480 The characteristics of patients with persistent HHV-6 infection after drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS)

Abstract

Background: Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS) is characterized by fever, cutaneous eruptions, hematological abnormalities, organ disorder, and reactivation of human herpesvirus 6 (HHV-6). In addition, autoimmune diseases such as type 1 diabetes and thyroiditis may develop long-term after resolution of DIHS. Reactivation of HHV-6 has been reported to be involved in clinical condition of DIHS. We found that quite a few patients harbor high levels (> 1000 copies / 106 PBMC) of HHV-6 DNA in PBMC over 4 months after onset of DIHS. However, it is unclear what effects persistent HHV-6 infection has on DIHS patients in chronic phase. Methods: We analyzed clinical symptoms, blood test findings, reactivation of herpes virus, expression of serum cytokines (IL-4, IL-5, IL-10, IFN-γ) and soluble IL-2 receptor for 8 DIHS patients with persistent HHV-6 infection and 10 patients with transient HHV-6 infection. Results: Compared to the transient HHV-6 infection group, persistent HHV-6 infection group showed 1) more severe acute phase cutaneous and mucosal eruptions, 2) higher levels of HHV-6 DNA in acute phase, 3) higher rate of cytomegalovirus reactivation, 4) higher levels of IL-4 in acute phase and higher levels of soluble IL-2 receptor in late phase, 5) higher rate of long-term complications (ie, interstitial nephritis, arthritis, thyroiditis). Conclusion: Persistent HHV-6 infection may have some influence on the pathological and immunological conditions of DIHS and may be involved in the clinical course and prognosis.