Immunoglobulin G (IgG)

General Information

Immunoglobulin G (IgG)Makes up 75% of plasma immunoglobulins. It is a major antibody that is produced in response to secondary contact with an antigen. It has the ability to cross the endothelium and placenta and is involved in the development of passive immunity in newborns.

IgG neutralizes bacterial toxins and acts as an opsonin (binds to the bacterial surface and promotes phagocytosis).

Significant, congenital, or acquired reductions in IgG lead to an increase in individual susceptibility to bacterial infections. Thus, serum immunoglobulin levels should be monitored in patients with recurrent infections.

On the other hand, elevated IgG levels are observed in immunocompetent humans in response to various infectious or inflammatory processes. IgG determination in conjunction with the determination of specific IgM facilitates the serological diagnostics of acute or chronic infection.

Elevated IgG concentrations have been reported in some cases of acquired immunodeficiency syndrome, multiple sclerosis, and chronic hepatitis.

An increase in IgG concentration is also observed in the majority of cases of multiple myeloma, in which case IgG> 3 g / dl - is the main diagnostic criterion.

When should I get tested for immunoglobulin G (IgG)?

• Assessment of humoral immunity;
• Diagnosis and monitoring of IgG myeloma;
• Assess the risk of infections, especially in children and patients with lymphomas.

How to prepare for the test?

The test should be performed on an empty stomach.

Research material

Venous blood

Possible interpretation of the results

Immunoglobulin G concentration increases:

• Sarcoidosis;
• Chronic liver disease;
• Autoimmune diseases;
• Parasitosis;
• Chronic infections;
• Hyperimmunization;
• Acute malnutrition;
• Dysproteinemia;
• IgG myeloma.

Immunoglobulin G concentration decreases:

• Current syndromes of protein loss;
• Pregnancy;
• Non-IgG myeloma;
• Waldenström's macroglobulinemia;
• Lymphoid aplasia;
• Chronic lymphocytic leukemia;
• Agammaglobulinemia;
• Selective IgG deficiency;