Clinical utility of urinary gluten immunogenic peptides in the follow‐up of patients with coeliac disease

Abstract

Summary Background Gluten‐free diet (GFD) is the only treatment for patients with coeliac disease (CD) and its compliance should be monitored to avoid cumulative damage. Aims To analyse gluten exposures of coeliac patients on GFD for at least 24 months using different monitoring tools and its impact on duodenal histology at 12‐month follow‐up and evaluate the interval of determination of urinary gluten immunogenic peptides (u‐GIP) for the monitoring of GFD adherence. Methods Ninety‐four patients with CD on a GFD for at least 24 months were prospectively included. Symptoms, serology, CDAT questionnaire, and u‐GIP (three samples/visit) were analysed at inclusion, 3, 6, and 12 months. Duodenal biopsy was performed at inclusion and 12 months. Results At inclusion, 25.8% presented duodenal mucosal damage; at 12 months, this percentage reduced by half. This histological improvement was indicated by a reduction in u‐GIP but did not correlate with the remaining tools. The determination of u‐GIP detected a higher number of transgressions than serology, regardless of histological evolution type. The presence of >4 u‐GIP‐positive samples out of 12 collected during 12 months predicted histological lesion with a specificity of 93%. Most patients (94%) with negative u‐GIP in ≥2 follow‐up visits showed the absence of histological lesions (p < 0.05). Conclusion This study suggests that the frequency of recurrent gluten exposures, according to serial determination of u‐GIP, could be related to the persistence of villous atrophy and that a more regular follow‐up every 6 months, instead of annually, provides more useful data about the adequate adherence to GFD and mucosal healing.

Editorial: coeliac disease follow‐up guided by gluten immunogenic peptides—are we there yet?

“…6 How can GIP testing inform patient follow-up? Garzón-Benavides et al 7 addressed this in a prospective study monitoring treated coeliac patients. Half of those with villous atrophy normalised over 12 months, consistent with an observed (Hawthorne) effect, but this improvement was not reflected by commensurate changes in coeliac serology, dietary adherence or symptoms.…”

“…Thus, the value of GIP testing is its high negative predictive value for villous atrophy conferred by a consistently negative test. 7,8 So are we ready to abandon follow-up biopsies and replace them with GIP assays? Not quite, as caveats and questions remain with their interpretation and performance.…”

“…The repeated absence of urinary GIP at two or more visits was significantly related to the absence of enteropathy (94%). Thus, the value of GIP testing is its high negative predictive value for villous atrophy conferred by a consistently negative test 7,8 …”

Editorial: coeliac disease follow‐up guided by gluten immunogenic peptides—are we there yet? Authors' reply

“…We thank Dr Tye-Din for his thoughtful comments 1 on our recent article on the clinical utility of urinary gluten immunogenic peptides (GIP) in the follow-up of patients with coeliac disease. 2 The determination of GIP in stool or urine is not meant to replace any tool of monitoring dietary adherence. Clinical and nutritional evaluation of the patient is basic, as is serological determination in the first months from beginning the gluten-free diet (GFD) until its normalisation.…”

“…We thank Dr Tye‐Din for his thoughtful comments 1 on our recent article on the clinical utility of urinary gluten immunogenic peptides (GIP) in the follow‐up of patients with coeliac disease 2 . The determination of GIP in stool or urine is not meant to replace any tool of monitoring dietary adherence.…”