The main difference between H. pylori IgG and IgA is that IgG provides the bulk of antibody-based immunity to invading pathogens, while IgA prevents colonization of pathogens. In addition, H. pylori IgG is the predominant circulating form of antibodies, while IgA is mainly found in the mucosal areas. In addition, H. pylori IgG antibodies can only be detected after the IgM antibody titer has been reduced , while IgA antibodies appear after a few weeks of infection. In addition, IgG helps in the qualitative diagnosis of H. pylori infection, while IgA helps in the diagnosis of chronic active gastritis.

In short, IgG and IgA are two types of immunoglobulin isotopes that are generated against H. pylori infection. Here H. pylori is a gram-negative , helical, microaerophilic bacterium that is common in the stomach.

Key areas covered

1. H. Pylori - definition, properties, meaning 2. What is H. Pylori IgG - definition, properties, meaning 3. What is H. Pylori IgA - definition, properties, meaning 4. What are the similarities between H. Pylori IgG and IgA - Overview of Common Features 5. What is the Difference Between H. pylori IgG and IgA - Comparison of Key Differences

key terms

Campylobacter pylori, H. pylori, H. pylori IgA, H. pylori IgG, mucosal areas, serum, stomach infection

H. pylori - definition, properties, meaning

Helicobacter pylori or Campylobacter pylori is a gram-negative, spiral-shaped bacterium that was first identified in 1982 by Australian doctors Barry Marshall and Robin Warren. The bacterium penetrates through its spiral shape into the lining of the stomach and thus causes the infection. In addition, H. pylori is associated with the mucous membrane-associated lymphatic tissue in the stomach, esophagus, colon, rectum and around the eye, as well as in the gastric lymphoid tissue.

Figure 1: H. pylori crosses the mucous layer of the stomach

In addition, H. pylori spread via the fecal-oral route. Accordingly, over 50% of the world's population have H. pylori infection in their upper respiratory tract. Developing countries in particular have significantly higher numbers of infections. Hence, it is one of the most common types of chronic bacterial infections. However, most of these infections remain asymptomatic.

Clinically, dyspepsia or indigestion occurs in the upper airways with symptoms such as malaise, gas, pain, nausea, and belching. Chronic gastritis, stomach ulcers and stomach cancer are also complications of the disease. More commonly, basic diagnostic methods of infection include the urea breath test, fecal antigen assay, and tissue biopsy. Unfortunately , an H. pylori infection does not heal spontaneously and the pathogen can persist for life. However, the majority of infected patients develop antibodies to H. pylori .

What is H. Pylori IgG?

H. pylori IgG is the type of antibody that appears as the titer of IgM antibodies decreases. It is important that it is the predominant form of antibodies in the serum in H. pylori infection. The main function of IgG antibodies in H. pylori infection is to prevent the invading pathogen.

Figure 2: H. pylori infection in a pit of the stomach

However, the detection of IgG antibodies in H. pylori infection only helps to diagnose the disease qualitatively. Therefore, positive results do not indicate the presence of gastrointestinal disease. Therefore, test results should be used in conjunction with other clinical and laboratory data to support patient management decisions.

What is H. Pylori IgA

H. pylori IgA is the second type of antibody that is tested for H. pylori infection. Significantly, it occurs a few weeks after infection. However, IgA antibodies occur in the mucous membrane areas and prevent the colonization of pathogens.

Figure 3: Structure of IgG and IgA

In addition, the detection of IgA antibodies is important in diagnosing H. pylori infections in patients with duodenal disease and in monitoring the eradication of H. pylori following antimicrobial therapy. Although the IgA-type systemic response is less pronounced, the significant values ​​may indicate more severe inflammation.

Similarities Between H. pylori IgG and IgA

• H. pylori IgG and IgA are two types of immunoglobulin - isotopes is produced in response to infection with H. pylori.
• They are antibodies, which are glycoprotein molecules produced by plasma B cells.
• In addition, they specifically recognize and bind the H. pylori antigens.
• In addition, they play a vital role in H. pylori destruction by developing adaptive immune responses.
• Therefore, the detection of antibodies helps both in diagnosing the disease and in monitoring treatments.
• Both types of antibodies also persist in the body for a long time.
• They are two of the three types of antibodies used to test for H. pylori infection, while the third type of antibody is IgM.
• However, testing both antibodies does not allow a distinction to be made between acute and chronic infections.

Difference between H. pylori IgG and IgA

definition

H. pylori IgG refers to the predominant form of antibodies in serum that is specific for H. pylori infection. Meanwhile, H. pylori IgA refers to the form of antibodies found in the areas of the mucous membrane specific to H. pylori .

structure

H. pylori IgG is a monomer while H. pylori IgA is a dimer.

Appearance

H. pylori IgG antibodies can only be detected after the IgM antibody titer has been decreased, but pylori IgA antibodies appear after a few weeks of infection.

Location

H. pylori IgG is the predominant circulating form of antibodies, but H. pylori IgA is mainly found in the mucosal areas.

function

H. pylori IgG provides most of the antibody-based immunity against invading pathogens, while H. pylori IgA prevents pathogen colonization.

Changing sides

The flow time of H. pylori IgG is 1-3 days, while the flow time of H. pylori IgA is 1-4 days.

Detection method

H. pylori IgG is detected by chemiluminescent immunoassay (CLIA), but H. pylori Ig A is detected by enzyme-linked immunosorbent assay (ELISA).

Role in disease diagnosis

H. pylori IgG helps in the qualitative diagnosis of the infection, while H. pylori IgA helps in the diagnosis of chronic active gastritis.

High levels

Higher levels of H. pylori IgG antibodies indicate the chronic infection, while high levels of H. pylori IgA in the systemic circulation indicate severe gastric inflammation.

diploma

H. pylori IgG is the type of antibody that forms after your IgM antibody titer has decreased. It is also the predominant form of serum antibodies. And the main function of H. pylori IgG is to keep pathogens from entering. In diagnostics, it helps to diagnose the diseases; its higher values ​​indicate chronic infection. H. pylori IgA, on the other hand, is another type of antibody that appears a few weeks after infection. In particular, it occurs in the areas of the mucous membrane and prevents the pathogen from colonizing. It also helps diagnose chronic active gastritis. Therefore, the main difference between H. pylori IgG and IgA is their role in infection.

References:

1. "Helicobacter pylori Antibody, IgG." LabCorp, Laboratory Corporation of America® Holdings and Lexi-Comp Inc., Jan. 29, 2020, available here. 2. "Helicobacter Pylori Antibodies, IgA." LabCorp, Laboratory Corporation of America® Holdings and Lexi-Comp Inc., January 29, 2020, available here. "Anti-Helicobacter Pylori ELSIA (IgA)." EUROIMMUN, EUROIMMUN AG. Available here .

Image courtesy:

1. "Ulcer-causing bacterium (H. pylori) that crosses the mucous layer of the stomach" By Zina Deretsky, National Science Foundation ( Public Domain ) via Commons Wikimedia 2. "Immunohistochemical detection of Helicobacter (1) Histopathology" By user: KGH - Own work ( CC BY-SA 3.0 ) via Commons Wikimedia 3. “Mono-and-Polymers” By Martin Brändli (brandlee86) - Own work ( CC BY-SA 2.5 ) via Commons Wikimedia