Tumor Inflammation-Associated Neurotoxicity Following CD19-targeted Chimeric Antigen Receptor T-cell Therapy In A Patient With High-Grade B-Cell Lymphoma

A 41-year-old man with high-grade B-cell lymphoma developed neurolymphomatosis (NL) after frontline chemotherapy. He received CD19 CAR T-cell therapy (lisocabtagene maraleucel) and subsequently developed tumor inflammation-associated neurotoxicity (TIAN) type 2, a localized neurological event distinct from immune effector cell-associated neurotoxicity syndrome. Conservative treatment resulted in a neurological recovery and complete remission. This case suggests that CD19 CAR T-cell therapy may be effective for NL, and it highlights the importance of recognizing TIAN in patients with CNS involvement. As CAR T-cell use has increased in Japan, awareness of such complications is crucial for performing safe and effective treatment.