Regression coefficients were estimated by 90% CI. study A, 51 of 150 baseline urine samples were GIP+ on Mcl1-IN-12 GFD and 7 of 17 were GIP+ after the zero-gluten challenge, whereas only 55 of 81 were GIP+ after the 10C1,000 mg gluten challenges. There was no significant change in the 24-hour urinary GIP when increasing gluten from 10 to 1 1,000 mg. In study B, 24 of 24 baseline urine samples were GIP?, whereas 8 of 24 were GIP+ after 5 or 10 mg of gluten. DISCUSSION: Traces of gluten in the standard GFD may cause positivity of urinary GIP determination, whereas a false negativity is common after a gluten intake of 10C1,000 mg. Owing to the impossibility of standardizing the test in normal conditions, it seems unlikely that urinary GIP determination may represent a reliable tool to assess the compliance to the GFD of patients with celiac disease or other gluten-related disorders. INTRODUCTION Celiac disease (CD) is a systemic autoimmune disorder triggered by the ingestion of gluten in genetically predisposed individuals (1). It is one of the Mcl1-IN-12 most frequent lifelong diseases, affecting approximately 1%C2% of the general population worldwide (2). A gluten-free diet (GFD), the only effective treatment of CD, determines clinical, serological, and histological remission and prevents long-term CD complications (3). However, a strict GFD is extremely difficult to maintain. Gluten is indeed a pervasive ingredient that may be used as a protein filler in a huge number of Mcl1-IN-12 commercial foods (e.g., sausages, soups, soy sauces, and hamburgers) or may contaminate originally gluten-free products in the production chain (4). Unfortunately, even traces of gluten in the diet (10 mg/d) are sufficient to cause damage to the celiac small intestinal mucosa when ingested repeatedly (5). Hence, it is very important to monitor GFD adherence of patients with CD. Dietary interview, clinical symptoms monitoring, CD serology, and small intestinal histology are significant choices; however, they provide only limited and indirect evidence of GFD adherence (6C8). Moreover, these tools are inadequately sensitive to detect the accidental exposure to traces of dietary gluten. Novel qualitative and quantitative immunochromatographic tests have been developed to directly detect recent dietary exposure to gluten by determining the excretion of gluten immunogenic peptides (GIP) in stools or urine (9C11). A growing interest has recently focused on the role of stool/urinary GIP determination in the follow-up of treated patients with CD, and this noninvasive and easy to perform test seems to be the most promising and reliable marker of dietary gluten transgressions (12C22). Inadequate information is available about the relationship between the amount of ingested gluten and the quantity of GIP excreted in urine or stool particularly at a low level of gluten ingestion (as is usually the case in treated patients with CD). The aim of this study was to assess the diagnostic performance of urinary GIP determination and the dose-response relationship between the amount of ingested gluten and the quantity of GIP recovered in urine, in a group of healthy and qualified volunteers adhering to a Mcl1-IN-12 GFD and undergoing repeated dietary challenges with increasing amounts of gluten. PATIENTS AND METHODS This study was a randomized, double-blind, controlled study aimed to investigate the relationship between the increasing amount of ingested gluten and the quantity of GIP in urine. Participants This study was conducted on a group of healthy young medical doctors who were all pediatric residents in the Division of Pediatrics at the DISCO Department of the Polytechnic University of Marche, Ancona, Italy. Written informed consent was obtained from each participant. The exclusion criteria were any chronic or acute disease, pregnancy or lactation, chronic intake of medications or supplements, or refusal/withdrawal of written informed consent. Before the study, serum immunoglobulin A (IgA) class anti-transglutaminase antibody was determined in all participants to exclude active CD. Study design Each participant underwent a random sequence of single-dose gluten Rabbit Polyclonal to ATP5G3 challenges, collection of all urine excreted during the.