Hepatic cholesteryl ester accumulation in lysosomal acid lipase deficiency: non-invasive identification and treatment monitoring by magnetic resonance.

Abstract

BACKGROUND & AIMS:

Lysosomal Acid Lipase (LAL) deficiency is a rare metabolic storage disease, caused by a marked reduction in activity of LAL, which leads to accumulation of cholesteryl esters (CE) and triglycerides (TG) in lysosomes in many tissues. We used (1)H magnetic resonance (MR) spectroscopy to characterize the abnormalities in hepatic lipid content and composition in patients with LAL deficiency, and in ex vivo liver tissue from a LAL deficiency rat model. Secondly, we used MR spectroscopy to monitor the effects of an enzyme replacement therapy (ERT), sebelipase alfa (a recombinant human lysosomal acid lipase), on hepatic TG and CE content in the preclinical model.

METHODS:

Human studies employed cohorts of LAL-deficient patients and NAFLD subjects. Rat experimental groups comprised ex vivo liver samples of wild type, NAFLD, LAL-deficient, and LAL-deficient rats receiving 4weeks of sebelipase alfa treatment. Hepatic (1)H MR spectroscopy was performed using 3T (human) and 7T (preclinical) MRI scanners to quantify hepatic cholesterol and triglyceride content.

RESULTS:

CE accumulation was identified in LAL deficiency in both human and preclinical studies. A significant decrease in hepatic CE was observed in LAL-deficient rats following treatment with sebelipase alfa.

CONCLUSIONS:

We demonstrate an entirely non-invasive method to identify and quantify the hepatic lipid signature associated with a rare genetic cause of fatty liver. The approach provides a more favorable alternative to repeated biopsy sampling for diagnosis and disease progression / treatment monitoring of patients with LAL deficiency and other disorders characterised by increased free cholesterol and/or cholesteryl esters.

• Authors: Peter E Thelwall, Fiona E Smith, Mark C Leavitt, David Canty, Wei Hu, Kieren G Hollingsworth, Christian Thoma, Michael I Trenell, Roy Taylor, Joseph V Rutkowski, Andrew M Blamire, Anthony G Quinn
• Journal: Journal of hepatology (J Hepatol) Vol. 59 Issue 3 Pg. 543-9 (Sep 2013) ISSN: 1600-0641 [Electronic] Netherlands
• PMID: 23624251 (Publication Type: Journal Article, Multicenter Study, Observational Study, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Chemical References

• Cholesterol Esters
• Fatty Acids
• Recombinant Proteins
• Triglycerides
• LIPA protein, human
• Sterol Esterase

Topics

• Animals
• Cholesterol Esters (metabolism)
• Disease Models, Animal
• Fatty Acids (metabolism)
• Fatty Liver (metabolism)
• Humans
• Liver (metabolism)
• Magnetic Resonance Spectroscopy
• Male
• Non-alcoholic Fatty Liver Disease
• Prospective Studies
• Rats
• Rats, Sprague-Dawley
• Rats, Transgenic
• Recombinant Proteins (therapeutic use)
• Sterol Esterase (deficiency, genetics, therapeutic use)
• Triglycerides (metabolism)
• Wolman Disease (drug therapy, genetics, metabolism)