# Poster Session I - A130 A COHORT REVIEW OF CELIAC PATIENTS WITH NORMAL SEROLOGY. IS FOLLOW-UP EGD INDICATED?

## TL;DR

This study examines whether follow-up biopsies are needed for celiac patients with normal blood tests, finding that most show normal intestinal healing.

## Contribution

The study provides real-world data on histologic recovery in celiac patients with normalized TTG levels.

## Key findings

- 91% of patients had normal or nearly normal intestinal biopsies despite non-celiac symptoms.
- A minority showed histologic discordance between different parts of the duodenum.
- Follow-up biopsies may not be routinely necessary for patients with normal TTG levels.

## Abstract

The role of follow-up small intestinal biopsy in celiac disease is unclear. Current guidelines do not recommend follow-up duodenal biopsies to confirm histologic recovery. The reported sensitivity and specificity of IgA TTG antibody (TTG) to predict histologic recovery in patients on a gluten free diet (GFD) is 50% and 83% respectively. Therefore, it is possible that patients may have ongoing villous injury despite normalization of their TTG. A frequent practice is to biopsy the small intestine of celiac patients undergoing endoscopy for other reasons.

The aim of this descriptive retrospective study is to evaluate the role of small intestinal biopsy when investigating non celiac related symptoms in patients with normalization of TTG.

Adult patients with non-celiac symptoms from the Celiac Clinic at St Boniface Hospital between January 2020 to April 2025 who had normalization of celiac serologies and follow-up gastroscopy with small intestinal biopsy were included. Patient demographics, laboratory investigations, and pathology was collected.

Of 477 patients in the celiac clinic cohort of 477 patients, 47 met inclusion criteria. Mean age was 47 with 71% being female. Mean follow-up labs included hemoglobin (140g/L), ferritin (120ug/L), Vitamin B12 (485pmol/L), TSH (2.1mIU/L), AST (22U/L), ALT (22U/L), Vitamin D (90nmol/L). 45% of patients had a family history of celiac disease and 100% had self-reported good adherence to a GFD. 62% were symptomatic to gluten exposure. Associated diseases included type 1 diabetes (2%), thyroid disease (21%), and microscopic colitis (7%). Mean baseline and follow-up TTG (normal < 19U/mL) at the time of endoscopy was 166.2 and 9.1, respectively. Indications for gastroscopy included dyspepsia, refractory reflux, and imaging abnormalities. All follow-up gastroscopies (N = 54) noted normal endoscopic duodenal mucosa. Follow-up small intestinal pathology was reported separately as duodenal bulb and second part duodenum (D2) in 37% of samples. Follow-up Marsh (M) histology was as follows: 0 (74%), 1 (17%), 2 (1.9%), 3a (3.7%), 3b (1.9%), 3c (1.9%). 91% of patients had M0 or 1 and 9% of patients had M2 or higher. Discordance was noted in 4/20 (20%) of samples: 2 had M3a in the bulb and M0 in D2, 1 had M2 in the bulb and M1 in D2 and 1 had M3c in the bulb and M3b in D2.

In this cohort of celiac patients with normal TTG and good self-reported adherence to GFD, 91% of patients had normal (M0/1) follow-up small intestinal biopsies. Although few, a significant minority of patients had discordance between the histology of D2 and the bulb. The results suggest that follow-up gastroscopy and small intestinal biopsy is not routinely needed to confirm histologic recovery in patients with a normal TTG. Further study is warranted in a larger clinic cohort including biopsies from D2 and the duodenal bulb.

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