Location of histopathological changes in diagnostic biopsies for paediatric coeliac disease

Objectives To evaluate the location of histological changes (first (D1) versus second part of the duodenum (D2)) in paediatric coeliac disease (CD). Methods A retrospective review of the departmental CD database at Royal Manchester Children’s Hospital, UK, identifying patients diagnosed with CD on biopsy between 2015 and 2022. Patients diagnosed in other centres or with duodenal samples collected in the same container (therefore without specification of D1 or D2 location) were excluded. Data were collected from patient records on gender, age at diagnosis, tissue transglutaminase IgA (TTG-IgA) antibody results and diagnostic biopsy reports. Results 77 patients (30 male, 47 female) were identified. Mean age at diagnosis was 9 years old (range 1–16 years). 47/77 patients (61%) had changes in both D1 and D2. 29/77 (38%) had changes in D1 only and 1/77 (1%) had changes in D2 only. Mean TTG-IgA at diagnosis in those with solitary changes to D1 was 62 units/millilitre (U/mL) compared with a mean of 157 U/mL in those with changes to both D1 and D2. Conclusions The majority of patients in this study had diagnostic changes in D1, with over a third having changes in D1 only. Solitary changes in D1 were noted particularly with lower levels of TTG-IgA upon diagnosis. These data suggest that a change in practice, to routinely collect more samples from D1, may be indicated in order to increase the likelihood of obtaining diagnostic samples during endoscopy.