Published online Oct 7, 2021. doi: 10.3748/wjg.v27.i37.6306
Peer-review started: March 22, 2021
First decision: June 14, 2021
Revised: June 28, 2021
Accepted: September 2, 2021
Article in press: September 2, 2021
Published online: October 7, 2021
A lifelong strict gluten-free diet (GFD) is the only available treatment for celiac disease (CeD), which reduces symptoms and allows the healing of the intestinal mucosa, preventing long-term complications. However, total exclusion of gluten is difficult to achieve in practice and voluntary and involuntary transgressions are highly frequent.
Gluten immunogenic peptides (GIP) detection in stool and urine is becoming increasingly apparent as a noninvasive and reliable marker for close and efficient GFD monitoring in patients with CeD.
The authors aimed to summarize published data regarding the performance of GIP determination in stool and urine in comparison to other available tools in assessing GFD adherence in patients with CeD.
The authors conducted a systematic review searching in PubMed and Web of Science clinical studies that reported the performance of GIP determination in stool and/or urine with other biomarkers for the evaluation of treatment adherence in adult and pediatric patients with CeD.
The authors screened 67 articles and 15 articles were included for full-text analysis. In the selected publications GIP determination in stool and/or urine were compared with at least one of the following markers: levels of CeD-specific serology, results from CeD-specific non-specific questionnaires, symptomatology, and duodenal biopsy. Fecal determination by ELISA was the most investigated GIP marker, followed by urine rapid test and stool rapid test. Variability was seen in the concordance between the different tools among the studies reviewed due to the differences found in the study design, the target population, and the methods used. One of the main outcome measures reviewed was the diagnostic accuracy of these tools in assessing mucosal healing. An association of mucosal status and GIP detection was observed in some publications, where serology, questionnaires, and symptomatology showed lower sensitivity. Furthermore, GIP detection may help in symptomatic patients to determine whether non-responsive CeD or refractory CeD occurs due to recurrent gluten exposure or due to additional factors.
The introduction of GIP detection in stool and/or urine as a non-invasive marker for GFD monitoring in patients with CeD may reduce health expenditure by preventing future complications arising from gluten exposure not detectable by other tools in use. Stool and urine rapid tests may be an option for disease self-managing by the patient, while fecal ELISA test could be used for GIP quantification in the laboratory.
The introduction of algorithms for GIP determination within the follow-up of patients with CeD in guidelines will allow its routine use in clinical practice. In addition, future studies may also determine their utility for other applications such as the confirmation of gluten consumption during the diagnosis process or the investigation of gluten metabolism.