81% vs 955/1162, 82.18%), and have an EHAD (128/306, 41.83% vs 218/1162, 18.76%; P=.001). The most frequent EHADs among cases were thyroid disease (49/306, 16.01% ), Sjögren syndrome (27/306, 8.82%), Raynaud phenomenon (23/306, 7.52%), and psoriasis (22/306, 7.19%). Overall, 55.88% (171/306) of cases and 35.71% (1601/4484) of controls reported at least 1 first-degree relative (FDR) with a history of EHAD (P=.001). Cases had a significantly higher risk of EHAD than controls after the adjustment for age, sex, race, and body mass index: odds ratio 2.46 (95% CI 1.8-3.3); P=.001.

Conclusions

Patients with AIH report higher prevalence of coexistent EHAD than healthy controls, and their FDRs are also more likely to have autoimmune disorders.

Prevalence of thyroid dysfunction in a Large Southern European Population. Analysis of modulatory factors. The APNA study

CONTEXT

To study the prevalence of thyroid dysfunction in a very large unselected population.

OBJECTIVE

To determine the prevalence of abnormal thyroid function and evaluate potential modulatory factors.

DESIGN AND SETTING

The Estudio de Atención Primaria de Navarra, The APNA Study, is a cross-sectional study conducted in northern Spain. It involved 303 883 people, of 20 years of age and older, who live in the Navarra region. Participants are covered by the public healthcare system and medical records are digitalized.

MAIN OUTCOME MEASURES

The information was gathered from e-registered data regarding serum thyrotropin (TSH), thyroid hormones, thyroid antibody concentration and clinical context. Measurements were logged (demographic information and potential thyroid function modulatory factors).

RESULTS

Serum TSH (mU/L) normal range was established at 0.7-4.28. At the time of the study, 87% of the Navarra population had a TSH level within the normal range. Mean serum TSH in euthyroid individuals was higher in women (2.15) than in men (1.96) (P < .001) and higher in the obese with body mass index (BMI) ≥30 kg/m² (2.12) as compared to the non-obese BMI <30 kg/m² (2.06) (P < .001). Mean TSH for the entire population was 1.9. The native Spanish population had statistically significantly lower TSH (1.87) than non-native Spanish (2.15) (P < .001). Additionally, we observed that serum TSH levels decreased with age and an increase in the prevalence of hypothyroidism in the elderly and among people with low-income levels. The prevalence of thyroid dysfunction in Navarra was 12.3%. The prevalence of hypothyroidism (or high TSH) in the population was 8.8% (13.3% in women, 4.2% in men), and the prevalence of hyperthyroidism (or low TSH) was 4.3% (5.6% in women, 3.0% in men).

CONCLUSIONS

Nearly 15% of the general population suffers from biochemical thyroid dysfunction. The serum TSH level appears to be influenced by sex, BMI, age, ethnic origin and socio-economic status.

Autoimmune Thyroid Diseases and Thyroid Cancer in Pemphigus: A Big Data Analysis

There is a little consensus regarding the association of pemphigus with autoimmune thyroid diseases. While this association had been confirmed by some observational studies, others had refuted it. We aimed to study the association between pemphigus and Hashimoto's thyroiditis, Grave's disease, and thyroid cancer using a large-scale real-life computerized database. A cross-sectional study was performed to compare pemphigus patients with age-, sex-, and ethnicity-matched control subjects regarding the prevalence of overt thyroid diseases. Chi-square and t-tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis. The study was performed using the computerized database of Clalit Healthcare Services ensuring 4.5 million individuals. A total of 1,985 pemphigus patients and 9,874 controls were included in the study. The prevalence of Hashimoto's thyroiditis (12.9 vs. 11.9%; P = 0.228), Graves's disease (0.7 vs. 0.7%; P = 0.986), and thyroid cancer (0.7 vs. 0.5%; P = 0.305) were comparable among patients with pemphigus and control subjects. In sex-stratified analysis, pemphigus associated significantly with Hashimoto's thyroiditis among male patients (OR, 1.36; 95% CI, 1.04-1.79). In multivariate analysis adjusting for potential confounding factors, no independent associations between the conditions were revealed. Study findings were robust to sensitivity analysis that included only patients under pemphigus-specific treatments. In conclusion, Hashimoto's thyroiditis was found to be associated with pemphigus only among male patients, but not among all patients. Physicians treating patients with pemphigus might be aware of this possible association. This study does not provide a clue for an association of pemphigus with Grave's disease or thyroid cancer.

Management of hypothyroidism with combination thyroxine (T4) and triiodothyronine (T3) hormone replacement in clinical practice: a review of suggested guidance

Background

Whilst trials of combination levothyroxine/liothyronine therapy versus levothyroxine monotherapy for thyroid hormone replacement have not shown any superiority, there remains a small subset of patients who do not feel well on monotherapy. Whilst current guidelines do not suggest routine use of combination therapy they do acknowledge a trial in such patients may be appropriate. It appears that use of combination therapy and dessicated thyroid extract is not uncommon but often being used by non-specialists and not adequately monitored. This review aims to provide practical advice on selecting patients, determining dose and monitoring of such a trial.

