Urinary Gluten Detection in Patients with Non-celiac Gluten/Wheat Sensitivity

Non-celiac gluten/wheat sensitivity (NCGS/NCWS) is a syndrome characterized by both intestinal (irritable bowel syndrome [IBS]-like presentation) and extraintestinal symptoms (headache, migraine, "foggy mind", depression, anxiety, fibromyalgia, joint and muscle pain, leg or arm numbness, eczema or skin rash), which occur after the ingestion of gluten/wheat in subjects in which celiac disease (CD) and wheat allergy diagnosis has been previously excluded. Recent data suggest that NCGS affect up to 3-6% of the general population, a higher prevalence than that reported for CD. NCGS/NCWS symptoms generally occur after the ingestion of gluten/wheat, disappear within a few days of a gluten-free diet (GFD) and quickly reappear when gluten/wheat is reintroduced. GDF is very difficult and onerous from a social (presence of gluten in many industrial food products and "contamination", both domestic and extra-domestic), psychological (e.g. for adolescents, exclusion from the "peer group", with difficulty in accepting the diagnosis) and economic point of view. A new assay, recently available on the Italian market, allows to ascertain the presence of immunogenic peptides of gluten (gluten immunogenic peptides, GIP) in the urine and stool. The test might allow to ascertain if the NCGS/NCWS patients, on GFD, eat even accidentally gluten. Of the 2 available assays, the urinary one allows the patient himself to test the presence of GIP in relation to symptoms/signs appearing and/or social activities (e.g. meal in a restaurant). The other one involves collecting a stool sample and allows to identify the gluten taken in the previous week, but it requires a laboratory, specifically equipped. To date, there are no observational studies that indicate the performance of the test in patients with NCGS/NCWS. The aims of the present study are: 1) to test, in patients with NCGS/NCWS on GFD, the adherence to the elimination diet; 2) to evaluate the correlation between the symptoms' reappearance and the presence of GIP in the urine.