Real-World Gluten Exposure in Patients With Celiac Disease on Gluten-Free Diets, Determined From Gliadin Immunogenic Peptides in Urine and Fecal Samples.

BACKGROUND & AIMS: It is not clear how often patients who are on gluten-free diets (GFDs) for treatment of celiac disease still are exposed to gluten. We studied levels of gluten immunogenic peptides (GIP) in fecal and urine samples, collected over 4 weeks, from patients with celiac disease on a long-term GFD. METHODS: We performed a prospective study of 53 adults with celiac disease who had been on a GFD for more than 2 years (median duration, 8 y; interquartile range, 5-12 y) in Argentina. At baseline, symptoms were assessed by the celiac symptom index questionnaire. Patients collected stool each Friday and Saturday and urine samples each Sunday for 4 weeks. We used a commercial enzyme-linked immunosorbent assay to measure GIP in stool and point-of-care tests to measure GIP in urine samples. RESULTS: Overall, 159 of 420 stool and urine samples (37.9%) were positive for GIP; 88.7% of patients had at least 1 fecal or urine sample that was positive for GIP (median, 3 excretions). On weekends (urine samples), 69.8% of patients excreted GIP at least once, compared with 62.3% during weekdays (stool). The number of patients with a sample that was positive for GIP increased over the 4-week study period (urine samples in week 1 vs week 4: P < .05). Patients with symptoms had more weeks in which GIP was detected in stool than patients without symptoms (P < .05). The number of samples that were positive for GIP correlated with titers of deamidated gliadin peptide IgA in patients' blood samples, but not with levels of tissue transglutaminase. CONCLUSIONS: Patients with celiac disease on a long-term GFD still frequently are exposed to gluten. Assays to detect GIP in stool and urine might be used to assist dietitians in assessment of GFD compliance.

Impaired Bone Microarchitecture Improves After One Year On Gluten-Free Diet: A Prospective Longitudinal HRpQCT Study in Women With Celiac Disease.

We have recently identified a significant deterioration of bone microarchitecture in premenopausal women with newly diagnosed celiac disease (CD) using high-resolution peripheral quantitative computed tomography (HRpQCT). The aim of this work was to assess changes in bone microarchitecture after 1 year on a gluten-free diet (GFD) in a cohort of premenopausal women. We prospectively enrolled 31 consecutive females at diagnosis of CD; 26 of them were reassessed 1 year after GFD. They all underwent HRpQCT scans of distal radius and tibia, areal BMD by DXA, and biochemical tests (bone-specific parameters and CD serology) at both time points. Secondary, we compared 1-year results with those of a control group of healthy premenopausal women of similar age and BMI in order to assess whether the microarchitectural parameters of treated CD patients had reached the values expected for their age. Compared with baseline, the trabecular compartment in the distal radius and tibia improved significantly (trabecular density, trabecular/bone volume fraction [BV/TV] [p < 0.0001], and trabecular thickness [p = 0.0004]). Trabecular number remained stable in both regions. Cortical density increased only in the tibia (p = 0.0004). Cortical thickness decreased significantly in both sites (radius: p = 0.03; tibia: p = 0.05). DXA increased in all regions (lumbar spine [LS], p = 0.01; femoral neck [FN], p = 0.009; ultradistal [UD] radius, p = 0.001). Most parameters continued to be significantly lower than those of healthy controls. This prospective HRpQCT study showed that most trabecular parameters altered at CD diagnosis improved significantly by specific treatment (GFD) and calcium and vitamin D supplementation. However, there were still significant differences with a control group of women of similar age and BMI. In the prospective follow-up of this group of patients we expect to be able to assess whether bone microarchitecture attains levels expected for their age. © 2016 American Society for Bone and Mineral Research.

Prevalence of celiac disease and celiac autoimmunity in the Toba Native Amerindian community of Argentina.

BACKGROUND: Celiac disease (CD) is mostly recognized among subjects with a Caucasian ethnic ancestry. No studies have explored conditions predisposing Amerindians to CD. OBJECTIVE: To prospectively assess environmental, genetic and serological conditions associated with CD among members of the Toba native population attending a multidisciplinary sanitary mission. METHODS: An expert nutritionist determined daily gluten intake using an established questionnaire. Gene typing for the human leukocyte antigen (HLA) class II alleles was performed on DNA extracted from peripheral blood (HLA DQ2/DQ8 haplotype). Serum antibodies were immunoglobulin (Ig) A tissue transglutaminase (tTG) and the composite deamidated gliadin peptides/tTG Screen test. Positive cases were tested for IgA endomysial antibodies. RESULTS: A total of 144 subjects (55% female) were screened. The estimated mean gluten consumption was 43 g/day (range 3 g/day to 185 g/day). Genetic typing showed that 73 of 144 (50.7%) subjects had alleles associated with CD; 69 (94.5%) of these subjects had alleles for HLA DQ8 and four had DQ2 (5.5%). Four and six subjects had antibody concentrations above the cut-off established by the authors' laboratory (>3 times the upper limit of normal) for IgA tTG and deamidated gliadin peptides/tTG screen, respectively. Four of these had concomitant positivity for both assays and endomysial antibodies were positive in three subjects who also presented a predisposing haplotype. CONCLUSION: The present study was the first to detect CD in Amerindians. The native Toba ethnic population has very high daily gluten consumption and a predisposing genetic background. We detected subjects with persistent CD autoimmunity and, at least, three of them fulfilled serological criteria for CD diagnosis.