Main body

It is important to select the correct patient for a trial so as to not delay diagnosis or potentially worsen an undiagnosed condition. An appropriate starting dose may be calculated but accuracy is limited by available formulations and cost. Monitoring of thyroid function, benefits and adverse effects are vital in the trial setting given lack of evidence of safe long term use. Also important is that patients understand set up of the trial, potential risks involved and give consent.

Conclusion

Whilst evidence is lacking on whether a small group of patients may benefit from combination therapy a trial may be indicated in those who remain symptomatic despite adequate levothyroxine monotherapy. This should be undertaken by clinicians experienced in the field with appropriate monitoring for adverse outcomes in both short and long term.

Autoimmune comorbidity in achalasia patients

BACKGROUND AND AIM

Idiopathic achalasia is a rare esophageal motor disorder. The disease state manifests local and systemic inflammation, and it appears that an autoimmune component and specific autoantibodies participate in the pathogenesis. The study aims to determine the prevalence of autoimmune and chronic inflammatory diseases in patients with achalasia and compare the results with those from patients with gastroesophageal reflux disease (GERD).

METHODS

It was a cross-sectional and included 114 patients with idiopathic achalasia and 114 age-matched and sex-matched control patients with GERD. Data on the presence of autoimmune and inflammatory diseases, the time of presentation, and any family history of autoimmune disease were obtained from the hospital's medical records.

RESULTS

Seventy three (64%) were female patients (mean age: 42.3 ± 15.5; median disease duration: 12 months). We identified the presence of autoimmune disease in 19 patients with achalasia (16.7%), hypothyroidism was the main diagnosis, and it was present in 52.6% of patients compared with 4.2% in controls. Thirteen of the 19 achalasia patients (68.4%) with autoimmune disease had history of familial autoimmunity. We identified 11 achalasia (9.6%) and 5 GERD patients (4.16%) with an inflammatory condition. Compared with the GERD, the achalasia group was 3.8 times more likely to have an autoimmune disease (95% CI: 1.47-9.83), 3.0 times more likely to have thyroidopathies (95% CI: 1.00-9.03), and 3.02 times more likely to suffer from any chronic inflammatory disease (95% CI: 1.65-6.20).

CONCLUSIONS

The non-negligible number of patients with autoimmune diseases identified among the patients with idiopathic achalasia supports the hypothesis that achalasia has an autoimmune component.

Autoimmune comorbidities in Hashimoto's thyroiditis: different patterns of association in adulthood and childhood/adolescence

OBJECTIVE

Hashimoto's thyroiditis (HT), the most common autoimmune thyroid disease at any age, is often associated with other autoimmune diseases. The present study was aimed to describe the type and frequency of non-thyroidal autoimmune diseases (NTADs) in HT patients and to delineate the clinical pattern of diseases clustering in pediatric/adolescent and adult age.

DESIGN

Cross-sectional study.

METHODS

1053 newly diagnosed HT patients (500 adults (467 F, mean age 40.2 ± 13.7 years) and 553 children/adolescents (449 F, mean age 11.1 ± 3.0 years)) were evaluated for common NTADs by means of careful recording of medical history, physical examination and assessment of selected autoantibody profiles.

RESULTS

The prevalence of associated NTADs was significantly higher in adults than that in pediatric/adolescent HT patients (P < .0001). In addition, the number of adult patients suffering from two or more associated NTADs was significantly higher than that of children/adolescent (P < 0.0001). A female prevalence was evident in both cohorts, but was significant in the adults (P < 0.0001). The epidemiological distribution of NTADs was strongly different in the two cohorts, the most frequent associated diseases being arthropathies and connective tissue diseases in adults and type 1 diabetes and coeliac disease in children/adolescents. Skin diseases were represented with similar prevalence in both cohorts, vitiligo being the most common.

CONCLUSIONS

Age at HT presentation may influence autoimmune diseases clustering, favoring the association of specific NTADs in different ages of life. Moreover, the association between HT and NTADs increases with age and occurs most frequently in adults.

Limited cutaneous systemic sclerosis arising in a patient with Graves' disease

Although Graves' disease and systemic sclerosis are both autoimmune disorders, their relationship is rarely reported. We present the case of a Filipino woman with goitre and thyrotoxic signs and symptoms. Diagnosed with Graves' disease at the outpatient clinic, she took antithyroid medications and underwent radioactive iodine ablation with resultant hypothyroidism after 6 months, during which she began to experience skin tightness over the face, neck and fingers. Workup revealed limited cutaneous systemic sclerosis, and the patient improved with methotrexate. This case highlights the increased prevalence of coincident autoimmune disorders in Graves' disease.

