Acute Hepatitis with Positive Autoantibodies: A Case of Natalizumab-Induced Early-Onset Liver Injury

BACKGROUND Natalizumab is an anti-integrin monoclonal antibody used as an alternative treatment regimen for patients with autoimmune disorders, especially multiple sclerosis and Crohn's disease. Natalizumab-induced liver injury has been rarely reported and may follow the first dose (with increases in liver enzymes usually after 6 or more days), or after multiple doses. In general, it is non-severe acute hepatitis (with a hepatocellular pattern) and autoantibodies can be positive, mainly anti-nuclear and anti-smooth muscle antibodies. CASE REPORT We are reporting the case of a 60-year-old woman diagnosed with multiple sclerosis previously treated with interferon-beta, dimethyl fumarate, and fingolimod, who presented jaundice 1 day after the first infusion of natalizumab. She had an early-onset acute hepatitis with aminotransferases levels higher than 1000 IU/L and total bilirubin almost 41 mg/dL. Anti-nuclear and anti-smooth muscle antibodies were positive and the histopathological analysis of the liver showed intrahepatic cholestasis associated with moderate necroinflammatory activity (subacute cholestatic hepatitis) and mild diffuse perisinusoidal fibrosis, which could be compatible with the hypothesis of drug-induced liver injury. The scenario of an autoimmune-like hepatitis led the medical team to start oral prednisone and she progressively improved in clinical and laboratory features. Serum levels of liver enzymes and bilirubin were normal within 3 months and there was no further increase after discontinuation of corticosteroid therapy. CONCLUSIONS Physicians should be aware of the risk of early-onset acute hepatitis in patients starting natalizumab, especially women with multiple sclerosis. Treatment with corticosteroid for a few months may be beneficial.