Drug-Induced liver injury with adebrelimab: how to assess causality using the updated RUCAM?

AIM: To report a case of Adebrelimab-related liver injury and emphasize the role of the updated RUCAM in causality assessment for suspected immune checkpoint inhibitor-induced hepatotoxicity. OBSERVATION: A 51-year-old male with small-cell lung cancer developed severe jaundice four days after his last dose of etoposide/carboplatin combined with adebrelimab, occurring after nine cycles of therapy (at 5 months) and later than the onset time described in the drug label. Baseline liver function was normal, and there was no history of hepatobiliary disease. Physical examination revealed jaundice and scleral icterus. The updated RUCAM score was 8, indicating a highly probable relationship between the regimen and liver injury, while the simplified AIH score (<6) ruled out autoimmune hepatitis. The patient's liver enzymes and bilirubin normalized, and clinical symptoms improved following treatment with low-dose methylprednisolone (1 mg/kg/d) and other supportive measures. CONCLUSION: This case highlights the value of applying the updated RUCAM to reliably distinguish drug-induced liver injury from other etiologies in immune checkpoint inhibitor recipients, thereby guiding appropriate clinical management.