Celiac disease and endocrine autoimmunity

Vitamin D: An Essential Nutrient in the Dual Relationship between Autoimmune Thyroid Diseases and Celiac Disease-A Comprehensive Review

Autoimmune thyroid diseases (AITD) are among the most frequent autoimmune disorders, with a multifactorial etiology in which both genetic and environmental determinants are probably involved. Celiac disease (CeD) also represents a public concern, given its increasing prevalence due to the recent improvement of screening programs, leading to the detection of silent subtypes. The two conditions may be closely associated due to common risk factors, including genetic setting, changes in the composition and diversity of the gut microbiota, and deficiency of nutrients like vitamin D. This comprehensive review discussed the current evidence on the pivotal role of vitamin D in modulating both gut microbiota dysbiosis and immune system dysfunction, shedding light on the possible relevance of an adequate intake of this nutrient in the primary prevention of AITD and CeD. While future technology-based strategies for proper vitamin D supplementation could be attractive in the context of personalized medicine, several issues remain to be defined, including standardized assays for vitamin D determination, timely recommendations on vitamin D intake for immune system functioning, and longitudinal studies and randomized controlled trials to definitely establish a causal relationship between serum vitamin D levels and the onset of AITD and CeD.

New and old criteria for diagnosing celiac disease: do they really differ? A retrospective observational study

BACKGROUND

The aim of this study is to compare two groups of celiac patients: the first one, in which diagnosis was based on a "biopsy sparing" approach according to the 2012 ESPGHAN criteria, and the second one, based on the biopsy approach like the one of the 1991 Revised Criteria, in order to find relevant difference for sex, M/F ratio, age at diagnosis, clinical features at the onset, presence and prevalence of concomitant autoimmune disorders.

METHODS

Our study involves 61 patients having the Celiac Disease (CD) onset from February 2013 to February 2020. The 32 patients who received diagnosis according "biopsy sparing" criteria were enrolled in group (1) The 29 patients who received diagnosis by duodenal biopsy were enrolled in group (2) Prevalence of comorbidities was analysed through chi-square test.

RESULTS

In group 1 the prevalence of comorbidities such as Insulin-Dependent Diabetes Mellitus (IDDM) and thyroiditis was of 53%, while in group 2 it was only of 24%. Analysing the IDDM prevalence between the two groups we found a relevant difference. At the same time, the prevalence of thyroiditis was also significantly different. In group 1, male patients, in particular, would seem to have a higher incidence of CD related autoimmune disorders.

CONCLUSIONS

An increased prevalence of IDDM, thyroiditis and juvenile idiopathic arthritis (JIA) in the first group would show that the "biopsy sparing" approach could expose patients to a greater length of disease activity that might be responsible for the onset of such comorbidities. Further studies should be carried out on more numerous samples of patients in order to confirm or not these data.

Single-Center Analysis of Essential Laboratory Testing in Patients with Newly Diagnosed Celiac Disease

OBJECTIVE

To analyze laboratory testing results from pediatric patients newly diagnosed with celiac disease to determine the usefulness of each test derived from recommended guidelines.

METHODS

Serological testing at the time of diagnosis from patients enrolled in our celiac disease registry from January 2018 through December 2021 was reviewed. The incidence of abnormal laboratory results, routinely obtained as per the recommendations of Snyder et al and our institution's Celiac Care Index, was assessed. Rates of abnormal laboratory values and estimated costs associated with these screening measures were analyzed.

RESULTS

Our data demonstrated abnormalities in all serological testing obtained at celiac diagnosis. Hemoglobin, alanine aminotransferase, ferritin, iron, and vitamin D screening were found to be abnormal with notable frequency. Only 7% of patients had an abnormal thyroid-stimulating hormone and <0.1% had an abnormal free T4. Nonresponse to hepatitis B vaccination was prominent, with 69% of patients considered nonimmune. Screening protocols as currently outlined in our Celiac Care Index resulted in an estimated cost of approximately $320 000 during our study.

