The use of urine peptidomics to define dietary gluten peptides from patients with celiac disease and the clinical relevance.

INTRODUCTION: Determination of urinary gluten immunogenic peptides (GIP) has emerged as one of the most attractive test to monitor the adherence to the gluten-free diet (GFD) of patients with celiac disease (CD), being a simple, noninvasive and direct method to detect gluten contamination of the GFD. AREAS COVERED: We conducted a scoping review in Medline (PubMed) of articles published up to April 2023 that analyzed any aspect of the clinical relevance of the use of urinary GIP measurement in patients with CD. A total of 17 articles reporting the clinical use of urinary peptidomics for the follow-up of CD patients were finally included. EXPERT OPINION: Available data suggest that a negative urinary GIP result is a reliable noninvasive predictor of intestinal mucosa healing in CD patients treated with the GFD, especially if testing three urine samples on different days including the weekend. Due to conflicting results about the sensitivity and the specificity of the urinary GIP determination, additional in-depth information is needed, particularly related to (1) the relationship between the amount of ingested gluten and the quantity of urinary GIP excreted in treated CD patients, (2) the GIP kinetics and best timing for sample collection.

The Gluten-Free Diet for Celiac Disease and Beyond.

The gluten-free diet (GFD) has gained popularity beyond its main medical indication as the treatment for gluten-induced immune-mediated disorders such as celiac disease (CD), dermatitis herpetiformis, gluten ataxia, wheat allergy, and non-celiac gluten sensitivity. However, the diet carries some disadvantages such as elevated costs, nutritional deficiencies, and social and psychological barriers. The present work aims to review indications, proven benefits, and adverse events of a gluten-free diet. Close follow-up with patients following the diet is recommended. More data is needed to assess the effectiveness of the diet in managing mental and cognitive disorders and to establish a connection between the brain and gluten.

Determination of Urinary Gluten Immunogenic Peptides to Assess Adherence to the Gluten-Free Diet: A Randomized, Double-Blind, Controlled Study.

INTRODUCTION: The adherence to a gluten-free diet (GFD) is a trending topic in the management of celiac disease. The aim of our study was to evaluate the diagnostic performance of urinary gluten immunogenic peptides (GIP) determination to detect gluten contamination of the GFD. METHODS: In study A, 25 healthy adults on a standard GFD performed 6 gluten challenges (0, 10, 50, 100, 500, and 1,000 mg) with quantification of urinary GIP before (T0) and during the following 24 hours. In study B, 12 participants on a gluten contamination elimination diet underwent urinary GIP determination at T0 and after challenge with 5 or 10 mg gluten. Urine GIP concentration was determined by an immunochromatographic assay. RESULTS: In study A, 51 of 150 baseline urine samples were GIP+ on GFD and 7 of 17 were GIP+ after the zero-gluten challenge, whereas only 55 of 81 were GIP+ after the 10-1,000 mg gluten challenges. There was no significant change in the 24-hour urinary GIP when increasing gluten from 10 to 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 10-1,000 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.

Iodine Absorption in Celiac Children: A Longitudinal Pilot Study.

Background: non-autoimmune thyroid disorder is a common finding in celiac patients, more frequent than in the general population. An impairment of iodine absorption has been hypothesized, but it has never been investigated so far. We aimed to evaluate the iodine absorption in children and adolescents with newly diagnosed celiac disease. Methods: 36 consecutive celiac patients (age 7.4 years, range 2.4-14.5 years) before starting a gluten-free diet (GFD) were enrolled. We assayed the urinary iodine concentration (UIC) in a 24-h urine sample, at baseline (T0) after 3 (T1) and 12 months (T2) of GFD. Results: UIC at T0 was 64 µg/L (IQR 45-93.25 µg/L) with an iodine deficiency rate of 77.8%. UIC was not different according to histological damage, clinical presentation (typical vs atypical); we found no correlation with the thyroid function tests and auxological parameters. UIC was not statistically different at T1 (76 µg/L) and T2 (89 µg/L) vs T0. UIC at T2 was similar between patients with positive and negative anti-transglutaminase antibodies at T2. No patients presented overt hypothyroidism during the study. Conclusions: We found that iodine absorption in celiac children is impaired compared to the general population; it increases slightly, but not significantly, during the GFD. We should regularly reinforce the need for a proper iodine intake in celiac disease patients to reduce iodine deficiency risk.

