Primary Biliary Cholangitis in a Teenage Boy

Abstract

Introduction: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease (AILD) that predominantly affects women (female-to-male ratios ranging from 9:1 to 22:1) in their 50's or 60's. Unlike other AILDs, PBC has rarely been reported in childhood. Based on literature review, there have been only 3 documented cases of pediatric-onset PBC, diagnosed in 3 girls at the age of 12, 15 and 16 years old respectively. To date, the occurrence of PBC in male children has not been reported. Case report: A 16 year-old boy was referred to our Centre in 2013 for abnormal liver function tests. He was asymptomatic and his liver enzyme levels at that time were as follows: total bilirubin, 0.70 mg/dL (normal, < 1.2); γ-glutamyltransferase (γ-GT), 640 U/L (normal, 10-49 U/L); serum aspartate aminotransferase (AST), 70 U/L (normal, 10-37 U/L); and serum alanine aminotransferase (ALT), 154 U/L (normal, 10-37 U/L). Abdominal ultrasound showed no abnormalities. Antimitochondrial antibody (AMA) was positive; serum quantitative immunoglobulins (Ig) showed IgM to be 308 mg/dL (normal, < 300 mg/dL), IgG and IgA were both normal. Antinuclear antibody, smooth muscle antibody, and liver/kidney microsomal antibody were all negative. Serum α1-antitrypsin, copper, and ceruloplasmin levels were normal. Serology for hepatitis A, B, and C was negative. Magnetic Resonance Cholangiopancreatography was normal. A liver biopsy specimen showed stage I PBC. The boy was then started on ursodeoxycholic acid 15 mg/Kg/day. Although asymptomatic and despite therapy, one year later liver enzyme levels showed no improvement (total bilirubin, 0.84 mg/dL; γ-GT, 467 U/L; AST, 78 U/L and, ALT, 172 U/L). In 2015, at the age of 18, he was transitioned to the Hepatology clinic, and by that time he had developed severe pruritus, for which he was started on cholestyramine. Liver enzymes at this point showed biochemical worsening: total bilirubin, 2.99 mg/dL; γ-GT, 849 U/L; ALP, 518 U/L; AST, 165 U/L and, ALT, 296 U/L. Liver biopsy was repeated and showed progression to stage II PBC. Discussion: We present the first biopsy proven AMA-positive PBC in a teenage boy. Three year follow-up showed biochemical and histological progression despite therapy. By raising awareness of pediatric-onset PBC, further cases may be diagnosed.