Should ESPGHAN guidelines for serologic diagnosis of celiac disease be used in adults? A prospective analysis in an adult patient cohort with high pretest probability

Accuracy of the No-Biopsy Approach for the Diagnosis of Celiac Disease in Adults: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Current international guidelines recommend duodenal biopsies to confirm the diagnosis of celiac disease in adult patients. However, growing evidence suggests that immunoglobulin A (IgA) anti-tissue transglutaminase (tTg) antibody levels ≥10 times the upper limit of normal (ULN) can accurately predict celiac disease, eliminating the need for biopsy. We performed a systematic review and meta-analysis to evaluate the accuracy of the no-biopsy approach to confirm the diagnosis of celiac disease in adults.

METHODS

We systematically searched MEDLINE, EMBASE, Cochrane Library, and Web of Science from January 1998 to October 2023 for studies reporting the sensitivity and specificity of IgA-tTG ≥10×ULN against duodenal biopsies (Marsh grade ≥2) in adults with suspected celiac disease. We used a bivariate random effects model to calculate the summary estimates of sensitivity, specificity, and positive and negative likelihood ratios. The positive and negative likelihood ratios were used to calculate the positive predictive value of the no-biopsy approach across different pretest probabilities of celiac disease. The methodological quality of the included studies was evaluated using the QUADAS-2 tool. This study was registered with PROSPERO, number CRD42023398812.

RESULTS

A total of 18 studies comprising 12,103 participants from 15 countries were included. The pooled prevalence of biopsy-proven celiac disease in the included studies was 62% (95% confidence interval [CI], 40%-83%). The proportion of patients with IgA-tTG ≥10×ULN was 32% (95% CI, 24%-40%). The summary sensitivity of IgA-tTG ≥10×ULN was 51% (95% CI, 42%-60%), and the summary specificity was 100% (95% CI, 98%-100%). The area under the summary receiver operating characteristic curve was 0.83 (95% CI, 0.77 - 0.89). The positive predictive value of the no-biopsy approach to identify patients with celiac disease was 65%, 88%, 95%, and 99% if celiac disease prevalence was 1%, 4%, 10%, and 40%, respectively. Between-study heterogeneity was moderate (I2 =30.3%), and additional sensitivity analyses did not significantly alter our findings. Only 1 study had a low risk of bias across all domains.

CONCLUSION

The results of this meta-analysis suggest that selected adult patients with IgA-tTG ≥10×ULN and a moderate to high pretest probability of celiac disease could be diagnosed without undergoing invasive endoscopy and duodenal biopsy.

Celiac disease: Understandings in diagnostic, nutritional, and medicinal aspects

Celiac disease (CD) is characterized by clinical polymorphism, with classic, asymptomatic or oligosymptomatic, and extra-intestinal forms, which may lead to diagnostic delay and exposure to serious complications. CD is a multidisciplinary health concern involving general medicine, pediatric, and adult gastroenterology, among other disciplines. Immunology and pathology laboratories have a fundamental role in diagnosing and monitoring CD. The diagnosis consists of serological testing based on IgA anti-transglutaminase (TG2) antibodies combined with IgA quantification to rule out IgA deficiency, a potential misleading factor of CD diagnosis. Positive TG2 serology should be corroborated by anti-endomysium antibody testing before considering an intestinal biopsy. Owing to multiple differential diagnoses, celiac disease cannot be confirmed based on serological positivity alone, nor on isolated villous atrophy. In children with classical signs or even when asymptomatic, with high levels of CD-linked markers and positive HLA DQ2 and/or DQ8 molecules, the current trend is to confirm the diagnosis on basis of the non-systematic use of the biopsy, which remains obligatory in adults. The main challenge in managing CD is the implementation and compliance with a gluten-free diet (GFD). This explains the key role of the dietitian and the active participation of patients and their families throughout the disease-management process. The presence of the gluten in several forms of medicine requires the sensitization of physicians when prescribing, and particularly when dispensing gluten-containing formulations by pharmacists. This underlines the importance of the contribution of the pharmacist in the care of patients with CD within the framework of close collaboration with physicians and nutritionists.

Avoiding Small Intestinal Biopsies for Diagnosis of Celiac Disease in Children: A Reliable Strategy for All Patients?

BACKGROUND

Current reports applying ESPGHAN exception criteria (EEC) to diagnose celiac disease (CD) without duodenal biopsies indicate that a high percentage of patients with CD may be identified when applied correctly in specialized settings. Application of the EEC, however, in "daily life conditions" at the different levels of medical services is not clear.

METHODS

EEC was applied to 130 pediatric patients evaluated for CD at 5 public hospitals in Santiago, Chile, during 2010 to 2015. Clinical presentation, serum anti-tissue transglutaminase 2 and anti-endomysium antibodies (EMA), genotyping, and small intestinal histology were obtained from clinical charts.

