Incidence of thyroid disorders in systemic sclerosis: results from a longitudinal follow-up

Negative causal exploration of systemic sclerosis: a Mendelian randomization analysis

Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune-related connective tissue disease with a complex and unknown pathophysiological mechanism with genes association. Several articles have reported a high prevalence of thyroid disease in SSc patients, while one study suggested a potential contribution of appendicitis to the development of SSc. To investigate this causal association, we conducted Mendelian randomization (MR) analysis using instrumental variables (IVs) to assess exposure and outcome. In the MR study involving two cohorts, all analyses were conducted using the TwoSampleMR package in R (version 4.3.0). Single nucleotide polymorphisms (SNPs) meeting a statistically significant threshold of 5E-08 were included in the analysis. Multiple complementary approaches including MR-IVW, MR-Egger, weighted median, simple mode, and weighted mode were employed to estimated the relationship between the exposure and outcome. Leave-one-out analysis and scatter plots were utilized for further investigation. Based on the locus-wide significance level, all of the MR analysis consequences manifested no causal association between the risk of appendicitis with SSc (IVW OR 0.319, 95% CI 0.063-14.055, P = 0.966). Negative causal effects of autoimmune thyroiditis (AT) on SSc (IVW OR 0.131, 95% CI 0.816-1.362, P = 0.686), Graves' disease (GD) on SSc (IVW OR 0.097, 95% CI 0.837-1.222, P = 0.908), and hypothyroidism on SSc (IVW OR 1.136, 95% CI 0.977-1.321, P = 0.096) were derived. The reverse MR revealed no significant causal effect of SSc on thyroid disease. According to the sensitivity analysis, horizontal pleiotropy was unlikely to distort the causal estimates. The consequences indicated no significant association between AT, GD, and hypothyroidism with SSc. Similarly, there was no observed relationship with appendicitis.

Thyroid Disorders in Systemic Sclerosis: A Comprehensive Review

Systemic sclerosis, also referred to as scleroderma, is a chronic autoimmune disease that affects both internal organs and the skin. Systemic sclerosis predominantly affects female patients and can coexist with other disorders, including those affecting the thyroid gland. Common symptoms such as fatigue and weight changes can be attributed to either systemic sclerosis or thyroid disease. In this comprehensive review, an extensive analysis is conducted using research from 2002 to 2022, sourced from PubMed. The main focus of this exploration is to understand the intricate relationship between thyroid disorders and systemic sclerosis. We obtained these results by analyzing a number of 32285 patients included in 21 original studies. The existing evidence suggests that there is a higher incidence of elevated TSH levels and hypothyroidism in patients with systemic sclerosis, particularly in females, compared to the general population. This remains true even when comparing patients from iodine-deficient regions. Additionally, there is an increased occurrence of hyperthyroidism in the context of systemic sclerosis, which negatively impacts the prognosis of these patients. Furthermore, thyroid antibodies, predominantly anti-thyroid peroxidase (anti-TPO) antibodies, and autoimmune disorders are more commonly observed in individuals with systemic sclerosis. Although thyroid nodules are not specifically linked to the disease, when considering thyroid volume, it is observed that the thyroid gland in systemic sclerosis patients has a decreased volume, possibly due to fibrosis. Conversely, other studies have revealed that patients without autoimmune thyroid diseases (AITDs) are more likely to have a history of digital ulcers, pulmonary fibrosis detected by computed tomography scan, and a requirement for immunosuppressive medication. The majority of the studies did not establish a connection between thyroid disease in these patients and the occurrence of the limited or diffuse forms of systemic sclerosis, as well as the presence of digital ulcers, calcinosis, pulmonary arterial hypertension, scleroderma renal crisis, Raynaud phenomenon, and various other clinical manifestations.

[Autoimmune and inflammatory pathologies associated with systemic scleroderma: Clinical, serological and prognostic profiles. Bi-centric retrospective series in the PACA region]

INTRODUCTION

Systemic sclerosis (SSc) is a rare auto-immune disease, affecting principally women between 40 and 60 years old. It is caracterised by a cutaneous and visceral fibrosis, an alteration of the microvascular network and the presence of autoantibodies. SSc can be associated with another connectivite tissue disease or to other autoimmune diseases, thus defining the overlap syndrome. The goal of our study is to describe these overlap syndromes.

