Immunoglobulins are divided into 5 major types based on the differences in their heavy chain constant regions. These are IgA, IgM, IgG, IgD and IgE.
IgE is one of the five isotypes of human immunoglobulins and plays role in helminthic infestations and allergic reactions.
Based on the location of antigenic determinants sites, immunoglobulins are divided into, isotypes, allotypes, and idiotypes.
IgA is the second most abundant class of immunoglobulin. sIgA is a dimer and is confers mucosal immunity.
Antibodies are Y-shaped tetra-peptide molecules consisting 2H and 2 L chains. There are 5 classes of immunoglobulins IgG, IgA, IgM, IgE, and IgD.
Neutralization of pathogens, phagocytosis, mucosal immunity, ADCC and complement mediated lysis are major functions of antibodies.
IgG antibody crosses the placenta and plays an important role in protecting the developing fetus. IgG is the most abundant Ig in serum.
IgM is the largest pentameric immunoglobulin which is used as a marker of recent infection. IgM also activates complement pathway.
