The "molecular man": from the concept of diathesis to HLA associated diseases

In recent years the concept of biological individuality has found ample acknowledgement in transplantation medicine; yet over 60 years ago Garrod had already grasped its real meaning in terms of a chemical individuality which he in turn envisaged as an explanation for the ancient concept of diathesis. HLA molecules have been recognized as being particularly representative of biological individuality, and their discovery has been followed by the observation that for some diseases there are measurable risks of predisposition which are indeed linked to certain antigenic-molecular HLA conformations. The biological individuality of man is thus acquiring an increasingly well-defined molecular characterization in which ancient diathesis presents a new and effective key for its interpretation.