Exposure sources, amounts and time course of gluten ingestion and excretion in patients with coeliac disease on a gluten-free diet.

BACKGROUND: A major deficit in understanding and improving treatment in coeliac disease (CD) is the lack of empiric data on real world gluten exposure. AIMS: To estimate gluten exposure on a gluten-free diet (GFD) using immunoassays for gluten immunogenic peptides (GIP) and to examine relationships among GIP detection, symptoms and suspected gluten exposures METHODS: Adults with biopsy-confirmed CD on a GFD for 24 months were recruited from a population-based inception cohort. Participants kept a diary and collected urine samples for 10 days and stools on days 4-10. 'Doggie bags' containing » portions of foods consumed were saved during the first 7 days. Gluten in food, stool and urine was quantified using A1/G12 ELISA. RESULTS: Eighteen participants with CD (12 female; age 21-70 years) and three participants on a gluten-containing diet enrolled and completed the study. Twelve out of 18 CD participants had a median 2.1 mg gluten per exposure (range 0.2 to >80 mg). Most exposures were asymptomatic and unsuspected. There was high intra-individual variability in the interval between gluten ingestion and excretion. Participants were generally unable to identify the food. CONCLUSIONS: Gluten exposure on a GFD is common, intermittent, and usually silent. Excretion kinetics are highly variable among individuals. The amount of gluten varied widely, but was typically in the milligram range, which was 10-100 times less than consumed by those on an unrestricted diet. These findings suggest that a strict GFD is difficult to attain, and specific exposures are difficult to detect due to variable time course of excretion.

Negative predictive value of the repeated absence of gluten immunogenic peptides in the urine of treated celiac patients in predicting mucosal healing: new proposals for follow-up in celiac disease.

BACKGROUND: The treatment of celiac disease (CD) is a lifelong gluten-free diet (GFD). The current methods for monitoring GFD conformance, such as a dietary questionnaire or serology tests, may be inaccurate in detecting dietary transgressions, and duodenal biopsies are invasive, expensive, and not a routine monitoring technique. OBJECTIVES: Our aim was to determine the clinical usefulness of urine gluten immunogenic peptides (GIP) as a biomarker monitoring GFD adherence in celiac patients and to evaluate the concordance of the results with the degree of mucosal damage. METHODS: A prospective observational study was conducted involving 22 de novo CD patients, 77 celiac patients consuming a GFD, and 13 nonceliac subjects. On 3 d of the week, urine samples were collected and the GIP concentrations were tested. Simultaneously, anti-tissue transglutaminase antibodies, questionnaire results, clinical manifestations, and histological findings were analyzed. RESULTS: Approximately 24% (18 of 76) of the celiac patients consuming a GFD exhibited Marsh II-III mucosal damage. Among this population, 94% (17 of 18) had detectable urine GIP; however, between 60% and 80% were asymptomatic and exhibited negative serology and appropriate GFD adherence based on the questionnaire. In contrast, 97% (31 of 32) of the celiac patients without duodenal damage had no detectable GIP. These results demonstrated the high sensitivity (94%) and negative predictive value (97%) of GIP measurements in relation to duodenal biopsy findings. In the de novo CD-diagnosed cohort, 82% (18 of 22) of patients had measurable amounts of GIP in the urine. CONCLUSIONS: Determining GIP concentrations in several urine samples may be an especially convenient approach to assess recent gluten exposure in celiac patients and appears to accurately predict the absence of histological lesions. The introduction of GIP testing as an assessment technique for GFD adherence may help in ascertaining dietary compliance and to target the most suitable intervention during follow-up.

Abnormalities in metabolic pathways in celiac disease investigated by the metabolic profiling of small intestinal mucosa, blood plasma and urine by NMR spectroscopy.

