AGA clinical practice update on the diagnosis and management of atrophic gastritis

Key points

• Atrophic gastritis is the loss of gastric glands, with or without metaplasia, in chronic inflammation mainly due to Helicobacter pylori or autoimmunity; the diagnosis should be confirmed by histopathology, and intestinal metaplasia almost invariably implies atrophic gastritis.
• Biopsies should follow the updated Sydney protocol: 2 from the antrum, 1 from the incisura and 2 from the corpus, at minimum placed in separate jars for antrum/incisura and body, plus targeted biopsies of any visible abnormality.
• All patients with atrophic gastritis should be tested for H pylori; if positive, it should be treated and eradication confirmed with a non-serological test.
• Surveillance endoscopy every 3 years should be considered in advanced atrophic gastritis; for autoimmune gastritis the interval should be individualised.
• In autoimmune gastritis, providers should check parietal cell and intrinsic factor antibodies, evaluate iron and vitamin B12 deficiency, screen for type 1 gastric neuroendocrine tumours and for autoimmune thyroid disease.

Overview

This AGA Clinical Practice Update gives 12 Best Practice Advice statements on diagnosing and managing atrophic gastritis, based on published evidence and expert consensus without formal evidence rating. Atrophic gastritis affects up to 15% of US populations; autoimmune gastritis is estimated at 0.5%-2% and pernicious anaemia at 0.15%-1%. The risk of progression to gastric adenocarcinoma is estimated at 0.1%-0.3% a year, and type I gastric neuroendocrine tumours occur at 0.4%-0.7% a year in chronic atrophic gastritis.

Endoscopic diagnosis

Typical features are pale mucosa, increased visibility of vessels and loss of gastric folds; intestinal metaplasia shows light blue crests and white opaque fields. Because changes are subtle, high-definition endoscopy, good mucosal cleansing and image-enhanced techniques such as narrow-band imaging should be used; in one multicentre study high-definition endoscopy with narrow-band imaging had a sensitivity of 87% and specificity of 97% for intestinal metaplasia.

Pernicious anaemia and neuroendocrine tumours

Pernicious anaemia is a late-stage manifestation of autoimmune gastritis; patients newly diagnosed without a recent endoscopy should undergo endoscopy with topographical biopsies. Small neuroendocrine tumours under 1 cm should be removed endoscopically, followed by surveillance every 1-2 years; larger tumours need endoscopic ultrasound, and tumours over 2 cm or with deep invasion or nodal spread need surgery. Iron deficiency, reported in up to 50% of corpus-predominant atrophic gastritis, often appears earlier than vitamin B12 deficiency.

FAQ

How is atrophic gastritis diagnosed?

By histopathology of biopsies taken according to the updated Sydney protocol, guided by typical endoscopic features.

How often should surveillance endoscopy be done?

Every 3 years should be considered for advanced atrophic gastritis; in autoimmune gastritis the interval is based on individual assessment and shared decision making.

What else should be checked in autoimmune gastritis?

Parietal cell and intrinsic factor antibodies, iron and vitamin B12 levels, type 1 gastric neuroendocrine tumours and autoimmune thyroid disease.

Source

Shah SC, Piazuelo MB, Kuipers EJ, Li D. AGA Clinical Practice Update on the Diagnosis and Management of Atrophic Gastritis: Expert Review. Gastroenterology 2021;161(4):1325-1332. DOI: 10.1053/j.gastro.2021.06.078. Published by Elsevier Inc. on behalf of the AGA Institute. Summary prepared by Medpresso from the original publication; it is not a substitute for the full text or for medical advice.