Fulminant Hepatic Failure of Autoimmune Aetiology in Children

OBJECTIVE:: Autoimmune hepatitis (AIH) is considered an underdiagnosed cause of fulminant hepatic failure (FHF). Autoimmune FHF (AI-FHF) is believed to lead invariably to liver transplantation (LTX) or death. We aimed to describe the autoimmune features of children diagnosed as having AI-FHF and indeterminate FHF (ID-FHF), and describe the outcome of patients with AI-FHF treated with immunosuppressive drugs. METHODS:: In this case-control study, the files of patients with AI-FHF and ID-FHF were reviewed and compared. AIH was diagnosed based on positive autoantibodies, raised immunoglobulin G, and histology when available. FHF was defined by raised transaminases, international normalised ratio≥2.0, presence of encephalopathy, and no previously recognised liver disease. RESULTS:: A total of 46 children with FHF were managed in the last 15 years: 10/46 (22%) had AI-FHF, 20/46 (43%) ID-FHF, and 16 had other diagnosis. The mean follow-up time was 4.6 years. AI-FHF and ID-FHF differed for the presence of autoantibodies (10/10, 6/10 liver/kidney microsome [LKM]-type, vs 3/20, none LKM, P<0.0001), immunoglobulin G level (1845 vs 880 mg/dL, P<0.001), median age at diagnosis (6.4 vs 1.8 years, P=0.017), and alanine aminotransferase level (1020 vs 2386 IU/L, P=0.029). Liver histology did not allow to differentiate the 2 conditions. Among the patients with AI-FHF, 4/9 who received steroids recovered; 5/9 required LTX and 1 died awaiting treatment. CONCLUSIONS:: AIH is a much more common cause of FHF than previously suggested, and a complete autoantibody testing including LKM-type is essential in this setting. Autoantibodies are uncommon in ID-FHF, and histology cannot distinguish it from AI-FHF. A cautious steroid trial may avoid LTX in some of the patients with AI-FHF.