Risk of Progression to Autoimmune Disease in Severe Drug Eruption: Risk Factors and the Factor-Guided Stratification

The identification of risk factors is key not only to uncover the pathogenesis of autoimmune disease but also to predict progression to autoimmune disease. Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms is likely the best prototypic example for analyzing the sequential events. We conducted a retrospective study of 55 patients with drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms followed up for the possibility of later development of autoimmune disease w18 years after resolution. Nine patients progressed to autoimmune sequelae regardless of treatment. The generation of autoantibodies was preceded by 8 years in eight of the nine patients. The combination of increases in lymphocyte counts, severe liver damage, a rebound increase in globulin, persistent reactivations of Epstein.Barr virus and human herpesvirus-6, and low IL-2 and IL-4 at the acute/subacute phases were significant risk factors for the future development of autoimmune disease. On the basis of these factors, we established a scoring system that can identify high-risk patients. When stratified these patients into three risk categories (low/ intermediate/high), occurrence of autoimmune disease was exclusively detected in the high group. Our data represent a scoring system to identify patients at high risk of developing autoimmune disease, although a larger study is required to validate the scoring system.