ABNORMAL LIPOPROTEIN PATTERN IN PATIENTS WITH ALAGILLE SYNDROME DEPENDS ON ICTERUS SEVERITY

Background & Aims: Children with Alagille syndrome have lipid abnormal ities that differ according to the severity of icteric periods, The li poprotein profiles of 22 patients with Alagille syndrome were determin ed and the findings were compared with the severity of jaundice, Metho ds: Plasma lipids and apolipoproteins (apos), isolated lipoprotein com position, and lecithin/cholesterol acyltransferase (LCAT) activity wer e analyzed in patients, Patients were classified into two groups accor ding to their bilirubin levels; patients in group I had total bilirubi n levels of >100 mu mol/L, and patients in group II had total bilirubi n levels of <100 mu mol/L. Results: In patients from group II, hyperch olesterolemia was associated with increased levels of high-density lip oprotein and high concentrations of apoAI and apoAII; in a few cases, an abnormal lipoprotein with a slow alpha migration was observed. In c ontrast, in patients from group I, the levels of high-density lipoprot ein cholesterol and apoAI and apoAII were very low, and the abnormal l ipoprotein X was in many cases responsible for hypercholesterolemia. I n group I, the decreased LCAT activity was consistent with the very hi gh 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 phospho lipids, Conclusions: The variations of LCAT activity caused by the deg ree of jaundice in patients with Alagille syndrome are implicated in t he abnormal lipid profiles.