Stool Gluten Peptide Detection Is Superior to Urinary Analysis, Coeliac Serology, Dietary Adherence Scores and Symptoms in the Detection of Intermittent Gluten Exposure in Coeliac Disease: A Randomised, Placebo-Controlled, Low-Dose Gluten Challenge Study.

Monitoring adherence to a gluten-free diet is an important goal of coeliac disease management. Urine and stool gluten immunogenic peptide (GIP) assays provide an objective readout of gluten ingestion, with the former favoured due to its convenience and acceptability. This study assessed stool GIP excretion after low-dose gluten challenge designed to mimic accidental gluten exposure. A total of 52 coeliac participants undertook a randomised, double-blind gluten (50-1000 mg) or placebo challenge. Stool and urinary GIP, serology, dietary adherence and symptoms were assessed. Stool GIP was 100% sensitive for gluten intake ≥250 mg and 71% for 50 mg. Peak GIP detection was 12-36 h after gluten exposure. The mean stool GIP after 1000 mg gluten ingestion remained above the limit of quantification for 5 days. Urine GIP assessment had poor sensitivity for GIP excretion compared to stool. Serology, dietary adherence score and symptoms did not correlate with gluten excretion during lead-in. We conclude that stool GIP detection is highly sensitive, with levels related to gluten dose and time from ingestion. Weekly or bi-weekly testing will detect low-level exposure more effectively than urine GIP assessments or traditional methods. In this seronegative, apparently well-treated cohort, a high frequency of baseline-positive GIP suggests ongoing gluten exposure, but the assessment of patient behaviour and assay specificity is needed.

Characterisation of clinical and immune reactivity to barley and rye ingestion in children with coeliac disease.

OBJECTIVE: Barley and rye are major components of the Western diet, and historic feeding studies indicate that they cause clinical effects in patients with coeliac disease (CD). This toxicity has been attributed to sequence homology with immunogenic wheat sequences, but in adults with CD, these cereals stimulate unique T cells, indicating a critical contribution to gluten immunity independent of wheat. Clinical and immune feeding studies with these grains in children with CD are sparse. We undertook a barley and rye feeding study to characterise the clinical and T-cell responses in children with CD. DESIGN: 42 children with human leucocyte antigen (HLA)-DQ2.5+ (aged 3-17 years) consumed barley or rye for 3 days. Blood-derived gluten-specific T cells were tested for reactivity against a panel of barley (hordein) and rye (secalin) peptides. Hordein and secalin-specific T-cell clones were generated and tested for grain cross-reactivity. T-cell receptor sequencing was performed on sorted single cells. T-cell responses were compared with those observed in adults with CD. RESULTS: 90% of the children experienced adverse symptoms, mostly GI, and 61% had detectable gluten-specific T-cell responses targeting peptides homologous to those immunogenic in adults. Deamidation was important for peptide reactivity. Homozygosity for HLA-DQ2.5 predicted a stronger T-cell response. Gluten-specific T cells showed striking similarities in their cross-reactivity between children and adults. CONCLUSIONS: Barley and rye induce a consistent range of clinical and T-cell responses in children with CD. The findings highlight the importance of a series of dominant hordein and secalin peptides pathogenic in children with CD, some independent of wheat, which closely correspond to those seen in adults.

Consistency in polyclonal T-cell responses to gluten between children and adults with celiac disease.

BACKGROUND & AIMS: Developing antigen-specific approaches for diagnosis and treatment of celiac disease requires a detailed understanding of the specificity of T cells for gluten. The existing paradigm is that T-cell lines and clones from children differ from those of adults in the hierarchy and diversity of peptide recognition. We aimed to characterize the T-cell response to gluten in children vs adults with celiac disease. METHODS: Forty-one children with biopsy-proven celiac disease (median age, 9 years old; 17 male), who had been on strict gluten-free diets for at least 3 months, were given a 3-day challenge with wheat; blood samples were collected and gluten-specific T cells were measured. We analyzed responses of T cells from these children and from 4 adults with celiac disease to a peptide library and measured T-cell receptor bias. We isolated T-cell clones that recognized dominant peptides and assessed whether gluten peptide recognition was similar between T-cell clones from children and adults. RESULTS: We detected gluten-specific responses by T cells from 30 of the children with celiac disease (73%). T cells from the children recognized the same peptides that were immunogenic to adults with celiac disease; deamidation of peptides increased these responses. Age and time since diagnosis did not affect the magnitude of T-cell responses to dominant peptides. T-cell clones specific for dominant α- or ω-gliadin peptides from children with celiac disease had comparable levels of reactivity to wheat, rye, and barley peptides as T-cell clones from adults with celiac disease. The α-gliadin-specific T cells from children had biases in T-cell receptor usage similar to those in adults. CONCLUSIONS: T cells from children with celiac disease recognize similar gluten peptides as T cells from adults with celiac disease. The findings indicate that peptide-based diagnostics and therapeutics for adults may also be used for children.