Thyroid in pregnancy: From physiology to screening

Thyroid hormones are crucial for the growth and maturation of many target tissues, especially the brain and skeleton. During critical periods in the first trimester of pregnancy, maternal thyroxine is essential for fetal development as it supplies thyroid hormone-dependent tissues. The ontogeny of mature thyroid function involves organogenesis, and maturation of the hypothalamus, pituitary and the thyroid gland; and it is almost complete by the 12th-14th gestational week. In case of maternal hypothyroidism, substitution with levothyroxine must be started in early pregnancy. After the 14th gestational week, fetal brain development may already be irreversibly affected by lack of thyroid hormones. The prevalence of manifest hypothyroidism in pregnancy is about 0.3-0.5%. The prevalence of subclinical hypothyroidism varies between 4 and 17%, strongly depending on the definition of the upper TSH cutoff limit. Hyperthyroidism occurs in 0.1-1% of all pregnancies. Positivity for antibodies against thyroid peroxidase (TPOAb) is common in women of childbearing age with an incidence rate of 5.1-12.4%. TPOAb-positivity may be regarded as a manifestation of a general autoimmune state which may alter the fertilization and implantation processes or cause early missed abortions. Women positive for TPOAb are at a significant risk of developing hypothyroidism during pregnancy and postpartum. Laboratory diagnosis of thyroid dysfunction during pregnancy is based upon serum TSH concentration. TSH in pregnancy is physiologically lower than the non-pregnant population. Results of multiple international studies point toward creation of trimester-specific reference intervals for TSH in pregnancy. Screening for hypothyroidism in pregnancy is controversial and its implementation varies from country to country. Currently, the case-finding approach of screening high-risk women is preferred in most countries to universal screening. However, numerous studies have shown that one-third to one-half of women with thyroid disorders escape the case-finding approach. Moreover, the universal screening has been shown to be more cost-effective. Screening for thyroid disorders in pregnancy should include assessment of both TSH and TPOAb, regardless of the screening approach. This review summarizes the current knowledge on physiology of thyroid hormones in pregnancy, causes of maternal thyroid dysfunction and its effects on pregnancy course and fetal development. We discuss the question of case-finding versus universal screening strategies and we display an overview of the analytical methods and their reference intervals in the assessment of thyroid function and thyroid autoimmunity in pregnancy. Finally, we present our results supporting the implementation of universal screening.

Frequency and determinants of thyroid autoimmunity in Ghanaian type 2 diabetes patients: a case-control study

BACKGROUND

The link between type 1 diabetes and thyroid autoimmunity is well described. The same cannot be said for type 2 diabetes where results have been mixed so far. We investigated the prevalence and determinants of thyroid autoimmunity among Ghanaian type 2 diabetes patients.

METHODS

This was a case-control study involving 302 type 2 diabetes patients and 310 non - diabetic controls aged 40-80 years. Anthropometric and blood pressure measurements were obtained. Fasting samples were analyzed for glucose, thyroid function, and antibodies to thyroglobulin and thyroid peroxidase.

RESULTS

The prevalence of thyroid autoimmunity was significantly higher among T2DM subjects (12.2% vs. 3.9%, p = 0.0004). Among T2DM subjects, 44 (14.7%) tested positive for TPOAb, 5 (1.7%) tested positive for TGAb and 15 (5.0%) tested positive for both autoantibodies. Females T2DM subjects showed a 3-fold increased risk of thyroid autoimmunity compared to males (OR:3.16, p =0.004), T2DM subjects with hyperthyroidism had a 41% increased risk of thyroid autoimmunity (OR: 1.41, p < 0.001), sub-clinical hyperthyroidism increased the risk of thyroid autoimmunity by 2 fold, (OR:2.19, p < 0.001), subclinical hypothyroidism increased the risk of autoimmunity by 4-fold, (OR:3.57 95% p < 0.0001), and hypothyroidism was associated with a 61% increased risk of thyroid autoimmunity (OR: 1.61,1.35-2.23). Dyslipidaemia was associated with a 44% increased risk of thyroid autoimmunity (OR: 1.44, p = 0.01) and a percentage increase in HbA1c was associated with 46% increased risk of thyroid autoimmunity (OR:1.46, p < 0.0001).

CONCLUSION

We observed a high prevalence of thyroid autoimmunity in Ghanaian T2DM subjects compared to the general population. Thyroid autoimmunity in T2DM subjects was significantly associated with female gender, thyroid dysfunction, dyslipidaemia and poor glycemic control.

Autoimmune Thyroiditis and Myasthenia Gravis

Autoimmune diseases (AIDs) are the result of specific immune responses directed against structures of the self. In normal conditions, the molecules recognized as "self" are tolerated by immune system, but when the self-tolerance is lost, the immune system could react against molecules from the body, causing the loss of self-tolerance, and subsequently the onset of AID that differs for organ target and etiology. Autoimmune thyroid disease (ATD) is caused by the development of autoimmunity against thyroid antigens and comprises Hashimoto's thyroiditis and Graves disease. They are frequently associated with other organ or non-organ specific AIDs, such as myasthenia gravis (MG). In fact, ATD seems to be the most associated pathology to MG. The etiology of both diseases is multifactorial and it is due to genetic and environmental factors, and each of them has specific characteristics. The two pathologies show many commonalities, such as the organ-specificity with a clear pathogenic effect of antibodies, the pathological mechanisms, such as deregulation of the immune system and the implication of the genetic predisposition. They also show some differences, such as the mode of action of the antibodies and therapies. In this review that focuses on ATD and MG, the common features and the differences between the two diseases are discussed.

