WBR0648
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Biochemistry |
| Sub Category | SubCategory::Gastrointestinal |
| Prompt | [[Prompt::A 34 year old healthy man presents to the primary care clinic for a general check-up. The man has no complaints except some fatigue during the day, but he relates this to his stressful life style. Physical exam is unremarkable except for mild scleral icterus. The primary care physician decides to order some tests to rule out any serious illness. Lab results return with a normal CBC, reticulocyte count, and blood smear. Transaminases, alkaline phosphatase, and GGT are also all within normal range. Indirect bilirubin is noted to be 2.6 mg/dL with direct bilirubin below the upper limit of normal. The patient remembers that he was noted to have an elevated indirect bilirubin several years earlier but his work-up back then also came back normal. Which of the following pathological mechanisms is involved in this patient's condition?]] |
| Answer A | AnswerA::Increased hemoglobin breakdown |
| Answer A Explanation | AnswerAExp:: |
| Answer B | AnswerB::Absent UDP-Glucuronyltransferase |
| Answer B Explanation | AnswerBExp:: |
| Answer C | AnswerC::Decreased bilirubin uptake in the liver |
| Answer C Explanation | AnswerCExp:: |
| Answer D | AnswerD::Bile outlet obstruction |
| Answer D Explanation | AnswerDExp:: |
| Answer E | AnswerE::Hydrolysis of conjugated bilirubin |
| Answer E Explanation | AnswerEExp:: |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::
Gilbert syndrome is a benign condition leading to elevated indirect bilirubin levels. Its main pathophysiologic mechanism is the decreased uptake of unconjugated bilirubin in the liver, although some decrease in the efficiency of UDP-glucuronyltransferase can be noted in some patients. Usually patients present with asymptomatic jaundice. Fatigue can be present in some patients. The increase in bilirubin is usually triggered by fasting, febrile illness, alcohol, exercise, or stress. It is important to rule out any other disease processes in patients suspected to have Gilbert syndrome. Lab tests include a CBC with reticulocyte count and blood smear for any signs of hemolysis, and liver function tests for any signs of liver disease. Gilbert's syndrome doesn't require treatment. Patients with Gilbert syndrome have no disease |
| Approved | Approved::No |
| Keyword | WBRKeyword::Gilbert Syndrome, WBRKeyword::unconjugated hyperbilirubinemia, WBRKeyword::bilirubin |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |