Markedly Elevated Indirect Bilirubin in an 11-Year-Old African American Boy: Normal or Aberrant?

Abstract

Patient: 11-year-old African American boy. History of Present Illness: The patient presented with a 1-week history of nausea and vomiting and a 1-day history of jaundice; he reported general fatigue. Past Medical History: The patient had a history of sickle cell disease (SS type) requiring seven blood transfusions in the past few years. Medications: Over-the-counter Motrin PRN (300 mg, Q8h). Physical Examination: Scleral icterus and yellow oral mucosa were observed. No hepatosplenomegaly or altered mental status was observed. Family History: Sickle cell trait. Social History: Unremarkable. Principle Laboratory Findings: Table 1 and Table 2 1. What are the most strikingly abnormal laboratory findings? 2. Are these abnormal laboratory findings reliable? 3. What may be causing the patient’s persistent hyperbilirubinemia? 4. What may have caused the discrepancy between the in-house laboratory and the reference laboratory bilirubin results? 5. What is your diagnosis? 1. The most striking laboratory finding is the markedly elevated total bilirubin level (74 mg/dL), consisting mostly of indirect (unconjugated) bilirubin and, to a lesser extent, direct (conjugated) bilirubin (Table 1). 2. The clinical and laboratory findings suggest a mixture of pre-, intra-, and posthepatic involvement. Under normal physiological conditions, indirect bilirubin approximates the amount of unconjugated bilirubin. A marked increase in unconjugated bilirubin, together with the patient’s history of sickle cell disease, and mildly elevated aspartate transaminase (AST) and alanine aminotransferase (ALT) enzymes, indicates a prehepatic injury due to red blood cell sickling and hemolysis or an intrahepatic injury due to sickle cell hepatopathy. …