LIPOPROTEIN(A) CONCENTRATION AND PHENOTYPES IN PRIMARY BILIARY-CIRRHOSIS

We studied a selected group of 39 female patients suffering from prima ry biliary cirrhosis (PBC). This disease is characterized by typical l ipoprotein alterations and elevated concentrations of serum cholestero l. Despite the increased concentration of atherogenic lipoproteins, en hanced atherogenesis is not characteristic of PBC, Serum total cholest erol, triglycerides, HDL(2) and HDL(3)-cholesterol concentrations were measured by enzymatic methods or in combination with precipitation pr ocedures. Apolipoproteins were determined by using immunonephelometric methods. ELISA sandwich method was used for lipoprotein(a) determinat ions. Apoprotein(a) phenotyping (isoforms) was performed by Western bl otting with specific antibodies. The concentrations of serum lipids, l ipoproteins and apoproteins (AI, AII and B) were found in the range of earlier investigations. The serum lipoprotein(a) concentration did no t differ between the PBC patients and control subjects (10.0/0.1-54/, median 2.55 vs. 11.5/0-75/, median 5.2 mg/dl). In the advanced stages of PBC we found a higher number of patients with low lipoprotein conce ntration (lower than 1 mg/dl). In patients with shorter durations and milder histological alterations high HDL(2) cholesterol subfractions h as been detected (stage I = 0.42 +/- 0.18, stage II = 0.53 +/- 0.29 an d stage III = 0.62 +/- 0.41 vs, stage IV = 0.26 +/- 0.15 mmol/l, P < 0 .05). Despite the elevation of atherogenic lipoproteins, high HDL(2)-c holesterol and normal lipoprotein(a) concentrations may be one of the reasons why patients with advanced PBC are not placed at increased ris k for atherosclerosis.