How should atrophic gastritis be managed in an adult patient (typically over 50 years old), including diagnostic work‑up, Helicobacter pylori eradication, treatment of vitamin B12 or iron deficiency, symptom control with proton‑pump inhibitors, lifestyle modifications, and endoscopic surveillance?

Management of Atrophic Gastritis

All patients with atrophic gastritis must undergo H. pylori testing and receive eradication therapy if positive, be screened for vitamin B12 and iron deficiencies with appropriate replacement, and enter endoscopic surveillance every 3 years if advanced disease is present. 1, 2

Diagnostic Work-Up and Confirmation

Endoscopic Recognition and Biopsy Protocol

• Recognize key endoscopic features: pale mucosa, increased vascular visibility from mucosal thinning, loss of gastric folds, and if intestinal metaplasia is present, light blue crests and white opaque fields. 1
• Obtain biopsies from body and antrum/incisura in separately labeled jars at minimum for histopathological confirmation and risk stratification. 1, 2
• Take targeted biopsies from any additional mucosal abnormalities identified during endoscopy. 1

Serologic Testing for Autoimmune Etiology

• Check antiparietal cell antibodies and anti-intrinsic factor antibodies when histology suggests autoimmune gastritis (corpus-predominant atrophy). 1, 2
• Screen for autoimmune thyroid disease in all autoimmune gastritis patients, as concomitant autoimmune disorders are common. 1, 2

H. Pylori Assessment and Eradication

This is the cornerstone of etiology-based treatment for non-autoimmune cases.

• Test all atrophic gastritis patients for H. pylori using non-serological methods (avoid serology as it remains positive after eradication). 1, 2
• Administer eradication therapy promptly if H. pylori is detected. 1, 2
• Confirm successful eradication using non-serological testing modalities. 1, 2
• H. pylori eradication may modify the natural history of atrophy, though it has less effect once intestinal metaplasia develops. 2
• In one study, H. pylori eradication alone improved vitamin B12 levels and anemia in 40% of infected patients with B12 deficiency. 3

Micronutrient Deficiency Management

Evaluate and treat iron and vitamin B12 deficiencies in all patients, especially those with corpus-predominant disease.

Screening Approach

• Screen for both iron and vitamin B12 deficiencies regardless of etiology, with particular attention to corpus-predominant atrophy. 1, 2
• Iron deficiency occurs in up to 50% of patients with corpus-predominant atrophic gastritis and often presents earlier than B12 deficiency. 2
• Autoimmune gastritis patients have significantly higher risk: 11.52-fold increased odds for vitamin B12 deficiency and 2.92-fold increased odds for iron deficiency compared to controls. 4

Treatment Considerations

• Vitamin B12 deficiency in autoimmune gastritis occurs in approximately 13.3% of patients, with median levels significantly lower than in H. pylori-related gastritis. 4
• Iron deficiency is present in 28.9-33.3% of autoimmune gastritis patients. 4
• Recognize pernicious anemia as a late-stage manifestation characterized by vitamin B12 deficiency and macrocytic anemia. 1
• In newly diagnosed pernicious anemia without recent endoscopy, perform upper endoscopy with topographical biopsies to confirm corpus-predominant atrophy and rule out gastric neoplasia. 1, 2

Endoscopic Surveillance Strategy

For Advanced Atrophic Gastritis (H. pylori-related)

• Perform surveillance endoscopy every 3 years for patients with advanced atrophic gastritis, defined by extensive anatomic distribution and high histologic grade. 1, 2
• The risk of gastric adenocarcinoma may be highest within the first year of pernicious anemia diagnosis, warranting prompt initial endoscopic evaluation. 2

For Autoimmune Gastritis

• Screen for type 1 gastric neuroendocrine tumors (NETs) with upper endoscopy, as these occur with 2.8% incidence per person-year. 2, 5
• Remove small NETs (<1 cm) endoscopically. 2
• Follow with surveillance endoscopy every 1-2 years depending on NET burden. 1, 2
• For NETs >1-2 cm, perform endoscopic ultrasound to assess invasion depth and local metastasis. 2
• Surgical resection is indicated for NETs >2 cm, those invading past submucosa, or with lymph node metastasis. 2
• Gastric cancer incidence is 0.5% per person-year in autoimmune gastritis patients. 5

Common Pitfalls and Caveats

• Atrophic gastritis is frequently underdiagnosed because endoscopic features are subtle and histopathological reporting is inconsistent. 2
• Ensure proper biopsy technique with separate specimen jars for body and antrum to avoid missing focal disease. 1, 2
• Seronegative autoimmune gastritis can occur (negative antiparietal cell and intrinsic factor antibodies), so do not exclude the diagnosis based solely on negative serology. 6
• Hemolytic anemia can rarely occur with severe vitamin B12 deficiency, mimicking thrombotic microangiopathy with schistocytes and thrombocytopenia (pseudothrombotic microangiopathy). 6
• Food-bound cobalamin malabsorption from achlorhydria is now the most common cause of B12 deficiency, not classic pernicious anemia. 6