A new method for the measurement of lysosomal acid lipase in dried blood spots using the inhibitor Lalistat 2

• Published in: Clinica chimica acta 2012-08, Vol.413 (15-16), p.1207-1210
• Main Authors: Hamilton, John, Jones, Iain, Srivastava, Rajeev, Galloway, Peter
• Format: Article
• Language: English
• Subjects: Carbamates - pharmacology; Cholesterol ester storage disease; Clinical Chemistry Tests - methods; Dried blood spot; Dried Blood Spot Testing - methods; Enzyme Inhibitors - pharmacology; Enzyme Stability; Humans; Lalistat 2; Lipase - antagonists & inhibitors; Lipase - blood; Lysosomal acid lipase; Method; Sterol Esterase - antagonists & inhibitors; Sterol Esterase - blood; Temperature; Thiadiazoles - pharmacology; Wolman disease
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2012.03.019

Cholesterol ester storage disease (CESD) and Wolman Disease (WD) are due to deficiency of lysosomal acid lipase (LAL). A new method is described for the measurement of LAL in dried blood spots (DBS) using Lalistat 2 an inhibitor of LAL. LAL activity in DBS extracts was measured using the substrate 4-methylumbelliferyl palmitate. LAL activity was determined by measuring total lipase activity and lipase activity in the presence of Lalistat 2. The specificity of Lalistat 2 was investigated using human recombinant LAL (hrLAL) and human pancreatic lipase (hPL). