LAUSR

Abstract Background The side effects of the immune checkpoint inhibitors are designated as immune-related adverse events (irAEs). Liver dysfunction is one of the well-known irAEs. According to the irAE guideline (JSMO), steroid treatment is definitely indicated for liver dysfunction developing as an irAE, however, there is no mention of evaluation of the prothrombin time, which is one of the most important parameters in the management of acute liver failure. In addition, the role of image evaluation is not documented. In this study, we retrospectively evaluated the severity of liver dysfunction and the most suitable treatment in cases of liver dysfunction occurring as an irAE. Methods From August 2015 to June 2018, 224 cases were treated with immune checkpoint inhibitors (nivolumab, 153; pembrolizumab, 62; ipilimumab, 9 cases) at our hospital. We conducted a retrospective evaluation of the incidence rate, severity, examination findings, treatment, and imaging findings of liver dysfunction occurring as an irAE. Results Twenty-three patients (10.2%) developed liver dysfunction as an irAE (nivolumab, 14; pembrolizumab, 7; ipilimumab, 2 cases). In one patient, HCV infection was detected and treated with direct-acting antiviral agents. Liver biopsy was performed in two patients. One patient with liver dysfunction who showed wall thickening of the common bile duct on CT and cholangitis on liver biopsy received steroid therapy. Four patients received treatment with Stronger Neo-Minophagen C (glycyrrhizin, SNMC) and four patients received treatment with ursodeoxycholic acid (UDCA). Conclusions It appears that most cases of liver dysfunction developing in patients receiving checkpoint inhibitors are not treated with a steroid, and that UDCA and SNMC are used more widely for the treatment. Liver biopsy and imaging findings (US and CT) could be useful for evaluating the pathophysiology of liver dysfunction occurring as an irAE.