Abstract
BACKGROUND AND AIM: Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events in the liver. The risk of exacerbating liver injury is of concern in patients infected with hepatitis B virus (HBV) or hepatitis C virus (HCV), as immunotherapy can damage liver function because of the immune response against viral antigens. We assessed the feasibility of immunotherapy in HBV- or HCV-infected patients. METHODS: This retrospective study included 266 patients with persistent or past HBV infection, 26 patients seropositive for anti-HCV, and 820 patients with negative viral markers for HBV and HCV, who were treated with ICIs. ICI-induced liver injury and changes in virological markers were analyzed. RESULTS: The occurrence rates of ICI-induced liver injury in the HBsAg-positive, anti-HBc-positive/anti-HBs-positive, and anti-HBc-positive/anti-HBs-negative groups were 12.5, 21.6, and 19.1%, respectively, which were comparable with those of the negative for HBV- and HCV-related markers group (20.9%). The frequency of any grade ICI-induced liver injury was different among the HCV RNA-positive (3/5; 60.0%), anti-HCV-positive/HCV RNA-negative (2/21; 9.5%), and negative for HBV- and HCV-related markers (171/820; 20.9%) groups (P = 0.045), with no significant difference in grade ≥2 ICI-induced liver injury. In patients with persistent infection, neither serum HBV DNA, HBsAg, nor HCV RNA level changed significantly during ICI treatment. One of five treatment-naïve HCV-infected patients required interruption of ICI treatment due to virus-related liver injury. CONCLUSION: Immunotherapy is feasible for most cancer patients with chronic HBV or HCV infection; however, liver function and virological markers should be carefully monitored in treatment-naïve patients, especially those with HCV infection, during ICI treatment.