Celiac disease (CeD) is an autoimmune enteropathy caused by gluten intake in genetically predisposed individuals. We investigated the metabolism of CeD by metabolic profiling of intestinal mucosa, blood plasma and urine using NMR spectroscopy and multivariate analysis. The metabolic profile of the small intestinal mucosa was compared between patients with CeD (n = 64) and disease controls (DCs, n = 30). The blood plasma and urinary metabolomes of CeD patients were compared with healthy controls (HCs, n = 39). Twelve metabolites (proline (Pro), arginine (Arg), glycine (Gly), histidine (His), glutamate (Glu), aspartate, tryptophan (Trp), fumarate, formate, succinate (Succ), glycerophosphocholine (GPC) and allantoin (Alln)) of intestinal mucosa differentiated CeD from controls. The metabolome of blood plasma with 18 metabolites (Pro, Arg, Gly, alanine, Glu, glutamine, glucose (Glc), lactate (Lac), acetate (Ace), acetoacetate (AcAc), ß-hydroxybutyrate (ß-OHB), pyruvate (Pyr), Succ, citrate (Cit), choline (Cho), creatine (Cr), phosphocreatine (PCr) and creatinine) and 9 metabolites of urine (Pro, Trp, ß-OHB, Pyr, Succ, N-methylnicotinamide (NMN), aminohippurate (AHA), indoxyl sulfate (IS) and Alln) distinguished CeD from HCs. Our data demonstrated changes in nine metabolic pathways. The altered metabolites were associated with increased oxidative stress (Alln), impaired healing and repair mechanisms (Pro, Arg), compromised anti-inflammatory and cytoprotective processes (Gly, His, NMN), altered energy metabolism (Glc, Lac, ß-OHB, Ace, AcAc, Pyr, Succ, Cit, Cho, Cr and PCr), impaired membrane metabolism (GPC and Cho) and intestinal dysbiosis (AHA and IS). An orthogonal partial least square discriminant analysis model provided clear differentiation between patients with CeD and controls in all three specimens. A classification model built by combining the distinguishing metabolites of blood plasma and urine samples gave an AUC of 0.99 with 97.7% sensitivity, 93.3% specificity and a predictive accuracy of 95.1%, which was higher than for the models built separately using small intestinal mucosa, blood plasma and urine. In conclusion, a panel of metabolic biomarkers in intestinal biopsies, plasma and urine samples has potential to differentiate CeD from controls and may complement traditional tests to improve the diagnosis of CeD.

A compact SPR biosensor device for the rapid and efficient monitoring of gluten-free diet directly in human urine.

Celiac disease (CD) is a chronic autoimmune disorder induced in genetically susceptible individuals by the ingestion of gluten from wheat, rye, barley, or certain varieties of oats. A careful diet follow-up is necessary to avoid health complications associated with long-term gluten intake by the celiac patients. Small peptides (GIP, gluten immunogenic peptides) derived from gluten digestion, which are excreted in the urine and feces, have emerged as promising biomarkers to monitor gluten intake. We have implemented a simple and sensitive label-free point-of-care (POC) device based on surface plasmon resonance for the direct detection of these biomarkers in urine. The assay employs specific monoclonal antibodies and has been optimized for the detection of the 33-mer α2-gliadin, known as the main immunogenic peptide of wheat gluten, and for the detection of GIP. Direct detection in undiluted urine has been accomplished by using biosensing chips containing a robust and stable biorecognition layer, obtained after carefully optimizing the biofunctionalization protocol. Excellent limits of detection have been reached (1.6-4.0 ng mL-1 using mAb G12 and A1, respectively), which ensures the detection of gluten peptides even when the gluten intake is around the maximum tolerable amount in the digestive tract (< 50 mg) for celiac individuals. No sample pretreatment, extraction, or dilution is required, and the analysis takes less than 15 min. The assays have excellent reproducibility' as demonstrated by measuring spiked urine samples containing the same target concentration using different biofunctionalized chips prepared and stored at different periods of time (i.e., CV% of 3.58% and 11.30%, for G12- and A1-based assays, respectively). The assay has been validated with real samples. These features pave the way towards an end-user easy-to-handle biosensor device for the rapid monitoring of gluten-free diet (GFD) and follow-up of the health status in celiac patients.

