Coeliac disease: the cause of the various associated disorders?

Pathophysiology and immunogenetics of celiac disease

Celiac disease (CD) is a chronic inflammatory enteropathy caused by gluten (protein from wheat, rye and, barley) in genetically predisposed individuals carrying the HLA-DQ2/HLA-DQ8 genotype. This pathology has a multifactorial etiology in which HLA genes, the microbiome, gluten and, other environmental factors are involved in the development of the disease. Its pathogenesis involves both innate and adaptive immunity as well as upregulation of IL-15. The objective of this review is to examine the results of current studies on genetic and environmental variables to better understand the pathogenesis of this enteropathy. The complex etiology of celiac disease makes our understanding of the pathogenesis of the disease incomplete, and a better knowledge of the many genetic and environmental components would help us better understand the pathophysiology of celiac disease.

Serological prevalence of celiac disease in Brazilian population of multiple sclerosis, neuromyelitis optica and myelitis

PURPOSE

Comorbidity of celiac disease with demyelinating diseases of the central nervous system has been reported since the 1960s. The objective of this study was to determine the serological prevalence of celiac disease in the largest series of patients diagnosed with multiple sclerosis, neuromyelitis optica, or myelitis.

METHODS

A prevalence study was conducted with patients evaluated at Sarah Network of Rehabilitation Hospitals between March 2012 and September 2013. They were previously diagnosed with multiple sclerosis, neuromyelitis optica, or idiopathic myelitis. The serum levels of antibodies against tissue transglutaminase and endomysium were assessed.

RESULTS

Of the 379 patients evaluated, 249 (65.70%) were diagnosed with multiple sclerosis, 37 (9.56%) with neuromyelitis optica, and 96 (24.54%) with idiopathic myelitis. Two patients (0.53%), one with multiple sclerosis and other with myelitis, tested positive for both antibodies.

CONCLUSION

Our study do not confirm the relationship between celiac serological antibodies with multiple sclerosis, neuromyelitis optica and inflammatory myelitis of an unknown etiology.

Coeliac disease as a potential cause of idiopathic portal hypertension: a case report

Idiopathic portal hypertension is a disorder that has various clinical features. It is mostly characterized by bleeding oesophageal varices, obvious splenomegaly, anaemia and, occasionally, jaundice and ascites. Here we described an interesting case of idiopathic portal hypertension caused by coeliac disease in a 38-year-old woman. By putting this patient on a gluten-free diet, liver function tests became normal and portal vein diameter returned to normal range. This report indicates that, in coeliac disease, repetitive stimulation by antigens along the portal vein-and immune responses to them-can result in the development of idiopathic portal hypertension.

Molecular diagnosis of celiac disease: are we there yet?

BACKGROUND

Celiac disease (CD) is a complex genetic disorder of the small intestine resulting from aberrant cellular responses to gluten peptides. It may affect as much as 1% of the Western population and the only treatment is a lifelong gluten-free diet. Allelic variants of the HLA-DQ locus, coding for the HLA-DQ2 and HLA-DQ8 molecules, contribute to ∼ 40% of CD etiology, whereas other genes, such as MYO9B, CTLA4, IL2, IL21, PARD3 and MAGI2, have only a modest effect. Most of these genes have shown varied association among different populations and an overlap with other autoimmune or inflammatory disorders, indicating that such disorders may share common pathways.

OBJECTIVES

In this review, a molecular approach into diagnostics of celiac disease is shown.

CONCLUSIONS

Genome-wide association studies will allow more genes to be identified, and knowing how risk variants combine will help to predict better the risk for the individual. HLA typing can already be used to identify high-risk individuals.

