2458 Autoimmune Hepatitis-Induced Hepatic Lobar Atrophy

Abstract

INTRODUCTION: Lobar atrophy of the liver can be a morphologic manifestation of benign and malignant liver or biliary duct disease. Rarely has it been associated with autoimmune hepatitis (AIH). CASE DESCRIPTION/METHODS: A 26 year old woman presented with a 2 month history of severe RUQ abdominal pain associated with anorexia, 10 lb weight loss, pruritus, and scleral icterus. Physical exam was notable for cachexia, jaundice, abdominal distension and tender hepatomegaly. Initial labs revealed: hemoglobin 10.1 g/dl, MCV 80, platelets 107, AST 968 U/L, ALT 487 U/L, ALP 369 U/L, total bilirubin 12.0 mg/dl, DB 9.0 mg/dl, total protein 6.4 g/dL, albumin 2.1 g/dl and INR 1.65. Serological data were as follows: AMA <1:20; ANA 1:160; and anti-smooth muscle antibody 1:20. Viral markers for hepatitis A, B and C were negative. CT abdomen revealed a large area of infiltrative hypoattenuation of the right hepatic lobe. Abdominal MRI noted a diffuse edema within both hepatic lobes. N-acetylcysteine was started for impending acute liver failure and prednisone for AIH. She improved clinically. A liver biopsy done showed diffuse liver cell necrosis with lobular collapse, acute and chronic inflammation in the portal tracts, and in the interface. She was deemed stable for discharge to return to clinic but she was lost to follow up. A year later, she returned with worsening RUQ pain, further weight loss of 30 pounds. Her LFTs were within normal limits but a CT abdomen showed portal hypertension, hypoattenuation of the right lobe, and cirrhosis with left hepatic lobe atrophy. Azathioprine was started in addition to Prednisone. DISCUSSION: This patient's left lobar atrophy was not deemed to be congenital due to the presence of the left hepatic lobe on prior imaging studies. Hepatic neoplasms which can as well cause lobar atrophy was also ruled out with imaging. This is one of the few reported cases of hepatic lobar atrophy attributed to AIH which is a chronic disease characterized by increased autoantibodies in circulation and inflammation around the portal vein. This inflammation can result in lobar atrophy via occlusion of the portal vein resulting in impairment of liver blood flow as well as a reduction in the supply of hepatotrophic substances, particularly insulin. This may cause ischemia in certain areas of the liver and subsequently, atrophy secondary to necrosis and apoptosis. This patient also had significant cholestasis on initial presentation which could also contribute to cellular apoptosis through the Fas ligand pathway.