Introduction
Gluten free diet (GFD) is the one therapy for patients affected by celiac disease (CD). Dietary products are considered safe (“without” gluten) when containing less of 20 ppm (20 mg/kg). CD diagnosis is quite simple in most cases, however some patients start GFD before the serological and histological approach, so significantly complicating the CD diagnostic work-up. In these cases, the Oslo guidelines for CD suggest a 14-day gluten intake > 3 gr (about 2 slices of bread/day) to induce serological and histological changes in most CD patients; though, many subjects refuse this method being fearful for symptoms reviving (1). In 2007, Catassi showed that the intake of a daily dose of 50 mg/day of gluten for 3 months was able to determine villous atrophy and serological positivity in most CD patients (2).
Aims & Methods
Aims: Starting from these considerations, we performed a pilot dietary study administering a daily low-dose of gluten in form of a package of “crackers” (2-4 crackers/day; about 60-120 mg of gluten/day) for 3 months, in order to detect serological/histological activation in subjects with doubt CD already on “self-prescribed” GFD.
Methods: From May 2019 to September 2022, all DQ2/DQ8+ adult patients with a doubt of CD who had started a self-prescribed GFD before the diagnostic work-up and that had refused the traditional gluten challenge. All patients were recruited at Gastroenterology Unit of University of Naples and Salerno. All subjects were invited to continue their GFD by adding a half (or full) package of crackers containing gluten for a 3-months period. At the end of 3 months, all patients were analysed for the presence of Ab anti-transglutaminases (a-tTG), anti-endomisyal antibodies (EMA) and deamidated gluten peptited (DGP). All patients with positive serology underwent endoscopic/histological evaluation. The diagnosis of CD was made by histology in accordance with Marsh-Oberhuber classification. Furthermore, the grade of satisfaction for this kind of challenge diet and the possible onset of adverse events were recorded. Patient’s satisfaction about this kind of challenge was evaluated by a simple VAS (1-10).
Results
At the end, we enrolled 120 patients (M/F 42/78; mean age 38 years). All patients could terminate the study without relevant adverse events. Serological positivity/activation was detected in 54 patients (45%): positive a-tTG: 51 patients; EMA (slight/full) positivity: 49 patients; DGP positivity: 48 patients. At histology, 47 (88%) were atrophic, while 7 subjects showed a Marsh 1-2 grade. The remaining 66 patients continued the trial for further 3 months without substantial serological modifications and, finally, were considered as not CD patients. Regarding patient’s satisfaction, 99 patients (83%) resulted to be satisfied and reassured by this dietary approach. About adverse events, 15 patients (12%) recorded bloating, 12 (10%) mild pain and 8 (6%) mild diarrhoea.
Conclusion
Low-dose gluten diet by using “crackers” could be a very simple, useful, and safe diagnostic approach in subject with doubt of CD who had start a GFD before the regular diagnostic work-up for CD.
References
1) Ludvigsson JF et. Diagnosis and management of adult coeliac disease: guidelines from the British Society of Gastroenterology. Gut 2014;63:1210-28.
2) Catassi C et al. A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease. Am J Clin Nutr 2007 Jan;85(1):160-6.