A protein encoded by the HP gene.
Binds free hemoglobin (Hb) released from erythrocytes and inhibits its oxidative activity.
The haptoglobin-hemoglobin complex is removed by the reticuloendothelial system.
Haptoglobin is a suicide molecule which binds with free hemoglobin released from red blood cells.
Haptoglobin-hemoglobin complexes are rapidly removed by phagocytes.
Haptoglobin is raised as part of the acute phase response, resulting in a typical elevation in the alpha-2 zone during inflammation.
Haptoglobulin level is used to screen for and monitor intravascular hemolytic anemia.
With intravascular hemolysis free hemoglobin is released into circulation and haptoglobin will bind the Hb, resulting in a declining haptoglobin level.
In the presence of extravascular hemolysis the reticuloendothelial system, especially spleen monocytes, phagocytize the erythrocytes without the release of hemoglobin into circulation and the serum haptoglobin levels are therefore normal.
Haptoglobin binding to free plasma hemoglobin allowing degradative enzymes to gain access to hemoglobin and prevents loss of iron through the kidneys and protects the kidneys from damage by hemoglobin.
Haptoglobin is a protein produced by the liver that forms a complex with free plasma hemoglobin, and the haptoglobin–hemoglobin complex is cleared by CD163-expressing macrophages of the reticuloendothelial system.
This process protects organs from the highly oxidative nature of hemoglobin, lowers the serum haptoglobin level.
The interpretation of a low haptoglobin level (<30 mg per deciliter) or low-normal haptoglobin level (30 to 100 mg per deciliter) is subject liver dysfunction, chronic hemolysis, mechanical hemolysis, recent transfusion, and congenital anhaptoglobinemia.
A suicide molecule which binds with free hemoglobin released from red blood cells and these complexes are rapidly removed by phagocytes.
Elevated as part of the acute phase response, resulting in a typical elevation in the alpha-2 zone during inflammation.
When binding hemoglobin, it sequesters the iron within hemoglobin, preventing iron-utilizing bacteria from benefiting from hemolysis.
An acute-phase protein.
Produced mostly by hepatocytes but also by the skin, lung, and kidney.
Mutations in the HP gene can cause ahaptoglobinemia or hypohaptoglobinemia.
HP gene linked to diabetic nephropathy, coronary artery disease in type 1 diabetes, Crohn’s disease, primary sclerosing cholangitis, susceptibility to Parkinson’s disease, and a reduced incidence of Plasmodium falciparum malaria, and the risk of schizophrenia..
Decreased levels support a diagnosis of hemolytic anemia, especially when associated with anemia, and an increased reticulocyte count.
Decreased levels not accompanied by anemia may indicate liver damage, as the liver is not producing enough haptoglobin.
As it is an acute-phase protein, any inflammatory process may increase the levels of plasma haptoglobin.