Antibody Deficiency Disorder (Archived)

Antibodies or immunoglobulins (Ig) play an important role in the immune system's mechanisms of defense. They fight off extracellular pathogens, for instance, bacteria, and can neutralize viruses when they are in the bloodstream and other body fluids. Normal individuals have 5 classes of immunoglobulins, which are IgM, IgG, IgA, IgD, and IgE, and immunoglobulin subclasses including IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. Sometimes an antibody deficiency disorder takes place. It can happen due to several causes, including a genetic absence of an important enzyme in B-cell development that renders immature B cells that are unable to proliferate into mature Ig-producing B cells or may be caused when T lymphocytes do not signal B lymphocytes or are idiopathic.  The most common antibody deficiency disorders include: X-linked agammaglobulinemia (Bruton disease). Transient hypogammaglobulinemia of newborn. Selective Ig immunodeficiencies, for example, IgA selective deficiency. Super IgM syndrome. Common variable immunodeficiency disorder.