Haptoglobin, Serum/Plasma

Haptoglobin which is synthesised in the liver, is an α-2- sialoglycoprotein with Haemoglobin binding capacity. The best known biological function of haptoglobin is the capture of Hemoglobin to prevent both iron loss and kidney damage during hemolysis. In addition, it is an acute phase protein characterised by molecular heterogeneity with three major phenotypes: Hp 1-1, Hp 2-2, and Hp 2-1. After destruction of erythrocytes, free Haemoglobin in the circulation passes through the glomerular filter, and renal damage may occur. haptoglobin reduces the loss of Haemoglobin and iron, because the haptoglobin-Haemoglobin complex is not filtered through the glomeruli but is transported to the liver. Haptoglobin also protects against free radicals and nitric oxide, which are extremely reactive molecules that can cause cell damage. Other functions include inhibition of prostaglandins synthesis and inhibition of bacterial survival and growth.

The concentration of haptoglobin in serum decreases after intravascular haemolysis, whether immune, infectious, hereditary, or mechanical. The amplitude of this decrease largely depends on the initial serum haptoglobin concentration. Haptoglobin concentrations decrease in malnutrition and chronic liver disease. The nephrotic syndrome may be associated with high or low concentrations of serum haptoglobin. As an acute phase protein, concentrations increase in response to a variety of stimuli, such as infection, neoplasia, pregnancy, trauma, acute myocardial infarction, and other inflammatory reactions.

1 ml Serum 1 ml Li-Heparin or K2-EDTA Plasma Stability: 3 Months at 15-25 °C 8 Months at 2-8 °C

Avoid haemolysed samples.

30-200 mg/dL