Autoimmune diabetes: the involvement of benign and malignant autoimmunity

Our studies in the NOD mouse demonstrate that the autoimmune response can be either benign or malignant. In the former case /=100 days of age make up a heterogeneous group where some are in a benign state of autoimmunity, which can continue for a further |LX200 days, others are in a state of transition to the malignant state of autoimmunity, and others have a fully malignant autoimmune response and are diabetic. This heterogeneity developing within members of the population, in terms of pancreatic damage, is not consistent with the proposal that autoimmune islet damage in the NOD mouse is a slow, progressive process affecting all disease prone members of the population. In the NOD mouse, massive islet destruction is a late event in the autoimmune process and only develops following the conversion of the autoimmune response from the benign to the malignant state.