Immune-Related Hepatotoxicity After Atezolizumab and Isoniazid

Immune checkpoint inhibitor therapy has transformed the prognosis of multiple solid-organ malignancies; however, such advances are not without significant adverse events known as immune-related adverse events. A novel pattern of autoimmune-like hepatitis following exposure to certain medications, including statins, isoniazid, nitrofurantoin, anti-tumor necrosis factor-alpha therapy and minocycline, has recently been recognized. We present the case of a 66-year-old male patient with extensive-stage small-cell lung carcinoma who developed acute liver injury while receiving concomitant atezolizumab therapy and isoniazid prophylaxis for latent tuberculosis. The patient subsequently developed grade 4 hepatotoxicity, which improved after discontinuation of isoniazid therapy and initiation of corticosteroid treatment. The aim of this report is to contribute to the literature by presenting a rare case of grade 4 immune-related hepatotoxicity under atezolizumab therapy in a patient receiving isoniazid prophylaxis for latent tuberculosis.