Autoimmune Thyroid Diseases in Patients Treated with Alemtuzumab for Multiple Sclerosis: An Example of Selective Anti-TSH-Receptor Immune Response

Alemtuzumab, a humanized anti-CD52 monoclonal antibody, is approved for the treatment of active relapsing-remitting multiple sclerosis (MS). Alemtuzumab induces a rapid and prolonged depletion of lymphocytes from the circulation, which results in a profound immuno-suppression status followed by an immune reconstitution phase. Secondary to reconstitution autoimmune diseases represent the most common side effect of Alemtuzumab treatment. Among them, Graves' disease (GD) is the most frequent one with an estimated prevalence ranging from 16.7 to 41.0% of MS patients receiving Alemtuzumab. Thyrotropin (TSH) receptor (R)-reactive B cells are typically observed in GD and eventually present this autoantigen to T-cells, which, in turn, secrete several pro-inflammatory cytokines and chemokines. Given that reconstitution autoimmunity is more frequently characterized by autoantibody-mediated diseases rather than by destructive Th1-mediated disorders, it is not surprising that GD is the most commonly reported side effect of Alemtuzumab treatment in patients with MS. On the other hand, immune reconstitution GD was not observed in a large series of patients with rheumatoid arthritis treated with Alemtuzumab. This negative finding supports the view that patients with MS are intrinsically more at risk for developing Alemtuzumab-related thyroid dysfunctions and in particular of GD. From a clinical point of view, Alemtuzumab-induced GD is characterized by a surprisingly high rate of remission, both spontaneous and after antithyroid drugs, as well as by a spontaneous shift to hypothyroidism, which is supposed to result from a change from stimulating to blocking TSH-receptor antibodies. These immune and clinical peculiarities support the concept that antithyroid drugs should be the first-line treatment in Alemtuzumab-induced Graves' hyperthyroidism.

Thyroid Autoimmunity and Function after Treatment with Biological Antirheumatic Agents in Rheumatoid Arthritis

With the increased pro-inflammatory response in both rheumatoid arthritis and thyroid autoimmune diseases, treatment with biological antirheumatic agents (BAAs) of the former may affect the course of the latter. In hepatitis C and cancer patients, treatment with biological agents substantially increases the risk of developing thyroid autoimmunity. As the use of BAAs in the treatment of rheumatoid arthritis is increasing, this review aimed to investigate if such use affected thyroid status in rheumatoid arthritis patients. We conducted a systematic literature search and included six studies with a total of 311 patients as well as three case reports. The patients were treated with tumor necrosis factor-α inhibitors (infliximab, etanercept, or adalimumab) or the monoclonal CD20-antibody rituximab. There was a non-significant trend of slight improvement of both thyroid function and autoantibody status: a reduction of thyroid peroxidase and thyroglobulin antibody concentrations, and a reduction of thyrotropin levels in hypothyroid patients. Despite the small number of studies, they presented compliant data. The BAAs used in rheumatoid arthritis thus did not seem to negatively affect thyroid status in patients with rheumatoid arthritis and can be considered safe with regard to thyroid autoimmunity. However, the well-established association between rheumatic diseases and thyroid autoimmunity necessitates continued monitoring of thyroid function in patients with rheumatoid arthritis. Each new BAA should be scrutinized for its effect on thyroid as well as other autoimmune diseases in order to establish concise recommendations for patient follow-up for each agent and each disease.

Thyroid dysfunction in the era of precision medicine

The launching of the Precision Medicine Initiative by the President of the United States in January 2015 was an invitation for all healthcare professionals to review their practice. This call should stimulate thyroidologists working in different areas (from basic research or epidemiology to the frontline of the clinical arena or to those designing public health programs) to be aware of this new outlook. The aim of the initiative is to eradicate imprecision in estimating the probability of a correct diagnosis, to be as sure as possible of the most effective treatment, and to maximize the chances of a successful outcome. This paper summarizes some of the current challenges faced by endocrinologists in the field of thyroid dysfunction, and illustrates how precision medicine may improve diagnosis and therapy in the future.

ATPase4A Autoreactivity and Its Association With Autoimmune Phenotypes in the Type 1 Diabetes Genetics Consortium Study

