Fulminant autoantibody-negative and type 1A diabetes phenotypes in a Korean HLA identical dizygotic twin

Challenges in diagnosing type 1 diabetes in different populations

Diabetes affects today an estimated 366 million people world-wide, including 20 million to 40 million of patients with type 1 diabetes (T1D). While T1D accounts for 5% to 20% of those with diabetes, it is associated with higher morbidity, mortality and health care cost than the more prevalent type 2 diabetes. Patients with T1D require exogenous insulin for survival and should be identified as soon as possible after diagnosis to avoid high morbidity due to a delay in insulin treatment. It is also important to present to the patient correct prognosis that differs by the type of diabetes. From the research point of view, correct classification should help to identify the etiologies and to develop specific prevention for T1D. This review summarizes evidence that may be helpful in diagnosing T1D in various ethnic groups. Challenges in interpretation of results commonly used to determine the type of diabetes are highlighted.

A mimic of viral double-stranded RNA triggers fulminant type 1 diabetes-like syndrome in regulatory T cell-deficient autoimmune diabetic mouse

Human fulminant type 1 diabetes (FT1D) is an extremely aggressive disease. The delay of proper diagnosis results in high mortality. However, the pathophysiology of this disease remains unclear. We took advantage of CD28-deficient NOD (CD28(-/-) NOD) mice, which have limited numbers of regulatory T cells and develop aggressive autoimmune diabetes, to create a FT1D model that mimicked the disease in humans. Young CD28(-/-) NOD mice were injected with polyinosinic-polycytidylic acid to activate innate immunity in an effort to induce diabetes onset. In this model, innate immune cell activation precedes the onset of diabetes similar to ∼70% of FT1D patients. Eighty-three percent of CD28(-/-) NOD mice developed diabetes within 1-6 d after injection of polyinosinic-polycytidylic acid. Moreover, T cells infiltrated the pancreatic exocrine tissue and destroyed α cells, an observation characteristic of human FT1D. We conclude that an FT1D-like phenotype can be induced in the background of autoimmune diabetes by a mimic of viral dsRNA, and this model is useful for understanding human FT1D.

Fulminant type 1 diabetes in Korea: high prevalence among patients with adult-onset type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to investigate the prevalence of fulminant type 1 diabetes and the clinical characteristics of the disease among newly diagnosed Korean patients.

METHODS

Using data retrieved from the Seoul National University Hospital database, we identified all patients newly diagnosed with type 1 diabetes from 1 January 1999 to 31 July 2006. Information on clinical manifestations and laboratory data, including the presence of islet autoantibodies detected at diagnosis, were obtained by reviewing medical records.

RESULTS

We identified 99 patients newly diagnosed with type 1 diabetes. Seven patients (7.1%) fulfilled the criteria for fulminant type 1 diabetes. Among the patients aged > or =18 years at onset, 30.4% had fulminant type 1 diabetes. Patients with this diabetes subtype tested negative for islet autoantibodies, had a higher age of onset (median 28 vs 10 years, p < 0.001) and a markedly shorter duration from onset of hyperglycaemic symptoms to first hospital visit (median 3 vs 30 days, p < 0.001) than patients with non-fulminant type 1 diabetes, and showed trends of increased serum aspartate aminotransferase and amylase levels and a decreased glucagon-stimulated serum C-peptide response.

CONCLUSIONS/INTERPRETATION

In Korea, the prevalence of fulminant type 1 diabetes was 7.1% among all patients newly diagnosed with type 1 diabetes and 30.4% among patients with adult-onset diabetes. The clinical and metabolic characteristics of the patients with fulminant type 1 diabetes were similar to those reported in Japanese studies.

Pathogenesis of fulminant type 1 diabetes

Fulminant type 1 diabetes is a new subtype of type 1 diabetes. The term was established in 2000. It is a syndrome characterized by a markedly rapid and almost complete destruction of pancreatic beta-cells. Several lines of evidence suggest that both genetic factors, such as human leukocyte antigen (HLA), and environmental factors, such as viral infection, contribute to the development of this disease. It is also suggested that autoimmune processes contribute less critically to fulminant type 1 diabetes than to classic type 1A diabetes. Based on the findings made to date, both viral infection and the subsequent immune reaction in genetically susceptible individuals cause beta-cell destruction and lead to fulminant type 1 diabetes.