De novo autoimmune hepatitis associated with PTH(1–34) and PTH(1–84) administration for severe osteoporosis in a liver transplant patient

De novo autoimmune hepatitis (AIH) is a rare graft dysfunction occurring in patients having undergone liver transplantation (LT) for causes other than AIH. We describe for the first time a case of de novo AIH associated with the administration of parathyroid hormone 1–34 [PTH(1–34)] and PTH(1–84) for severe osteoporosis. A 61-year-old woman was referred to our metabolic bone clinic due to severe osteoporosis, 3 years after LT for primary biliary cirrhosis. Initial treatment with PTH(1–34) led to asymptomatic hypertransaminasemia (two-fold the upper limit of normal), which normalized after drug discontinuation. A new flare of transaminases (three-fold the upper limit of normal) along with elevated alkaline phosphatase was observed after administration of PTH(1–84), which did not resolve after PTH(1–84) withdrawal. Subsequently, after exclusion of common causes of liver enzyme elevation, a liver biopsy was performed. Histological findings showed de novo AIH, which responded rapidly to treatment with methylprednisolone.