Autoantibodies targeting the H+/K+-ATPase proton pump of the gastric parietal cell (parietal cell antibodies [PCA]) are diagnostic of atrophic body gastritis (ABG) leading to pernicious anemia (PA). PCA, ABG, and PA occur in increased frequency in patients with type 1 diabetes and their relatives and are considered "minor" components of forms of autoimmune polyglandular syndrome (APS). A customized radioimmunoprecipitation assay was applied to 6,749 samples from the Type 1 Diabetes Genetics Consortium to measure ATP4A autoreactivity. Autoantibody prevalence was correlated with variants in HLA class II, PTPN22, and CTLA4 genes. With an ATP4A radioimmunoprecipitation assay, PCA were detected in sera from 20.9% of affected individuals. PCA prevalence increased with age and was greater in females (25.3%) than males (16.5%) and among Hispanics (36.3%) and blacks (26.2%) compared with non-Hispanic whites (20.8%) and Asians (16.7%). PCA and other organ-specific autoantibodies GAD65, IA-2, thyroid peroxidase (TPO), 21-hydroxylase (21-OH), and transglutaminase (TG) clustered within families with heritability estimates from 71 to 95%. PCA clustered with TPO, 21-OH, and persistent GAD65 autoantibodies but not with celiac (TG) or IA-2 autoantibodies. PCA-positive subjects showed an increased frequency of DRB1*0404, DPB1*0201, and PTPN22 R620W (rs2476601-T) and a decreased frequency of DRB1*0101, DPB1*0301, and CTLA4 CT60 (rs3087243-T). Genetic variants accounted for 4-5% of the heritable risk for PCA. The same alleles were associated with other autoantibody phenotypes in a consistent pattern. Whereas most of the heritable risk for PCA and other antibodies reflects genetic effects that are tissue specific, parietal cell autoimmunity is a major pathogenetic contributor in APS2.

High Frequency of Thyroid Disorders in Patients Presenting With Neutropenia to an Outpatient Hematology Clinic STROBE-Compliant Article

Granulopoiesis abnormalities have been described in association with thyroid disorders (TD). However, data regarding systematic evaluation of adult neutropenia and concurrent or prior TD are scarce. To investigate the frequency of TD among patients presenting with neutropenia, and the immunophenotypic and immunologic profile of neutropenic patients with concomitant thyroidopathy. Two hundred eighteen consecutive neutropenic patients were prospectively evaluated in our outpatient Hematology Clinic, with a detailed laboratory screen, including thyroid function tests, antineutrophil antibodies, blood lymphocytes immunophenotyping, and detection of T-cell clonality by PCR. Among 218 patients with neutropenia, 95 (43.6%) had TD, 65 chronic immunologic neutropenia, 20 clonal proliferation of T-large granular lymphocytes (T-LGL), 5 autoimmune disorders, and 33 other diagnoses. TD-patients had an increased frequency of recurrent infections compared with other patients (P = 0.045). The following correlations were found: negative correlation between FT3 and absolute neutrophil count (ANC) (r² = -0.274, P = 0.007), negative correlation between TPO-Abs/TG-Abs and C4 (r² = -0.16, P = 0.045; r² = -0.266, P = 0.001), and CD4⁺ counts were inversely correlated to T4 and positively to TSH (r² = -0.274, P = 0.024; r² = 0.16, P = 0.045). In addition, TD-patients had significantly higher percentages of CD4⁺ lymphocytes (P = 0.003). Among TD-patients, 23.4% had Hashimoto thyroiditis (HT), 4.1%, Graves disease (GD), 8.2% nontoxic multinodular goiter (NTMG), 5% subclinical hypothyroidism, and 2.8% had undergone total thyroidectomy associated with nodules (TTM). Thirteen TD-patients displayed T-LGL. Patients with autoimmune thyroidopathy had an increased frequency of concomitant autoimmune manifestations (P = 0.03). Significant differences between the different thyroidopathies included: HT-patients had higher percentages of B-lymphocytes, while the opposite was evident for the TTM-subgroup (P = 0.009, 0.02); GD-patients showed an increase of the proportion of NK cells and a decrease in the percentage of TCRγδ+ lymphocytes (P = 0.001, 0.045); and NTMG-patients had significantly higher ANC (P = 0.004) compared to other thyroidopathies. Antineutrophil antibodies were found in 37.2% of TD-patients tested. Anti-TPO titers were significantly higher in patients with positive antineutrophil antibodies (P = 0.04). The frequency of TD among neutropenic patients may be higher than previously reported. The existence of antineutrophil antibodies, as well as the different distribution of lymphocyte subsets among patients with different TD, suggests both humoral and cellular mechanisms in the pathophysiology of thyroid disease-associated neutropenia.

A genetic risk score for thyroid peroxidase antibodies associates with clinical thyroid disease in community-based populations

CONTEXT

Antibodies against thyroid peroxidase (TPOAbs) are detected in 90% of all patients with Hashimoto thyroiditis, the most common cause of hypothyroidism. Hypothyroidism is associated with a range of adverse outcomes. The current knowledge of its genetic underpinnings is limited.

OBJECTIVE

The purpose of this study was to identify novel genetic variants associated with TPOAb concentrations and positivity using genome-wide association data and to characterize their association with thyroid function and disease.

DESIGN, SETTING, AND PARTICIPANTS

We studied European ancestry participants of 3 independent prospective population-based studies: Atherosclerosis Risk In Communities study (n = 7524), Study of Health in Pomerania (n = 3803), and Study of Health in Pomerania-TREND (n = 887).

EXPOSURE

Single nucleotide polymorphisms (SNPs), individually and combined into a genetic risk score (GRS), were examined.

MAIN OUTCOMES

The main outcomes were TPOAb concentrations and positivity, thyroid hormone concentrations (TSH, free T4), and clinical thyroid diseases (subclinical and overt hypothyroidism and goiter).

