Body proteins that act as antibodies. 1. IgG: The immunoglobulin that can be measured in the serum approximately two weeks after a challenge by an antigen. Can cross the placenta from mother to foetus. 2. IgM: The immunoglobulin that can be measured very soon after a challenge by an antigen. The level returns to a non-measurable level very quickly and so this measurement is useful as a test for recent envenomation (or illness). Cannot cross the placenta from mother to foetus. Presence in a neonate therefore indicates infection of the body. 3. IgE: Reaginic antibody; immunoglobulin found in association with allergic or homocytotrophic responses. 4. IgA: Secretory antibody; immunoglobulin found in nonvascular fluids, such as the saliva, bile, aqueous humor, synovial fluide etc.
Article Categories:Dictionary of Tropical Medicine