Until two decades ago, clinicians relied upon the simple measurement of the albumin and globulin fraction as a guide toward understanding disorders of serum globulins. Electrophoretic techniques with use of paper and cellulose acetate strips became available later and allowed detection of alpha, beta, and gamma fractions of the globulin component. More recently, immunoprecipitation in agar gel and other methods have revealed five immunoglobulins, the term preferred to γ-globulins since this class of proteins migrates in both the gamma and faster-moving regions of the electrophoretogram. This rapid application of research techniques to the bedside has permitted a more detailed description of immunoglobulin abnormalities. Studies have multiplied and a more logical classification of disease states has emerged. Since antibody function resides in immunoglobulins, perhaps all immunoglobulins have an antibody function. Such a regrouping of diverse clinical conditions has enlarged our understanding of the biology of the immune system.
Immunoglobulinopathies by Engle