[Latest Treatment of Viral Hepatitis--Overcoming Hepatitis C and Reactivation of Hepatitis B].

Hepatitis B virus (HBV) and hepatitis C virus (HCV), discovered as causative viruses of post-transfusion hepatitis, become persistent infections, leading to chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). For HCV, recent IFN-free direct-acting antiviral (DAA) therapies have increased sustained virological response (SVR) rates and reduced adverse events. IFN-based therapies, still the standard of care in Asian countries, are influenced by IL28B genetic variants and the liver fibrosis stage, but the DAA combinations obscure the influence of these factors. These new therapies can eradicate HCV and prevent HCC development. On the other hand, it is difficult to eradicate HBV completely. Although HBV infection can be prevented by vaccination, reactivation of HBV following anti-cancer chemotherapy and immunosuppressive therapy is a well-known complication. HBV reactivation has been reported to be associated with anti-CD20 monoclonal antibody rituximab-containing chemotherapy and TNF-α inhibitor-containing immunosuppressive therapy in HBV-resolved patients. Our prospective observational study revealed that monthly monitoring of HBV DNA was useful for preventing HBV reactivation-related hepatitis among B-cell non-Hodgkin lymphoma patients with resolved HBV infection following rituximab-steroid-chemo, suggesting that preemptive therapy guided by serial HBV DNA monitoring should be recommended. Recently, highly sensitive HBsAg detection by Lumipulse HBsAg-HQ may be useful for several clinical applications. The sensitivity of this assay (5 mIU/mL) was approximately 10-fold higher than Abbott ARCHITECT, but still lower than HBV-DNA assays. The convenient HBsAg-HQ may be useful for detecting occult HBV infection and HBV reactivation in relatively low-risk groups except for those receiving rituximab-steroid-chemo. [