Definition

1. Noun:
   • A specific class of antibody: Immunoglobulin G (IgG) is one of the five primary types of antibodies (immunoglobulins) found in the blood and tissue fluids of vertebrates.
   • The primary antibody for bacterial defense: It is the most abundant antibody and plays the central role in the body's humoral immune response against bacterial infections.

Usage Examples

• Noun:
  • The test showed high levels of immunoglobulin G, indicating a past infection.
  • Immunoglobulin G can cross the placenta, providing passive immunity to the fetus.

Advanced Usage

• "IgG seropositivity": The state of having detectable IgG antibodies against a specific pathogen in the blood serum, often indicating prior exposure or vaccination.

  • IgG seropositivity for measles confirms the individual is immune.

• "IgG subclass deficiency": A medical condition characterized by low levels of one or more of the four subclasses of Immunoglobulin G, leading to increased susceptibility to infections.

  • The child's recurrent pneumonia was linked to an IgG subclass deficiency.

Variants and Related Words

• IgG (n): The common abbreviation for Immunoglobulin G.

  • The lab report listed the IgG level.

• Immunoglobulin (n): The general term for a class of glycoprotein molecules produced by plasma cells that function as antibodies. Immunoglobulin G is a subtype.

  • There are five major types of immunoglobulins: IgA, IgD, IgE, IgG, and IgM.

Synonyms

• Gamma globulin: A broad category of blood plasma proteins that includes antibodies; IgG is a major component.
• Antibody: A protein produced by the immune system to neutralize pathogens. IgG is a specific type of antibody.

Related Phrases

• IgG antibody titer: A measurement of the concentration of a specific IgG antibody in the blood.

  • A rising IgG antibody titer suggests an active or recent infection.

• Intravenous Immunoglobulin (IVIG): A therapeutic preparation containing pooled IgG antibodies from donors, used to treat various immune deficiencies and autoimmune diseases.

  • The patient receives monthly IVIG infusions for their primary immunodeficiency.

Noun

1. one of the five major classes of immunoglobulins; the main antibody defense against bacteria