Determination of IgG to Helicobacter pylori (HP) in blood serum by ELISA method

Helicobacter Pylori is a gram–negative bacillus, which is the main cause of the development of peptic ulcer of the stomach and duodenum. Previously, it was believed that ulcers are caused by completely different factors, since microorganisms that could survive in the acidic environment of gastric juice have never been found in the stomach. Australian scientists B.J. Marshall and J.R. Warren published the results of their analysis in 1983, which served as a turning point in their views on the nature of inflammatory diseases of the upper digestive tract. They were able to isolate and cultivate spiral-shaped microorganisms from the gastric mucosa of a patient suffering from gastritis, subsequently named Helicobacter pylori. The discovery of the bacterium Helicobacter Pylori has become a sensational breakthrough in the treatment of such a common peptic ulcer disease. The principle of therapy has radically changed, as the use of antibiotics has become necessary.


Helicobacter Pylori penetrates through the oral cavity into the stomach and "sticks" to the cells of the gastric epithelium in the area of the intercellular gap. Helicobacter finds similar "loopholes", since urea and hemin are released from these gaps in large quantities, which are captured by the bacterium. These substances are necessary for the normal functioning of the microorganism: Helicobacter Pylori uses the enzyme urease to break down urea to form ammonia and carbon dioxide. The latter change the acidity around the bacterium, creating favorable conditions for its existence. Subsequently, helicobacter toxically affects the stomach wall, damaging it and causing a persistent defect – an ulcer!


There are many direct and indirect ways to identify Helicobacter Pylori. The most reliable is a swab from the surface of the gastroscope, followed by the determination of the presence of a DNA microorganism in the mucus from the stomach. The main "disadvantage" of this technique is the technical complexity of the procedure – it is necessary to insert a special device through the oral cavity and esophagus – a fibrogastroduodenoscope, and to take material. Special training is required. Therefore, the method is not used on a large scale. It is prescribed only when there are already obvious manifestations of peptic ulcer disease and it is necessary to confirm the diagnosis.


There is another technique for detecting Helicobacter: determination of immunoglobulin class G (IgG) to Helicobacter Pylori. The method is based on determining the presence of specific antibodies that the body produces in response to the presence of a microbe. The presence of IgG means that Helicobacter Pylori has been in the body for a long time, that is, about a chronic infectious process. The method has high sensitivity, accessibility and low price, which makes it "screening", that is, necessary for widespread use in order to indicate a group of patients (from the general mass) with a high risk of helicobacter infection. If the test is positive, then the patient needs to undergo a biopsy, if negative, there is no need for this.