METHODS

We have analysed the data of a retrospective and bicentrique cohort, from the internal medicine unit of Hôpital Nord in Marseille and from the internal medicine unit of the Hôpital Sainte-Anne in Toulon, of patients followed for a SSc between January 1st, 2019 and December 1st, 2021. We have collected clinical, imunological features, associated auto-immune and inflammatory diseases with its morbidity and mortality.

RESULTS

The cohort included 151 patients including 134 limited cutaneous SSc. Fifty-two (34.4%) patients presented at least one associated auto-immune or inflammatory disease. The association of two connectivite tissue diseases including SSc was found in 24 patients (15.9%), a third with Sjögren's syndrome and a third with autoimmune myositis. The principal associated disease to SSc was the autoimmune thyroiditis found in 17 patients (11.3%). The occurrence of complications (hospitalization, long-term oxygene therapy, death) was not significantly different depending on the existence or not of an overlap syndrom.

CONCLUSION

SSc is often associated with other autoimmune diseases. This interrelation between associated pathologies and SSc, modifying sometimes the evolution of SSc, enhances the need of a personalized follow-up.

An Assessment of Thyroid Dysfunction and Related Parameters in Patients With Systemic Autoimmune Disorders

Background and objective Systemic autoimmune disorders involve abnormal immune responses leading to tissue damage. Dysfunction of the thyroid gland due to autoimmune mechanisms is common in such disorders, which can cause either hypofunctioning or hyperfunctioning of the gland. This study aimed to investigate the prevalence of thyroid dysfunction among patients with various systemic autoimmune disorders. Material and methods This cross-sectional observational study included 110 adult patients either diagnosed with or having clinical/biological features of systemic autoimmune diseases. The patients underwent a detailed clinical history assessment, physical examination, and necessary investigations. Data were analyzed using IBM SPSS Statistics for Windows, Version 26.0. (IBM Corp., Armonk, NY). Results Among the 110 autoimmune disorder patients, 22.7% had thyroid dysfunction, specifically hypothyroidism, while 77.3% were euthyroid. Hypothyroidism was prevalent among patients with rheumatoid arthritis (RA, 20.3%), systemic sclerosis (SSc, 20%), ankylosing spondylitis (AS, 15.8%), and systemic lupus erythematosus (SLE, 54.5%). Moreover, 60% of patients were anemic, and the prevalence of anemia was higher among female patients and younger individuals. Conclusions This study showed a higher prevalence of thyroid dysfunction, particularly hypothyroidism, in patients with systemic autoimmune disorders. Female patients and younger individuals were more susceptible to autoimmune disorders, thyroid dysfunction, and anemia. These findings highlight the need for simultaneous screening and evaluation for thyroid dysfunction and anemia in systemic autoimmune disease patients, particularly in female patients and those of younger age groups.

The prevalence and clinical features associated of hypothyroidism among Thai systemic sclerosis patients

Thyroid disease, particularly hypothyroidism, has been reported in systemic sclerosis (SSc). Some clinical features of SSc can also present in hypothyroidism. Our aims were to determine the prevalence of, and describe clinical features associated with, hypothyroidism in SSc patients. We conducted a historical cohort study of adult SSc patients who underwent screening thyroid function tests at the Scleroderma Clinic, Khon Kaen University, Thailand, between 2009 and 2018. The patients who had any thyroid disorders before the onset of SSc and were diagnosed as an overlap syndrome were excluded. A total of 200 SSc were included according to sample size calculation, among whom the female to male ratio was 2:1. The majority of cases (137; 69.5%) were diffuse cutaneous SSc subset. The mean age was 55.8 ± 10.7 years and the median duration of disease 4.9 (IQR 1.6–9.9) years. Of the total, 9 had primary hypothyroidism (prevalence 4.5%; 95%CI 2.1–8.4) and 22 had subclinical hypothyroidism (prevalence 11%; 95%CI 7.0–16.2). Of the latter 22, 71% had dcSSc. Logistic regression analysis indicated that unexplained anemia was significantly associated with either subclinical hypothyroid or hypothyroidism (OR 2.74; 95% CI 1.17–6.47), whereas Raynaud’s phenomenon had a negative association (OR 0.28; 95% CI 0.11–0.66). Neither severity of skin tightness nor internal organ involvement were associated with hypothyroidism among SSc patients. Clinical-subclinical hypothyroidism is uncommon among SSc patients, it is frequently associated with anemia, and less so Raynaud’s phenomenon. Clinical-subclinical hypothyroidism should thus be considered in cases of unexplained anemia in SSc patients.

