Diagnosis of helicobacter infection

The bacterium Helicobacter pylori is the only one of the bacteria that is marked by the WHO classification as a class 1 carcinogen. Its presence in the gastric mucosa positively affects the presence and development of gastritis, stomach ulcers and gastric cancer.

To diagnose H. pylori infection, we can use invasive and non-invasive methods.

Invasive tests

Invasive tests mainly include a biopsy of the gastric or duodenal mucosa. The collected sample can be cultivated, using a rapid urease test or PCR.

• The culture test shows the highest sensitivity and specificity. However, bacteria are very sensitive to oxygen, so collection and transport require special conditions.
• The Rapid Urease Test is based on the intensity of urease activity, which is a surface marker of the bacterium. This test is a routine demonstration in endoscopy.
• Newer tests include immunological detection of bacteria – the so-called iRUT method – and the PCR method, which detects the bacterium in biopsies and stool samples.

Non-invasive tests

Non-invasive tests include the urease breath test, which is now the gold standard, the detection of the surface antigens of the bacterium and the determination of antibodies to H. pylori in serum or urine samples.

• The Urea Breath Test (UBT) is based on the detection of urease activity. The change in ¹³CO₂: ¹²CO₂ ratio in exhaled air after cleavage of orally administered urea labelled with the stable carbon ¹³C isotope is determined. This test is mainly used for primary diagnostics due to its high specificity and sensitivity.
• Determination of Helicobacter pylori surface antigens in the stool. This test is suitable for monitoring the course of eradication treatment.
• Serological detection of antibodies to H. pylori in serum, saliva or urine sample. The method is only used to determine antibodies and not active infections.

GastroPanel

GastroPanel is a non-invasive method, whereby by determining the levels of certain parameters we can evaluate the risk of H. pylori infection and the risk of developing atrophic gastritis or gastric cancer. These parameters include:

• gastrin-17
• pepsinogen I
• antibodies to H. pylori class IgG

Links

Related articles

• Determination of antibodies against Helicobacter pylori
• Carbon-13 labeled urea breath test
• Detection of Helicobacter pylori antigen in stool

Source

• KOCNA, Petr. GastroLab : MiniEncyklopedie laboratorních metod v gastroenterologii [online]. ©2002. Poslední revize 2011-01-08, [cit. 2011-03-04]. <http://www1.lf1.cuni.cz/~kocna/glab/glency1.htm>.

Literature

• BURES, J, et al. Epidemiology of Helicobacter pylori infection in the Czech Republic. Helicobacter. 2006, vol. 11, no. 1, s. 56–65, ISSN 1523-5378 [online], 1083-4389 [print]. 

• BONAMICO, M, et al. Evaluation of stool antigen test, PCR on ORAL samples and serology for the noninvasive detection of Helicobacter pylori infection in children. Helicobacter. 2004, vol. 9, no. 1, s. 69–76, ISSN 1083-4389 [print], 1523-5378 [online]. 

• SMITH, SI, et al. Comparison of three PCR methods for detection of Helicobacter pylori DNA and detection of cagA gene in gastric biopsy specimens. World J Gastroenterol. 2004, vol. 10, no. 13, s. 1958–1960, ISSN 1007-9327. 

• NAKATA, H, et al. Immunological rapid urease test using monoclonal antibody for Helicobacter pylori. Journal of Gastroenterology and Hepatology. 2004, roč. 19, vol. 9, s. 970–974, ISSN 08159319. 

• HINO, B, et al. Comparison of invasive and non-invasive tests diagnosis and monitoring of Helicobacter pylori infection in children. Journal of pediatric gastroenterology and nutrition. 2004, vol. 39, no. 5, s. 519–523, ISSN 0277-2116 [print], 1536-4801 [online].