Haptoglobin
From Free net encyclopedia
Haptoglobins (frequently abbreviated as Hp) are proteins in the blood that bind free hemoglobin, preventing bacteria from using the iron to grow. Three phenotypes exist in the human population: 1-1, 2-1, and 2-2.
Like most plasma proteins, haptoglobins are produced by the liver. These proteins float throughout the body to bind any excess hemoglobin.
Normally, all the iron in the blood is contained in haemoglobin in red blood cells. If hemoglobin is released from these cells, (for instance by haemolysis), haptoglobins will bind it strongly. The haptoglobins will then be removed by the reticuloendothelial system (mostly the spleen).
For this reason, haptoglobin levels will be decreased in haemolytic anaemias.