Abnormal lipoprotein pattern in patients with Alagille syndrome depends on icterus severity

Background & Aims: Children with Alagille syndrome have lipid abnormalities that differ according to the severity of icteric periods, The lipoprotein profiles of 22 patients with Alagille syndrome were determined and the findings were compared with the severity of jaundice, Methods: Plasma lipids and apolipoproteins (apos), isolated lipoprotein composition, and lecithin/cholesterol acyltransferase (LCAT) activity were analyzed in patients, Patients were classified into two groups according to their bilirubin levels; patients in group I had total bilirubin levels of >100 mu mol/L, and patients in group II had total bilirubin levels of <100 mu mol/L. Results: In patients from group II, hypercholesterolemia was associated with increased levels of high-density lipoprotein and high concentrations of apoAI and apoAII; in a few cases, an abnormal lipoprotein with a slow alpha migration was observed. In contrast, in patients from group I, the levels of high-density lipoprotein cholesterol and apoAI and apoAII were very low, and the abnormal lipoprotein X was in many cases responsible for hypercholesterolemia. In group I, the decreased LCAT activity was consistent with the very high level of unesterified cholesterol and the emergence of lipoprotein X, In both groups of patients, the levels of apoE, apoCII, and apoCIII were high, and all the lipoprotein fractions were enriched in phospholipids, Conclusions: The variations of LCAT activity caused by the degree of jaundice in patients with Alagille syndrome are implicated in the abnormal lipid profiles.