Drug-induced autoimmune hepatitis due to atorvastatin: a complex clinical case and literature review

Abstract Drug-induced liver injury with autoimmune-like features is an uncommon yet clinically significant adverse effect of several medications, including statins. Although generally considered safe, atorvastatin has been associated with rare cases of hepatotoxicity that mimic autoimmune hepatitis on histology. We describe a 53-year-old woman with recently diagnosed chronic kidney disease who developed progressive jaundice and right upper quadrant pain shortly after starting atorvastatin. Laboratory evaluation revealed a mixed pattern of liver injury with worsening liver function tests, while serologic studies for viral hepatitis, autoimmune markers, and metabolic diseases were negative. Imaging ruled out biliary or structural abnormalities. Liver biopsy showed features compatible with autoimmune hepatitis. Given the diagnostic challenge, particularly in seronegative presentations, causality and phenotype assessment tools are essential. The updated Roussel Uclaf Causality Assessment Method (RUCAM) is a validated, widely used instrument with good reproducibility in both idiosyncratic DILI and drug-induced autoimmune hepatitis (DIAIH). Similarly, although the Simplified Autoimmune Hepatitis Score was developed for idiopathic autoimmune hepatitis, it can help identify immunemediated features in DILI when interpreted in a clinical context. In this patient, a RUCAM and S-AIH score of 6, together with compatible histology and a clear temporal association with atorvastatin, supported the diagnosis of statin-induced autoimmune-like hepatitis. The patient received corticosteroids, achieving marked clinical and biochemical improvement. This case highlights the need to consider DILI with autoimmune features in patients with unexplained liver injury after recent statin exposure. When autoimmune serologies are negative, liver biopsy and structured tools such as updated RUCAM and S-AIH are crucial to establish the diagnosis and guide timely immunosuppressive therapy. Although rare, statin-induced autoimmune-like hepatitis is serious but potentially reversible.