What is the expected haptoglobin level in intravascular hemolysis?

What is the expected haptoglobin level in intravascular hemolysis?

• A. Decreased
• B. Normal
• C. Increased
• D. Not affected

Answer: (A)

Intravascular hemolysis releases a lot of free hemoglobin directly into the bloodstream. Haptoglobin binds this free hemoglobin to form a complex that is quickly cleared from circulation. As more hemoglobin floods the plasma, haptoglobin is consumed faster than it can be produced, leading to a drop in its level. So, a decreased haptoglobin level is a hallmark of intravascular hemolysis. In contrast, hemolysis that occurs mainly outside the vessels (extravascular) releases less free hemoglobin into plasma, so haptoglobin is not depleted as markedly and may remain normal or only slightly reduced. An increased haptoglobin level is not expected in hemolysis (it can rise with inflammation), and saying it is not affected would miss the clear depletion that occurs with intravascular hemolysis.

Intravascular hemolysis releases a lot of free hemoglobin directly into the bloodstream. Haptoglobin binds this free hemoglobin to form a complex that is quickly cleared from circulation. As more hemoglobin floods the plasma, haptoglobin is consumed faster than it can be produced, leading to a drop in its level. So, a decreased haptoglobin level is a hallmark of intravascular hemolysis.

In contrast, hemolysis that occurs mainly outside the vessels (extravascular) releases less free hemoglobin into plasma, so haptoglobin is not depleted as markedly and may remain normal or only slightly reduced. An increased haptoglobin level is not expected in hemolysis (it can rise with inflammation), and saying it is not affected would miss the clear depletion that occurs with intravascular hemolysis.