Globulins
Globulins can be divided into three fractions based on their electrophoretic mobility. Most
of the α and β globulins are synthesized by the liver, whereas γ globulins are produced
by lymphocytes and plasma cells in lymphoid tissue.
- α globulins: consist of α-1 and α-2 globulins.
α-1 globulins include α-1 antitrypsin, α-1 antichymotrypsin, orosomucoid (acid glycoprotein), serum amyloid A, and α-1 lipoprotein (HDL).
α-2 globulins include α-2 macroglobulin (protease inhibitor), haptoglobin (binds free hemoglobin), protein C (inhibitor of activated coagulation factors FVIII and FV), ceruloplasmin (carrier of copper) and α-2 lipoprotein (VLDL).
- β globulins: consist of β-1 and β-2 globulins.
β-1 globulins include transferrin (binds iron) and hemopexin.
β-2 globulins include complement factors 3 and 4, C-reactive protein, plasminogen, β-2 lipoprotein (LDL), hemopexin, β-2 microglobulin and some proportion of IgA (especially) and IgM. Fibrinogen also migrates in this region.
- γ globulins: consists of the immunoglobulins: IgM, IgA, IgG, although IgA and IgM also migrate in the late β region.
For the routine chemistry profile, total globulins are calculated as follows:
TP - albumin = globulin
Globulins can also be measured quantitively and qualitatively with electrophoresis. Radial immunodiffusion is used for accurate quantification of immunoglobulins and has also replaced immunoelectophoresis for determining the immunoglobulin comprising a monoclonal gammopathy.
[Hypoglobulinemia]
[Hyperglobulinemia]
|