The aggregation between AITD with rheumatologic, or dermatologic, autoimmune diseases

Autoimmune thyroid diseases (AITD) are organ-specific autoimmune disorders mediated by Th1 lymphocytes, whose main clinical presentations are Hashimoto's thyroiditis (HT), or Graves' disease (GD). HT, GD, thyroid autoantibodies and thyroid dysfunctions have been shown in systemic rheumatologic diseases (as Sjögren's syndrome, systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, or cryoglobulinemia). New associations of AITD with other autoimmune diseases are being discovered, for example with psoriatic arthritis and dermatological diseases. Several investigations suggest the importance of a shared genetic susceptibility and of environmental factors in patients with AITD and associated systemic autoimmunity. A major Th1 autoimmune response occurs in the initial, and/or active phases of organ-specific autoimmune disorders and/or systemic rheumatologic diseases with increased serum, or tissue, expressions of the Th1 chemokine CXCL10. Thyroid dysfunctions might have an important clinical impact, so a periodic thyroid screening in women with systemic or dermatological autoimmunity, overall in presence of thyroid autoantibodies is suggested.

High Prevalence of Antithyroid Antibodies in a New Zealand Cohort of Patients With Systemic Sclerosis

BACKGROUND

Autoimmune thyroid disease affects 1% of the general population, and autoimmune thyroid antibodies are noted in up to 15%.

OBJECTIVE

We hypothesized systemic sclerosis (SSc) is associated with higher prevalence of antithyroglobulin (anti-Tg) and anti-thyroid peroxidase (anti-TPO) antibodies) to justify monitoring of thyroid function for earlier detection and treatment.

METHODS

Waikato Hospital SSc clinic patients were prospectively tested for thyroid function tests and antithyroid antibodies (ATAs).

RESULTS

Of the 75 patients with SSc and 10 patients with SSc overlap syndrome (SOS) followed up in the SSc clinic, anti-Tg and anti-TPO were prospectively tested in 61 (70.6%) of the 85 patients. The cohort comprised 38 patients with limited cutaneous SSc (lcSSc), 15 with diffuse cutaneous SSc, and 8 with SOS.Anti-Tg and anti-TPO antibodies were found in 34.2% in lcSSc patients and 33.3% in diffuse cutaneous SSc patients, whereas in SOS they were found in 25% (Tg) and in 12.5% (TPO) of patients.At baseline, 10 patients (11.7%) had thyroid dysfunction: 8 (9.4%) with subclinical hypothyroidism and 1 each (1.2%) with subclinical hyperthyroidism and with clinical hyperthyroidism.After 18 months, 1 woman with lcSSc, positive for both ATAs, developed clinical hypothyroidism.

CONCLUSIONS

There is a higher prevalence of ATAs in SSc and SOS compared with the general population. Screening these patients for ATAs is a reasonable measure.

CD32b expression is down-regulated on double-negative memory B cells in patients with Hashimoto's thyroiditis

Inhibitory CD32b receptors on B cells are critical for humoral immunity. The humoral response plays a role in the pathogenesis of Hashimoto's thyroiditis (HT). This study aimed to investigate B cell subset distribution and CD32b expression within these subsets in HT patients. B cell subset distribution and CD32b expression were analyzed in 60 HT patients and 21 healthy donors. Subset distribution and CD32b expression following stimulation with α-Ig and α-CD40 were also assessed. The percentage of double-negative (DN) memory cells was increased in the HT patients, while the expression level of CD32b on DN memory cells was decreased. Redistribution of B cell subsets was detected in response to stimulation with α-Ig. In addition, the expression level of CD32b was reduced following α-CD40 stimulation. These results suggest that abnormal B cell subset distribution and decreased CD32b expression on DN memory cells might be involved in the pathogenesis of HT.

