TBA (25S102)

Comparative Effectiveness of Urine vs. Stool GIP Testing in Monitoring Gluten Intake in Coeliac Patients: A Systematic Review and Meta-Analysis

Author(s)

S Moghal, J Soldera

Department(s)/Institutions

University of South Wales, UK

Introduction

Coeliac disease is an autoimmune condition caused by gluten ingestion, leading to intestinal damage. Traditional monitoring methods often miss low-level exposure. Gluten Immunogenic Peptide (GIP) testing offers a novel alternative, with urine tests detecting recent intake and stool tests identifying intermittent exposure over a longer period

Aims/Background

This systematic review and meta-analysis compare the effectiveness of urine versus stool GIP testing in monitoring gluten intake in coeliac patients to guide clinical practice.

Method

A comprehensive search of PubMed, Embase, and Cochrane databases identified studies evaluating urine and stool GIP testing in coeliac patients. Sensitivity, specificity, and diagnostic accuracy were assessed. Study quality was evaluated using the Cochrane Risk of Bias Tool, and a meta-analysis was conducted, calculating pooled estimates using a random-effects model. Heterogeneity was assessed using the I² statistic.

Results

Six studies (n=572) were included. Stool GIP testing demonstrated a pooled sensitivity of 85.1% (95% CI: 79.0%–89.9%) and specificity of 92.5% (95% CI: 88.3%–95.6%), with an AUC of 0.9853, indicating high diagnostic accuracy. Urine GIP testing had a lower sensitivity (55.4% [95% CI: 49.6%–61.2%]) and specificity (73.0% [95% CI: 67.4%–78.1%]), with an AUC of 0.7898. Significant heterogeneity (I² > 80%) was observed, likely due to variations in population characteristics and testing protocols.

Conclusions

Stool GIP testing offers superior sensitivity and specificity, making it the preferred method for detecting gluten exposure in coeliac disease. Urine GIP testing remains useful for recent exposure but is less reliable. Standardised methodologies are needed to improve test reliability.