Comparison of clinical methods with the faecal gluten immunogenic peptide to assess gluten intake in coeliac disease

Objectives: Detection of faecal gluten immunogenic peptides (GIP) is a biomarker of recent gluten consumption. GIP levels can be used to monitor gluten intake and compliment clinical methods to evaluate compliance to gluten free diet (GFD). In this study, recent gluten intake was measured by GIP in CD children and compared to routine clinical measures to evaluate GFD compliance. Methods: GIP was measured in 90 samples from 63 CD children (44 previously and 19 newly diagnosed with follow-up samples at 6 and 12 months on GFD). Compliance to GFD was evaluated based on clinical assessment, tTG levels and Biagi score. Results: GIP was detectable in 16% of patients with previous CD diagnosis on GFD. BMI z-score (p=0.774), height z-score (p=0.723), haemoglobin concentration (p=0.233), age (p=0.448), gender (p=0.734) or disease duration (p=0.488) did not differ between those with detectable and non-detectable GIP. In newly diagnosed patients, on gluten containing diet, GIP was detectable in 95% of them. Following GFD initiation, GIP decreased (p<0.001); 17% and 27% had detectable levels at 6 and 12 months, respectively. Compared to GIP, the Biagi score, tTG and clinical assessment presented sensitivity of 17%, 42% and 17%. Likewise, GIP was detectable in 16%, 16%, 14% of patients evaluated as GFD compliant according to the Biagi score, tTG and clinical assessment. A combination of methods did not improve identification of patients who were non-compliant. Conclusions: Inclusion of faecal GIP measurements is likely to improve identification of GFD recent noncompliance in CD management and could be incorporated into current follow-up strategies

The CHIC Study: Child Health in Coeliac Disease

Coeliac disease (CD) is an autoimmune condition of the gastrointestinal tract. In untreated patients, an inflammatory response to gluten results in destruction of the gut mucosa resulting in villus atrophy. This often presents with overt clinical symptoms but can also be silent in nature. Continual gluten insult can inevitably lead to a range of complications including nutritional problems from poor growth to deficits in bone mineral density (BMD). The CHIC study aimed to create a comprehensive picture of CD in children, taking into account growth and nutritional status, bone health, micronutrient status and further assessing children with the dual diagnosis of type 1 diabetes mellitus and CD. It is well established that early diagnosis of CD and the prompt initiation of gluten free dietary treatment (GFD) reduces the manifestation of complications. Yet in many previous studies the quality of a GFD and children's compliance to it have not been accounted for. This study assessed nutritional status and body composition in paediatric patients with newly diagnosed CD and found that the presentation of CD has changed, with the majority of patients presenting with normal and even over nutrition. Furthermore, the introduction of GFD with good compliance supports normal growth velocities and enables catch up growth in children presenting with short stature. When considering bone health in paediatric patients with CD the results remain inconclusive. Many previous studies have used the widely available DXA to assess bone mineral content, but in paediatric patients this may not accurately determine bone health. This study used peripheral quantitative computed tomography to distinguish changes in bone mineral density and investigate any alterations in bone microarchitecture. Thus, for the first time in paediatric CD patients identifying disruption to the remodelling mechanisms of trabecular bone, which may be particularly sensitive to resorption and mineral loss in patients with active CD. Furthermore, restoration of BMD was evident with good compliance to dietary treatment. Investigations into micronutrient status revealed that newly diagnosed children are vulnerable to micronutrient deficiency, this is likely due to malabsorption in the gut in patients with active CD. Deficiencies in zinc and magnesium were also identified in children treated with a GFD. This may be due to the inadequate micronutrients intakes with consumption levels of riboflavin, vitamin A, vitamin K, calcium, iron, magnesium and zinc lower than expected in treated CD children