Things worth knowing about "Immunoglobulins (Ig)"
Immunoglobulins (Ig) - also known as antibodies - are specialised proteins that are produced by the immune system to specifically recognise pathogens such as bacteria, viruses or fungi and render them harmless.
Immunoglobulins are produced by B cells (plasma cells) and are a central component of the specific (adaptive) immune defence. They circulate in the blood and mucous membranes, recognise foreign structures (antigens) and mark them for other immune cells.
There are five main classes with different functions:
- IgG: Most common antibody in the blood, provides long-term protection after infections or vaccinations, placental.
- IgA: Predominantly found in mucous membranes and secretions (e.g. saliva, tears, breast milk), protects against pathogens at ports of entry.
- IgM: Formed as the first antibody in acute infections
- IgE: Plays a central role in allergies and parasite defence
- IgD: Occurs in small amounts, function not yet fully understood.
In medical diagnostics, immunoglobulins serve as markers for acute or chronic infections, immune diseases or allergies. Certain patterns, e.g. increased IgE levels in allergies or a lack of IgA, can indicate autoimmune diseases, chronic inflammation or immunodeficiencies. They also play an important role in Covid-19, vaccination reactions or immunotherapies.
Immunoglobulin preparations are also gaining therapeutic importance in immunology - for example as IVIG (intravenous immunoglobulins) for autoimmune diseases or for passive immunisation. The combination of antibodies with targeted therapy is also used in cancer immunotherapy or monoclonal antibody therapy.
Important properties of immunoglobulins:
- Antibodies of the adaptive immune system
- Recognition and binding of antigens
- Classes: IgG, IgA, IgM, IgE, IgD
- Application in diagnostics, vaccinations, allergy tests, immunotherapies
- Therapeutically usable as IVIG or monoclonal antibodies
Literature references
- Janeway, C. A. et al (2022). ""Immunobiology - The Immune System in Health and Disease.""
- Abbas, A. K. et al. (2021). ""Cellular and Molecular Immunology.""
- Paul, W. E. (2012). ""Fundamental Immunology.""