[Practical value of the selective precipitation of LDL, LDL-phospholipids and the molar ratio of cholesterol to LDL-phospholipids in lecithin-cholesterol-acyltransferase deficiency].

There is a high morbidity from hepato-biliary disease in France. These diseases are often accompanied by a reduction in serum lecithin-cholesterol-acyl-transferase activity, which is difficult and costly to diagnose in the laboratory. Thanks to a simple and inexpensive method of selective precipitation of light lipoproteins, we have been able to establish the practical value of the determination of the LDL-phospholipids and the molar cholesterol ratio on the phospholipids in the LDL (MCPR) in familial or secondary deficiencies of Lecithin-Cholesterol-Acyl-Transferase. These conditions are characterized by a high proportion of serum phospholipids transported by the LDL (more than 60%) and by the marked reduction in the cholesterol ratio of the phospholipids in the LDL. The authors propose a classification for the commonest causes of lecithin-cholesterol-acyl-transferase deficiency.