Lipoprotein-X in a Patient with Lymphoplasmacytic Sclerosing Cholangitis: An Unusual Cause of Secondary Hypercholesterolemia

ABSTRACT Objective: To describe the presence of lipoprotein-X in a patient with obstructive liver disease and review the available literature on secondary hypercholesteremia occurring in the presence of lipoprotein-X. Methods: Reported is the case of a 40-year-old man who presented with severe hypercholesterolemia due to obstructive cholestasis secondary to lymphoplasmacytic sclerosing cholangitis. A literature search was conducted through PubMed for references from 1976 to 2013 regarding the appearance of lipoprotein-X in plasma secondary to cholestasis. Twenty-eight articles were found that addressed the physiology, pathogenesis, complications, or treatments of lipoprotein-X in the context of cholestasis. Results: Severe hypercholesterolemia was found in a patient with lymphoplasmacytic sclerosing cholangitis. His elevated plasma cholesterol level was due to the presence of lipoprotein-X, which is a particle with a density similar to low-density lipoprotein (LDL) that does not contain apolipoprotein B. The pathogenesis of lipoprotein-X is poorly understood. Unlike LDL, lipoprotein-X may not be atherogenic. Neither statins nor other lipid-lowering agents have been shown to be useful in treating the hypercholesterolemia that results from production of lipoprotein-X. Conclusion: Lipoprotein-X may occur in obstructive liver disease, and the therapy is focused on treating the underlying disease. Abbreviations: ALP = alkaline phosphatase ALT = alanine aminotransferase apo = apolipoprotein AST = aspartate aminotransferase ERCP = endoscopic retrograde cholangiopancreatography HDL = highdensity lipoprotein LCAT = lecithin:cholesterol acyltransferase LDL = low-density lipoprotein Lp-X = lipoprotein-X PBC = primary biliary cirrhosis