Distinguishing Autoimmune Hepatitis From Steatohepatitis in Adolescents With Obesity and Positive Screening Alanine Aminotransferase

Abstract

Screening children with obesity for nonalcoholic fatty liver disease leads to identification of elevated alanine aminotransferase (ALT) and is a common cause for referral to pediatric gastroenterology. Guidelines recommend that children with positive screening ALT be evaluated for causes of ALT elevation beyond nonalcoholic fatty liver disease. One clinical challenge is that autoantibodies can be present in patients with obesity and thus may or may not represent autoimmune hepatitis. This case series highlights the importance of a comprehensive evaluation to reach an accurate diagnosis.

Keywords: liver histology; nonalcoholic fatty liver disease; ultrasound.

FIGURE 1.

Ultrasound images for patients A, B, and C. Patient A: (A) Sagittal ultrasound image demonstrating increased echogenicity related to the kidney. There is decreased delineation of the vasculature. There is good penetration of the transducer with visualization of the diaphragm. Rib artifact present. Patient B: (B) Sagittal ultrasound image demonstrating increased echogenicity of the liver relative to the kidney. There is good delineation of the vasculature. There is good penetration of the transducer with visualization of the diaphragm and posterior structures. Patient C: (C) Sagittal ultrasound image demonstrating increased echogenicity of the liver relative to the kidney. There is decreased delineation of the vasculature. There is good penetration of the transducer with visualization of the diaphragm and posterior structures.

FIGURE 2.

Liver histology for patients A, B, and C. Patient A: Steatohepatitis: (A)—H&E at 20× objective, histologic sections demonstrate a predominantly macrovesicular steatosis with scattered lobular inflammatory foci seen. There is no significant increase in plasma cells noted. D) Trichrome at 20× objective highlights central venular perisinusoidal/pericellular fibrosis and periportal fibrosis. Patient B: NAFLD and autoimmune hepatitis: (B) H&E at 40× objective, histologic sections demonstrate a portal-based plasma cell-rich inflammatory infiltrate with an associated moderate interface activity. There is moderate macrovesicular steatosis. E) Trichrome at 20× objective shows mild (stage 1) fibrosis. Patient C: autoimmune hepatitis: (C) H&E at 10× objective, histologic sections demonstrate a portal-based plasma cell-rich inflammatory infiltrate with an associated marked interface activity. No steatosis is present. F) Trichrome at 10× objective demonstrates focal parenchymal collapse with bridging fibrosis bordering on early cirrhotic nodule formation. NAFLD = nonalcoholic fatty liver disease.