Clinically relevant thyroid disorders and inflammatory bowel disease are inversely related: a retrospective case-control study

OBJECTIVES

The risk of thyroid disorders (TDs) in inflammatory bowel disease (IBD) is still controversial. The aim of this retrospective, single-center, case-control study was to explore the association between clinically relevant functional TDs and IBD.

METHODS

Consecutive individuals for a total of 313 IBD patients [90 Crohn's disease (CD); 223 ulcerative colitis (UC)], and 833 individuals undergoing colonoscopy for screening without IBD were collected. In the study, subject's information on thyroid status were retrieved. Thyroid disorders were classified, according to the functional status, as hypothyroidism or hyperthyroidism. Patients with TDs (cases) were compared with 941 without (controls) according to IBD exposure. Unadjusted and adjusted odds ratios (ORs) and their 95% confidence interval (CI) were calculated.

RESULTS

Clinically relevant TDs were detected in 205 (17,9%) patients and the prevalence was significantly lower in IBD patients compared with subjects without (8.3% vs 12.9%; p = 0.029). After adjusting for potential confounders, a higher TDs risk was confirmed in female (OR 2.72; 95%CI 1.88‒3.92) and older subjects (OR 1.01; 95%CI 1.00‒1.03), and a lower risk in IBD (OR 0.51; 95%CI 0.34‒0.76), especially for hypothyroidism (OR 0.33; 95%CI 0.17‒0.66) in UC. Among four thyroid cancers, only one was detected in IBD patients.

CONCLUSIONS

Overall, in our study, the risk of TDs was lower in IBD patients. To assess routinely hormones and/or thyroid gland imaging in the absence of clinical signs or symptoms seems unnecessary in IBD patients, at least in our geographic area.

Infliximab Therapy Could Decrease the Risk of the Development of Thyroid Disorders in Pediatric Patients With Crohn's Disease

Autoimmune diseases, including autoimmune thyroid diseases (AITDs), may be associated with Crohn's disease (CD). Taking into consideration the role of tumor necrosis factor alpha (TNF-alpha) in the immune-mediated inflammation that underlies both diseases, we evaluated an ultrasound of thyroid gland in pediatric CD patients, naïve, and treated with infliximab (IFX), an anti-TNF-alpha antibody, to assess the risk for AITD and evaluated the usefulness of ultrasonography to diagnose AITD in patients with CD. Sixty-one patients with CD were enrolled in the study, including 36 patients (mean age 14.5 ± 3.5 years) treated with IFX (IFX group) for a mean of 13.9 ± 16.6 months and 25 patients (mean age 14.7 ± 2.3 years) who never received anti-TNF-alpha therapy (control group). An ultrasound examination of the thyroid gland was performed; thyroid function tests and thyroid antibodies were assessed. We found 10-times higher prevalence of decreased thyroid echogenicity in CD and IFX-naive patients compared to IFX-treated group [a significant reduction in thyroid echogenicity in 1/36 (2.8%) patients receiving IFX compared to 7/25 (28%) patients naive to biologic therapy]. The latter showed significantly lower thyroid-stimulating hormone (TSH) levels (p = 0.034) and higher levels of thyroid antibodies (p = 0.042) in comparison to control. Our data suggest the protective role of IFX therapy in the development of thyroid disorders and indicate the usefulness of thyroid ultrasound to identify the risk of probable AITD in pediatric patients with CD.

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.

Thyroid Hormone Receptor Alpha Mutations Lead to Epithelial Defects in the Adult Intestine in a Mouse Model of Resistance to Thyroid Hormone

BACKGROUND

The thyroid hormone triiodothyronine (T3) is critical for vertebrate development and affects the function of many adult tissues and organs. Its genomic effects are mediated by thyroid hormone nuclear receptors (TRs) present in all vertebrates. The discovery of patients with resistance to thyroid hormone (RTHβ) >50 years ago and subsequent identification of genetic mutations in only the THRB gene in these patients suggest that mutations in the THRA gene may have different pathological manifestations in humans. Indeed, the recent discovery of a number of human patients carrying heterozygous mutations in the THRA gene (RTHα) revealed a distinct phenotype that was not observed in RTH patients with THRB gene mutations (RTHβ). That is, RTHα patients have constipation, implicating intestinal defects caused by THRA gene mutations.

METHODS

To determine how TRα1 mutations affect the intestine, this study analyzed a mutant mouse expressing a strong dominantly negative TRα1 mutant (denoted TRα1PV; Thra1^PV mice). This mutant mouse faithfully reproduces RTHα phenotypes observed in patients.

RESULTS

In adult Thra1^PV/+ mice, constipation was observed just like in patients with TRα mutations. Importantly, significant intestinal defects were discovered, including shorter villi and increased differentiated cells in the crypt, accompanied by reduced stem-cell proliferation in the intestine.

CONCLUSIONS

The findings suggest that further analysis of this mouse model should help to reveal the molecular and physiological defects in the intestine caused by TRα mutations and to determine the underlying mechanisms.

Involvement of epigenetic modifications in thyroid hormone-dependent formation of adult intestinal stem cells during amphibian metamorphosis

Amphibian metamorphosis has long been used as model to study postembryonic development in vertebrates, a period around birth in mammals when many organs/tissues mature into their adult forms and is characterized by peak levels of plasma thyroid hormone (T3). Of particular interest is the remodeling of the intestine during metamorphosis. In the highly-related anurans Xenopus laevis and Xenopus tropicalis, this remodeling process involves larval epithelial cell death and de novo formation of adult stem cells via dedifferentiation of some larval cells under the induction of T3, making it a valuable system to investigate how adult organ-specific stem cells are formed during vertebrate development. Here, we will review some studies by us and others on how T3 regulates the formation of the intestinal stem cells during metamorphosis. We will highlight the involvement of nucleosome removal and a positive feedback mechanism involving the histone methyltransferases in gene regulation by T3 receptor (TR) during this process.