CONCLUSIONS

Review of screening laboratory results at our center reveals that abnormal values for several recommended measures are uncommon. Thyroid screening was infrequently abnormal and the usefulness of screening for hepatitis B at diagnosis is uncertain. Similarly, our data suggest that iron deficiency screening may be condensed effectively into hemoglobin and ferritin testing, eliminating the need for initial iron studies. Decreasing baseline screening measures could safely decrease the burden of testing on patients and overall healthcare expenditures.

Serologic Testing for Celiac Disease in Graves' Hyperthyroidism: Should We Act Early?

BACKGROUND

The general practice is to screen patients with autoimmune thyroid disease for celiac disease (CD); however, optimal timing for CD screening for patients with Graves'Disease (GD) has not been identified yet. The aim of the study was to show whether positive celiac antibodies persist after euthyroidism is achieved.

MATERIALS AND METHODS

Serum samples were collected from 35 patients with GD (23 female and 12 male) who applied to the endocrine outpatient clinic. Patients and healthy controls were screened for CD with IgG and IgA antigliadin antibodies (IgG - AGA and IgA - AGA), IgA endomysial antibody (IgA-EMA) and IgA tissue transglutaminase antibody (IgA anti-tTG). These antibodies were reevaluated when patients were euthyroid under antithyroid therapy. Small intestine biopsy was offered to the patients who remained antibody positive after being euthyroid.

RESULTS

Screening 35 patients with GD revealed positive results for IgA-AGA (n = 6/35, 17%), IgG-AGA (n = 9/35, 26%), IgA-EmA (n = 2/35, 6%) and IgA-tTG (n = 2/35, 6%). No patient had multiple antibodies positive. Selective IgA deficiency was not detected in patients and controls. When patients were euthyroid, baseline positive IgA-AGA, IgG-AGA, and IgA-EmA became negative, while positive anti-tTG persisted in two patients. Endoscopic duodenal biopsy showed a normal villi/crypts ratio in these patients. None of the controls had positive antibodies.

CONCLUSION

Due to possibility of false seropositivity of celiac antibodies in patients with Graves' thyrotoxicosis, one should defer testing for CD until euthyroidism has been achieved.

Frequency of auto-antibodies of type 1 diabetes in adult patients with celiac disease

Both celiac disease (CD) and type 1 diabetes (T1D) are autoimmune diseases resulting from a complex interplay between genetic susceptibility and environmental factors.

Celiac Disease and the Thyroid: Highlighting the Roles of Vitamin D and Iron

Celiac disease (CD) and autoimmune thyroid diseases (AITD) like Hashimoto’s thyroiditis (HT) and Graves’ disease (GD) frequently coexist, entailing numerous potential impacts on diagnostic and therapeutic approaches. Possible correlations might exist through gut microbiota, regulating the immune system and inflammatory responses, promoting autoimmune diseases, as well as shared cytokines in pathogenesis pathways, cross-reacting antibodies or malabsorption of micronutrients that are essential for the thyroid like iron or vitamin D. Vitamin D deficiency is a common finding in patients with AITD, but might protect from autoimmunity by wielding immunoregulatory and tolerogenic impacts. Additionally, vitamin D is assumed to be involved in the onset and progression of CD, presumably plays a substantial protective role for intestinal mucosa and affects the thyroid via its immunomodulatory effects. Iron is an essential micronutrient for the thyroid gland needed for effective iodine utilization by the iron-dependent enzyme thyroid iodine peroxidase (TPO). Despite being crucial for thyroid hormone synthesis, iron deficiency (ID) is a common finding in patients with hypothyroidism like HT and is frequently found in patients with CD. A literature research was conducted to examine the interplay between CD, AITD, vitamin D and iron deficiency. This narrative review highlights the relevant correlation of the two disease entities CD and AITD, their reciprocal impact and possible therapeutic options that should be further explored by future studies.

Type 1 diabetes and associated autoimmune diseases

BACKGROUND

Common autoimmune diseases (AID) tend to occur together in the same individual and families. Type 1 diabetes (T1D) is caused by an autoimmune-induced inflammatory destruction of the pancreatic tissue and clusters with several other AID.

AIM

To compare the demographic, clinical, and serological features of patients with single T1D vs those with T1D and associated AID.

METHODS

From October 1999 to February 2020, a total of 665 patients with T1D and their first-degree relatives were evaluated.

