An IgM test is a blood test that measures the level of IgM antibodies in your blood. IgM, or Immunoglobulin M, is a type of antibody produced by the body's immune system to fight off infections, particularly during the early stages of an infection.
Understanding IgM Antibodies
- First Responder: IgM is typically the first antibody the body produces when it encounters a new antigen, such as a bacteria or virus.
- Indicates Recent Infection: Elevated levels of IgM often indicate a recent or current infection.
- Short-Lived: Unlike other antibodies like IgG, IgM levels tend to decrease relatively quickly after the infection has resolved.
Why is an IgM Test Performed?
An IgM test is performed to:
- Detect recent infections: Help diagnose acute infections, as elevated IgM levels suggest a recent exposure to a pathogen.
- Diagnose certain autoimmune diseases: Some autoimmune diseases can cause elevated IgM levels.
- Evaluate immune system function: Assess the body's ability to produce antibodies in response to an infection.
- Diagnose congenital infections in newborns: Detect infections acquired during pregnancy.
What Do the Results Mean?
- High IgM Levels: May indicate a recent or current infection, such as:
- Viral infections (e.g., mononucleosis, cytomegalovirus (CMV))
- Bacterial infections (e.g., pneumonia)
- Parasitic infections
- Autoimmune disorders (e.g., rheumatoid arthritis, Waldenstrom macroglobulinemia)
- Low IgM Levels: May indicate:
- Immunodeficiency disorders
- Certain medications that suppress the immune system
Important Considerations
It's important to remember that IgM test results should always be interpreted by a healthcare professional in conjunction with other clinical findings, medical history, and other laboratory tests. A single IgM test result is rarely diagnostic on its own.
