Safety of occasional ingestion of gluten in patients with celiac disease: a real-life study

Background Gluten-free diet (GFD) decreases the quality of life of celiac disease (CD) patients, who frequently ask to occasionally ingest gluten-containing food. We evaluated CD patients reporting voluntary and occasional transgressions to their GFD. Methods From October 2017 to September 2018, the patients reporting occasional and voluntary gluten ingestion (GFD-noncompliant) were prospectively enrolled. These patients underwent clinical examination, blood tests, duodenal biopsy, capsule enteroscopy (CE), and a validated food-frequency questionnaire (FFQ) assessing the frequency and quantity of gluten intake. Mortality was calculated and compared to the general population. A group of patients on strict GFD (GFD-adherent) acted as controls. Results One thousand three hundred seventy-eight CD patients were evaluated during the study period. One hundred nine (8%) reported occasional (weekly or monthly) voluntary ingestion of gluten. The mean gluten intake was 185.2 +/- 336.9 g/year, and the duration of their incorrect GFD was 8.6 +/- 6.9 years. Among the noncompliant patients, 57% did not present any histological alteration; furthermore, the Marsh score profile was not different between compliant and noncompliant patients. Seventy percent did not present any alteration at CE. Seventy-five percent of patients reported no gastrointestinal symptoms after gluten ingestion. Twenty-three percent of patients in the GFD-noncompliant group presented positive tTG-IgA. No association was found between gluten intake, clinical symptoms, and biomarkers. Mortality was not different between the groups and the general population. Conclusions Our results are that in a real-life scenario, a group of CD patients on long-term gluten intake showed no significant clinical symptoms or small bowel damage, thus suggesting that a degree of tolerance towards gluten consumption can be reached.