[Quantitative determination of immunoglobulin G (IgG) subclasses].

The four IgG subclasses differ with respect to structure and biological function. Within the last 26 years, numerous immunological methods have been developed to study the role of the individual subclasses in humoral immune response. Different methods for quantitative IgG-subclass determinations are discussed with special reference to reliability and standardization. The clinical indications for measuring IgG-subclass levels are listed.