Oxidative stress, DNA stability and evoked inflammatory signaling in young celiac patients consuming a gluten-free diet.

PURPOSE: Celiac disease (CD) is a multifactorial, autoimmune, gluten-sensitive inflammatory disorder of the small intestine. Taking into account the pathogenesis of CD, a strict gluten-free diet (GFD) is the only treatment able to restore epithelium integrity and eliminate complications. The current study was designed to assess whether the use of a GFD is sufficient for maintaining a correct oxidative/antioxidant balance and ameliorating the evoked inflammatory signaling in young patients with CD. METHODS: The study covered 80 children, aged between 7 and 18 years, attending the Gastroenterology Service of the Gastroenterology, Hepatology and Child Nutrition Service from the Virgen de las Nieves Hospital in Granada. Children with CD diagnosed were included in the celiac group who followed a strict GFD for 2 years (n = 40) and the control group (n = 40) included healthy children, with negative serological screening. Soluble superoxide dismutase 1 and 2, total antioxidant status, 8-hydroxy-2'-deoxyguanosine, cortisol, melatonin and inflammatory parameters in plasma, 15-F2t-isoprostanes in urine, and DNA breaks in peripheral blood lymphocytes were analysed. RESULTS: No differences were found in oxidative stress between CD patients and controls; however, IFN-γ, IL-1α, IP-10 and TNF-ß were higher in the CD patients. VEGF was also higher than in the control group. CONCLUSION: The GFD in the CD patients is enough to reduce the oxidative stress; however, in the case of the inflammatory signaling, the initial exposure to gluten prior to stablish the GFD is strong enough to induce an inflammatory state which is maintained (even when consuming the GFD); meanwhile the increase in VEGF recorded in the CD group could be a compensatory mechanism to restore the damaged mucosa and duodenal villous atrophy, due to its role in endothelial activation and generation of new functional and stable vascular networks.

The Profile of Urinary Headspace Volatile Organic Compounds After 12-Week Intake of Oligofructose-Enriched Inulin by Children and Adolescents with Celiac Disease on a Gluten-Free Diet: Results of a Pilot, Randomized, Placebo-Controlled Clinical Trial.

The concentration of volatile organic compounds (VOCs) can inform about the metabolic condition of the body. In the small intestine of untreated persons with celiac disease (CD), chronic inflammation can occur, leading to nutritional deficiencies, and consequently to functional impairments of the whole body. Metabolomic studies showed differences in the profile of VOCs in biological fluids of patients with CD in comparison to healthy persons; however, there is scarce quantitative and nutritional intervention information. The aim of this study was to evaluate the effect of the supplementation of a gluten-free diet (GFD) with prebiotic oligofructose-enriched inulin (Synergy 1) on the concentration of VOCs in the urine of children and adolescents with CD. Twenty-three participants were randomized to the group receiving Synergy 1 (10 g per day) or placebo for 12 weeks. Urinary VOCs were analyzed using solid-phase microextraction and gas chromatography⁻mass spectrometry. Sixteen compounds were identified and quantified in urine samples. The supplementation of GFD with Synergy 1 resulted in an average concentration drop (36%) of benzaldehyde in urine samples. In summary, Synergy 1, applied as a supplement of GFD for 12 weeks had a moderate impact on the VOC concentrations in the urine of children with CD.

Gluten immunogenic peptide excretion detects dietary transgressions in treated celiac disease patients.

