Immunoglobulins are a group of proteins (albumen) formed in plasma cells that specifically bind as antibodies with foreign substances (antigens) to render them harmless.
The following classes of immunoglobulins can be distinguished:
- Immunoglobulin A (IgA) – secreted on all mucous membranes of the respiratory tract, eyes, gastrointestinal tract, genitourinary tract, and via special glands around the nipple of mothers, where it protects against pathogens; found in blood serum and body secretions.
- Immunoglobulin D (IgD) – occurs in the membrane of B lymphocytes.
- Immunoglobulin E (IgE) – mediates protection against parasites, such as worms. Upon antigen contact, it leads to the release of histamines, granzymes, etc.; found in the membrane of mast cells and basophilic granulocytes (allergic immediate reaction).
- Immunoglobulin G (IgG) – is formed only in a delayed defense phase (3 weeks) and remains for a long time. Detection of Ig G indicates a passed infection or vaccination; occurrence in blood serum and breast milk; placental.
- Immunoglobulin M (IgM) – is the first class of antibodies formed on initial contact with antigens and indicates the acute infectious phase of a disease; occurrence in blood serum.
Immunoglobulins are composed of two light and two heavy polypeptide chains connected by disulfide bridges.
The function of IgD is largely unknown.
The process
Material needed
- Blood serum
Preparation of the patient
- Not necessary
Disruptive factors
- Not known
Normal value
| Normal value in U/ml | < 100 |
Indications
- Suspected chronic infection
- Suspicion of autoimmune disease
Interpretation
Interpretation of increased values
- Autoimmune diseases, unspecified
- Chronic infections of all kinds
- Plasmocytoma (multiple myeloma)
Interpretation of decreased values
- Not relevant to the disease