Introduction
Current international guidelines recommend duodenal biopsies to confirm the diagnosis of coeliac disease in adult patients. However, growing evidence suggests that IgA anti-tissue transglutaminase (tTg) antibody levels ≥10 times the upper limit of normal (ULN) can accurately predict coeliac disease, eliminating the need for biopsy. We performed a systematic review and meta-analysis to evaluate the diagnostic accuracy of the no-biopsy approach for the diagnosis of coeliac disease in adults.
Aims & Methods
We systematically searched MEDLINE, EMBASE, Cochrane Library and Web of Science from January 1998 to April 2023 for studies reporting the sensitivity and specificity of IgA-tTG ≥10×ULN against duodenal biopsies (Marsh grade ≥2) in adults with suspected coeliac disease. We used a bivariate random-effects model to calculate the summary estimates of sensitivity, specificity, positive and negative likelihood ratios. The positive and negative likelihood ratios were used to calculate the positive predictive value (PPV) of the no-biopsy approach across different pre-test probabilities of coeliac disease. This study was registered with PROSPERO, number CRD42023398812.
Results
Thirteen studies comprising 10,078 participants from 11 countries were included. The pooled prevalence of biopsy-proven coeliac disease in the included studies was 60% (95% CI, 36% - 84%). The summary sensitivity of IgA-tTG ≥10×ULN was 52% (95% CI, 41% - 62%), and the summary specificity was 100% (95% CI, 98% - 100%). The area under the summary receiver operator characteristic curve was 0.84 (95% CI, 0.77 – 0.89). The PPV of the no-biopsy approach to identify patients with coeliac disease was 68%, 90%, 96%, and 99% if coeliac disease prevalence was 1%, 4%, 10% and 30%, respectively. Between-study heterogeneity was moderate (I2=25%), and additional sensitivity analyses did not significantly alter our findings.
Conclusion
The results of this meta-analysis support the adoption of the no-biopsy approach to diagnose adult patients with coeliac disease in secondary care settings, where the pre-test probability of coeliac disease is high. Biopsy could be avoided in almost one-in-three patients referred to gastroenterology with suspected coeliac disease. Our findings may inform future guidelines for the diagnosis of coeliac disease in adults.