RESULTS

Significantly associated single nucleotide polymorphisms (P < 5 · 10(-8)) mapped into 4 genomic regions not previously implicated for TPOAbs (RERE, extended HLA region) and into 5 previously described loci. A higher Genetic Risk Score (GRS) based on these 9 SNPs showed strong and graded associations with higher TPOAb, TSH, and lower free T4 concentrations (P < .001). Compared with individuals in the lowest GRS quartile, those in the highest quartile had 1.80-fold higher odds of subclinical hypothyroidism (95% confidence interval, 1.27-2.55) and 1.89-fold higher odds of overt hypothyroidism (95% confidence interval, 1.24-2.87).

CONCLUSION

The identification of 4 novel genetic loci associated with TPOAb concentrations and positivity gives further insight into the genetic underpinnings of hypothyroidism. A GRS showed strong and graded associations with markers of thyroid function and disease in independent population-based studies.

Autoimmune thyroid disorders

Autoimmune thyroid diseases (AITD) result from a dysregulation of the immune system leading to an immune attack on the thyroid. AITD are T cell-mediated organ-specific autoimmune disorders. The prevalence of AITD is estimated to be 5%; however, the prevalence of antithyroid antibodies may be even higher. The AITD comprise two main clinical presentations: Graves' disease (GD) and Hashimoto's thyroiditis (HT), both characterized by lymphocytic infiltration of the thyroid parenchyma. The clinical hallmarks of GD and HT are thyrotoxicosis and hypothyroidism, respectively. The mechanisms that trigger the autoimmune attack to the thyroid are still under investigation. Epidemiological data suggest an interaction among genetic susceptibility and environmental triggers as the key factor leading to the breakdown of tolerance and the development of disease. Recent studies have shown the importance of cytokines and chemokines in the pathogenesis of AT and GD. In thyroid tissue, recruited T helper 1 (Th1) lymphocytes may be responsible for enhanced IFN-γ and TNF-α production, which in turn stimulates CXCL10 (the prototype of the IFN-γ-inducible Th1 chemokines) secretion from the thyroid cells, therefore creating an amplification feedback loop, initiating and perpetuating the autoimmune process. Associations exist between AITD and other organ specific (polyglandular autoimmune syndromes), or systemic autoimmune disorders (Sjögren's syndrome, rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, cryoglobulinemia, sarcoidosis, psoriatic arthritis). Moreover, several studies have shown an association of AITD and papillary thyroid cancer. These data suggest that AITD patients should be accurately monitored for thyroid dysfunctions, the appearance of thyroid nodules, and other autoimmune disorders.

Rheumatologic manifestations in Iranian patients with autoimmune thyroid diseases

BACKGROUND

Autoimmune thyroid diseases (ATDs) are the most common endocrine diseases which result in rheumatologic manifestations. Some studies have shown association between rheumatologic disorders and ATDs. Thus, the aim of this study was to assess the frequency of rheumatologic manifestations in patients with ATDs.

MATERIALS AND METHODS

In this cross-sectional descriptive study during 2010 to 2011, 65 patients with ATDs referred to the Rheumatology clinic of 5 Azar Hospital in Gorgan (North of Iran) were studied via systematic random sampling and patients with positive antithyroid peroxides (anti-TPO) were included in the study. These patients were examined by a rheumatologist for diagnosis of rheumatologic manifestations and tested for serum levels of TSH, Free T3 and T4, Anti-Nuclear Antibodies (ANAs) and Rheumatoid Factor (RF). SPSS software (version 16) and descriptive statistics were used for data analysis.

RESULTS

Nine males (14.8%) and 56 females (86.2%) with mean age of 38.81±1.44 years were studied. Overall, Rheumatologic manifestations were seen in 86.2 % (n=56). In this study, the most frequent rheumatologic manifestations were Carpal Tunnel Syndrome (36.1%) and Osteoarthritis (23%). Reynaud's phenomenon (RP) (10.7%), Discopathy (8.9%), Fibromyalgia (5.3%), Myopathy (3.6%), Rheumatoid arthritis (3.6%) and trigger finger (3.6%) were other manifestations, respectively.

CONCLUSION

In this region, there is a high frequency of rheumatologic manifestations in patients with ATDs. Thus, initial evaluation and regular checkings are recommended.

Serum negative autoimmune thyroiditis displays a milder clinical picture compared with classic Hashimoto's thyroiditis

BACKGROUND

Despite high sensitivity of current assays for autoantibodies to thyroperoxidase (TPO) and to thyroglobulin (Tg), some hypothyroid patients still present with negative tests for circulating anti-thyroid Abs. These patients usually referred to as having seronegative autoimmune thyroiditis (seronegative CAT) have not been characterized, and definite proof that their clinical phenotype is similar to that of patients with classic chronic autoimmune thyroiditis (CAT) is lacking.

OBJECTIVE

To compare the clinical phenotype of seronegative CAT (SN-CAT) and CAT as diagnosed according to a raised serum level of TSH with negative and positive tests for anti-thyroid Abs respectively.

METHODS

A case-control retrospective study enrolling 55 patients with SN-CAT and 110 patients with CAT was performed. Serum free triiodothyronine (FT3), free thyroxine (FT4), TSH, Tg Abs, and TPO Abs were measured in all patients.

