WHAT’S KNOWN?
Successful anti-PD-1 / PD-L1 immunotherapy requires an adequate number of specific T cells in the tumor microenvironment. Similar to the tumor microenvironment, the chronic viral infection is a strong immunosuppression environment, leading to specific T cells exhausting, in theory, it may influence the effect of ICI which has reversed the role of T cell failure at the same time and undermine the balance between the host immune system and virus control that has caused the risk of liver damage. But there is not any consensus yet and appropriate strategy of ICIs in this population needs in depth assessment. In the existing published articles about safety and efficacy of ICIs in patients with chronic viral infection and advanced-stage cancer, the types of cancer involved are not comprehensive, with liver cancer and melanoma accounting for the majority and NSCLC accounting for less than five percent. In one retrospective study of PD-1 inhibitors for NSCLC with special issues involving 32 HBV-infected patients, four of nine patients experienced severe AST/ALT elevation (grade 3 or higher) were HBV patients. And three patients developed viral reactivations or flares, despite receiving anti-HBV therapy prior to the immunotherapy.