Advances in coeliac disease

Celiac Disease: Diagnostic Standards and Dilemmas

Celiac Disease (CD) affects at least 1% of the population and evidence suggests that prevalence is increasing. The diagnosis of CD depends on providers being alert to both typical and atypical presentations and those situations in which patients are at high risk for the disease. Because of variable presentation, physicians need to have a low threshold for celiac testing. Robust knowledge of the pathogenesis of this autoimmune disease has served as a catalyst for the development of novel diagnostic tools. Highly sensitive and specific serological assays including Endomysial Antibody (EMA), tissue transglutaminase (tTG), and Deamidated Gliadin Peptide (DGP) have greatly simplified testing for CD and serve as the foundation for celiac diagnosis. In addition, genetic testing for HLA DQ2 and DQ8 has become more widely available and there has been refinement of the gluten challenge for use in diagnostic algorithms. While diagnosis is usually straightforward, in special conditions including IgA deficiency, very young children, discrepant histology and serology, and adoption of a gluten free diet prior to testing, CD can be difficult to diagnose. In this review, we provide an overview of the history and current state of celiac disease diagnosis and provide guidance for evaluation of CD in difficult diagnostic circumstances.

Coeliac disease-associated antibodies in psoriasis

Background

The possible relationship between psoriasis and coeliac disease (CD) has been attributed to the common pathogenic mechanisms of the two diseases and the presence of antigliadin antibodies in patients has been reported to increase the incidence of CD.

Objective

The aim of this report was to study CD-associated antibodies serum antigliadin antibody immunoglobulin (Ig)A, IgG, anti-endomysial antibody IgA and anti-transglutaminase antibody IgA and to demonstrate whether there is an increase in the frequency of those markers of CD in patients with psoriasis.

Methods

Serum antigliadin antibody IgG and IgA, antiendomysial antibody IgA and anti-transglutaminase antibody IgA were studied in 37 (19 males) patients with psoriasis and 50 (23 males) healthy controls. Upper gastrointestinal endoscopy and duodenal biopsies were performed in patients with at least one positive marker.

Results

Antigliadin IgA was statistically higher in the psoriasis group than in the controls (p<0.05). Serological markers were found positive in 6 patients with psoriasis and 1 person from the control group. Upper gastrointestinal endoscopy was performed in all these persons, with biopsies collected from the duodenum. The diagnosis of CD was reported in only one patient with psoriasis following the pathological examination of the biopsies. Whereas one person of the control group was found to be positive for antigliadin antibody IgA, pathological examination of the duodenal biopsies obtain from this patient were found to be normal.

Conclusion

Antigliadin IgA prominently increases in patients diagnosed with psoriasis. Patients with psoriasis should be investigated for latent CD and should be followed up.

Young adults with coeliac disease may be at increased risk of early atherosclerosis

BACKGROUND

Accelerated progression of atherosclerosis and increased cardiovascular risk have been described in immune-mediated disorders, but few data are available in coeliac disease.

AIM

To evaluate instrumental and biochemical signs of atherosclerosis risk in 20 adults at first diagnosis of coeliac disease and after 6-8 months of gluten-free diet with mucosal recovery.

METHODS

We analysed total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglycerides, homocysteine, C-reactive protein, folate and vitamin B12; ultrasound measurement of carotid intima-media thickness (IMT) and endothelium-dependent dilatation were both carried on at diagnosis and after gluten withdrawal. Twenty-two healthy members of the hospital staff served as matched controls for vascular examinations.

RESULTS

At baseline, mean total and HDL-cholesterol (HDL-C) were both within normal range, while mean LDL-cholesterol concentration was slightly increased; diet was associated with an increment in total and HDL-C (68.2 ± 17.4 vs. 51.4 ± 18.6 mg/dL; P < 0.001) and a significant improvement in total/HDL-C ratio (3.05 ± 0.71 vs. 3.77 ± 0.92; P < 0.02). Mean plasma homocysteine was elevated and not influenced by diet. C-reactive protein significantly decreased with diet (1.073 ± 0.51 vs. 1.92 ± 1.38 mg/dL; P < 0.05). At baseline, in coeliacs, IMT was increased (0.082 ± 0.011 vs. 0.058 ± 0.012 cm; P < 0.005), while endothelium-dependent dilatation was decreased (9.3 ± 1.3 vs. 11.2 ± 1.2%; P < 0.05). Both parameters improved after gluten abstinence.

CONCLUSIONS

Adults with coeliac disease seem to be at potentially increased risk of early atherosclerosis as suggested by vascular impairment and unfavourable biochemical risk pattern. Chronic inflammation might play a determining role. Gluten abstinence with mucosal normalisation reverts to normal the observed alterations.

[Symptoms of Celiac disease in childhood]

The knowledge regarding celiac disease has increased dramatically in recent years, due to the availability of accurate serologic markers. Mass screening studies have shown that the prevalence of sensitization can be as high as 1/80. The range of symptoms is wide, from the classic growth failure, denutrition and diarrhea in infancy to clinically and histologically asymptomatic sensitized subjects. The interest of a routine mass screening is debated. The classical celiac disease in infancy is well known. Atypical symptoms and potentially associated disease are more frequent and potentially confounding. Physicians should be aware of any clue for celiac disease in atypical cases in order to improve the diagnostic yield, and therefore avoiding short or long term consequences.

Recent advances in coeliac disease

PURPOSE OF REVIEW

Worldwide awareness of coeliac disease in all ages continues to grow. This article aims to summarize critically the recent research advances in coeliac disease.

RECENT FINDINGS

Large multicentre studies have provided further evidence of the role of environmental and nonhuman leucocyte antigen genetic factors in coeliac disease. Siblings of coeliac patients carry a high risk, but those found to have negative coeliac serology are very unlikely to develop the disease. Advances in the efficacy of serological antibody testing potentiate the possibility of future accurate screening programmes in the community. Adherence to a gluten-free diet remains paramount as the recognition of coeliac related complications increases.

SUMMARY

Despite the encouraging progress that has taken place in our genetic and immunological knowledge of coeliac disease, early introduction of a gluten-free diet remains the cornerstone of treatment. Alternatives, however, aimed at altering the toxicity of cereal proteins are now looking more promising.