“The crackers challenge”: A reassuring low-dose gluten challenge in adults on gluten-free diet without proper diagnosis of coeliac disease

Background: Gluten-free diet (GFD) is the one therapy in coeliac disease (CeD). Unfortunately, some patients adopt GFD before the diagnostic work-up. The guidelines suggest a 14-day gluten intake > 3 gr to get CeD diagnosis, although many subjects refuse this approach. Other evidence showed that the intake of 50 mg/day of gluten for 3 months could be useful for CeD diagnosis. Aims: We performed a dietary study, administering a low dose of gluten in form of "crackers" (about 60-120 mg of gluten/day) for 3 months, to get a final diagnosis of CeD in subjects already on GFD. Methods: We enrolled adult patients with a suspicion of CeD on self-prescribed GFD. All subjects performed the crackers challenge for 3 months. At the end, all patients were analysed for CeD serology and if positive underwent endoscopy/histology. Also, we recorded the grade of satisfaction for the gluten challenge and the onset of adverse events. Results: We enrolled 120 patients. All patients concluded the challenge without relevant adverse events. Serological positivity was detected in 54 patients (45%). Histology showed atrophy in 87% and Marsh 1-2 grade in 13% of patients. Ninety-nine patients (83%) were satisfied by this challenge. Conclusions: The "crackers challenge" is a useful and safe diagnostic approach in people on self-administered GFD.