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IgM Antibody

Immunoglobulin M (IgM)

IgM or Immunoglobulin M is the first antibody formed in response to an infection and activates the immune system immediately. An increase in IgM levels is a clear indication of an ongoing or recent infection.

What is Immunoglobulin M (IgM)?

Immunoglobulin M (IgM) is a type of antibody that plays a central role in the body's immune system. It is the first antibody produced by the immune system in response to an infection. IgM constitutes a significant part of the initial, nonspecific immune response and is effective in neutralizing pathogens and activating the complement system. IgM is mainly found in blood and lymph fluid and is important in limiting the spread of infections in the early stages.

What function does Immunoglobulin M have in the body?

IgM has several important functions in the immune system. Above all, IgM forms pentamers, which means that five IgM molecules are linked together in order to bind and neutralize antigens. This structure makes IgM particularly effective at clumping together bacteria and viruses. Which then facilitates the reading from the body. IgM also activates the complement cascade as a series of proteins in the blood that help destroy microorganisms. In addition, IgM plays a role in stimulating other parts of the immune system, including the production of other types of antibodies such as IgG.

Analysis of IgM

IgM analysis is used to diagnose and monitor various infections and immune-related conditions. A blood sample is taken to measure the IgM levels in the blood. Elevated levels of IgM may indicate an ongoing or recent infection, as IgM is the first antibody produced in response to an infection. Analysis of IgM can also be useful in the investigation of autoimmune diseases and certain types of immunodeficiency conditions. Specific IgM tests are used to identify antibodies against specific pathogens, such as viruses or bacteria.

The importance of IgM in diagnostics

IgM plays an important role in the diagnosis of acute infections. Because IgM is the first antibody produced upon a new infection, elevated levels of specific IgM are often indicative of a recent infection. This makes IgM assays useful in the diagnosis of acute phases of infections such as hepatitis, influenza and other viral or bacterial infections. In autoimmune diseases, elevated levels of IgM can also indicate an immune response against the body's own tissues.

In addition to indicating ongoing infections, IgM analysis may also be important to monitor treatment efficacy. For example, falling IgM levels may indicate that an infection is subsiding or that a treatment is successful. In addition, IgM tests are used to distinguish between primary and secondary infection. In cases of, for example, dengue fever, the presence of specific IgM may indicate a primary infection, while IgG is more prominent in secondary infection.

IgM analysis is also useful for diagnosing and monitoring immunodeficiency diseases. People with primary immunodeficiency disorders, such as X-linked agammaglobulinemia (XLA), may have low or absent levels of IgM, making IgM measurements important for the diagnosis and monitoring of these conditions.

Use of IgM in clinical practice

In clinical practice, IgM assays are used to quickly identify and treat acute infections. For example, IgM levels can be measured to diagnose acute hepatitis B or Epstein-Barr virus infection. IgM assays are also used to monitor patients with recurrent infections or immunodeficiency states to assess their immune response. It is important to interpret IgM levels in conjunction with other clinical findings and laboratory results to ensure correct diagnosis and treatment.

Normal value for IgM

Normal values for IgM vary depending on laboratory methods and reference ranges. Generally, normal levels of IgM are considered to be between 0.1 and 0.4 g/L. However, it is important to note that these values can vary depending on the individual's age, gender and health status. High levels of IgM may indicate an active infection or an immune response, while low levels may indicate an immune deficiency. To get an accurate assessment, IgM levels should always be discussed with a doctor who can interpret the results in light of the overall clinical picture.

Reference values for IgM

Analysis Age Gender Lower Upper Device
S-Immunoglobulin M 0-14 days KM 0.1 0.4 g / L
15 days - 3 months KM 0.1 0.7 g / L
3 months - 1 year KM 0.2 0.9 g / L
1-17 years KM 0.5 1.7 g / L
>=18 years KM 0.3 2.1 g / L

In conclusion, IgM is a critical component of the early immune response and analysis of IgM levels is an important part of the diagnostics for many infections and immune-related conditions. By measuring IgM, doctors can quickly and efficiently identify ongoing infections and assess immune function, which contributes to a more targeted and effective treatment.

Tests containing the marker Immunoglobulin M (IgM)



  • Analysis of Immunoglobulin M
  • For identification of ongoing infection.
  • Evaluation of the immune system status.

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