The discovery of type 1 diabetes

The etiological heterogeneity of idiopathic diabetes has been recognized fo r 25 years, and subdivision into type 1 and type 2 diabetes is fundamental to the way we think about the disease. Review of the literature suggests th at the concept of type 1 diabetes as an immune-mediated disease emerged rap idly over the period from 1974 to 1976 and showed many of the features of a classic paradigm shift. A few key observations triggered recognition and a cceptance of the new paradigm, but the necessary context was provided by sc ientific developments in areas mainly unrelated to diabetes. The disease pa radigm established by 1976 is still widely accepted, and its essential feat ures have been modified only in detail by the revolution in molecular biolo gy that has occurred over the intervening period. Notwithstanding, some of the underlying assumptions remain imprecise, unchallenged, or unconfirmed. Appreciation of the historical origin and subsequent evolution of these fun damental concepts could stimulate critical analysis and help prepare the wa y for a new paradigm.