GASTROENTEROLOGY ARTICLE OF THE WEEK
December 12, 2002
Suerbaum S, Michetti P. Helicobacter pylori infection. N Engl J Med 2002;347:1175-1186.
1. VacA
a. is Dr. Rodriguez’s favorite cytotoxin
b. is essential for colonization
c. strains of H. pylori that are unable to produce VacA are not pathogenic
d. production of VacA confers and advantage to H. pylori strains.
e. it is a vacuolating cytotoxin, possibly provides nutrients for H. pylori.
2. Cag-A
a. is Dr. Rodriguez’s favorite chemokine
b. mediates a strong interleukin-8 response by the host gastric epithelium
c. when present, it leads to profound neutrophil activation
d. if absent, the H. pylori is not pathogenic
e. CagA leads to cytoskeletal rearrangements in host cells
3. Epidemiologic features of H. pylori include
a. usually transmitted from animals to humans
b. spontaneous elimination of H. pylori is common in children
c. transmission is primarily from person to person
d. H. heilmannii does not infect humans
True or False
4. Nexium has been approved by the FDA as a once a day PPI in conjuction with antibiotics for H. Pylori eradication
5. The cell wall of H. pylori is resistant to gastric acid.
6. Patients with antral-predominant colonization by H. pylori are at the highest risk for gastric carcinoma
7. Once H. pylori penetrates the gastric mucus, it invades the gastric epithelial cells.
8. Eradication of H. pylori is indicated in patients with severe erosive esophagitis.
9. Stool antigen test can be done 3 weeks after antibiotic therapy to assess eradication.
10. H. pylori infection becomes chronic in most adults because it does not trigger a systemic or mucosal humoral response.
11. Second line therapies include quadruple therapy or triple therapy avoiding the antibiotics used in the initial therapy.
12. Polymorphisms of the interleukin-1b gene may determine whether the H. pylori infection will be predominantly in the body of the stomach – leading to hypochlorhydria; or in the antrum leading to normal or high acid production.
13. The lifetime risk of peptic ulcer disease in a person infected with H. pylori in the US is
a. 90%
b. 80%
c. 50%
d. 60%
e. 3%
14. H. pylori infection
a. increases the risk of gastric cancer
b. is strongly associated with non-ulcer dyspepsia
c. is responsible for over 70% of MALT lymphomas
d. when eradicated in a case of MALT, the remission is lifelong
15. H pylori antibiotic resistance patterns in the US include
a. 10% resistance to clarithromycin
b. 20% to 30% resistance to metronidazole, more common in men
c. uncommon to amoxicillin and tetracycline
d. triple or quadruple therapy may overcome resistance
16. Urease breath test
a. determines the presence of CagA
b. can be used for initial diagnosis and to confirm eradication
c. should be repeated 2-3 weeks after antibiotic therapy to confirm eradication
d. has a sensitivity and specificity of over 90%
17. Indications for eradication of H. pylori include
a. past or present DU
b. non-ulcer dyspepsia
c. T-cell lymphoma of the stomach
d. Prior to institution of chronic NSAID therapy
e. During NSAID therapy if a GU develops
f. Family history of gastric cancer