Lipoprotein X in a patient with cholestasis and hypertriglyceridaemia

Abstract

Hypertriglyceridaemia is an established cause of acute pancreatitis and responds to insulin therapy in addition to lipid lowering medication. We report a case of severe hypertriglycaeridemia of 149 mmol/L in a 36-year-old man with type 2 diabetes who presented to the surgical ward with abdominal pain due to pancreatitis and developed acute cholestasis, jaundice and eruptive xanthomata. His triglycerides improved to 3.8 mmol/L with sliding scale insulin within two weeks of in-hospital stay. However, his total cholesterol remained raised at 23.7 mmol/L. The lipoprotein electrophoresis confirmed the presence of lipoprotein X associated with bile obstruction, which contributed to an increase in total cholesterol. The total cholesterol normalized on improvement of his cholestasis. 2013; 50: 173-175. DOI: 10.1258 50: 173-175. DOI: 10. /acb.2012 Case A 36-year-old Caucasian man was admitted to the surgical ward in this hospital with the third episode of acute on chronic pancreatitis in the previous six years. Two earlier such events were followed by recurrent complex pancreatic surgery. He also had a cholecystectomy performed for gallstones. The patient had an eight-year history of type 2 diabetes, poorly controlled by treatment with metformin and insulin (glycosylated haemoglobin [HbA1c] 12.5%, 113 mmol/mol) and a history of non-alcoholic steatohepatitis. Prior to the admission in order to control his lipid profile he had been on atorvastatin tablets for months but had run out of his medications and was off them for approximately eight weeks. He has never smoked and ceased drinking alcohol after the first episode of pancreatitis in 2005. His past history included self-administration of steroid and testosterone injections in the year 2000 for building muscle strength before participating in heavy-lifting competitions. Ann Clin Biochem

Detection of lipoprotein X (LPX) – a challenge in patients with severe hypercholesterolaemia

“…LpX contains cholesterol but not apoB; thus, TC/apoB ratios are increased in patients with LpX. Reference values for TC/apoB ratios have been developed, and significantly increased TC/apoB ratios have been observed in many patients with LpX (13,19,22,(25)(26)(27)30). As well, in our patient the TC/apoB ratio was significantly increased.…”

“…Phatlhane et al (3), in the case of a patient with LpX, observed intense staining in the b area, with minor cathodic migration and a slight green tinge. Less frequently, LpX has been observed (11) at the site of origin, suggesting the presence of chylomicrons (19,27) or as a smearing lipoprotein band with slow migration (18).…”

Characterization of LP-Z Lipoprotein Particles and Quantification in Subjects with Liver Disease Using a Newly Developed NMR-Based Assay

“…In fact, patients with late-stage cholestatic liver diseases are known to have a distinct pattern of dyslipidemia in which circulating lipoproteins have abnormal compositions, electrophoretic mobility, and appearance [ 7 ]. One of these lipoproteins, called lipoprotein X (LP-X), has a multilamellar structure that is enriched in phospholipids and free cholesterol (FC) [ 8 , 9 , 10 , 11 ]. Its density is similar to that of LDL, but its size is in the VLDL range (40–100 nm) [ 8 , 9 , 10 , 11 ].…”

“…One of these lipoproteins, called lipoprotein X (LP-X), has a multilamellar structure that is enriched in phospholipids and free cholesterol (FC) [ 8 , 9 , 10 , 11 ]. Its density is similar to that of LDL, but its size is in the VLDL range (40–100 nm) [ 8 , 9 , 10 , 11 ]. LP-X concentrations are increased in subjects with lecithin-cholesterol acyltransferase (LCAT) deficiency and primary biliary cholangitis (PBC) [ 8 , 9 , 10 , 11 ].…”

“…Its density is similar to that of LDL, but its size is in the VLDL range (40–100 nm) [ 8 , 9 , 10 , 11 ]. LP-X concentrations are increased in subjects with lecithin-cholesterol acyltransferase (LCAT) deficiency and primary biliary cholangitis (PBC) [ 8 , 9 , 10 , 11 ]. LP-X does not carry apolipoprotein (apo)B and has an aqueous core containing albumin.…”