[Extreme values of alpha-fetoprotein in a patient with autoimmune hepatitis].

We present the case of a 29-year-old woman with a 5-year history of liver function test abnormalities who consulted for polyarthritis, fever, and jaundice lasting one month. Initial studies showed predominantly direct hyperbilirubinemia and elevated transaminases, alkaline phosphatase and gamma-glutamyl transferase. Viral hepatitis was ruled out by negative serology and toxic hepatitis by absence of exposure to hepatotoxic drugs. The antibody panel showed elevated antinuclear antibodies and positive anti-Ro titers. She also presented elevated polyclonal immunoglobulin G levels. Given the chronicity of the condition, alpha-fetoprotein measurement was requested for hepatocellular carcinoma screening, which results showed a value of 5966 ng/ml (reference value less than 10 ng/ml). Since these values were suggestive of underlying neoplasia (whether it is hepatocellular carcinoma or a germ cell tumor), magnetic resonance imaging of the abdomen and pelvis with contrast and transvaginal ultrasound were performed, which did not show tumor images. Liver biopsy evidenced interface hepatitis, confirming the diagnosis of autoimmune hepatitis. Treatment with corticosteroids and azathioprine resulted in normalization of both the liver function tests and alpha-fetoprotein. We therefore assume that the alpha-fetoprotein elevation reflected inflammatory activity and not neoplastic disease. Based on this case and similar reports, we consider that autoimmune hepatitis should be considered among the possible causes of extreme alpha-fetoprotein elevation.