Progression Biobank of Achalasia and autoimmune gastritis

A lack of knowledge of the pathogenesis of autoimmune digestive disorders leads
to a delay in disease diagnosis and treatment, especially for autoimmune
gastritis (AIG) and achalasia. Therefore, we want to set up a prospective
cohort to further investigate the natural course of AIG and achalasia, and the
molecular mechanisms involved in these two diseases. In addition, by
prospectively following these patients, we aim to enhance our knowledge
regarding the origin of these diseases and develop insights to guide clinical
practices (such as whether surveillance of these patients may be useful). Two
such cohorts are currently already under investigation in our centre. Patients
with Barrett*s esophagus (Probar study) and gastric intestinal metaplasia
(Proregal cohort), two premalignant lesions associated with increased risk to
cancer progression, are already being prospectively followed and the associated
databases have already proven their worth. With the current cohort, we aim to
extend our investigation to autoimmune disorders of the esophagus and stomach,
which may predispose for cancer.

1. To validate the existing guidelines with prospective and retrospective data
from this cohort by performing an upper endoscopy at baseline, one year after
inclusion and subsequently every three years thereafter in order to assess the
risk of progression to cancer in this cohort
2. To set up a biobank to further study the pathogenesis of autoimmune
digestive disorders, including:
2a. To evaluate the overlap of achalasia and autoimmune gastritis with other
autoimmune diseases (i.e. autoimmune thyroid disease, type 1 diabetes), and
investigate the family history of autoimmune diseases
2b. To identify potential triggers of the autoinflammation by investigating the
patients* medical history, particularly the history of herpes simplex virus-1
(HSV), varicella-zoster virus and H. pylori infection in achalasia and
autoimmune gastritis patients and the composition of microbiota in the
esophagus and gastric mucosa.
2c. To study the underlying mechanism of the malignant progression by analysis
the HLA genotyping, proportions of infiltrating immunological cells in the
esophagus and gastric mucosa.

This research is a multi-center prospective study on autoimmune upper GI
diseases, i.e. AIG and achalasia. Included patients will be asked to fill in a
questionnaire to collect information about family history and history of other
autoimmune diseases. At baseline, we will collect biopsies, blood, and serum
samples for biobanking from patients for subsequent DNA extraction,
immunophenotyping, and autoantibody testing, amongst others. Serum and biopsies
will additionally be collected during each follow-up visit. Moreover, we will
identify patients with AIG and achalasia through PALGA and DBC search and
collect pathology data (e.g. FFPE block numbers for immunophenotyping) and
other laboratory results from EPD and HIX separately.

Participants will be asked to donate blood (<30ml), and biopsies are collected
during endoscopy follow-up. Therefore, the burden and risk of this study are
negligible. This study is expected to benefit future patients with these
diseases. Additionally, closer surveillance may result in detection of early
cancerous lesion, allowing better treatment of patients.