Pancreatic pathology in type 1 diabetes in human.
In type 1 autoimmune diabetes there is a selective destruction of insulin-secreting beta cells. Around the time of clinical presentation, insulitis, a chronic inflammatory infiltrate of the islets affecting primarily insulin containing islets, is present in the majority of cases. The inflammatory infiltrate consists primarily of T lymphocytes; CD8 cells outnumber CD4 cells, there are fewer B lymphocytes and macrophages are relatively scarce. beta cell death may involve the Fas apoptotic pathway since they have been shown to express Fas, infiltrating T lymphocytes express Fas-L and apoptotic beta cells have been described. Hyperexpression of class I MHC by all the endocrine cells in many insulin-containing islets is a well recognized phenomenon, characteristic of the disease. It has been argued that this is an earlier event than insulitis within a given islet and appears to be due to secretion of interferon alpha by beta cells within that islet. A recent study has found evidence of Coxsackie virus infection in beta cells in three out of six pancreases of patients with recent-onset type 1 diabetes. Coxsackie viruses are known to induce interferon alpha secretion by beta cells and this could initiate the sequence of events that culminates in their autoimmune destruction.
Foulis
Alan K
AK
Department of Pathology, Royal Infirmary, Glasgow G4 OSF, UK.
D017209:Apoptosis / Q000276:immunology; D003384:Coxsackievirus Infections / Q000150:complications / Q000276:immunology / Q000473:pathology*; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology / Q000473:pathology* / Q000821:virology*; D053222:Fas Ligand Protein / Q000276:immunology / Q000378:metabolism; D006649:Histocompatibility Antigens / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000473:pathology; D007328:Insulin / Q000276:immunology / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000276:immunology / Q000473:pathology* / Q000821:virology*; D010179:Pancreas / Q000276:immunology / Q000473:pathology / Q000821:virology; D019014:fas Receptor / Q000276:immunology / Q000378:metabolism
D016207:Cytokines; D053222:Fas Ligand Protein; D006649:Histocompatibility Antigens; D007328:Insulin; D019014:fas Receptor