Immunoglobulin M (IgM)

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 IgM is the antibody in the primary immune response, that is, it becomes active when there is contact with a pathogen. In addition to infectious IgM antibodies, there are also non-infectious IgM antibodies. These include AB0 blood group isohemagglutinins rhesus antibodies and cold agglutinins.

The procedure

Material needed

  • Blood serum

Preparation of the patient

  • Not necessary

Disruptive factors

  • Not known

Standard values

Age Normal value in mg/dl Normal value in IU/ml
Newborn 6-21 0,69-2,41
3rd month of life 17-66 1,95-7,59
6th month of life 26-100 2,99-11,5
9. month of life 33-125 3,79-14,37
1 year 37-143 40-150 4,71-16,44 4,6-17,25
2 years 41-156 47-175 4,71-17,94 5,40-20,12
4 years 43-163 52-193 4,94-18,74 5,98-22,19
6 years 45-169 56-208 5,17-19,43 6,44-23,92
8 years 47-175 60-220 5,40-20,12 6,9-25,30
10 years 48-179 62-231 5,52-20,58 7,13-26,56
12 years 49-183 65-240 5,63-21,04 7,47-27,60
14 years 50-187 66-248 5,75-21,50 7,59-28,52
16 years 50-191 68-255 5,75-21,96 7,82-29,32
18 years 51-194 68-261 5,86-22,31 7,82-30,01
> 18 years 40-230 40-280 4,6-26,45 4,6-32,2

Indications

  • Suspected plasmacytoma (multiple myeloma).

Interpretation

Interpretation of increased values

  • Acute hepatitis (inflammation of the liver).
  • Acute infections, unspecified
  • Autoimmune diseases, unspecified
  • Chronic infections, acute relapse
  • Hyper-IgM syndrome – genetic disease that leads to severely reduced IgA and IgG levels in addition to excessively high IgM levels.
  • Liver cirrhosis – connective tissue remodeling of the liver leading to functional impairment.
  • Plasmocytoma (multiple myeloma)

Interpretation of decreased values

  • Primary IgM antibody deficiency syndromes such as X-linked hypogammaglobulinemia.
  • Secondary IgG antibody deficiency syndromes due to increased loss (burns, nephrotic syndrome) or decreased formation (chemotherapy, radiation therapy; tumors, unspecified)