[Idiopathic type 1 diabetes: a heterogenous disease or result of our ignorance?]

Based on etiology a new classification for diabetes mellitus was proposed by the Experts of WHO in 1999. According to the classification, type 1 diabetes was subclassified as type 1A (autoimmune) and type 1B (idiopathic). Both forms result from the destruction of beta cells, however in type 1A the process is immune-mediated but in type 1B the origin of the beta cells impairment is still unknown. Moreover, subtype B is considered to be very heterogeneous and the diagnostic criteria are still not clear. The purpose of this article was to review studies on the pathogenesis of idiopathic type 1 diabetes.