RESULTS

Patients with SN-CAT displayed significantly lower mean levels of TSH (6.6±3.4 vs 10.2±9.8 μU/ml; P=0.009), higher mean FT4 levels (1.1±0.2 vs 0.9±0.2 ng/dl; P=0.0002), and similar FT3 levels when compared with CAT patients. Mean thyroid volume was significantly greater in patients with CAT when compared with SN-CAT patients (11.2±6.5 vs 8.1±3.7 ml; P=0.001). Logistic regression demonstrated that FT4 (0.123 (0.019-0.775); (P=0.026)) and thyroid volume (1.243 (1.108-1.394); (P=0.0002)) were significantly and independently related to the diagnosis (CAT/SN-CAT). Patients with SN-CAT had a similar prevalence of thyroid nodules and female gender but a lower prevalence of overt hypothyroidism (5.4 vs 20.9%; P=0.012) as opposed to patients with CAT.

CONCLUSIONS

These results suggest an autoimmune etiology of SN-CAT, which, however, seems to have a milder clinical course when compared with CAT.

Paradigm shifts in thyroid hormone replacement therapies for hypothyroidism

Impaired psychological well-being, depression or anxiety are observed in 5-10% of hypothyroid patients receiving levothyroxine, despite normal TSH levels. Such complaints might hypothetically be related to increased free T₄ and decreased free T₃ serum concentrations, which result in the abnormally low free T₄:free T₃ ratios observed in 30% of patients on levothyroxine. Evidence is mounting that levothyroxine monotherapy cannot assure a euthyroid state in all tissues simultaneously, and that normal serum TSH levels in patients receiving levothyroxine reflect pituitary euthyroidism alone. Levothyroxine plus liothyronine combination therapy is gaining in popularity; although the evidence suggests it is generally not superior to levothyroxine monotherapy, in some of the 14 published trials this combination was definitely preferred by patients and associated with improved metabolic profiles. Disappointing results with combination therapy could be related to use of inappropriate levothyroxine and liothyronine doses, resulting in abnormal serum free T₄:free T₃ ratios. Alternatively, its potential benefit might be confined to patients with specific genetic polymorphisms in thyroid hormone transporters and deiodinases that affect the intracellular levels of T₃ available for binding to T₃ receptors. Levothyroxine monotherapy remains the standard treatment for hypothyroidism. However, in selected patients, new guidelines suggest that experimental combination therapy might be considered.

Identification of novel genetic Loci associated with thyroid peroxidase antibodies and clinical thyroid disease

Autoimmune thyroid diseases (AITD) are common, affecting 2-5% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto's thyroiditis), as well as autoimmune hyperthyroidism (Graves' disease). As the possible causative genes of TPOAbs and AITD remain largely unknown, we performed GWAS meta-analyses in 18,297 individuals for TPOAb-positivity (1769 TPOAb-positives and 16,528 TPOAb-negatives) and in 12,353 individuals for TPOAb serum levels, with replication in 8,990 individuals. Significant associations (P<5×10(-8)) were detected at TPO-rs11675434, ATXN2-rs653178, and BACH2-rs10944479 for TPOAb-positivity, and at TPO-rs11675434, MAGI3-rs1230666, and KALRN-rs2010099 for TPOAb levels. Individual and combined effects (genetic risk scores) of these variants on (subclinical) hypo- and hyperthyroidism, goiter and thyroid cancer were studied. Individuals with a high genetic risk score had, besides an increased risk of TPOAb-positivity (OR: 2.18, 95% CI 1.68-2.81, P = 8.1×10(-8)), a higher risk of increased thyroid-stimulating hormone levels (OR: 1.51, 95% CI 1.26-1.82, P = 2.9×10(-6)), as well as a decreased risk of goiter (OR: 0.77, 95% CI 0.66-0.89, P = 6.5×10(-4)). The MAGI3 and BACH2 variants were associated with an increased risk of hyperthyroidism, which was replicated in an independent cohort of patients with Graves' disease (OR: 1.37, 95% CI 1.22-1.54, P = 1.2×10(-7) and OR: 1.25, 95% CI 1.12-1.39, P = 6.2×10(-5)). The MAGI3 variant was also associated with an increased risk of hypothyroidism (OR: 1.57, 95% CI 1.18-2.10, P = 1.9×10(-3)). This first GWAS meta-analysis for TPOAbs identified five newly associated loci, three of which were also associated with clinical thyroid disease. With these markers we identified a large subgroup in the general population with a substantially increased risk of TPOAbs. The results provide insight into why individuals with thyroid autoimmunity do or do not eventually develop thyroid disease, and these markers may therefore predict which TPOAb-positives are particularly at risk of developing clinical thyroid dysfunction.

Achalasia and thyroid disease: possible autoimmune connection?

