Chronic Gastritis

Question 1

Causes of Chronic Gastritis

Answer 1

1. H pylori (most common)
2. Auto-immune gastritis leading to pernicious anaemia
3. Gastro-duodenal reflux

Question 2

H pylori associated chronic gastritis pogresses according to the following 2 main topographic patterns, which have different clinical consequences:

Answer 2

1. Antral predominant gastritis: inflammation limited to antrum,
   Consequence: individuals with PUD usually demonstrate this pattern
2. Multifocal atrophic gastritis (pan gastritis): involvement of corpus and gastric antrum with progressive development of gastric atrophy (loss of gastric glands) and partial replacement of gastric glands by an intestinal type epithelium (intestinal metaplasia)
   Consequence: those who develop gastric carcinoma and gastric ulcers usually demonstrate this pattern

Question 3

Do carriers of H pylori normally develop gastritis?

Answer 3

50% of the world’s population is infected with H pylori, but do not develop clinical complications

Question 4

What are the clinical complications of carrying H pylori?

Answer 4

Chronic gastritis
PUD
GALT lymphomas (gastric mucosa associated lymphoid tissue)
Gastric adenocarcinomas

Question 5

How do duodenal ulcer occur as a complication of chronic gastritis?

Answer 5

• Increased duodenal acid load may occur and overload bile salts (that normally inhibit growth of H pylori)
• Damage to the duodenum promotes gastric metaplasia there
• Provides site for H pylori growth and more inflammation
• Duodenum is unable to neutralise acid from entering stomach therefore promotes ulcer formation

Question 6

How do gastric MALT lymphomas occur as a complication of chronic gastritis?

Answer 6

• MALT lymphomas (neoplastic B cell proliferation) may develop in association with chronic gastritis secondary to H pylori infection
• The stomach usually lacks organized lymphoid tissue, but after infection with H pylori, lymphoid tissue is universally present
• Acquisition of gastric lymphoid tissue is thought to be due to persistent antigen stimulation from byproducts of chronic infection with H pylori
• Persistence of MALT can lead to low or high grade lymphoma

Question 7

How do gastric carcinomas occur as a complication of chronic gastritis?

Answer 7

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