A 17-year-old girl is brought to the office due to yellow eyes for the past day. The patient has no other symptoms, including fever, rash, abdominal pain, vomiting, or diarrhea. She has been preparing for her high school exit examination and has been quite stressed. Temperature is 37.1 C (98.8 F) , blood pressure is 110/78 mm Hg, pulse is 80/min, and respirations are 14/min. Mild scleral icterus is present. The abdomen is soft with no hepatosplenomegaly. Serum laboratory results are as follows: Two weeks after her examination, the patient's symptoms resolve. Repeat testing shows a total bilirubin concentration of 1.5 mg/dL. Which of the following changes most likely contributed to this patient's hyperbilirubinemia?

Question

A 17-year-old girl is brought to the office due to yellow eyes for the past day. The patient has no other symptoms, including fever, rash, abdominal pain, vomiting, or diarrhea. She has been preparing for her high school exit examination and has been quite stressed. Temperature is 37.1 C (98.8 F) , blood pressure is 110/78 mm Hg, pulse is 80/min, and respirations are 14/min. Mild scleral icterus is present. The abdomen is soft with no hepatosplenomegaly. Serum laboratory results are as follows:

Two weeks after her examination, the patient's symptoms resolve. Repeat testing shows a total bilirubin concentration of 1.5 mg/dL. Which of the following changes most likely contributed to this patient's hyperbilirubinemia?

Quizplus · Accepted Answer

11ec160b_3ae1_ca8d_9249_a1e00704efa8_MD0001_00 This patient had self-resolving scleral icterus and isolated indirect hyperbilirubinemia associated with a period of stress. These findings are consistent with Gilbert syndrome, the most common inherited disorder of bilirubin metabolism. Normal bilirubin metabolism begins with hepatic uptake of unconjugated bilirubin produced from red blood cell turnover. Within the liver, UDP glucuronosyltransferase conjugates bilirubin with glucuronic acid, after which conjugated bilirubin is excreted into bile canaliculi. In Gilbert syndrome, a genetic mutation results in reduced enzymatic activity of UDP glucuronosyltransferase and therefore decreased bilirubin conjugation (Choices B and D). Triggers associated with increased bilirubin production (eg, stress, illness, hemolysis) result in episodic exacerbations of indirect hyperbilirubinemia, as seen in this patient. Because bilirubin excretion into the bile duct is normal in Gilbert syndrome, hepatocyte bilirubin storage is also normal, as is liver histology (Choices A and E). Notably, impaired bilirubin conjugation also occurs in Crigler-Najjar syndrome, but patients typically have severe, chronic hyperbilirubinemia that begins in the neonatal period and can be associated with bilirubin-induced neurologic dysfunction. (Choice C) Dubin-Johnson syndrome is a benign, inherited disorder of bilirubin metabolism characterized by defective hepatic excretion of bilirubin into the biliary system. Bilirubin conjugation is normal, but defective excretion results in increased hepatocyte storage of bilirubin, resulting in dense liver pigmentation. Although patients often have recurrent episodes of scleral icterus, elevated direct bilirubin is expected due to reflux of conjugated bilirubin back into the plasma. Educational objective: Gilbert syndrome is characterized by indirect hyperbilirubinemia due to decreased bilirubin conjugation. Patients have recurrent, self-resolving episodes of scleral icterus and jaundice triggered by stress.

A 17-Year-Old Girl Is Brought to the Office Due to Yellow