Associations between Systemic Sclerosis and Thyroid Diseases

We have reviewed scientific literature about the association of systemic sclerosis (SSc) and thyroid disorders. A high incidence, and prevalence, of new cases of autoimmune thyroiditis (AT) and/or hypothyroidism have been shown in sclerodermic patients (overall in the female gender). An association among a Th1 immune-predominance, low vitamin D levels, and AT have been also shown in SSc patients. Cases of Graves' disease (GD) have been described in SSc patients, too, according with the higher prevalence of thyroid autoimmunity. It has been also shown a higher prevalence of papillary thyroid cancer (PTC), in association with AT, in SSc patients. However, in order to confirm results about GD and thyroid cancer, studies in larger number of patients with SSc are needed. During the follow-up of SSc patients it would be appropriate to monitor carefully their thyroid status. The abovementioned data strongly suggest a periodic thyroid function follow-up in female SSc patients [showing a borderline high (although in the normal range) thyroid-stimulating hormone level, antithyroid peroxidase antibody positivity, and a small thyroid with a hypoechoic pattern], and, when necessary, appropriate treatments. In conclusion, most of the studies show an association among SSc, AT, and hypothyroidism, such as an increased prevalence of TC overall in SSc patients with AT. Only few cases of GD have been also described in SSc.

Connective tissue diseases and autoimmune thyroid disorders in the first trimester of pregnancy

OBJECTIVE

To investigate the rates and coexistence of autoimmune thyroid and connective tissue diseases (CTD) during the first trimester of pregnancy and their influence on pregnancy outcome.

STUDY DESIGN

A cohort study of 150 women with CTD diagnosed during first trimester of pregnancy and 150 negative controls.

MAIN OUTCOME MEASURES

Screening of CTD by a self-reported questionnaire, rheumatic and thyroid autoantibody detection, clinical rheumatological evaluation and obstetric outcomes.

RESULTS

Out of 3852 women screened, 61 (1.6%) were diagnosed with undefined connective tissue disease (UCTD), 28 (0.7%) with major CTD (six rheumatoid arthritis, five systemic lupus erythematosus, eight Sjogren syndrome, five anti-phospholipid syndrome, two systemic sclerosis, one mixed CTD and one monoarticular arthritis) and 61 (1.6%) had insufficient criteria for a diagnosis of a rheumatic disease. The overall prevalence of either thyroid peroxidase (TPO-a) or thyroglobulin (TG-a) autoantibodies detection was 8% (12/150) among controls, 62.3% (38/61) among UCTD and 60.7% (17/28) in women with a major CTD (p<.001 compared to controls for both comparisons). After adjustment for confounders, overall CTDs (major or undefined) (OR=3.54, 95% CI; 1.61-7.78) and TPO-a plus TG-a positivity (OR=2.78, 95% CI;1.29-5.98) were independently associated with increased risks of moderate-severe complications of pregnancy (miscarriage, fetal growth restriction, preeclampsia, delivery before 34 weeks).

CONCLUSIONS

Rheumatic and thyroid autoantibodies during pregnancy are closely associated. Thyroid antibodies could add to the risk of adverse pregnancy outcome associated with connective tissue diseases.

Can thyroid volume predict thyroid dysfunction in patients with systemic sclerosis? A prospective cross-sectional study from a tertiary care center in North West India

Previous studies have documented an association between thyroid dysfunction, predominant hypothyroidism, and antibody positivity in patients with systemic sclerosis (SSc). There are no studies reporting the relationship between thyroid volume and thyroid functions in patients with SSc. This study was conducted to correlate thyroid dysfunction with thyroid volume as measured on ultrasound and antibody positivity. Complete thyroid workup was done in 106 patients of SSc which included thyroid function test, antithyroid peroxidase (TPO) antibody, antithyroid-stimulating hormone receptor (TSHR) antibody, antithyroglobulin antibody, and thyroid ultrasound to assess thyroid volume, echogenicity and blood flow, and fine needle aspiration cytology of suspicious thyroid lesions. Prevalence of subclinical hypothyroidism was 8.5 %, overt hypothyroidism 1.9 %, subclinical hyperthyroidism 2.8 %, and overt hyperthyroidism in 0.9 % of the patients. Antithyroid peroxidase antibody was positive in 16 %, anti-TSH receptor antibody in 5.7 %, and antithyroglobulin antibody in none of the patients. Thyroid volume was in the range of atrophy (<4.5 ml) in 57.5 % patients, echogenicity altered in 15.1 %, and blood flow increased in 15.1 %. Thyroid volume correlated strongly with the pulmonary function test (FEV1). Routine thyroid ultrasound and thyroid function tests may be included in the workup of patients with SSc for the early detection of hypothyroidism since a small but significant percentage of patients developed thyroid dysfunction. Antithyroid antibodies may not correlate with the thyroid functions and hence should not be recommended.