RESULTS

A total of 78 of 130 patients reviewed had some of the data required for analysis, but EMA was determined in 54% and genotyping in 2.3% of patients, limiting the study. After offering free genotyping, only 12 of 78 (15%) had all data required for EEC application. In this small group, 10 of 12 (83.3%) patients could avoid duodenal biopsies and 2 (16.7%) with potential CD were misdiagnosed. Main reasons for not doing EMA and genotyping were that they are expensive, unavailable in the local health care center, and considered "not necessary" for diagnosis.

CONCLUSION

Limited resources in clinical settings reduce availability of EMA and genotyping, making application of EEC criteria difficult and only possible only in 15% of our patients. Within this subgroup, biopsies could be avoided in 83.3%, and 16.7% of patients with potential CD were misdiagnosed. Insufficient studies and incorrect interpretation of EEC contributed to incomplete assessment in 52 of 130 (40%) patients. The Chilean public health system is likely representative of several others present in developing and developed countries.

Coeliac disease

Coeliac disease occurs in about 1% of people in most populations. Diagnosis rates are increasing, and this seems to be due to a true rise in incidence rather than increased awareness and detection. Coeliac disease develops in genetically susceptible individuals who, in response to unknown environmental factors, develop an immune response that is subsequently triggered by the ingestion of gluten. The disease has many clinical manifestations, ranging from severe malabsorption to minimally symptomatic or non-symptomatic presentations. Diagnosis requires the presence of duodenal villous atrophy, and most patients have circulating antibodies against tissue transglutaminase; in children, European guidelines allow a diagnosis without a duodenal biopsy provided that strict symptomatic and serological criteria are met. Although a gluten-free diet is an effective treatment in most individuals, a substantial minority develop persistent or recurrent symptoms. Difficulties adhering to a gluten-free diet have led to the development of non-dietary therapies, several of which are undergoing trials in human beings.

Coeliac disease: to biopsy or not?

Coeliac disease is increasingly recognized as a global problem in both children and adults. Traditionally, the findings of characteristic changes of villous atrophy and increased intraepithelial lymphocytosis identified in duodenal biopsy samples taken during upper gastrointestinal endoscopy have been required for diagnosis. Although biopsies remain advised as necessary for the diagnosis of coeliac disease in adults, European guidelines for children provide a biopsy-sparing diagnostic pathway. This approach has been enabled by the high specificity and sensitivity of serological testing. However, these guidelines are not universally accepted. In this Perspective, we discuss the pros and cons of a biopsy-avoiding pathway for the diagnosis of coeliac disease, especially in this current era of the call for more biopsies, even from the duodenal bulb, in the diagnosis of coeliac disease. In addition, a contrast between paediatric and adult guidelines is presented.

Application of the Biopsy-Sparing ESPGHAN Guidelines for Celiac Disease Diagnosis in Adults: A Real-Life Study

BACKGROUND

Current adult celiac disease diagnosis requires histological confirmation. However, pediatric guidelines have proposed biopsy-sparing algorithms.

AIMS

To explore the applicability of the ESPGHAN criteria and assess the accuracy of serology in predicting disease in adults.

METHODS

We evaluated 234 consecutive adults showing elevated anti-tTG titers, EMA-positivity, and genetic susceptibility. Patients underwent upper endoscopy with duodenal biopsy. We determined optimal anti-tTG cutoff levels using ROC curves.

RESULTS

Mean anti-tTG levels were 71.1 ± 66.5 U/ml; mean normalized levels were 14.8 ± 14.1 × ULN (mean ± SD). Partial/total villous atrophy was present in 36%/55% of cases, respectively. Anti-tTG levels correlated with histology (r _s = 0.397, p < 0.001). AUC was similar before and after normalization (0.803 vs 0.807). Applying the ESPGHAN criterion (≥10 × ULN), we calculated a 97.66% PPV. ROC curve analysis showed an optimal cutoff of ≥16 × ULN, with a PPV of 98.86%. Eleven different assays were used for anti-tTG titer determination: Two were prevalent, labeled A (n = 141) and B (n = 59). They performed differently regarding disease prediction (AUC = 0.689 vs 0.925, p < 0.01), showing distinct optimal cutoff values (14.3 × ULN vs 3.7 × ULN), even after standardization (-0.14 vs -1.2).

CONCLUSION

In adult symptomatic patients showing EMA-positivity and genetic susceptibility, anti-tTG titers correlated with histology. ESPGHAN criteria performed similarly to previous studies. However, a calculated 16 × ULN cutoff showed an improved PPV. Among prevalent assays, PPV peaked differently both after normalization and standardization, indicating intrinsic differences in performance, thus preventing uniform prediction of disease in a real-life setting. Assay-specific optimal cutoffs seem possible, but would complicate diagnostic criteria. However, biopsy-sparing strategies in adults could prove useful in challenging patients.

