Management of Autoimmune Gastritis
For a middle-aged woman with autoimmune gastritis and other autoimmune disorders, management is entirely supportive with nutritional replacement and endoscopic surveillance—there is no disease-modifying immunosuppressive therapy for this condition. 1
Core Management Framework
The management strategy differs fundamentally from other autoimmune conditions like autoimmune hepatitis, as corticosteroids and immunosuppressive agents have no role in autoimmune gastritis treatment. 1 The approach centers on three pillars: nutritional deficiency correction, H. pylori assessment, and surveillance for gastric neoplasia. 1, 2
Initial Diagnostic Workup
At diagnosis, obtain the following assessments simultaneously:
- Iron studies regardless of whether anemia is present, as corpus-predominant atrophy impairs iron absorption and deficiency occurs in up to 50% of patients 3, 2
- Vitamin B12 levels and complete blood count to assess for macrocytic anemia and pernicious anemia 1, 2
- H. pylori testing using non-serological methods (stool antigen or urea breath test) 1, 2
- Thyroid function tests since up to one-third of patients with autoimmune thyroid disease have autoimmune gastritis 1, 2
- Upper endoscopy with topographical biopsies from body and antrum (in separate jars) to confirm corpus-predominant atrophic gastritis, assess disease extent, and rule out prevalent neuroendocrine tumors or adenocarcinoma 2
Nutritional Deficiency Management
Iron Replacement
Iron deficiency manifests much earlier than vitamin B12 deficiency because iron stores deplete rapidly while hepatic B12 stores can last years. 3 Screen and treat all patients for iron deficiency even without anemia, as reduced gastric acid secretion impairs dietary iron absorption. 3, 2
Vitamin B12 Replacement
Vitamin B12 deficiency develops from both reduced gastric acid and loss of intrinsic factor from parietal cell destruction. 3 When pernicious anemia is present (a late-stage manifestation with megaloblastic anemia), lifelong B12 replacement is required. 1, 2
H. pylori Eradication
Test all patients for H. pylori using non-serological methods, and if positive, administer eradication therapy followed by confirmation of successful eradication. 1, 2 This addresses a potentially modifiable risk factor for gastric cancer progression. 1
Endoscopic Surveillance Strategy
For Type 1 Gastric Neuroendocrine Tumors (NETs)
- Screen with upper endoscopy at diagnosis, as hypergastrinemia from achlorhydria drives NET development 1, 2
- Remove small NETs endoscopically when identified 1, 2
- Perform surveillance endoscopy every 1-2 years if NETs are present, with frequency depending on tumor burden 1, 2
For Gastric Adenocarcinoma
Consider surveillance endoscopy every 3 years in patients with advanced autoimmune gastritis (defined by anatomic extent and histologic grade). 1, 2 The risk of progression to gastric adenocarcinoma is estimated at 0.1-0.3% per year, with patients having pernicious anemia showing a 2- to 7-fold higher relative risk. 4
Screening for Associated Autoimmune Conditions
Given the patient's history of autoimmune disorders, actively screen for:
- Autoimmune thyroid disease (present in up to one-third of patients with autoimmune gastritis) 4, 1, 2
- Type 1 diabetes mellitus (increased prevalence in autoimmune gastritis) 4, 1
Critical Pitfalls to Avoid
Do not prescribe immunosuppressive therapy (corticosteroids, azathioprine, or other immunomodulators) for autoimmune gastritis—these agents are indicated for autoimmune hepatitis but have no role in gastritis management. 1 This is a common misconception given the autoimmune nature of the disease. 1
Ongoing Management Algorithm
At each follow-up visit:
- Monitor and replace iron and vitamin B12 as needed 1, 2
- Assess for symptoms of other autoimmune conditions 1
Surveillance schedule: