Helicobacter pylori infection diagnostic tests: Difference between revisions
Jump to navigation
Jump to search
Line 35: | Line 35: | ||
:*Greater curvature of the antrum | :*Greater curvature of the antrum | ||
*The sensitivity of histology is greatly effected by the use of medications such as bismuth, antibiotics, and PPI. | *The sensitivity of histology is greatly effected by the use of medications such as bismuth, antibiotics, and PPI. | ||
===Rapid Urease Testing (RUT)=== | |||
*Identifies active H.pylori infection through the organism's urease activity. | |||
*'''Method''' | |||
:*The gastric biopsies obtained are placed into an agar gel or on a reaction strip containing urea, a buffer,and a pH-sensitive indicator. | |||
:*The urea is metabolized to ammonia and bicarbonate in the presence of H.pylori's urease leading to a pH increase in the microenvironment of the organism. | |||
:*A change in color of the pH sensitive indicator signifies the presence of the active infection. | |||
*The sensitivity of the RUT decreases due to medications such as bismuth-containing compounds, antibiotics, or PPIs which reduce the density and/or urease activity of H.pylori. | |||
*It is recommended that biopsies are taken from two sites due to patchy distribution of H.pylori infection after antibiotics use. The sites include: | |||
:*The body at the gastric angularis | |||
:*Greater curvature of the antrum | |||
*PPIs are withheld for 1-2 wk before performance of RUT as they reduce the sensitivity of test. | |||
===Culture=== | |||
==References== | ==References== | ||
{{Reflist|2}} | {{Reflist|2}} |
Revision as of 19:13, 16 January 2017
Helicobacter pylori infection Microchapters |
Differentiating Helicobacter pylori infection from other Diseases |
---|
Diagnosis |
Guideline Recommendation |
Treatment |
Case Studies |
Helicobacter pylori infection diagnostic tests On the Web |
American Roentgen Ray Society Images of Helicobacter pylori infection diagnostic tests |
Directions to Hospitals Treating Helicobacter pylori infection |
Risk calculators and risk factors for Helicobacter pylori infection diagnostic tests |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Yamuna Kondapally, M.B.B.S[2]
Overview
Endoscopic Diagnostic Tests
| |||
| |||
|
Endoscopic diagnostic tests are biopsy-based diagnostic methods for H.pylori infection. These include:
- Histology
- Rapid urease testing
- Culture
- Polymerase chain reaction
Histology
- Histology for H.pylori detection depends on:
- Site, number, and size of gastric biopsies
- Method of staining
- Level of experience of the examining pathologist
- Advantage of histology over other diagnostic studies is its ability to detect the pathological changes associated with H.pylori infection such as inflammation, atrophy, intestinal metaplasia and malignancy.
- Multiple biopsies are required for accurate diagnosis as the prevalence and density of H.pylori varies throughout the stomach. Therefore a minimum of three biopsies are taken from different sites. They are:
- Angularis
- Greater curvature of the corpus
- Greater curvature of the antrum
- The sensitivity of histology is greatly effected by the use of medications such as bismuth, antibiotics, and PPI.
Rapid Urease Testing (RUT)
- Identifies active H.pylori infection through the organism's urease activity.
- Method
- The gastric biopsies obtained are placed into an agar gel or on a reaction strip containing urea, a buffer,and a pH-sensitive indicator.
- The urea is metabolized to ammonia and bicarbonate in the presence of H.pylori's urease leading to a pH increase in the microenvironment of the organism.
- A change in color of the pH sensitive indicator signifies the presence of the active infection.
- The sensitivity of the RUT decreases due to medications such as bismuth-containing compounds, antibiotics, or PPIs which reduce the density and/or urease activity of H.pylori.
- It is recommended that biopsies are taken from two sites due to patchy distribution of H.pylori infection after antibiotics use. The sites include:
- The body at the gastric angularis
- Greater curvature of the antrum
- PPIs are withheld for 1-2 wk before performance of RUT as they reduce the sensitivity of test.