Clinical perspective of lipoprotein – x

Abstract

Lipoprotein – X(abnormal lipoprotein ) is rich in phospholipids and unesterified cholesterol. The main protein component is albumin within the core and apolipoprotein C upon the surface. It is cleared by the reticuloendothelial system and the kidneys. Earlier studies reported presence of lipoprotein X (LP-X) in patients with cholestasis. Bile lipoprotein is a precursor of LP-X and in cholestasis this refluxes into the plasma pool , binds to albumin to form LP-X. Cholestasis of pregnancy and Primary biliary cirrhosis patients also reported high LP-X levels. LP-X may not be atherogenic and it may have antioxidant LDL activity. LP- X is found in LCAT deficiency which is characterised by low High Density Lipoprotein(HDL), anaemia , corneal opacity and chronic kidney diseases. The presence of serum LP-X can be associated with severe hyperlipidaemia , pseudohyponatremia and it also interfere with some serum LDLc assays and complexes with Alkaline phosphatase.