BACKGROUND: Life-long removal of gluten from the diet is currently the only way to manage celiac disease (CeD). Until now, no objective test has proven useful to objectively detect ingested gluten in clinical practice. Recently, tests that determine consumption of gluten by assessing excretion of gluten immunogenic peptides (GIP) in stool and urine have been developed. Their utility, in comparison with conventional dietary and analytical follow-up strategies, has not been fully established. AIM: To assess the performance of enzyme-linked immunosorbent assay (ELISA) and point-of-care tests (PoCTs) for GIP excretion in CeD patients on gluten-free diet (GFD). METHODS: We conducted an observational, prospective, cross-sectional study in patients following a GFD for at least two years. Using the Gastrointestinal Symptom Rating Scale questionnaire, patients were classified at enrollment as asymptomatic or symptomatic. Gluten consumption was assessed twice by 3-d dietary recall and GIP excretion (by ELISA in stool and PoCTs (commercial kits for stool and urine) in two consecutive samples. These samples and dietary reports were obtained 10 day apart one from the other. Patients were encouraged to follow their usual GFD during the study period. RESULTS: Forty-four patients were enrolled, of which 19 (43.2%) were symptomatic despite being on a GFD. Overall, 83 sets of stool and/or urine samples were collected. Eleven out of 44 patients (25.0%) had at least one positive GIP test. The occurrence of at least one positive test was 32% in asymptomatic patients compared with 15.8% in symptomatic patients. GIP was concordant with dietary reports in 65.9% of cases (Cohen´s kappa: 0.317). PoCT detected dietary indiscretions. Both ELISA and PoCT in stool were concordant (concomitantly positive or negative) in 67 out of 74 (90.5%) samples. Excretion of GIP was detected in 7 (8.4%) stool and/or urine samples from patients considered to be strictly compliant with the GFD by dietary reports. CONCLUSION: GIP detects dietary transgressions in patients on long-term GFD, irrespective of the presence of symptoms. PoCT for GIP detection constitutes a simple home-based method for self-assessment of dietary indiscretions.

Genetic predictors of celiac disease, lactose intolerance, and vitamin D function and presence of peptide morphins in urine of children with neurodevelopmental disorders.

Gastrointestinal disturbances, nutritional deficiencies, and food intolerances are frequently observed in children with neurodevelopmental disorders (NDD). To reveal possible association of celiac disease risk variants (HLA-DQ), lactose intolerance associated variant (LCT-13910C>T) as well as variant associated with vitamin D function (VDR FokI) with NDD, polymerase chain reaction-based methodology was used. Additionally, intestinal peptide permeability was estimated in NDD patients and healthy children by measuring the level of peptides in urine using high-performance liquid chromatography. Levels of opioid peptides, casomorphin 8, and gluten exorphin C were significantly elevated in urine samples of NDD patients (P = 0.004 and P = 0.005, respectively), but no association of genetic risk variants for celiac disease and lactose intolerance with NDD was found. Our results indicate that increased intestinal peptide permeability observed in analyzed NDD patients is not associated with genetic predictors of celiac disease or lactose intolerance. We have also found that FF genotype of VDR FokI and lower serum levels of vitamin D (25-OH) showed association with childhood autism (CHA), a subgroup of NDD. We hypothesize that vitamin D might be important for the development of CHA.

Metabolic Signature of Primary Biliary Cholangitis and Its Comparison with Celiac Disease.

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by ongoing inflammatory destruction of the interlobular bile ducts, eventually leading to chronic cholestasis and biliary cirrhosis. This study primarily aims to define the metabolomic signature of PBC after comparison with healthy controls (HC). Second, it aims to evaluate the possible metabolic association between PBC and celiac disease (CD), an immune-mediated disorder frequently associated with PBC. Serum and urine samples from 20 PBC, 21 CD, and 19 sex-matched HC subjects were collected. 1H nuclear magnetic resonance (NMR) spectra for all samples were acquired, and multivariate statistics were used to evaluate the differences among the three groups and to provide information about the involved metabolites. The classification accuracies to discriminate PBC and HC groups were 78.9-84.6% for serum and 76.9% for urine. In comparison to HC, PBC patient sera were characterized by altered levels ( p value <0.05) of pyruvate, citrate, glutamate, glutamine, serine, tyrosine, phenylalanine, and lactate. PBC patient urine showed lower levels ( p value <0.05) of trigonelline and hippurate with respect to HC. Furthermore, the NMR metabolomic fingerprint was able to cluster PBC with respect to CD patients, and the classification accuracies in the discriminations between these groups were 81.9-91.7% for serum and 77.7% for urine. Our results show that PBC displays a unique metabolomic fingerprint, which led to speculation about an impaired energy metabolism, probably associated with an altered gut microbiota. PBC and CD showed two distinct metabolic fingerprints. These data could provide clues for the comprehension of the PBC pathogenetic mechanisms and the detection of novel therapeutic targets.

