Immunological aspects of 'fulminant type 1 diabetes'

'Fulminant diabetes' has been recognized as a super-acute onset and non-autoimmune type 1 diabetes. To evaluate autoimmunity against pancreatic beta cell in fulminant diabetes, ELISPOT assay was applied to the peripheral blood of these patients. In our ELISPOT system, GAD65-reactive and insulin B9-23-reactive IFN-gamma spots were detected in 46.3 and 26.0% of autoantibody-positive type 1 diabetes. Also, in fulminant type 1 diabetic patients, IFN-gamma spots in response to GAD65 and insulin B9-23 peptide were detected in 69.2 and 25.0%, respectively. These results suggest that anti-beta cell autoimmunity contributes to develop fulminant type 1 diabetes. Fulminant type 1 diabetes is known to have IDDM-resistant HLA DR2 with similar frequency of non-T1D subjects. In a mouse model, when islet-reactive CD8 cells are transferred to young NOD mice, the recipients develop overt diabetes within 1 week with massive insulitis. In (NOD x Balb/c) F1 mice, which hold idd-resistant genes, transfer of islet-reactive CD8 cells induced diabetes to 60% F1 recipients within 1 week with the later disappearance of insulitis. This mouse model shows very similar feathers to fulminant type 1 diabetes; idd-resistant HLA and no insulitis. These results implicated that once anti-islet immunity is optimally activated, subjects with partially resistant alleles could become overt diabetes.