Many cases have been published showing a co-existence of autoimmune thyroid diseases (AITDs) and other autoimmune diseases. About a quarter of patients with achalasia have a concurrent thyroid disease, most commonly associated with hypothyroidism. Although relatively rare, the association of achalasia and hyperthyroidism requires attention. The physiopathology of Grave's Disease (GD) involves B- and T-mediator lymphocytes, which have an affinity for known thyroid antigens: thyroglobulin, thyroid-peroxidase, and thyrotrophin receptor. Currently, however, the real physiopathogenesis of achalasia continues to be unknown. Some important findings are suggestive of an autoimmune mechanism: significant infiltration of the myoenteric plexus by monocytes, presence of the class II-Human Histocompatibility Complex DQwl antigen and antibodies to myoenteric neurons. The present case reports a patient who, despite testing negative for Chagas' disease, had achalasia, progressed to developing significant wasting and worsening of his quality of life, was later diagnosed with hyperthyroidism. After endoscopic esophageal dilatation and radioiodine ablation of the thyroid gland, there was great improvement in the patient clinical condition.

The differences in T and B cell subsets in thyroid of children with Graves' disease and Hashimoto's thyroiditis

BACKGROUND

The differences between Graves' disease (GD) and Hashimoto's thyroiditis (HT) suggest that changes in the subsets of T cells may have an influence on the course of these reactions.

METHODS

This study included 90 children: 30 with GD, 30 with HT, and 30 healthy children as controls. After thyroidectomy, standard histological examinations and immunohistochemical reactions were performed in paraffin specimens with monoclonal antibodies against T cell markers CD3, CD4, CD8 as well as against CD79 alpha B cells. Ultrathin sections were examined under a transmission electron microscope.

RESULTS

Autoimmune reaction in GD consisted of an increased number of CD4+ T cells (3.17±4.27%) and plasma cells (22.89±8.61%) producing thyroidstimulating hormone-receptors and stimulating thyrocytes to activity. The number of CD8+ T cells was increased in children with HT (20.54±0.68%) as compared with the controls (0.65±0.30%). The autoimmune reaction in the HT children showed antibody dependent cytotoxicity with a low number of CD4+ T cells and an increased number of CD8+ T cells in the thyroid tissue in comparison with that in the GD children and the controls. Plasma cells (31.65±9.11%) in this situation produced the antibodies involved in cytotoxic reactions against thyrocytes.

CONCLUSIONS

Graves' disease is characterized by the increased number of CD4+ T cells and CD8+ T cells. Hashimoto's thyroiditis is characterized by the low number of CD4+ T cells and increased number of CD8+ T cells. CD8+ T cells have cytotoxic properties only in Hashimoto's thyroiditis.

2012 ETA Guidelines: The Use of L-T4 + L-T3 in the Treatment of Hypothyroidism

BACKGROUND

Data suggest symptoms of hypothyroidism persist in 5-10% of levothyroxine (L-T4)-treated hypothyroid patients with normal serum thyrotrophin (TSH). The use of L-T4 + liothyronine (L-T3) combination therapy in such patients is controversial. The ETA nominated a task force to review the topic and formulate guidelines in this area.

METHODS

Task force members developed a list of relevant topics. Recommendations on each topic are based on a systematic literature search, discussions within the task force, and comments from the European Thyroid Association (ETA) membership at large.

RESULTS

SUGGESTED EXPLANATIONS FOR PERSISTING SYMPTOMS INCLUDE: awareness of a chronic disease, presence of associated autoimmune diseases, thyroid autoimmunity per se, and inadequacy of L-T4 treatment to restore physiological thyroxine (T4) and triiodothyronine (T3) concentrations in serum and tissues. There is insufficient evidence that L-T4 + L-T3 combination therapy is better than L-T4 monotherapy, and it is recommended that L-T4 monotherapy remains the standard treatment of hypothyroidism. L-T4 + L-T3 combination therapy might be considered as an experimental approach in compliant L-T4-treated hypothyroid patients who have persistent complaints despite serum TSH values within the reference range, provided they have previously received support to deal with the chronic nature of their disease, and associated autoimmune diseases have been excluded. Treatment should only be instituted by accredited internists/endocrinologists, and discontinued if no improvement is experienced after 3 months. It is suggested to start combination therapy in an L-T4/L-T3 dose ratio between 13:1 and 20:1 by weight (L-T4 once daily, and the daily L-T3 dose in two doses). Currently available combined preparations all have an L-T4/L-T3 dose ratio of less than 13:1, and are not recommended. Close monitoring is indicated, aiming not only to normalize serum TSH and free T4 but also normal serum free T4/free T3 ratios. Suggestions are made for further research.

CONCLUSION

L-T4 + L-T3 combination therapy should be considered solely as an experimental treatment modality. The present guidelines are offered to enhance its safety and to counter its indiscriminate use.

Autoimmune thyroid disease

PURPOSE OF REVIEW

Autoimmune thyroid disorders (AITDs) are the most common organ-specific autoimmune disorders. The genetics as well as clinical and laboratory manifestations of AITDs are reviewed.

RECENT FINDINGS

We discuss the association between specific rheumatologic disorders and AITDs and manifestations of AITDs that mimic rheumatologic disorders. The recently discovered common molecular pathways involved in these processes are discussed.

SUMMARY

AITDs and rheumatologic disorders have significant commonalities both clinically and etiologically. This information is important for rheumatologists and primary care physicians who care for patients with these disorders.