Helicobacter pylori Gastritis

Key Features

Essentials of Diagnosis

• Helicobacter pylori is a spiral gram-negative rod that causes gastric mucosal inflammation

General Considerations

• Acute infection causes a transient illness of nausea and abdominal pain for several days associated with acute histologic gastritis with polymorphonuclear neutrophils (PMNs)

• After these symptoms resolve, the majority progress to chronic infection with chronic, diffuse mucosal inflammation characterized by PMNs and lymphocytes

• Eradication achieved with antibiotics in > 85% leads to resolution of the chronic gastritis

• Majority of those with chronic infection are asymptomatic and suffer no sequelae

• Patients with inflammation that predominates in the gastric antrum but spares the gastric body (where acid is secreted) have

  • Increased gastrin

  • Increased acid production

  • Increased risk of developing peptic ulcers, especially duodenal ulcers

• Long-term treatment with proton pump inhibitors can potentiate the development of H pylori-associated atrophic gastritis

• Chronic H pylori gastritis leads to the development of

  • Duodenal or gastric ulcers up to 10%

  • Gastric cancer in 0.1-3%

  • Low-grade B cell gastric lymphoma (mucosa-associated lymphoid tissue lymphoma; MALToma) in < 0.01%

Demographics

• Infection usually acquired in childhood through person-to-person spread

• In the United States, the prevalence of infection is < 10% in nonimmigrants younger than 30 years to > 50% in those older than 60 years

• Prevalence is higher in nonwhites and immigrants from developing countries

Clinical Findings

Symptoms and Signs

• Acute infection: transient epigastric pain, nausea, vomiting

• Chronic infection

  • Usually asymptomatic

  • Symptoms arise in patients in whom peptic ulcer disease or gastric cancer develops

  • Controversial whether chronic infection may cause dyspepsia

Differential Diagnosis

• Peptic ulcer disease

• Functional dyspepsia

• Gastroesophageal reflux disease or hiatal hernia

• Biliary disease or pancreatitis

• Gastric or pancreatic cancer

• Viral gastroenteritis

• "Indigestion" from overeating, high-fat foods, coffee

• Angina pectoris

Diagnosis

Laboratory Tests

Noninvasive testing for H pylori

• Serologic tests no longer endorsed because they are less accurate than other noninvasive tests

• Fecal antigen immunoassay and ¹³C-urea breath tests

  • Have sensitivity and specificity of > 90–95%

  • Positive test indicates active infection

  • Although more expensive than serology, they may be more cost-effective because they reduce unnecessary treatment in patients without active infection

• Laboratory-based serologic ELISA test has overall accuracy of 80%

• Proton pump inhibitors significantly reduce the sensitivity of urea breath tests and fecal antigen assays (but not serologic tests) and should be discontinued 7–14 days prior to testing

Endoscopic testing for H pylori

• Gastric biopsy specimens can be obtained for histology and detection of H pylori with a sensitivity and specificity of > 95%

Diagnostic Procedures