RESULTS

Compared to patients with isolated T1D, those with T1D + AID were older and had a higher female: male ratio. Average patient age and age at disease onset were higher in T1D + AID vs T1D only. The average time interval between T1D onset and the onset of a second glandular AID was markedly shorter than the time interval between T1D and the occurrence of a non-endocrine AID. T1D-specific autoantibodies were more frequent in patients with T1D + AID and relatives vs those with T1D only. However, the prevalence of AID and autoantibodies against various tissues were found to be higher in relatives of patients with T1D only compared to relatives of patients with T1D + AID.

CONCLUSION

Annual serological and subsequent functional screening for AID in patients with T1D and their first-degree relatives is recommended.

Chromogranin Serves as Novel Biomarker of Endocrine and Gastric Autoimmunity

CONTEXT

The glycoprotein chromogranin A (CgA) is expressed by endocrine and neuroendocrine cells. High levels of serum CgA serve as markers of neuroendocrine tumors (NET), but its role in autoimmunity has not been assessed.

OBJECTIVE

To investigate CgA utility as a marker of endocrine autoimmunity.

METHODS

CgA serum levels were evaluated in 807 consecutive unselected participants (cross-sectional study) with the time-resolved amplified cryptate emission technology.

RESULTS

Serum CgA concentrations were increased in 66%, 39%, 38%, and 24% of patients with NET, type 1 diabetes (T1D), autoimmune gastritis (AG) and autoimmune polyendocrinopathy (AP), respectively. Compared with healthy participant controls (C), the odds of positive CgA measurement were up to 28 times higher in the disease groups. In detail, the odds ratios (ORs) for positive CgA levels were 27.98, 15.22, 7.32 (all P < 0.0001) and 3.89 (P = 0.0073) in patients with NET, T1D, AG, and AP, respectively. In AG, CgA and serum gastrin correlated positively (r = 0.55; P < 0.0001). The area under the receiver operating characteristic curve to predict AG was higher for parietal cell antibody (PCA) positivity than for CgA (0.84 vs 0.67; P < 0.0001). However, in combination with PCA and intrinsic factor autoantibodies, CgA independently improved prediction of AG (OR 6.5; P = 0.031). An impact of age on CgA positivity and on CgA value was detected (P < 0.0001) while current smoking significantly increased CgA serum levels by 25% (P = 0.0080).

CONCLUSION

CgA qualifies as a novel biomarker for T1D, AP, and AG.

Type 1 diabetes, thyroid, gastric and adrenal humoral autoantibodies are present altogether in almost one third of adult celiac patients at diagnosis, with a higher frequency than children and adolescent celiac patients

Background: No data are available on the frequency of organ-specific humoral autoimmunity at diagnosis of adult celiac disease (CD).Aim: To evaluate the humoral immunoreactivities specific of type 1 diabetes (T1D), thyroid (THD), atrophic-gastritis (AG) and Addison's (AD) diseases in 92 adult CD patients at diagnosis and 237 adult healthy subjects (CTRL).Methods: T1D, THD and AD specific autoantibodies were analyzed by radioimmunoprecipitation assays. AG autoantibodies were detected by enzyme-linked immunosorbent assay.Results: Of 92 CD patients, 31.5% were positive for at least one of the organ-specific autoantibodies investigated (p < .0001 vs CTRL). Thyroid, diabetes, gastric and adrenal-autoantibodies, that increase with age at diagnosis, were detected in 12.0%, 10.9%, 10.9%, 2.2% of CD patients, respectively. Gastric- and diabetes- rather than thyroid- and adrenal-autoimmunity seem to be specifically related to presence of CD.Conclusions: One third of adult CD patients at diagnosis is target of at least one organ-specific autoantibody. A systematic organ-specific autoantibody screening in these patients might be of value to promptly identify, prevent or treat the relative diseases.

Interaction between food antigens and the immune system: Association with autoimmune disorders

It has been shown that environmental factors such as infections, chemicals, and diet play a major role in autoimmune diseases; however, relatively little attention has been given to food components as the most prevalent modifiers of these afflictions. This review summarizes the current body of knowledge related to different mechanisms and associations between food proteins/peptides and autoimmune disorders. The primary factor controlling food-related immune reactions is the oral tolerance mechanism. The failure of oral tolerance triggers immune reactivity against dietary antigens, which may initiate or exacerbate autoimmune disease when the food antigen shares homology with human tissue antigens. Because the conformational fit between food antigens and a host's self-determinants has been determined for only a few food proteins, we examined evidence related to the reaction of affinity-purified disease-specific antibody with different food antigens. We also studied the reaction of monoclonal or polyclonal tissue-specific antibodies with various food antigens and the reaction of food-specific antibodies with human tissue antigens. Examining the assembled information, we postulated that chemical modification of food proteins by different toxicants in food may result in immune reaction against modified food proteins that cross-react with tissue antigens, resulting in autoimmune reactivity. Because we are what our microbiome eats, food can change the gut commensals, and toxins can breach the gut barrier, penetrating into different organs where they can initiate autoimmune response. Conversely, there are also foods and supplements that help maintain oral tolerance and microbiome homeostasis. Understanding the potential link between specific food consumption and autoimmunity in humans may lay the foundation for further research about the proper diet in the prevention of autoimmune diseases.

Persistent Myocardial Ischaemia due to Anaemia in a Patient with Coeliac Disease – A Case Report

Collapse

Autoimmune polyglandular diseases

Autoimmune polyglandular diseases (APD) are defined as the presence of two autoimmune -induced endocrine failures. With respect to the significant morbidity and potential mortality of APD, the diagnostic objective is to detect APD at an early stage, with the advantage of less frequent complications, effective therapy and better prognosis. This requires that patients at risk be regularly screened for subclinical endocrinopathies prior to clinical manifestation. Regarding the time interval between manifestation of first and further endocrinopathies, regular and long-term follow-up is warranted. Quality of life and psychosocial status are poor in APD patients and involved relatives. Familial clustering is high in patients with APD. Considering the high incidence of one or more endocrinopathies in first-degree relatives of patients with APD, family members should be regularly screened since they may also develop autoimmune endocrinopathies. Multidisciplinary management of these multiplex families in specialized centers is warranted.

Thyroid hormone therapy in congenital hypothyroidism and pediatric hypothyroidism

The evaluation and management of hypothyroidism in children are similar to adults, but there are important differences based on the dependence on normal thyroid function for neurocognitive and physical development. In the pediatric population, hypothyroidism is frequently categorized as congenital or acquired hypothyroidism, depending on the age of presentation and the underlying etiology. The evaluation and management of children and adolescents with hypothyroidism are determined by the etiology as well as by the age at diagnosis, severity of the hypothyroidism, and the response to thyroid hormone replacement therapy. Children and adolescents require higher weight-based doses for thyroid hormone replacement than do adults, likely due to a shorter half-life of thyroxine (T4) and triiodothyronine (T3) in children, but weight-based dose requirements decrease as the child advances into adulthood. Multiple gaps in knowledge remains regarding how to optimize the treatment of hypothyroidism in pediatric patients, including (but not limited to) the selection of patients with subclinical hypothyroidism for treatment, and the potential benefit of combined LT3/LT4 therapy for patients with persistent symptoms and/or low T3 on LT4 monotherapy. The life-long impact on growth and development, and potentially on long-term cardiovascular and psychosocial health, are significant and highlight the importance of future prospective studies in pediatric patients to explore these areas of uncertainty.

Autoimmune Polyendocrinopathy

CONTEXT

This mini-review offers an update on the rare autoimmune polyendocrinopathy (AP) syndrome with a synopsis of recent developments.

DESIGN AND RESULTS

Systematic search for studies related to pathogenesis, immunogenetics, screening, diagnosis, clinical spectrum, and epidemiology of AP. AP (orphan code ORPHA 282196) is defined as the autoimmune-induced failure of at least two glands. AP is divided into the rare juvenile type I and the adult types II to IV. The prevalence is 1:100,000 and 1:20,000 for types I and types II to IV, respectively. Whereas type I (ORPHA 3453) is a monogenetic syndrome with an autosomal recessive transmission related to mutations in the autoimmune regulator (AIRE) gene, types II to IV are genetically complex multifactorial syndromes that are strongly associated with certain alleles of HLA genes within the major histocompatibility complex located on chromosome 6, as well as the cytotoxic T lymphocyte antigen 4 and the protein tyrosine phosphatase nonreceptor type 22 genes. Addison disease is the major endocrine component of type II (ORPHA 3143), whereas the coexistence of type 1 diabetes and autoimmune thyroid disease is characteristic for type III (ORPHA 227982). Genetic screening for the AIRE gene is useful in patients with suspected type I, whereas serological screening (i.e., diabetes/adrenal antibodies) is required in patients with monoglandular autoimmunity and suspected AP. If positive, functional endocrine testing of the antibody-positive patients as well as serological screening of their first-degree relatives is recommended.

