title: The heterogeneity of diabetes: unraveling a dispute: is systemic inflammation related to islet autoimmunity?
abstract: Diabetes is an emblematic example of a heterogeneous disease. Systemic inflammation has emerged as a prominent factor in the type 2 diabetes pathoetiology, but it remains ill-defined in type 1 diabetes. There is a wide spectrum of associations between inflammatory responses and diabetic syndromes. At one end of this spectrum, there is type 1 diabetes for which there is convincing evidence that chronic inflammation of pancreatic islets is a central aspect of disease pathogenesis. At the opposite end, is type 2 diabetes that is clearly associated with systemic inflammation, which could be either the cause or simply mark the underlying pathology. Accumulating evidence has substantiated that a subgroup of adult patients clinically diagnosed with type 2 diabetes exhibit autoantibody responses to islet autoantigens. The presence of these immunologic abnormalities is associated with a severe insulin secretory defect and the absence of signs of systemic inflammation as documented by plasma C-reactive protein and fibrinogen levels that are comparable with those of control populations. Islet autoantibody evaluation should be part of the diagnostic assessment for clinically diagnosed type 2 diabetes not only because it might predict the rate of progression to insulin requirement in adult populations but also to identify a pathogenically distinct disease phenotype characterized by the absence of systemic inflammation and its related disorders. A more appropriate characterization of this subgroup of clinically diagnosed type 2 diabetes, diabetes of autoimmune pathogenesis, will promote future research into the etiology, natural history, and treatment.
authors.affiliation: Laboratory of Immunogenetics, The Brehm Center for Type 1 Diabetes and Analysis, Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA. maxtp@umich.edu
authors.forename: Massimo
authors.initials: M
authors.lastname: Pietropaolo
authors.forename: Emma
authors.initials: E
authors.lastname: Barinas-Mitchell
authors.forename: Lewis H
authors.initials: LH
authors.lastname: Kuller
mesh_terms: D015551:Autoimmunity; D002318:Cardiovascular Diseases / Q000453:epidemiology; D048909:Diabetes Complications / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology*; D006801:Humans; D007113:Immunity, Innate; D007249:Inflammation / Q000276:immunology / Q000503:physiopathology*; D007515:Islets of Langerhans / Q000276:immunology*; D012307:Risk Factors