Noninvasive biomarkers of gut barrier function identify two subtypes of patients suffering from diarrhoea predominant-IBS: a case-control study.

BACKGROUND: Alterations of the small-intestinal permeability (s-IP) might play an essential role in both diarrhoea-predominant IBS (D-IBS) and celiac disease (CD) patients. Our aims were to analyse in D-IBS patients the symptom profile along with the levels of urinary sucrose (Su), lactulose (La), mannitol (Ma), and circulating biomarkers (zonulin, intestinal fatty acid binding protein - I-FABP, and diamine oxidase - DAO) of the gastrointestinal (GI) barrier function. The pro-inflammatory interleukins 6 and 8 (IL-6 and IL-8), the plasma values of lipopolysaccharide (LPS), and Toll-like receptor 4 (TLR-4) were also investigated. Besides, these biomarkers were compared with those in CD and healthy controls (HC). Finally, comparisons were performed between D-IBS patients with [D-IBS(+)] and without [D-IBS(-)] increased s-IP according to normal or altered La/Ma ratio. METHODS: The study included 39 D-IBS patients, 32 CD patients, and 20 HC. GI permeability was assayed by high-performance liquid chromatography determination in the urine of Su and La/Ma ratio. ELISA kits assayed circulating concentrations of zonulin, I-FABP, DAO, IL-6, IL-8, LPS, and TLR-4. The Mann-Whitney or the Kruskal-Wallis with Dunn's post-test was used to assess differences among the groups. RESULTS: As for the La/Ma ratio, %Su, and I-FABP levels, D-IBS patients were significantly different from CD, but not HC. IL-6 levels were significantly higher in CD than HC, whereas IL-8 levels were significantly higher in both D-IBS and CD patients than HC. By opposite, LPS, and TLR-4 concentrations did not differ significantly among the groups. When D-IBS patients were categorised according to normal or altered s-IP, D-IBS(+) patients had %La, %Su, I-FABP, and DAO levels significantly higher than D-IBS(-) ones. The inflammatory parameters and markers of bacterial translocation (namely, IL-6 and LPS) were significantly higher in D-IBS(+) patients than D-IBS(-) ones. CONCLUSIONS: The present study suggests that two distinct D-IBS subtypes could be identified. The investigation of possible s-IP alterations (i.e., considering the La/Ma ratio) might be useful to assess better and categorise this heterogeneous D-IBS population. TRIAL REGISTRATION: NCT01574209 . Registered March 2012. First recruitment started in April 2012.

Plasma profile and urine excretion of amino acids in children with celiac disease on gluten-free diet after oligofructose-enriched inulin intervention: results of a randomised placebo-controlled pilot study.

The circulating amino acid (AAs) concentrations are indicators of dietary protein intake and metabolic status. In celiac disease (CD), the AA imbalance is frequently observed. Prebiotics are found to alleviate nutrient deficiencies. Therefore, the aim of this study was to analyse the impact of oligrofructose-enriched inulin (Synergy 1), administered for 3 months as a gluten-free diet (GFD) supplement to children with CD, on the plasma and urine concentrations of AAs. CD children (N = 34) were randomised into two groups, receiving Synergy 1 (10 g/day) or placebo (maltodextrin) for 3 months. The AA profile and concentration was determined in plasma and urine before and after the dietary intervention by gas chromatography. 22 and 28 AAs were determined in plasma and urine samples, respectively. After the intervention, the plasma concentrations of several AAs (Ala, Pro, Asn, Glu, Tyr, Lys, His, Orn) increased significantly in both experimental groups, while Gln increased only in the Synergy 1 group. The urinary excretion of Asn, Lys and Aaa increased significantly in the Synergy 1 group, and the excretion of Asp and Met decreased (p < 0.05) in the placebo group. The Gln:Glu ratio in urine increased in both groups after the intervention. An increased urinary excretion of AAs observed in Synergy 1 group with a simultaneous increase in the content of circulating AAs could be attributed to higher absorption or intensified metabolism of AAs, and on the other hand further healing of the intestinal mucosa being the result of continuous treatment with GFD. Moreover, the observed changes in Glu concentration suggest that oligofructose-enriched inulin could improve the intestinal condition and permeability. To conclude, a prebiotic-supplemented GFD influences beneficially the overall AAs metabolism in CD children; however, further prospective cohort studies are needed to confirm the results obtained.

