Haptoglobin

Haptoglobins are proteins in the blood that bind free iron; they do this to stop bacteria from using the iron to grow.

Like most plasma proteins, haptoglobins are produced by the liver. These proteins float throughout the body to mop up any excess iron.

Normally, all the iron in the blood is contained in haemoglobin in red blood cells. If iron 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.