Immunosuppressive therapy, and particularly corticosteroids with or without azathioprine, can achieve a remission in more than 80% of patients with autoimmune hepatitis (AIH). By contrast, the usefulness of corticosteroid therapy in severe forms of AIH remains a subject of debate. Between 1986 and 2005, 16 patients (14 females, 2 males; mean age: 36.6 +/- 13.1 yr) presenting with acute, severe, or fulminant disease due to type 1 AIH (n = 13) or type 2 AIH (n = 3) were admitted to our liver intensive care unit. At admission, 10 of 16 (62.5%) patients presented with encephalopathy. Median international normalized ratio (INR), bilirubin, alanine aminotransferase (ALT), and creatinine values were 5.36 (range, 1.7-12.2), 425 micromol/L (range, 278-850), 678 IU/L (range, 60-2867), and 72 muicrool/L (range, 52-133), respectively. A total of 12 patients received corticosteroid therapy: 8 had started in the referring center a median of 2.5 days (range, 1-89) previously, and this therapy was initiated in 4 patients at their admission to our unit (median: 2 days; range: 0-5). Four patients were not treated because of a rapid deterioration in their AIH. Before treatment, 4 of 12 patients had been suffering from encephalopathy. The median duration of corticosteroid therapy was 7 days (range: 2-135). Of 16 patients, 13 underwent liver transplantation (LT) (81%), at which time all were encephalopathic. Median values for INR, total bilirubin, and ALT were 7.2 (range: 3.3-15.9), 400 micromol/L (range: 301-550), and 706 IU/L (range: 69-1,932), respectively, at the time of transplantation. All patients treated with corticosteroids had experienced a clinical (encephalopathy) and biochemical (Model for End-Stage Liver Disease [MELD] score) deterioration at the time of transplantation. Histological findings did not reveal any features of underlying chronic liver disease. Of the 13 patients undergoing transplantation, 10 had received prior corticosteroid therapy. Of the 2 nontransplanted patients treated with corticosteroids, a clinical improvement was observed in only 1 patient. Severe septic complications occurred in 3 patients under corticosteroid therapy (gram-negative septicemia n = 2; disseminated aspergillus n = 1). Nine of the treated patients are still alive; 1 died after liver transplantation (LT) (recurrence of AIH, acute pancreatitis, sepsis), 1 survived without LT, and 1 died without LT. Among the untreated patients, 3 survived after LT and 1 died without LT. In conclusion, corticosteroid therapy is of little benefit in severe and fulminant forms of AIH; it may favor septic complications and should not delay LT.