HLA: its role in pathogenesis of disease

The complexity of the HLA system, the major histocompatibility complex in man, is reviewed with regard both to the isotypic complexity (the number of loci) as well as the polymorphism of the individual loci. Different methods used to define polymorphism, including serological analysis and T lymphocyte response analysis, are considered. The possible role of HLA antigens in association with a variety of diseases is discussed.