Autoimmune diseases and infections as risk factors for schizophrenia

Immunological hypotheses have become increasingly prominent when studying the etiology of schizophrenia. Autoimmune diseases, and especially the number of infections requiring hospitalization, have been identified as significant risk factors for schizophrenia in a dose-response relationship, which seem compatible with an immunological hypothesis for subgroups of patients with schizophrenia. Inflammation and infections may affect the brain through many different pathways that are not necessarily mutually exclusive and can possibly increase the risk of schizophrenia in vulnerable individuals. However, the findings could also be an epiphenomenon and not causal, due to, for instance, common genetic vulnerability, which could be supported by the observations of an increased prevalence of autoimmune diseases and infections in parents of patients with schizophrenia. Nevertheless, autoimmune diseases and infections should be considered in the treatment of individuals with schizophrenia symptoms, and further research is needed of the immune system's possible contributing pathogenic factors in the etiology of schizophrenia.

Prevalence of celiac disease in multiple sclerosis

BACKGROUND

Celiac disease (CD) is a common systemic disease related to a permanent intolerance to gluten and is often associated with different autoimmune and neurological diseases. Its mean prevalence in the general population is 1-2% worldwide. Our aim was to study the prevalence of celiac disease in a prospective series of Multiple Sclerosis (MS) patients and their first-degree relatives.

METHODS

We analyzed the prevalence of serological, histological and genetic CD markers in a series of 72 MS patients and in their 126 first-degree relatives, compared to 123 healthy controls.

RESULTS

Tissue IgA-anti-transglutaminase-2 antibodies were positive in 7 MS patients (10%), compared to 3 healthy controls (2.4%) (p < 0.05). OR: 5.33 (CI-95%: 1.074-26.425). No differences were found in HLA-DQ2 markers between MS patients (29%) and controls (26%) (NS).We detected mild or moderate villous atrophy (Marsh III type) in duodenal biopsies, in 8 MS patients (11.1%). We also found a high proportion of CD among first-degree relatives: 23/126 (32%). Several associated diseases were detected, mainly dermatitis 41 (57%) and iron deficiency anemia in 28 (39%) MS patients. We also found in them, an increased frequency of circulating auto-antibodies such as anti-TPO in 19 (26%), ANA in 11 (15%) and AMA in 2 (3%).

CONCLUSIONS

We have found an increased prevalence of CD in 8 of the 72 MS patients (11.1%) and also in their first-degree relatives (23/126 [32%]). Therefore, increased efforts aimed at the early detection and dietary treatment of CD, among antibody-positive MS patients, are advisable.

Epidemiology of autoimmune diseases in Denmark

An epidemiologic study of the autoimmune diseases taken together has not been done heretofore. The National Patient Register of Denmark is used to estimate the population prevalence of 31 possible or probable autoimmune diseases. Record linkage is used to estimate 465 pairwise co-morbidities in individuals among the 31 diseases, and familial aggregation among sibs, parents and offspring. The prevalence of any of the 31 diseases in the population is more than 5%. Within individuals, there is extensive comorbidity across the 31 diseases. Within families, aggregation is strongest for individual diseases and weak across diseases. These data confirm the importance of the autoimmune diseases as a group and suggest that common etiopathologies exist among them.

Celiac disease

Celiac disease (CD) is a common autoimmune disorder, induced by the intake of gluten proteins present in wheat, barley and rye. Contrary to common belief, this disorder is a protean systemic disease, rather than merely a pure digestive alteration. CD is closely associated with genes that code HLA-II antigens, mainly of DQ2 and DQ8 classes. Previously, it was considered to be a rare childhood disorder, but is actually considered a frequent condition, present at any age, which may have multiple complications. Tissue transglutaminase-2 (tTG), appears to be an important component of this disease, both, in its pathogenesis and diagnosis. Active CD is characterized by intestinal and/or extra-intestinal symptoms, villous atrophy and crypt hyperplasia, and strongly positive tTG auto-antibodies. The duodenal biopsy is considered to be the "gold standard" for diagnosis, but its practice has significant limitations in its interpretation, especially in adults. Occasionally, it results in a false-negative because of patchy mucosal changes and the presence of mucosal villous atrophy is often more severe in the proximal jejunum, usually not reached by endoscopic biopsies. CD is associated with increased rates of several diseases, such as iron deficiency anemia, osteoporosis, dermatitis herpetiformis, several neurologic and endocrine diseases, persistent chronic hypertransami-nasemia of unknown origin, various types of cancer and other autoimmune disorders. Treatment of CD dictates a strict, life-long gluten-free diet, which results in remission for most individuals, although its effect on some associated extraintestinal manifestations remains to be established.