Flow cytometry of duodenal intraepithelial lymphocytes improves diagnosis of celiac disease in difficult cases

BACKGROUND

Diagnosis of celiac disease is difficult when the combined results of serology and histology are inconclusive. Studies using flow cytometry of intraepithelial lymphocytes (IELs) have found that celiac patients have increased numbers of γδ IELs, along with a decrease in CD3-CD103 + IELs.

OBJECTIVE

The objective of this article is to assess the role of flow cytometric analysis of IELs in the diagnosis of celiac disease in difficult cases.

METHODS

A total of 312 patients with suspicion of celiac disease were included in the study. Duodenal biopsy samples were used for histological assessment and for flow cytometric analysis of IELs.

RESULTS

In 46 out of 312 cases (14.7%) the combination of serology and histology did not allow the confirmation or exclusion of celiac disease. HLA typing had been performed in 42 of these difficult cases. Taking into account HLA typing and the response to a gluten-free diet, celiac disease was excluded in 30 of these cases and confirmed in the remaining 12. Flow cytometric analysis of IELs allowed a correct diagnosis in 39 out of 42 difficult cases (92.8%) and had a sensitivity of 91.7% (95% CI: 61.5% to 99.8%) and a specificity of 93.3% (95% CI: 77.9% to 99.2%) for the diagnosis of celiac disease in this setting.

CONCLUSION

Flow cytometric analysis of IELs is useful for the diagnosis of celiac disease in difficult cases.

Identification of a serum transglutaminase threshold value for the noninvasive diagnosis of symptomatic adult celiac disease patients: a retrospective study

BACKGROUND

A celiac disease (CD) diagnosis is based on duodenal histology, with the exception of children showing anti-tissue transglutaminase (anti-tTG) serum levels exceeding ten times the cut-off. Our aim was to reproduce this simplified approach in adults, identifying an anti-tTG threshold value useful to diagnose CD without endoscopic procedures.

METHODS

A total of 671 adult CD patients were subjected to blood sampling to determine anti-tTG serum levels, as well as to endoscopy with biopsy to perform duodenal histology. The anti-tTG serum levels/cut-off ratio was compared with the degree of duodenal lesions.

RESULTS

Anti-tTG serum levels/cut-off ratio determined in patients with type IIIc was significantly higher than that measured in patients with type IIIb (p < 0.001), IIIa (p < 0.001), II (p < 0.05) and 0 (p < 0.001) of Marsh-Oberhuber histological classification. A significant correlation (r = 0.297, p < 0.0001) was found between the anti-tTG serum levels/cut-off ratio and the degree of duodenal lesions. The anti-tTG serum levels/cut-off ratio was classified as an accurate parameter (AUC = 0.715, p < 0.0001), with the best diagnostic performance obtained considering the threshold value >3.6 (sensitivity = 76.8 %, PPV = 97.2 %).

CONCLUSIONS

The anti-tTG serum levels/cut-off ratio correlates with the degree of duodenal lesions and, if used with the threshold value >3.6, could avoid endoscopy with biopsy in about 75 % of seropositive adults waiting for CD diagnosis. However, since this procedure could also imply CD diagnosis in almost 3 % of seropositive patients with normal villous architecture, a consensus opinion is needed to suggest its use in the diagnosis of adult CD.

Novel diagnostic techniques for celiac disease

The diagnosis of celiac disease has long been based on the demonstration of gluten-induced small-bowel mucosal damage. However, due to the constantly increasing disease prevalence and limitations in the histology-based criteria there is a pressure towards more serology-based diagnostics. The serological tools are being improved and new non-invasive methods are being developed, but the constantly refined endoscopic and histologic techniques may still prove helpful. Moreover, growing understanding of the disease pathogenesis has led researchers to suggest completely novel approaches to celiac disease diagnostics regardless of disease activity. In this review, we will elucidate the most recent development and possible future innovations in the diagnostic techniques for celiac disease.

Contemporary celiac disease diagnosis: is a biopsy avoidable?

PURPOSE OF REVIEW

The duodenal biopsy is the gold standard for the diagnosis of celiac disease. However, given improvements in the performance of serological testing, the possibility of accurately diagnosing celiac disease without the need of a biopsy has attracted interest. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition has revised its recommendations to include a diagnostic algorithm that includes sequential serological testing and human leukocyte antigen genotyping for symptomatic children which would enable a diagnosis of celiac disease to be made in the absence of a confirmatory intestinal biopsy.

RECENT FINDINGS

Recent studies have evaluated the ESPGHAN guidelines and have mostly corroborated that celiac disease can be accurately diagnosed in specific pediatric patient populations without the need of a biopsy. However, two cautionary points have been raised that warrant further consideration - the success of this approach is highly dependent targeting a population with a high pretest probability of celiac disease, as well, the performance of serology assays must be established and the appropriate use of cutoffs is essential.

SUMMARY

The duodenal biopsy will remain the gold standard for diagnosing celiac disease in a majority of patients. However, as serology assays evolve and as a greater understanding of the genetic risk factors of celiac disease is achieved, more patients may be accurately diagnosed without the need for a biopsy.