Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gastro > H. Pylori > Flashcards

H. Pylori Flashcards

1
Q

What is H. pylori?

A

A gram negative rod found on the luminal surface of gastric epithelium. Its prominent flagella facilitate its penetration into the mucous layer of the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why can H. pylori exist in the highly acidic stomach?

A

it produces urease which converts the urea present in gastric juices to ammonia and CO2. This increases the pH of the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the 3 gastric diseases H.pylori has been found to be a cofactor in

A
  1. duodenal and gastric ulcers
  2. gastric cancer
  3. MALT lymphoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What changes in the stomach are associated with duodenal ulcer in patients with H. pylori?

A
  • Antral predominant diffuse gastritis
  • increased acid
  • increased gastrin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What changes in the stomach are associated with gastric ulcers or gastric cancer caused by H. pylori?

A
  • Corpus predominant multifocal atrophic gastritis
  • decreased acid
  • increased gastrin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What bacterial virulence factors of H. pylori are associated with carcinogenesis?

A
  • cagA and vac A genes are associated with increased carcinogenesis
  • cagA causes neutrophil recruitment and inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What % of those infected with H. pylori develop gastric cancer?

A

only 1-3% however, 95% of patients burg gastric cancer have H. pylori

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What % of patients with H. pylori have PUD?

A

~10%

  • 90% of duodenal ulcers are associated with H. pylori
  • 70-80% of gastric ulcers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why is H. pylori eradication important in PUD?

A
  • improves healing of ulcers
  • reduces rebreeding rates (if GIB as presentation)
  • 95-98% of duodenal ulcers heal with H. pylori treatment vs. 85-95% with acid suppression alone
  • 85% of gastric ulcers vs 60% with acid suppression alone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What extra-GI diseases are associated with H. pylori?

A

ITP

idiopathic iron deficiency anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does H. pylori cause gastric and duodenal ulcers?

A
  1. depletion of astral D cell somatostatin
  2. increased gastrin secretion by G cells and histamine secretion by ECL cells (lack of negative feedback from somatostatin)
  3. increased gastrin and histamine stimulates acid release by gastric parietal cells
  4. increased acid leads to metaplasia and ulcer formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What different tests can be done to detect H. pylori?

A 
Serology - HP specific IgG
HP stool Ag
C13 urea breath test
Rapid urease - CLO test
culture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the pros and cons of HP serology?

A

simple, cheap
sens/spec only 80-85%
unreliable in low prevalence areas
cannot use to test for eradication post treatment as IgG levels persist for 6-12 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the pros and cons of the HP stool Ag test?

A

cheap, easy
sens, spec good - 94% and 91% respectively
affected by PPI, H2 antagonists and ABs - must withheld for 2-4 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the pros and cons of the C13 urea breath test?

A

most reliable non-invasive test
- sens and spec 98%
expensive
affected by PPI, H2 antagonists and ABs - withheld for 2-4 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the CLO test, what are its pros and cons?

A

biopsy placed in urea containing medium
urease from H. pylori converts urea -> ammonia and medium changes colour

endoscopy required
sens spec 90-95% - improved with multiple biopsies

17
Q

What is the standard initial treatment for H. pylori?

A

Triple therapy for 10 days

  • amoxicillin*
  • clarithromycin
  • PPI
  • Metronidazole if penicillin allergic
18
Q

What is the standard treatment for triple therapy failure?

A

Quadruple therapy

  • bismuth
  • metronidazole
  • tetracycline
  • PPI

this is first line therapy in high Clarithromycin resistance areas (>15%)

19
Q

What is the main reason for treatment failure with triple therapy?

A

adherence

Clarithromycin +/- Metronidazole resistance

20
Q

Who should be tested for H. pylori?

A 
Patients with dyspepsia
proven PUD
FH of stomach cancer
high risk ethnic groups for gastric cancer
- japanese, Chinese, Korean, Russians
Long-term NSAID/Aspirin use
partners of treatment failures
21
Q

Who should be tested after treatment to ensure eradication?

A
  • H. pylori associated ulcer
  • persistent dyspepsia after treatment
  • H. pylori associated MALT
  • post resection for early gastric cancer
22
Q

What is MALT?

A

Low grade B cell lymphoma strongly associated with H. pylori infection
- HP virulence genes play little role (compared to gastric cancer)

23
Q

What is the treatment for MALT?

A

H. pylori eradication 1st line treatment in early stage disease (confined to stomach or peri-gastric LNs)
- complete remission in 75%

chemo, RT, surgery if eradication fails to treat

Gastro (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions