What are the different types of gastritis and their respective treatments?

Types of Gastritis and Their Respective Treatments

Gastritis is primarily classified into two main types based on etiology: Helicobacter pylori-associated gastritis and autoimmune gastritis, each requiring distinct diagnostic approaches and treatment strategies. 1, 2

Major Types of Gastritis

1. Helicobacter pylori-Associated Gastritis (HpAG)

• Most common form of gastritis, with prevalence up to 15% in US populations 1
• Typically begins in the antrum/incisura and can progress to involve the corpus 1
• Risk factors include age, tobacco use, high-salt diet, and possibly chronic bile acid reflux 1
• Treatment:
  • Eradication therapy is the cornerstone of treatment 2
  • Bismuth quadruple therapy recommended as first-line due to increasing clarithromycin resistance 2
  • Successful eradication must be confirmed using non-serological testing 1

2. Autoimmune Gastritis (AIG)

• Less common (0.5-2% prevalence) 1
• Characterized by corpus-predominant atrophy with relative antral sparing 1
• Associated with antiparietal cell and anti-intrinsic factor antibodies 1
• Treatment:
  • No specific treatment to reverse the autoimmune process 2
  • Management focuses on monitoring and treating complications:
    • Vitamin B12 and iron supplementation for deficiencies 1
    • Surveillance for gastric neoplasia, including neuroendocrine tumors 1
    • Screening for concomitant autoimmune disorders, particularly thyroid disease 1

3. Chemical/Reactive Gastritis (Type C)

• Caused by bile reflux, NSAIDs, alcohol, or other chemical irritants 3
• Often seen in post-gastrectomy patients due to biliary reflux 3
• Treatment:
  • Removal of offending agent when possible 3
  • Proton pump inhibitors like omeprazole or pantoprazole for symptom management 4, 5
  • Severe cases with biliary reflux may require surgical biliary diversion (Roux-Y-gastrojejunostomy) 3

Histopathologic Classification

Based on Mucosal Changes

• Superficial gastritis: Inflammation limited to the superficial epithelium 6, 7
• Erosive gastritis: Characterized by multiple small mucosal erosions 7
• Atrophic gastritis: Loss of gastric glands with or without metaplasia 1
• Metaplastic gastritis: Replacement of normal gastric mucosa with intestinal-type epithelium 1
• Verrucous gastritis: Characterized by nodular mucosal changes 7

Based on Distribution

• Antral-predominant: Typically associated with H. pylori infection 1
• Corpus-predominant: Characteristic of autoimmune gastritis 1
• Pangastritis: Involving both antrum and corpus, often seen in advanced H. pylori infection 1

Diagnostic Approach

• Diagnosis should be confirmed by histopathology with biopsies from both gastric body and antrum 1, 2
• All patients should be assessed for H. pylori using non-serological testing 1, 2
• For suspected autoimmune gastritis, check antiparietal cell and anti-intrinsic factor antibodies 1
• Evaluate for vitamin B12 and iron deficiencies in all patients with atrophic gastritis 1

Treatment Algorithm

For H. pylori-Positive Gastritis:

1. Eradication therapy with bismuth quadruple therapy (preferred first-line) 2
2. Confirm successful eradication using urea breath test, stool antigen test, or histology 1
3. If eradication fails, use alternative regimens based on antibiotic susceptibility testing 4

For Autoimmune Gastritis:

1. Regular vitamin B12 and iron monitoring and supplementation as needed 1
2. Endoscopic surveillance every 3 years for advanced atrophic gastritis 1
3. More frequent surveillance (every 1-2 years) if neuroendocrine tumors are present 1
4. Screen for concomitant autoimmune disorders, particularly thyroid disease 1

For Chemical/Reactive Gastritis:

1. Discontinue offending agents (NSAIDs, alcohol) when possible 3
2. Proton pump inhibitor therapy for symptom management 4, 5
3. Consider surgical intervention for severe biliary reflux cases 3

Risk Stratification and Surveillance

• The OLGA (Operative Link for Gastritis Assessment) and OLGIM (Operative Link for Gastric Intestinal Metaplasia Assessment) staging systems help identify high-risk patients 1, 8
• Patients with advanced atrophic gastritis should undergo surveillance endoscopy every 3 years 1
• Patients with autoimmune gastritis and neuroendocrine tumors require more frequent surveillance 1

Important Clinical Considerations

• Some cases of autoimmune gastritis may evolve from long-standing H. pylori gastritis 9
• H. pylori eradication reduces gastric cancer risk, especially before development of preneoplastic conditions 2
• Decreased gastric acidity from proton pump inhibitors may increase risk of certain gastrointestinal infections 4
• Small gastric neuroendocrine tumors in autoimmune gastritis should be removed endoscopically 1