What are the different Classes of immunoglobulins?

IgG = Largest, most common; only one thst crosses the placenta IgE = Important in allergic responses IgD = help B cells IgM = first Ab produced during immune response, then declines when IgG increases IgA = found in glandular secretions( mucus, tears, saliva) 5 classes determined by structural differences IgG = Largest, most common; only one thst crosses the placenta IgE = Important in allergic responses IgD = help B cells IgM = first Ab produced during immune response, then declines when IgG increases IgA = found in glandular secretions( mucus, tears, saliva) 5 classes determined by structural differences