Neonatal thymectomy prevents spontaneous diabetes mellitus in the BB/W rat.

Complete neonatal thymectomy reduced the frequency of spontaneous diabetes mellitus in BioBreeding/Worcester rats from 27 to 3 percent. Incomplete thymectomy also significantly reduced the frequency of diabetes (to 9 percent). These findings strengthen the hypothesis that thymus-dependent, cell-mediated autoimmune destruction of pancreatic B cells is responsible for the pathogenesis of diabetes in this experimental animal.