Skin fibrosis correlates with circulating thyrotropin levels in systemic sclerosis: translational association with Hashimoto's thyroiditis

Systemic sclerosis (SSc) is a connective tissue disease, characterized by cutaneous and multi-organ fibrosis, and vascular abnormalities. Skin thickening is a characteristic feature of SSc and resembles myxedematous skin. Our aim was to correlate the degree of skin involvement in SSc patients with serum TSH levels, since TSH receptors are widely expressed in human tissues, including the skin. In this cross-sectional study, we enrolled 70 SSc patients, all females with a mean age of 47 ± 11 year. Thirty-five age- and sex-matched HT patients were recruited, as controls. Subjects under L-thyroxine therapy and/or with positive anti-TSH receptor antibodies were excluded. In all subjects, we measured serum TSH, FT4, and free tri-iodothyronine (FT3) levels. Skin thickness was evaluated using the modified Rodnan total skin score (mRSS). mRSS averaged 14 ± 9 for SSc and 4 ± 6 for HT patients. TSH levels positively correlated with skin scores in both SSc and HT patients groups. In SSc patients, FT3 and FT4 showed an inverse correlation with mRSS, while in HT only FT4 levels showed this inverse significance. When divided by cutaneous extent, SSc patients with diffuse disease form had higher TSH serum levels compared to those with the limited form; additionally, the correlations between TSH, FT4, and mRSS reached statistical significance. Our preliminary data clearly indicate that serum TSH is higher in SSc patients with more severe skin disease, and significantly correlate with the mRSS. Therefore, TSH could play a role in the development of cutaneous changes in SSc patients.

Increased risk of papillary thyroid cancer in systemic sclerosis associated with autoimmune thyroiditis

OBJECTIVES

Patients with SSc have an increased risk of malignancy compared with the general population. Before now, no study has evaluated the risk of thyroid cancer (TC) in SSc patients. The aim of the study was to evaluate the prevalence of TC in SSc patients.

METHODS

We studied the prevalence of TC in 327 unselected SSc patients in comparison with two population-based, gender- and age-matched control groups (654 subjects from an iodine-deficient area and 654 subjects from an iodine-sufficient area). Thyroid status was assessed by measurement of circulating thyroid hormones and autoantibodies, thyroid ultrasonography and fine-needle aspiration cytology (when necessary).

RESULTS

Circulating thyroid-stimulating hormone, anti-thyroglobulin and anti-thyroperoxidase antibody levels, and the prevalence of hypothyroidism were significantly higher in SSc patients (P < 0.01, for all). Six patients with papillary TC (PTC) were detected among SSc patients, whereas only one case was observed in each of controls 1 and 2 (P = 0.007, for both). In SSc all patients with TC had evidence of thyroid autoimmunity vs 40% of the other SSc patients (P = 0.001).

CONCLUSION

These data suggest a high prevalence of papillary TC in SSc patients, in particular in the presence of thyroid autoimmunity; careful thyroid monitoring would be opportune during the follow-up of these patients.

Demographic and clinical features of autoimmune thyroid disorder in Japanese patients with systemic sclerosis

Autoimmune thyroid disorders (AITD) are characterized by the impairment of the thyroid gland as a result of systemic or organ-specific autoimmune disorders, and the presence of antithyroid autoantibodies, such as antithyroglobulin antibody (AbTg) and antithyroid peroxidase antibody (AbTPO). Several studies have reported the association of AITD with systemic sclerosis (SSc). However, none of those studies analyzed the association between AITD and skin sclerosis in SSc patients. The aim of this study was to examine the demographic and clinical features of SSc patients with AITD treated in our department. Of a total of 210 SSc patients, we identified 30 with AITD (14.3%), including 29 with Hashimoto's disease (13.8%) and one patient with Graves' disease (0.5%), indicating that hypothyroidism was more common among SSc patients with AITD. All patients with AITD were female, and anticentromere antibody positivity, the complication of Sjögren's syndrome, severe facial skin sclerosis and atrophy of the thyroid gland were significantly prevalent in SSc patients with AITD. SSc patients with such clinical features may be at high risk of AITD and require regular follow up of thyroid function including ultrasonography and the examination of serum hormone levels to start an early treatment.

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.