HELICOBACTER PYLORI INFECTION Flashcards
Overview (6)
1- Gram-negative urease-producing spiral-shaped bacterium found predominantly in the gastric antrum and areas of gastric metaplasia in the duodenum.
2- Closely associated with chronic active gastritis, peptic ulcer disease (gastric and duodenal ulcers), gastric cancer, and gastric B cell lymphoma
3- Most patients are asymptomatic (acquired in childhood via fecal-oral route, persists for life unless treated)
4- Most patients present with gastritis (mainly in the antrum of the stomach)
5- Some cases have gastritis involving the body of stomach —> atrophic gastritis
6- Some cases have intestinal metaplasia (premalignant condition)
Proposed pathogenic mechanisms (4)
1- Increased gastric acid secretion due to:
- increased gastric secretion
- increased parietal cell mass
- decreased somatostatin production due to antral gastritis
2- Disruption of mucous protective layer
3- Reduced duodenal bicarbonate production
4- Production of virulence factors
Diagnosis of infection- Noninvasive tests (3)
1- Serology (serum antibody detection)
2- Urea breath test (for diagnosis of infection and monitoring after eradication)
3- Stool antigen
Diagnosis of infection- Invasive test (3)
1- Antral biopsy for patients undergoing endoscopy
2- Histology with direct visualization of H.pylori (silver stain)
3- Rapid urease test (CLO)
Management (4)
1- Eradication of H.pylori is indicated for:
- all patients with peptic ulcer disease, atrophic gastritis, gastric B cell lymphoma, after gastric cancer resection and in patients with dyspepsia
- patients who have a first-degree relative with gastric cancer
2- Recurrence is rare after successful eradication
3- PPI-based triple therapy regimens for 14 days are favored, such as:
- Omeprazole 20 mg + metronidazole 400 mg + clarithromycin 500 mg —> all twice daily
- Omeprazole 20 mg + amoxicillin 1 g + clarithromycin 500 mg —> all twice daily
4- Quadruple therapy using bismuth chelate, omeprazole, metronidazole, and tetracycline