Systematic review: the use of serology to exclude or diagnose coeliac disease (a comparison of the endomysial and tissue transglutaminase antibody tests)

BACKGROUND

With the appreciation of the high prevalence of coeliac disease there is increasing use of serology in screening asymptomatic people and testing those with suggestive features.

AIM

To compare the sensitivities and specificities of the endomysial antibody and the tissue transglutaminase antibody tests.

METHODS

Using electronic databases a search was made for relevant papers using the terms tissue transglutaminase and endomysial antibody.

RESULTS

Both the endomysial antibody and tissue transglutaminase antibody have very high sensitivities (93% for both) and specificities (>99% and >98% respectively) for the diagnosis of typical coeliac disease with villous atrophy. Human recombinant tissue transglutaminase performs much better than guinea pig tissue transglutaminase. Review of studies comparing endomysial antibody with human recombinant tissue transglutaminase antibody shows that endomysial antibody more often has a higher specificity and human recombinant tissue transglutaminase antibody more often has a higher sensitivity.

CONCLUSION

The human recombinant tissue transglutaminase antibody is the preferred test for screening asymptomatic people and for excluding coeliac disease in symptomatic individuals with a low pretest probability (i.e. <25%) for coeliac disease. Furthermore, it has a number of practical and financial advantages. If the pretest probability is >25%, biopsy is preferred as the post-test probability of coeliac disease with a negative test is still >2%.

Coeliac disease presenting as dermatitis herpetiformis in infancy

The incidence of reporting and diagnosis of coeliac disease (CD) in children is increasing with the improvement in sensitivity and specificity of screening markers. This in turn has led to an increasing awareness of gluten-sensitive enteropathy and associated disorders. We report the unusual case of an 8-month-old child presenting to his general practitioner with pruritic skin lesions, subsequently proven to be dermatitis herpetiformis (DH) as the first sign of gluten-sensitive disease. This infant is the youngest child presenting with DH who could be identified from published report dating from 1966 onwards. Dermatitis herpetiformis is the commonest associated pathology of CD, although rare in infancy, it should be considered in any child presenting with failure to thrive and atypical, chronic rash not responding to simple measures.

Clinical features and diagnosis of celiac disease

Celiac disease is a chronic enteropathy caused by intolerance to gluten. The true prevalence of this condition is much greater than previously recognized, with increasing numbers of silent cases being diagnosed. Population-based studies, using serologic screening, have indicated that the prevalence of celiac disease in Caucasian populations is .5%-1%. The pattern of incidence is changing, with a greater proportion of cases diagnosed later in adulthood. The pathologic lesion is characterized by a flattened small intestinal mucosa with a lymphocytic infiltrate, crypt hyperplasia, and villous atrophy. Absorptive function may be impaired and patients can experience gastrointestinal symptoms and malabsorption leading to development of anemia, osteoporosis, or other complications. Untreated celiac disease is associated with significant morbidity and increased mortality, largely owing to the development of enteropathy-associated intestinal lymphoma. The pathologic changes and symptoms resolve when gluten is excluded from the diet for a sustained period.

The prevalence of coeliac disease in rheumatoid arthritis

OBJECTIVE

To determine the prevalence of coeliac disease in rheumatoid arthritis.

METHODS

One hundred and sixty patients with seropositive rheumatoid arthritis were tested for the endomysial antibody. Those found positive were studied further with endoscopic small bowel biopsy.

RESULTS

Only one patient was found to have coeliac disease, and that had already been diagnosed. Thus the prevalence of previously undiagnosed coeliac disease in rheumatoid arthritis is 0 (95% CI 0-0.24%) and the overall prevalence of coeliac disease is 0.63% (95% CI 0.1-3.5%). These prevalences are not significantly different from the reported prevalences of coeliac disease in the general population.

CONCLUSIONS

This study does not support an association between coeliac disease and seropositive rheumatoid arthritis or the screening of such patients for coeliac disease.