Patient's question:
A few days ago, all the employees from my friends' company union went to a nearby hospital for a thorough check-up. After the check-up, a colleague of my friend took the medical record and asked my friend what it meant that his urinary bilirubin was negative. What does it mean if the extravascular hemolysis bilirubin is negative?Doctor's answer:
Hemolysis of red blood cells outside the vasculature is absorbed and destroyed by macrophages. Phagocytes compress hemoglobin, producing bilirubin. Bilirubin diffuses into the blood within macrophages, leading to a significant decrease in blood bilirubin levels. In intravascular hemolysis, red blood cells are directly destroyed, releasing hemoglobin. This hemoglobin then binds to haptoglobin and is gradually metabolized into bilirubin within liver cells. However, the total amount of haptoglobin is limited, so its ability to bind free hemoglobin is also limited.