ABSTRACT
IDDM is also known as juvenile onset diabetes because it usually appears in childhood or early adolescence. At the beginning of the disease, the islets of Langerhans in the pancreas become infiltrated with lymphocytes, which selectively destroy the b cells of the islets (Fig. 46.5). The antigen that provokes the autoimmune attack on the b cells is not known and has been difficult to identify. An excellent animal model of IDDM is provided by NOD (non-obese diabetic) mice, in which, as in humans, a specific MHC class II allele is associated with the development of diabetes. A very high proportion of these mice develop diabetes but not all, which, as in humans, indicates an environmental factor.
