Evolving Paradigms in the Diagnosis of Adult Patients With Celiac Disease

Celiac Disease-Related Conditions: Who to Test?

Celiac disease (CeD) is a chronic immune-mediated condition triggered by gluten consumption in genetically predisposed individuals. Approximately 1% of the general population is affected by the disorder. Disease presentation is heterogeneous and, despite growing awareness among physicians and the public, it continues to be underestimated. The most effective strategy for identifying undiagnosed CeD is proactive case finding through serologic testing in high-risk groups. We reviewed the most recent evidence on the association between CeD and more than 20 conditions. In light of this review, CeD screening is recommended in individuals with (1) autoimmune disease and accompanying symptoms suggestive of CeD; (2) diseases that may mimic CeD (eg, irritable bowel syndrome [IBS], inflammatory bowel disease [IBD], and microscopic colitis); and (3) among patients with conditions with a high CeD prevalence: first-degree relatives, idiopathic pancreatitis, unexplained liver enzyme abnormalities, autoimmune hepatitis, primary biliary cholangitis, hyposplenism or functional asplenia with severe bacterial infection, type 1 diabetes mellitus, Hashimoto's thyroiditis and Graves' disease, Sjögren's syndrome, dermatitis herpetiformis, recurrent aphthous syndrome and enamel defects, unexplained ataxia, peripheral neuropathy, delayed menarche or premature menopause, Down syndrome, Turner syndrome, Williams syndrome, chronic fatigue syndrome, IgA nephropathy, and IgA deficiency. CeD serology should be the initial step in the screening process. However, for patients with any of the aforementioned disorders who are undergoing upper endoscopy, biopsies should be performed to rule out CeD.

Feasibility of a "No-Biopsy" Approach for the Diagnosis of Celiac Disease in Symptomatic Adults

Celiac disease (CD) is an immune-mediated enteropathy, caused by hypersensitivity to gluten in genetically predisposed individuals. The worldwide prevalence of CD has been estimated to be approximately 1%. Most guidelines for diagnosis of CD rely on a sequential approach, with serological testing of antibodies against tissue transglutaminase (tTG) as a first-line test, followed by a duodenal biopsy. However, GI biopsy is an invasive procedure with various complications. Hence, this study was planned to ascertain whether it could be possible to have a non-biopsy approach, using only serological markers to establish the diagnosis of CD in adults.

MATERIAL AND METHODS

It was a retrospective analysis of medical records of all biopsy-diagnosed CD patients with available anti-tTGA antibodies reports from 2019 to 2023. The patients were divided into three groups based on Marsh grading and anti-tTGA antibody levels were compared using various statistical tests.

RESULTS

A total of 94 biopsy-diagnosed symptomatic CD patients with anti-tTGA antibody reports available formed the study group. Of these, 54 had biopsy findings consistent with Marsh 3 lesion, three had Marsh 2 lesion, and 37 had Marsh 1 lesion. A significant correlation existed between Marsh grading 3 lesion and anti-tTGA antibody levels above the upper limit of normal (ULN) x 10.

CONCLUSION

Serum levels of anti-tTGA antibodies greater than 10 x ULN can be used to identify symptomatic patients with Marsh grade 3 CD lesions.

Accuracy of a no-biopsy approach for the diagnosis of coeliac disease across different adult cohorts

OBJECTIVE

We aimed to determine the predictive capacity and diagnostic yield of a 10-fold increase in serum IgA antitissue transglutaminase (tTG) antibody levels for detecting small intestinal injury diagnostic of coeliac disease (CD) in adult patients.

DESIGN

The study comprised three adult cohorts. Cohort 1: 740 patients assessed in the specialist CD clinic at a UK centre; cohort 2: 532 patients with low suspicion for CD referred for upper GI endoscopy at a UK centre; cohort 3: 145 patients with raised tTG titres from multiple international sites. Marsh 3 histology was used as a reference standard against which we determined the performance characteristics of an IgA tTG titre of ≥10×ULN for a diagnosis of CD.

RESULTS

Cohort 1: the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for IgA tTG levels of ≥10×ULN at identifying individuals with Marsh 3 lesions were 54.0%, 90.0%, 98.7% and 12.5%, respectively. Cohort 2: the sensitivity, specificity, PPV and NPV for IgA tTG levels of ≥10×ULN at identifying individuals with Marsh 3 lesions were 50.0%, 100.0%, 100.0% and 98.3%, respectively. Cohort 3: the sensitivity, specificity, PPV and NPV for IgA tTG levels of ≥10×ULN at identifying individuals with Marsh 3 lesions were 30.0%, 83.0%, 95.2% and 9.5%, respectively.

CONCLUSION

Our results show that IgA tTG titres of ≥10×ULN have a strong predictive value at identifying adults with intestinal changes diagnostic of CD. This study supports the use of a no-biopsy approach for the diagnosis of adult CD.

Progress in the serology-based diagnosis and management of adult celiac disease

Introduction: This article provides a comprehensive overview of the development and application of serological tests used routinely in clinical practice for the diagnosis and management of adult celiac disease.Areas covered: We summarize existing scientific literature related to anti-endomyseal, anti-tissue transglutaminase, and anti-deamidated gliadin peptide antibodies and detail the current and potential future applications of these tests in celiac disease.Expert commentary: Current serological tests in celiac disease have some of the best performance characteristics among disease-specific tests. However, in adult celiac disease, current diagnostic algorithms still rely on duodenal biopsies to confirm the diagnosis. A 'biopsy avoidance strategy' has been implemented in pediatric celiac disease. Future high-quality studies will help inform on whether this approach can be implemented into adult gastroenterology services. It is envisaged that the next 5 years will see an increasing reliance on serology in the diagnosis of adult celiac disease.