Immunoglobulin A (IgA)

What is Immunoglobulin A (IgA)?

IgA is important for mucosal immunity, also called the mucosal immune system, and occurs in high concentrations in particular mucous membranes, for example the respiratory tract and the gastrointestinal tract. IgA is also found in secretions such as saliva, tears and breast milk. This antibody protects the body's external surfaces from infection by neutralizing pathogens and preventing their attachment to cells.

What function does Immunoglobulin A have in the body?

IgA has several important functions in the immune system. Above all, IgA forms dimers, which means that two IgA molecules are linked together to effectively bind and neutralize antigens. This structure makes IgA particularly effective at protecting mucous membranes from infection by preventing pathogens from penetrating and infecting the body's tissues. IgA also plays a role in modulating immune responses and maintaining a balance between immunity and tolerance in mucosal membranes.

Why is Analysis of IgA carried out

IgA analysis is used to diagnose and monitor various infections and immune-related conditions. A blood sample is taken to measure the IgA levels in the blood. Elevated levels of IgA may indicate an ongoing infection, autoimmune diseases, or liver and intestinal disorders. Low levels of IgA may indicate an immune deficiency, such as selective IgA deficiency. Specific IgA tests are used to identify antibodies against specific pathogens, such as viruses or bacteria.

During the analysis, a blood sample is taken, which is then processed in the laboratory to measure the IgA concentrations. Elevated levels of IgA usually indicate an active or recently completed infection, while low levels may indicate an immunodeficiency or chronic infection.

Interpretation of IgA in diagnostics

IgA plays an important role in the diagnosis of mucosal infections. Since IgA is the main antibody in mucous membranes, elevated levels of specific IgA can often be a sign of an infection or inflammatory condition in these areas. This makes IgA assays useful in the diagnosis of conditions such as celiac disease, inflammatory bowel disease, and certain types of liver and intestinal disease. In autoimmune diseases, elevated levels of IgA can also indicate an immune response against the body's own tissues.

In addition to indicating ongoing infections, IgA assay can also be important to monitor treatment effectiveness. For example, falling IgA levels may indicate that an infection is subsiding or that a treatment is successful. In addition, IgA tests are used to differentiate between primary and secondary infection. In cases of, for example, celiac disease, the presence of specific IgA may indicate an active autoimmune reaction against gluten.

IgA analysis is also useful for diagnosing and monitoring immunodeficiency diseases. People with selective IgA deficiency have low or absent levels of IgA, making IgA measurements important for diagnosis and monitoring of these conditions.

Use of IgA in clinical practice

In clinical practice, IgA assays are used to quickly identify and treat mucosal infections and autoimmune diseases. For example, IgA levels can be measured to diagnose celiac disease or monitor inflammatory bowel disease. IgA assays are also used to monitor patients with recurrent infections or immunodeficiency states to assess their immune response. It is important to interpret IgA levels in conjunction with other clinical findings and laboratory results to ensure correct diagnosis and treatment.

Normal value for IgA

Normal values for IgA vary depending on laboratory methods and reference ranges. Generally, normal levels of IgA are considered to be between 0.7 and 4.0 g/L for adults. However, it is important to note that these values may vary depending on the individual's age, gender and state of health. High levels of IgA may indicate an active infection or an immune response, while low levels may indicate an immune deficiency. To get an accurate assessment, IgA levels should always be discussed with a doctor who can interpret the results in light of the overall clinical picture.

Reference values for IgA