CONCLUSION

Timely diagnosis, genetic counseling, and optimal long-term management of AP is best offered in specialized centers.

Management of celiac disease in daily clinical practice

Celiac disease (CD) is the most common autoimmune enteropathy worldwide. In CD, dietary gluten triggers a T cell driven small intestinal inflammation in a subset of genetically predisposed subjects, expressing the HLA DQ2 and/or DQ8 genes on their antigen presenting cells. HLA DQ2/DQ8 can bind gluten peptides after their prior modification by the CD autoantigen, tissue transglutaminase (TG2). This process leads to the activation of gluten reactive T cells, small bowel villous atrophy, crypt hyperplasia and intraepithelial lymphocytosis, the histological hallmarks of CD. The clinical picture of CD is extremely heterogeneous including intestinal (especially diarrhea, abdominal pain, bloating) and extraintestinal (especially associated autoimmune diseases, anemia, osteoporosis) manifestations. The prevalence of CD in most parts of the world is estimated at 1:100-1:150 and its diagnosis is based on the presence of circulating autoantibodies (anti-TG2) and the histological detection of villous atrophy. Treatment is a lifelong gluten free diet but adjunctive therapies are in development. Although CD is a well-characterized disease, it is grossly underdiagnosed, despite the severe consequences of long-term gluten ingestion in CD, such as enhanced autoimmunity, refractory CD and intestinal T cell lymphoma. The aim of the presented review is to provide a clinical guide and to summarize the most recent clinical progress in CD research.

IMMUNE MEDIATED DISEASES IN PATIENTS WITH CELIAC DISEASE AND THEIR RELATIVES: A COMPARATIVE STUDY OF AGE AND SEX

ABSTRACT BACKGROUND: Up to 15% of other immune-mediated diseases (IMDs) can occur in patients with CD throughout their lives and are associated with multiple factors, including sex and sex hormone levels. Moreover, sex is associated with differences in clinical presentation, onset, progression, and outcomes of disorders. OBJECTIVE: To investigate the prevalence of IMDs at diagnosis in patients with celiac disease (CD) and their first-degree relatives and to compare the findings between female and male patients of different age. METHODS: A retrospective study including Brazilian patients with CD who visited the same doctor during January 2012 to January 2017 was performed. Demographic and medical history data were collected through self-administered questionnaires and medical charts of the patients. In total, 213 patients were examined at diagnosis: 52 males (mean age, 40.0 years) and 161 females (mean age, 41.4 years). The patients were divided into two groups according to sex and age. RESULTS: IMDs were observed in 60.2% of the female (97/161) and 42.3% of the male patients (22/52; P=0.22). However, the frequency of IMDs was significantly higher in females aged 51-60 years than in males with same age (P=0.0002). Dermatitis herpetiformis (DH) was significantly more prevalent in males (P=0.02), whereas atopy was more prevalent in females (P=0.02). IMDs observed in first-degree relatives were similar to those observed in patients (70.9%; P<0.001), with a higher number observed in female relatives. CONCLUSION: The frequency of IMDs in CD patients was similar in all age groups and both sexes, except women diagnosed with CD after 51 years of age presented with an increased frequency of IMDs compared with males. Dermatitis herpetiformis was more prevalent in males, whereas atopy was more prevalent in females. No difference was observed in the type of IMDs between the first-degree relatives of both sexes.

