Classification and characteristics of interferon-related diabetes mellitus in Japan.

Aim:   The aim of this study was to assess the classification and clinical characteristics of interferon (IFN)-related diabetes.

Methods:   Cases with IFN-related diabetes in Japan were retrieved through web search engines for medical literature until July in 2009, and unreported data were obtained from the authors by letter or e-mail.

Results:   We collected 143 cases with IFN-related diabetes consisting of 104 type 1 diabetes including 4 own cases, and 39 non-autoimmune type 2-like diabetes. We found a marked increase in IFN-related type 1 diabetes for these 3 years. In contrast, no increase was observed in IFN-related type 2-like diabetes in the literature. Polyethylene glycol (PEG)-IFN and ribavirin had been more frequently used in patients with type 1 diabetes than in patients with type 2-like diabetes. The age of diabetes onset was comparable between type 1 and type 2-like diabetes, while the ratio of male patients was higher and the latency before diabetes was shorter in type 2-like diabetes. Patients with IFN-related type 1 diabetes had HLA types susceptible to Japanese type 1 diabetic patients, and a high positive rate of GAD antibodies.

Conclusion:   Potent combination therapy with PEG-IFN and ribavirin is likely associated with the increase in IFN-related type 1 diabetes. The combined measurement of GAD antibody and HLA-typing could be an effective strategy to predict the onset of type 1 diabetes associated with IFN therapy.