Thyroid hormone regulation of adult intestinal stem cells: Implications on intestinal development and homeostasis

Organ-specific adult stem cells are essential for organ homeostasis, tissue repair and regeneration. The formation of such stem cells often takes place during postembryonic development, a period around birth in mammals when plasma thyroid hormone concentration is high. The life-long self-renewal of the intestinal epithelium has made mammalian intestine a valuable model to study the function and regulation and adult stem cells. On the other hand, much less is known about how the adult intestinal stem cells are formed during vertebrate development. Here, we will review some recent progresses on this subject, focusing mainly on the formation of the adult intestine during Xenopus metamorphosis. We will discuss the role of thyroid hormone signaling pathway in the process and potential molecular conservations between amphibians and mammals as well as the implications in organ homeostasis and human diseases.

Concomitant Thyroid Disorders and Inflammatory Bowel Disease: A Literature Review

The aim of this report was to review and summarize the literature on cases of concomitant inflammatory bowel disease (IBD) and thyroid diseases. We included the following previous case reports of concomitant IBD and thyroid diseases: 16 cases of ulcerative colitis (UC) and Graves' disease (GD), 3 cases of Crohn's disease (CD) and GD, 10 cases of CD and Hashimoto's thyroiditis (HT), 4 cases of IBD and subacute thyroiditis (SAT) or SAT-like symptoms, and 13 cases of IBD (12/13 cases were CD) and amyloid goiter. There might be no obvious differences of prevalence of thyroid dysfunction (hyper- or hypothyroidism), GD, and thyroid cancer between IBD patients and general populations. However, concomitant UC and HT might be relatively common in patients with multiple autoimmune disorders, and AG is one of the complications with CD patients. There might be no obvious differences of fatal prognoses between IBD patients with thyroid diseases and patients with thyroid diseases without IBD.

Thyroid disorders and gastrointestinal and liver dysfunction: A state of the art review

Thyroid disorders commonly impact on the gastrointestinal system and may even present with gastrointestinal symptoms in isolation; for example, metastatic medullary thyroid carcinoma typically presents with diarrhoea. Delays in identifying and treating the underlying thyroid dysfunction may lead to unnecessary investigations and treatment, with ongoing morbidity, and can potentially be life-threatening. Similarly, gastrointestinal diseases can impact on thyroid function tests, and an awareness of the concept and management of non-thyroidal illness is necessary to avoid giving unnecessary thyroid therapies that could potentially exacerbate the underlying gastrointestinal disease. Dual thyroid and gastrointestinal pathologies are also common, with presentations occurring concurrently or sequentially, the latter after a variable time lag that can even extend over decades. Such an association aetiologically relates to the autoimmune background of many thyroid disorders (e.g. Graves' disease and Hashimoto's thyroiditis) and gastrointestinal disorders (e.g. coeliac disease and inflammatory bowel disease); such autoimmune conditions can sometimes occur in the context of autoimmune polyglandular syndrome. Emphasis should also be given to the gastrointestinal side effects of some of the medications used for thyroid disease (e.g. anti-thyroid drugs causing hepatotoxicity) and vice versa (e.g. interferon therapy causing autoimmune thyroid dysfunction). In this review, we discuss disorders of the thyroid-gut axis and identify the evidence base behind the management of such disorders.

Nonthyroidal illness syndrome: is it far away from Crohn's disease?

GOALS

This study was designed to investigate the clinical features of nonthyroidal illness syndrome (NTIS) compared with euthyroid patients in Crohn's disease (CD), to explore the etiology of NTIS in CD, to evaluate the clinical outcomes of NTIS patients, and to inspect the correlation of clinical variables and NTIS, and their ability of differentiating NTIS from euthyroid patients.

BACKGROUND

NTIS has been described for more than 30 years. However, only few studies focused on the relationship between NTIS and CD. The incidence, underlying pathogenesis, clinical outcomes, and correlation with other inflammatory disease severity and nutritional variables of NTIS in CD have not been completely established.

METHODS

Prospectively, 44 CD patients were enrolled. Medical records and various laboratory values (including thyroidal, nutritional, and inflammatory variables) were collected in all participants.

RESULTS

The incidence of NTIS in CD was 36.4%. Albumin, Acute Physiology and Chronic Health Evaluation II score, and Crohn's Disease Activity Index score in NTIS group were statistically different from those in euthyroid group. A decreased sum activity of deiodinases and a reduced ratio of TT4/FT4 were observed in NTIS group. Duration of hospitalization was significantly longer for NTIS patients than euthyroid patients. Albumin was confirmed as a protective factor of NTIS in CD. Receiver operating characteristic curve analysis demonstrated the differentiating capacity of albumin, suggesting 37.6 g/L as optimal cut-off value with sensitivity and specificity of 81.3% and 79.2%, respectively.

CONCLUSIONS

NTIS was a common complication in CD. NTIS patients showed worse nutrition status and clinical outcome, and more critical disease activity and severity compared with euthyroid patients. A hypodeiodination condition and a potential thyroid-hormone-binding dysfunction may play a role in the etiology of NTIS in CD. Albumin was a meaningful protective and distinguishing marker of NTIS in CD.