Procainamide-induced autoimmunity: Relationship to T-helper 2-type T-cell activation

Drug-induced autoimmunity (DIA) refers to a group of adverse drug reactions, and they remain unpredictable largely due to the limited understanding of the mechanisms involved. There is evidence that procainamide can cause autoimmune reactions in humans but the mechanisms involved remain unclear. To examine the cellular and genetic factors involved in the procainamide-induced autoimmune response, we compared rats that are genetically T-helper (Th)2-predisposed (Brown Norway (BN)), Th1-predisposed (Lewis (LEW)) or not genetically predisposed (Sprague Dawley (SD)). We revealed significant differences in response to autoimmunity induced by procainamide among three strains rats, BN was the most sensitive one, SD exhibited less sensitive, while LEW resistance to procainamide. Much more pronounced of Th2-type responses and more complex differentially expressed genes involved in immune regulation and response in BN might contribute to its susceptibleness to DIA. Moreover, similar immune mechanisms were found between BN and SD, which suggesting that these changes would serve as the potential bridge biomarkers to predict DIA among species. This study may also benefit to further understand the toxicological mechanism of drug-induced autoimmune reactions.