Celiac disease and endocrine autoimmunity - the genetic link

Celiac disease is a small intestinal inflammatory disease with autoimmune features that is triggered and maintained by the ingestion of the storage proteins (gluten) of wheat, barley and rye. The prevalence of celiac disease is increased in patients with monoglandular and/or polyglandular autoimmunity and their relatives. Between 10 and 30% of patients with celiac disease are thyroid and/or type 1 diabetes antibody positive, while around 5 to 7% of patients with autoimmune thyroid disease and/or type 1 diabetes are IgA anti-tissue transglutaminase antibody positive. The close relationship between celiac disease and endocrine autoimmunity is largely explained by sharing a common genetic background. The HLA antigens DQ2 (DQA1*0501-DQB1*0201) and/or DQ8 (DQA1*0301-DQB1*0302), that are tightly linked to DR3 and DR4, respectively, are the major common genetic predisposition. Moreover, functional single nucleotide polymorphisms of various genes that are involved in immune regulation have been identified as "overlap" susceptibility genes for both celiac disease and monoglandular or polyglandular autoimmunity. While plausible, it remains to be established how far a gluten free diet may prevent or ameliorate glandular autoimmunity. In conclusion, all patients with celiac disease should be screened for type 1 diabetes and/or autoimmune thyroid disease. Conversely, patients with the above autoimmune endocrine disorders should be also screened for celiac disease.

Celiac Disease and Glandular Autoimmunity

Celiac disease is a small intestinal inflammatory disease with autoimmune features that is triggered and maintained by the ingestion of the storage proteins (gluten) of wheat, barley, and rye. Prevalence of celiac disease is increased in patients with mono- and/or polyglandular autoimmunity and their relatives. We have reviewed the current and pertinent literature that addresses the close association between celiac disease and endocrine autoimmunity. The close relationship between celiac disease and glandular autoimmunity can be largely explained by sharing of a common genetic background. Further, between 10 and 30% of patients with celiac disease are thyroid and/or type 1 diabetes antibody positive, while around 5–7% of patients with autoimmune thyroid disease, type 1 diabetes, and/or polyglandular autoimmunity are IgA anti-tissue transglutaminase antibody positive. While a gluten free diet does not reverse glandular autoimmunity, its early institution may delay or even prevent its first manifestation. In conclusion, this brief review highlighting the close association between celiac disease and both monoglandular and polyglandular autoimmunity, aims to underline the need for prospective studies to establish whether an early diagnosis of celiac disease and a prompt gluten-free diet may positively impact the evolution and manifestation of glandular autoimmunity.

The distribution of HLA DQ2 and DQ8 haplotypes and their association with health indicators in a general Danish population

Background

Human leukocyte antigen (HLA) DQ2 and DQ8 are important risk factors for some autoimmune diseases such as celiac disease (CD), but their possible role in other diseases and health conditions is not fully explored.

Objectives

The objective of this article is to examine the distribution of HLA DQ2 and HLA DQ8 in an adult general population, and their association with health indicators (diseases, symptoms and biomarkers).

Methods

In this cross-sectional, population-based study, 2293 individuals were screened for HLA DQ2 and DQ8; CD-associated alleles (DQA*0201*03*05/DQB*02*0301/0304*0302/0305) and DQB1*02 homozygosity were determined for screen-positive participants. The National Patient Registry provided diagnosis information.

Results

A total of 47.7% (1093/2293) individuals were positive for DQ2 and/or DQ8: 31.2% (716/2293) only DQ2, 11.9% (273/2293) only DQ8, 4.1% (93/2293) both DQ2 and DQ8. Among nine individuals diagnosed with CD, 89.9% (8/9) had DQ2.5cis, 22.2% (2/9) DQ8 and 22.2% (2/9) DQ2.2 (two both DQ2 and DQ8). HLA DQ2.5 was associated with higher thyroid-stimulating hormone levels, while DQ2/DQ8-positive participants had significantly lower prevalence of irritable bowel syndrome (IBS). DQ2/DQ8 were strongly associated with CD, but no other registry-based diagnoses.

Conclusion

In this general Danish population, 47.7% were HLA DQ2/DQ8 positive and thus potentially at risk for CD. All individuals with CD were DQ2/DQ8 positive; the majority DQ2.5. Surprisingly, DQ2/DQ8-positivity was associated with lower IBS prevalence.

