Definition

Noun: - Immunoglobulin D (IgD): One of the five major classes of immunoglobulins (antibodies) found in the immune system. It is present in the blood serum in very small quantities and is primarily found on the surface of mature B-lymphocytes, where it functions as part of the B cell receptor complex.

Usage and Examples

• Noun:
  • IgD, or immunoglobulin D, is a membrane-bound antibody on naive B cells.
  • The exact role of immunoglobulin D in the immune response is still an area of research.
  • A deficiency in immunoglobulin D is rare and its clinical significance is not fully understood.

Advanced Usage

• "Surface immunoglobulin D": Refers specifically to the membrane-bound form of IgD that acts as a receptor on B cells.
  • The activation of the B cell can be mediated through its surface immunoglobulin D.

Variants and Related Words

• IgD: The common abbreviation for immunoglobulin D.
• Immunoglobulin (Ig): The general term for the class of proteins to which IgD belongs. The other major classes are IgA, IgE, IgG, and IgM.
• Antibody: A synonym for immunoglobulin, a protein produced by B cells that binds to specific antigens.

Synonyms

• Antibody D: A less common synonym emphasizing its function.
• IgD: The standard abbreviated form.

Notes on Meaning

This term has a highly specific, technical meaning in immunology and medicine. It refers exclusively to this one class of antibody and is not used in a general or figurative sense. Its primary context is scientific discussion of the immune system.

Noun

1. one of the five major classes of immunoglobulins; present in blood serum in small amounts