Coexistence of Anti-Hu and Anti-SOX1 Autoantibodies in Atezolizumab-related Encephalitis

Although immune checkpoint inhibitor-related encephalitis has been reported, its underlying mechanism and treatment strategies remain unclear. Here, we present the case of a 60-yearold male patient with small cell lung cancer who developed autoimmune encephalitis during treatment with atezolizumab. Notably, this case involved the concurrent detection of two paraneoplastic autoantibodies (anti-Hu and anti-SOX1). Encephalitis was treated by discontinuing atezolizumab and administering steroids, despite the persistence of the antibodies. This case provides insights into the interaction between immune checkpoint inhibitors and paraneoplastic autoantibodies.