In hemolytic anemia, which laboratory value is typically decreased?

In hemolytic anemia, which laboratory value is typically decreased?

• A. Haptoglobin
• B. Fibrinogen
• C. Albumin
• D. Bilirubin

Answer: (A)

In intravascular hemolysis, red cells break open within the vessels, releasing hemoglobin into the plasma. Haptoglobin binds this free hemoglobin to form a complex that is cleared from circulation. When hemolysis is ongoing, large amounts of free hemoglobin are present, so haptoglobin is rapidly used up and its serum level falls. This makes low haptoglobin a hallmark clue for intravascular hemolysis. Bilirubin usually increases because of enhanced heme breakdown, not decreases. Fibrinogen and albumin aren’t specifically affected by red cell destruction in the way haptoglobin is. So the laboratory value that’s typically decreased is haptoglobin.

In intravascular hemolysis, red cells break open within the vessels, releasing hemoglobin into the plasma. Haptoglobin binds this free hemoglobin to form a complex that is cleared from circulation. When hemolysis is ongoing, large amounts of free hemoglobin are present, so haptoglobin is rapidly used up and its serum level falls. This makes low haptoglobin a hallmark clue for intravascular hemolysis. Bilirubin usually increases because of enhanced heme breakdown, not decreases. Fibrinogen and albumin aren’t specifically affected by red cell destruction in the way haptoglobin is. So the laboratory value that’s typically decreased is haptoglobin.