THE MULTIFOLD character of the human immune response has been recognized for many years by the variety of antibodies which result from infection or immunization. Until recently, the basis for such discrimination has been limited to the electrophoretic mobility or biologic effects of antibody in vitro. Biophysical tools which permit the isolation and structural investigation of proteins and other macromolecules have been applied to antibody molecules with such effectiveness that it is now possible to describe the heterogeneity of the human immune response in exquisite detail. These major advances in knowledge require and justify an updated nomenclature.
THE NOMENCLATURE
A group of leaders in this field met in 1964 at Geneva under the auspices of WHO and recommended international adoption of the terms shown in Table I A-1.
The preexisting confusion over nomenclature appears to have been resolved by nearly unanimous adoption of their recommendations by workers in the field with the result that it is standard in most current technical literature on the subject. Popular usage to date appears to favor the notation employing the Greek letter gamma: γG, γM, γA, and γD for the major classes of immunoglobulins, rather than the equally acceptable, but phonetically clumsy Ig-G, Ig-M, Ig-A, and Ig-D notation. Because the data involved, as well as the nomenclature, are too new to have appeared in textbooks or review journals usually read by those interested in child health, it is appropriate to review briefly the structure and functions of the immunoglobulin molecules as currently understood, and to suggest some actual and potentially important applications of this information in diagnosis and therapy.