Enzyme therapy for management of coeliac disease.

OBJECTIVE: Enzyme therapy based on animal digestive extracts was investigated as a means of completely digesting toxic residues from gluten in the small intestine, thus providing a means of protection of the mucosa. MATERIAL AND METHODS: A randomized, placebo-controlled, clinical trial of an encapsulated enzyme extract was conducted in 21 coeliac patients in remission who were challenged with a modest amount of gluten daily over 2 weeks. Enzyme extract (900 mg) in three divided doses was administered during this challenge to half the group and a placebo to the other half in a double-blind, crossover design. Symptoms were recorded in daily diaries; blood was taken for tissue transglutaminase antibodies (anti-tTG) at the start and at intervals up to 12 weeks. Duodenal biopsies were performed for histological assessment at the start and end of each challenge period for 6 patients chosen at random from volunteers. After a further 10 weeks, the groups were changed over, and the same assessments carried out. RESULTS: Only 8 of the 21 patients (38%) had more than 5 episodes of moderate to severe symptoms during either of the gluten challenge periods, and in these, symptoms scores were ameliorated during enzyme therapy compared with the placebo period (p<0.02). Rises of 5 U/ml or more in anti-tTG occurred in only 5 patients at about 6-8 weeks after challenge, but were not correlated with symptoms. CONCLUSIONS: Only 1 of the 6 patients had normal histology at entry, thus focusing attention on the need for better management of the disease. By histological criteria, enzyme therapy offered better protection than placebo during the gluten challenges. The study supports the use of enzyme supplementation as a safeguard for patients with coeliac disease because of the difficulty of ensuring a strictly gluten-free diet.

Combining wheat bran with resistant starch has more beneficial effects on fecal indexes than does wheat bran alone.

BACKGROUND: Wheat bran (WB) increases fecal bulk and hastens colonic transit, whereas resistant starch (RS) has effects on colonic fermentation, including increasing concentrations of butyrate. OBJECTIVE: We hypothesized that a diet combining WB with RS would produce more favorable changes in fecal variables (eg, fecal bulk, rapid transit time, lower pH, and higher butyrate) than would WB alone. DESIGN: This was a randomized crossover block-design study for which 20 volunteers with a family history of colorectal cancer were recruited. The study included 3 diets: control, WB (12 g fiber/d), and WBRS (12 g WB fiber/d plus 22 g RS/d), each continued for 3 wk. In each diet, the major source of protein was lean red meat. During 5 consecutive days (days 15-19) of each dietary period, the subjects collected their total fecal output for analysis. RESULTS: The WB diet resulted in greater fecal output (by 23% and 21% for wet and dry weights, respectively) and a lesser transit time (-11 h) than did the control diet but did not have major effects on fermentation variables. Compared with the control diet, the WBRS diet resulted in greater fecal output (by 56%) and a shorter transit time (-10 h), lower fecal pH (-0.15 units), higher fecal concentration (by 14%) and daily excretion (by 101%) of acetate, higher fecal concentration (by 79%) and daily excretion (by 162%) of butyrate, a higher fecal ratio of butyrate to total short-chain fatty acids (by 45%), and lower concentrations of total phenols (-34%) and ammonia (-27%). CONCLUSIONS: Combining WB with RS had more benefits than did WB alone. This finding may have important implications for the dietary modulation of luminal contents, especially in the distal colon (the most common site of tumor formation).