It is a serum protein which transports free hemoglobin to the liver for breakdown and production of bilirubin and bile salt. So it prevents Hb from damaging kidneys.
Alleles - Hp1/Hp2. Hp1/Hp1 in 60% in Africa and Central and South America.
Increase red blood cells destruction means haptoglobin is depleted.
In adults it varies from 30 to 200 mg/dl.
Absent in neonates and adult levels are reached by age 4.
Increase level due to infection, trauma, hepatitis, collagen disease, leukaemia. Smoking, diabetes.
Decrease level when intravascular hemolysis and extravascular hemolysis.
Population variation
Absent in one percent of whites and 4 to 10% blacks
Hp1 gene is 40% incidence in western Europe. 60% in tropical Africa. Some African populations 30% have no have to globins. 10 to 20% in Asia.