Nonviral or Drug-Induced Etiologies of Acute-on-Chronic Liver Failure (Autoimmune, Vascular, and Malignant).

Vascular, autoimmune hepatitis, and malignant causes of acute-on-chronic liver failure are rare but important to consider and investigate in patients with underlying liver disease who present with acute deterioration and other more common etiologies have been excluded. Vascular processes including Budd-Chiari syndrome and portal vein thrombosis require imaging for diagnosis and anticoagulation is the mainstay of therapy. Patients may require advanced interventional therapy including transjugular intrahepatic portosystemic shunt or consideration of liver transplantation. Autoimmune hepatitis is a complex disease entity that requires a high degree of clinical suspicion and can present heterogeneously.