Immunoglobulin metabolism in disease

Immunodeficiency and hypogammaglobulinemia are shown to occur by a variety of pathophysiologic mechanisms. Hypogammaglobulinemia may be caused by decreased synthesis of all classes of immunoglobulins, or may involve defective synthesis of selective classes of immunoglobulins. Alternatively, hypogammaglobulinemia may be due to a disorder of endogenous catabolic pathways of a single immunoglobulin class, or of all immunoglobulin classes. Finally, hypogammaglobulinemia may be caused by excessive loss of immunoglobulins into the urinary or gastrointestinal tracts.