Haptoglobin (HP)

As a result of hemolysis, hemoglobin is found to accumulate in the kidney and is secreted in the urine. Haptoglobin captures, and combines with free plasma hemoglobin to allow hepatic recycling of heme iron and to prevent kidney damage.

Haptoglobin also acts as an Antimicrobial; Antioxidant, has antibacterial activity and plays a role in regulating many aspects of the acute phase response. Hemoglobin/haptoglobin complexes are rapidely cleared from the macrophage CD163 scavenger receptor expressed on the surface of liver Kupfer cells through an endocytic lysosomal degradation pathway.