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 onall mucous membranes of the respiratory tract, eyes, gastrointestinal tract, urogenital tract, and via special glands around the nipple ofmothers, where it protects against pathogens; found inblood 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 ofHistamines, granzymes, etc.; Occur in the membrane of mast cells and basophilic granulocytes (allergic immediate reaction).
- ImmunoglobulinG (IgG) – is formed only in a delayed defense phase (3 weeks)and remains for a long time. Detection of Ig G indicates an infection or vaccination; occurrence in blood serumand breast milk; placental.
- ImmunoglobulinM (IgM) – is the first class of antibodies formed on first contactwith antigens and indicates the acute infection phase of adisease; occurrence in blood serum.
Immunoglobulins are composed of two light and two heavy polypeptide chains connected by disulfide bridges.
Immunoglobin A (IgA1 and IgA2) provides an immunological mucosal barrier by binding foreign substances on the surface of the mucosa. Furthermore, it leads to inflammatory responses.
The procedure
Material needed
- Blood serum
- Saliva – secretory IgA
Preparation of the patient
- Not necessary
Disruptive factors
- Not known
Normal values – blood serum
| Age | Normal value in mg/dl | Normal value in IU/ml |
| 3rd month of life | 5-34 | 2,075-20,23 |
| 6th month of life | 8-57 | 4,76-33,915 |
| 9th month of life | 11-76 | 6,545-45,22 |
| 1 year | 14-91 | 8,33-54,145 |
| 2 years | 21-145 | 12,495-86,275 |
| 4 years | 30-188 | 17,85-111,86 |
| 6 years | 38-222 | 22,61-132,09 |
| 8 years | 46-251 | 27,37-149,345 |
| 10 years | 52-274 | 30,94-163,03 |
| 12 years | 58-291 | 34,51-173,145 |
| 14 years | 63-304 | 37,485-180,88 |
| 16 years | 67-314 | 39,865-186,83 |
| 18 years | 70-321 | 41,65-190,995 |
| > 18 years | 70-380 | 41,65-226,1 |
Normal value – saliva
| Normal value in mg/dl | 8-12 |
Indications
- Suspected chronic infection
- Suspicion of autoimmune disease
- Suspected immunodeficiency with serum IgA ↓
Interpretation
Interpretation of increased values
- Autoimmune diseases, unspecified
- Chronic infections of all kinds
- Hepatopahy/liver damage due to alcohol
- Cirrhosis of the liver – connective tissue remodeling of the liver leading to functional limitations.
- Monoclonal gammopathy – form of multiple myeloma (plasmacytoma).
- Celiac disease (gluten-induced enteropathy) – chronic disease of the mucosa of the small intestine (small intestinal mucosa), which is based on hypersensitivity to the cereal protein gluten.
Interpretation of lowered values
- Primary IgA antibody deficiency syndrome – common form of immunodeficiency.
