## Core Concept
Haptoglobin is a protein that binds free hemoglobin in the blood, and its levels can be affected by conditions involving hemolysis. In hemolytic anemia, red blood cells are destroyed faster than they can be made. This destruction leads to the release of hemoglobin into the bloodstream.

## Why the Correct Answer is Right
In hemolytic anemia, the level of haptoglobin decreases. This decrease occurs because haptoglobin binds to free hemoglobin released from lysed red blood cells, forming a haptoglobin-hemoglobin complex that is then removed from the circulation by the reticuloendothelial system. As a result, the concentration of haptoglobin in the blood drops. This is a compensatory mechanism to protect the kidneys from damage by free hemoglobin.

## Why Each Wrong Option is Incorrect
- **Option A:** Increase - This is incorrect because haptoglobin levels decrease in hemolytic anemia due to its consumption in binding free hemoglobin.
- **Option B:** Remain the same - This is incorrect because hemolytic anemia leads to a decrease in haptoglobin levels due to the increased binding and clearance of hemoglobin.
- **Option D:** Variable - While it's true that haptoglobin levels can be influenced by various factors, in the context of hemolytic anemia, there is a predictable decrease in haptoglobin levels.

## Clinical Pearl / High-Yield Fact
A key clinical point to remember is that decreased haptoglobin levels are a marker of hemolysis. Haptoglobin levels can be used as a diagnostic tool to differentiate between hemolytic and non-hemolytic anemias. In cases of hemolytic anemia, one would expect to see a decrease in haptoglobin, an increase in indirect bilirubin, and possibly an increase in lactate dehydrogenase (LDH) levels.

## Correct Answer: C. Decrease.