Autoimmune hepatitis presenting as severe anemia.

Autoimmune hepatitis (AIH) is relatively rare in children. Herein, our case demonstrates a unique presentation of AIH in a previously healthy 18-year-old female presenting with a mild cough, fatigue, and severe anemia (hemoglobin 2.9 g/dL). Initial evaluation revealed jaundice and scleral icterus, prompting transfer of care and further testing, which demonstrated severe microcytic anemia, pancytopenia, elevated liver enzymes, direct hyperbilirubinemia, and marked splenomegaly. Concern for autoimmune hemolytic anemia resulted in a delayed diagnosis. The combination of triple antibody positivity (anti-nuclear antibodies, anti-actin, and anti-liver-kidney microsomal-1) and liver histology findings confirmed the diagnosis of AIH. Intravenous methylprednisolone was initiated to induce remission. Due to pancytopenia and persistently elevated international normalized ratio, tacrolimus was chosen as the maintenance immunosuppression instead of azathioprine. This case highlights several significant considerations for clinicians, including the importance of a timely clinicopathologic diagnosis, the severe anemia presentation secondary to hypersplenism, and the rare finding of triple autoantibody-positive AIH.