Haptoglobin Test / Haptoglobulin Test
Haptoglobin is a blood protein made by the liver. Haemoglobin is the protein in the red blood cell that carries oxygen throughout the body. Iron is an essential part of Haemoglobin; without iron, Haemoglobin cannot function. Haptoglobin’s main role is to save iron by attaching itself to any Haemoglobin released from a red cell.
When red blood cells are destroyed, the Haemoglobin is released. Haptoglobin is always present in the blood waiting to bind to released Haemoglobin. White blood cells (called macrophages) bring the haptoglobin-haemoglobin complex to the liver, where the haptoglobin and haemoglobin are separated and the iron is recycled.
In hemolytic anemia, so many red cells are destroyed that most of the available haptoglobin is needed to bind the released haemoglobin. The more severe the haemolysis, the less haptoglobin remains in the blood. The haptoglobin test is ordered when someone has symptoms and signs of anemia, such as paleness and weakness, along with findings suggestive of hemolytic anemia, such as jaundice and sometimes dark urine. Since jaundice and dark urine may also be seen with liver disease, a total or indirect bilirubin test may also be ordered to evaluate liver function.
The haptoglobin test may be ordered along with LDH, a reticulocyte count, and a blood smear when a person has an abnormally low RBC count, hemoglobin, and/or hematocrit test result.
|Related Tests||CBC; Reticulocyte Count; Blood Smear; Hemoglobin; Hematocrit; Bilirubin; LDH; Direct Antiglobulin Test|