Detection of gluten immunogenic peptides in the urine of patients with coeliac disease reveals transgressions in the gluten-free diet and incomplete mucosal healing.

OBJECTIVE: Gluten-free diet (GFD) is the only management for coeliac disease (CD). Available methods to assess GFD compliance are insufficiently sensitive to detect occasional dietary transgressions that may cause gut mucosal damage. We aimed to develop a method to determine gluten intake and monitor GFD compliance in patients with CD and to evaluate its correlation with mucosal damage. DESIGN: Urine samples of 76 healthy subjects and 58 patients with CD subjected to different gluten dietary conditions were collected. A lateral flow test (LFT) with the highly sensitive and specific G12 monoclonal antibody for the most dominant gluten immunogenic peptides (GIP) and a LFT reader were used to quantify GIP in solid-phase extracted urines. RESULTS: GIP were detectable in concentrated urines from healthy individuals previously subjected to GFD as early as 4-6 h after single gluten intake, and remained detectable for 1-2 days. The urine assay revealed infringement of the GFD in about 50% of the patients. Analysis of duodenal biopsies revealed that most of patients with CD (89%) with no villous atrophy had no detectable GIP in urine, while all patients with quantifiable GIP in urine showed incomplete intestinal mucosa recovery. CONCLUSION: GIP are detected in urine after gluten consumption, enabling a new and non-invasive method to monitor GFD compliance and transgressions. The method was sensitive, specific and simple enough to be convenient for clinical monitoring of patients with CD as well as for basic and clinical research applications including drug development. TRIAL REGISTRATION NUMBER: NCT02344758.

Are Treated Celiac Patients at Risk for Mycotoxins? An Italian Case-Study.

Urinary biomarkers of mycotoxin exposure were evaluated in a group of celiac patients (n = 55) and in a control group of healthy subjects (n = 50) following their habitual diet. Deoxynivalenol (DON), zearalenone (ZEN), and fumonisin B1 (FB1) were monitored in 105 urinary samples collected from the two groups. Dietary habits were also recorded through compilation of a seven-day weighed dietary diary. Biomarkers of mycotoxin exposure were detected in 21 celiac patients and in 15 control subjects, corresponding to about 34% of total participants. In particular, ZEN was the most detected mycotoxin among all the studied subjects with a total of 19 positive cases. Results did not show a statistically significant difference in mycotoxin exposure between the two groups, and the presence of specific mycotoxins was not related to the intake of any particular food category. Our findings suggest little urgency of specific regulation for gluten free products, although the prevalence of exposure observed in free-living diets of both celiac and healthy subjects underlines the need of a constant surveillance on mycotoxins occurrence at large.

The urinary inflammatory profile in gluten free diet-adherent adolescents with type 1 diabetes and celiac disease.

