Immunoglobulin G (IgG)

What is Immunoglobulin G (IgG)?

IgG is the most common antibody in the blood and occurs in all body fluids with the aim of protecting the body against both bacterial and viral infections by neutralizing pathogens and promoting phagocytosis. IgG is also important for long-term immunity, as it provides protection after vaccination and previous infections.

What function does Immunoglobulin G have in the body?

IgG has several important functions in the immune system. It binds to pathogens, such as bacteria and viruses, and neutralizes them. IgG also activates the complement cascade, a series of proteins that help destroy microorganisms. In addition, IgG enhances phagocytosis, which means it helps immune cells identify and eat pathogens. IgG is also important for transferring immunity from mother to child via the placenta.

Why is Analysis of IgG carried out?

IgG analysis is used to diagnose and monitor various infections and immune-related conditions. A blood sample is taken to measure the IgG levels in the blood. Elevated levels of IgG may indicate an ongoing or past infection, autoimmune diseases, or inflammatory conditions. Low levels of IgG may indicate an immune deficiency, such as hypogammaglobulinemia. Specific IgG 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 IgG concentrations. Elevated levels of IgG usually indicate an active or past infection, while low levels may indicate an immune deficiency or chronic infection.

Interpretation of IgG in diagnostics

IgG plays an important role in the diagnosis of many infections and autoimmune diseases. Because IgG is the most abundant antibody in the blood, elevated levels of specific IgG can often be a sign of an ongoing or past infection. This makes IgG assays useful in the diagnosis of conditions such as chronic infections, autoimmune diseases and allergies. In autoimmune diseases, elevated levels of IgG can also indicate an immune response against the body's own tissues.

In addition to indicating current or past infections, IgG analysis may also be important to monitor treatment efficacy. For example, decreasing IgG levels may indicate that an infection is subsiding or that a treatment is successful. IgG tests are also used to distinguish between different stages of infection and to assess the immune status of individuals who have undergone vaccination.

IgG analysis is also useful for diagnosing and monitoring immunodeficiency diseases. People with hypogammaglobulinemia or other immunodeficiency diseases often have low levels of IgG, making IgG measurements important for the diagnosis and monitoring of these conditions.

Use of IgG in clinical practice

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

Reference values for Immunoglobulin G (IgG)

Normal values for IgG vary depending on laboratory methods and reference ranges. Generally, normal levels of IgG are considered to be between 7 and 15 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 IgG may indicate an active or past infection or an immune response, while low levels may indicate an immune deficiency. In order to get an accurate assessment, IgG levels should always be discussed with a doctor who can interpret the results in the light of the overall clinical picture.

Referensvärden för Immunglobulin G (IgG)

K= female, M= male gender