Altered Composition of Lipoproteins in Liver Cirrhosis Compromises Three Homogeneous Methods for HDL-Cholesterol

Despite the obvious clinical advantages, the measurement of HDL-cholesterol (HDL-C) by reliable and easy-to-perform methods is not yet completely free of problems. Several reports have described homogeneous (direct) assays for HDL-C that are readily adaptable to automated analyzers as online procedures (1)(2)(3). These methods have proved to be effective and inexpensive tools for the routine screening of HDL-C in large populations. However, in a recent article (4) we observed that one of these techniques significantly undervalued the concentrations of HDL-C in patients with liver cirrhosis, a condition in which alterations in lipoprotein structure and composition are commonly found (5). Although HDL-C is not a clinically important determination in liver cirrhosis, our finding may have consequences for research groups investigating lipoprotein metabolism and its alterations.The aims of the present study were (a) to compare three different techniques for homogeneous HDL-C measurement with a reference method [single vertical-spin ultracentrifugation (SVS)] in a group of patients with cirrhosis; and (b) to investigate whether there was a relationship between the method biases and abnormal composition of lipoproteins.The study was performed on 58 control subjects and 37 patients with liver cirrhosis. Control subjects were chosen randomly from the routine health and safety-at-work checks conducted in several industrial companies in our area. Excluded were those subjects with clinical or laboratory evidence of diabetes, neoplasia, renal disease, hepatic damage, and cardiovascular disease. Cirrhotic patients were diagnosed by liver biopsy and proceeded from the outpatient clinics of the Hospital Universitari de Sant Joan de Reus. The etiology of cirrhosis was alcoholic in 23 patients (62%), viral in 12 (32%), and cryptogenic in 2 (6%). Twelve of the 23 alcoholic cirrhotic patients had quit alcohol consumption at least 3 months prior to the study. …