[Celiac disease : Pathogenesis, clinics, epidemiology, diagnostics, therapy]

Celiac disease is induced by the consumption of gluten containing cereals (wheat, spelt, barley, rye). With a prevalence of ~ 1 %, it is the most common non-infectious chronic inflammatory intestinal disease worldwide. It manifests in all age groups, either classically with abdominal pain, diarrhoea and growth failure or weight loss, more commonly with indirect consequences of malabsorption, such as anaemia and osteoporosis, or with associated autoimmune diseases like type 1 diabetes, autoimmune thyroiditis or dermatitis herpetiformis. The pathogenesis of celiac disease is well explored. Gluten, the cereal storage protein, is not completely digested and reaches the intestinal mucosa where it activates inflammatory T cells, which cause atrophy of the resorptive villi. This T‑cell activation requires a genetic predisposition (the molecules HLA-DQ2 or -DQ8 on antigen-presenting immune cells). Moreover, the enzyme tissue transglutaminase (TG2) which is released in the mucosa increases the immunogenicity of the gluten peptides by a deamidation reaction. The test for serum antibodies to the autoantigen TG2 is one of the best diagnostic markers in medicine, which in combination with endoscopically obtained biopsies, secures the diagnosis of celiac disease. Despite these tools celiac disease is severely underdiagnosed, with 80-90 % of those affected being undetected. The untreated condition can lead to grave complications. These include the consequences of malabsorption, cancers (especially intestinal T‑cell lymphoma), and likely also the promotion of autoimmune diseases. The therapy of celiac disease, a strict gluten-free diet, is difficult to maintain and not always effective. Alternative, supporting pharmacological therapies are urgently needed and are currently in development.

Low testosterone in non-responsive coeliac disease: A case series, case-control study with comparisons to the National Health and Nutrition Examination Survey

BACKGROUND

Adults with coeliac disease (CD) often report persistent fatigue, even when CD appears well controlled for unknown reasons.

AIMS

To evaluate common indications for testosterone panel (TP) testing and prevalence of low testosterone (T) in CD.

METHODS

In our case series, we determined common indications for checking TP in CD. Next, we conducted a case-control study to compare TP in CD vs. healthy controls (HC). We compared mean total T (TT), free T (FT) based on serologic, histologic disease activity. Finally, we assessed TT in tissue transglutaminase (tTG)+ vs. tTG- subjects and CD vs. HC obtained from the National Health and Nutrition Examination Survey (NHANES).

RESULTS

53 coeliac males had TP tested. Common indications included osteoporosis and fatigue. Low FT was observed in 7/13 men with osteoporosis and 5/6 with fatigue. In our case-control study (n=26 each), there was no difference in mean TT or FT between CD vs. HC, tTG+ vs tTG- or Marsh 0 vs. Marsh 3 groups. NHANES data showed no difference in mean TT between tTG+ vs tTG- (n=16 each) or CD vs. HC subjects (n=5 each).

CONCLUSIONS

Low T occurs in CD patients at a similar rate as the general population. Common presentations of low T may mimic non-responsive CD symptoms.

Coeliac disease and autoimmune disease-genetic overlap and screening

Coeliac disease is a treatable, gluten-induced disease that often occurs concurrently with other autoimmune diseases. In genetic studies since 2007, a partial genetic overlap between these diseases has been revealed and further insights into the pathophysiology of coeliac disease and autoimmunity have been gained. However, genetic screening is not sensitive and specific enough to accurately predict disease development. The current method to diagnose individuals with coeliac disease is serological testing for the presence of autoantibodies whilst the patient is on a regular, gluten-containing diet, followed by gastroduodenoscopy with duodenal biopsy. Serological test results can also predict the probability of coeliac disease development, even if asymptomatic. In patients with autoimmune diseases known to occur alongside coeliac disease (particularly type 1 diabetes mellitus or thyroid disorders), disease screening-and subsequent treatment if coeliac disease is detected-could have beneficial effects on progression or potential complications of both diseases, owing to the effectiveness of gluten-free dietary interventions in coeliac disease. However, whether diagnosis of coeliac disease and subsequent dietary treatment can prevent autoimmune diseases is debated. In this Review, the genetic and immunological features of coeliac disease, overlap with other autoimmune diseases and implications for current screening strategies will be discussed.