AIMS: Our objective was to characterize urinary cytokine/chemokine excretion in adolescents with type 1 diabetes (T1D) and celiac disease (CD) adhering to gluten free diet (GFD) compared to matched T1D patients and healthy control (HC) group from an existing cohort. METHODS: Eighteen T1D+CD+GFD patients aged 10-16years were identified and matched 2:1 for age, sex, diabetes duration and glycated hemoglobin to 36 T1D subjects and 36 HC. T1D+CD+GFD patients were adherent with a GFD. Urine and serum levels of cytokines/chemokines as well as baseline clinical and laboratory variables were assessed. RESULTS: T1D+CD+GFD patients exhibited lower levels of urinary IL-1B, IL-4, IL-5 (p<0.05) and IFN-γ, IL-8 and G-CSF levels (p<0.07) compared with T1D patients. Urinary biomarker levels between T1D+CD+GFD and HC were mostly similar. In contrast, urinary FGF-2, Flt-3, IL-1B, IL-1RA, IL-4, IL-5, IL-9, IL-10, IL-12p40, IL-15, MIP-1ß, and TNF-ß (p<0.05) were higher in T1D patients compared to HC. Similar levels of inflammatory markers were seen in the serum for all 3 groups. CONCLUSIONS: T1D+CD+GFD patients demonstrated decreased urinary inflammatory cytokine/chemokines compared to T1D and some similar to HC, which is suggestive of a potential modulatory role of treated CD on urinary markers.

Urinary polyaromatic hydrocarbons are associated with adult celiac disease and kidney stones: USA NHANES, 2011-2012.

Links between environmental chemicals and human health have emerged over the last few decades, but the effects from polyaromatic hydrocarbons (PAH) were less studied, compared to other commonly known environmental chemicals such as heavy metals, phthalates, arsenic, phenols, and pesticides. Therefore, it was aimed to study the relationships of urinary PAH and adult digestive conditions using a large human sample in a national and population-based study in recent years. Data was retrieved from the US National Health and Nutrition Examination Surveys, 2011-2012 including demographics, self-reported health conditions, and urinary PAH. Statistical analyses included chi-square test, t test, survey-weighted logistic regression modeling, and population attributable risk (PAR) estimation. Of 5560 American adults aged 20-80 and included in the statistical analysis, urinary 4-hydroxyphenanthrene was significantly associated with celiac disease (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.14-2.26, P = 0.009). In addition, urinary 2-hydroxyfluorene (OR 1.35, 95% CI 1.02-1.78, P = 0.038), 3-hydroxyfluorene (OR 1.35, 95% CI 1.07-1.70, P = 0.015), 1-hydroxyphenanthrene (OR 1.48, 95% CI 1.08-2.03, P = 0.017), 1-hydroxypyrene (OR 1.36, 95% CI 1.05-1.77, P = 0.023), and 2-hydroxynapthalene (OR 1.25, 95% CI 1.00-1.58, P = 0.054) were significantly associated with kidney stones, although not necessarily failing kidney. There were no statistically significant associations observed in the relationship of urinary PAH and liver problems, although higher levels of PAHs were observed. Urinary PAHs are associated with adult digestive conditions, although the causality cannot be established. From the research perspective, longitudinal monitoring from observational studies and experimental research understanding mechanism would be suggested. Regulation of minimizing PAHs exposure might need to be considered in future health and environmental policies.

Label-free SPR detection of gluten peptides in urine for non-invasive celiac disease follow-up.

Motivated by the necessity of new and efficient methods for dietary gluten control of celiac patients, we have developed a simple and highly sensitive SPR biosensor for the detection of gluten peptides in urine. The sensing methodology enables rapid and label-free quantification of the gluten immunogenic peptides (GIP) by using G12 mAb. The overall performance of the biosensor has been in-depth optimized and evaluated in terms of sensitivity, selectivity and reproducibility, reaching a limit of detection of 0.33 ng mL(-1). Besides, the robustness and stability of the methodology permit the continuous use of the biosensor for more than 100 cycles with excellent repeatability. Special efforts have been focused on preventing and minimizing possible interferences coming from urine matrix enabling a direct analysis in this fluid without requiring extraction or purification procedures. Our SPR biosensor has proven to detect and identify gluten consumption by evaluating urine samples from healthy and celiac individuals with different dietary gluten conditions. This novel biosensor methodology represents a novel approach to quantify the digested gluten peptides in human urine with outstanding sensitivity in a rapid and non-invasive manner. Our technique should be considered as a promising opportunity to develop Point-of-Care (POC) devices for an efficient, simple and accurate gluten free diet (GFD) monitoring as well as therapy follow-up of celiac disease patients.