CRC Crit Rev Clin Lab Sci. 1979 Aug;11(1):31-51. doi: 10.3109/10408367909105853.


Lipoprotein-X is an abnormal lipoprotein that appears in the sera of patients with obstructive jaundice, and thus is a sensitive indicator of cholestasis. In patients with familial plasma lecithin, Cholesterol acyltransferase (LCAT) deficiency, there is an inverse relationship between plasma Lp-X levels and LCAT activity. Ultracentrifugation procedures utilized for isolation of Lp-X have shown that it is associated with the low density lipoprotein fraction. Lp-X can be visualized by electrophoresis on either Agar or Agarose. The purity of Lp-X preparations has been documented by immunochemical procedures. The availability of highly purified antisera to Lp-X has served as a basis of one of the assay procedures for this lipoprotein. It's chemical composition has been established. Phospholipids and unesterified cholesterol constitute the bulk of the Lp-X molecule. Electron microscopic studies have demonstrated that Lp-X is a spherical particle which has strong aggregating properties. Membrane bound enzymes have been shown to aggregate with Lp-X. The fact that bile lipoprotein can be converted to Lp-X by the addition of albumin and that Lp-X can be converted to bile lipoprotein by the addition of bile salts offers a possible explanation for the origins of Lp-X. Phospholipases of plasma might play a role in the catabolism of Lp-X. The value and limitations of Lp-X determinations will also be addressed in this review.

Publication types

  • Review

MeSH terms

  • Alkaline Phosphatase / metabolism
  • Amino Acids / blood
  • Animals
  • Apoproteins / blood
  • Bile Acids and Salts / blood
  • Chemical Phenomena
  • Chemistry
  • Cholestasis / blood*
  • Cholestasis / diagnosis
  • Cholesterol / blood
  • Cholesterol Esters / blood
  • Humans
  • Immunologic Techniques
  • Lecithin Cholesterol Acyltransferase Deficiency / blood
  • Lipoprotein-X / blood*
  • Lipoprotein-X / isolation & purification
  • Lipoprotein-X / physiology
  • Lipoproteins / blood
  • Nucleotidases / metabolism
  • Phospholipids / blood
  • Pyrophosphatases / metabolism
  • Research


  • Amino Acids
  • Apoproteins
  • Bile Acids and Salts
  • Cholesterol Esters
  • Lipoprotein-X
  • Lipoproteins
  • Phospholipids
  • Cholesterol
  • Nucleotidases
  • Alkaline Phosphatase
  • Pyrophosphatases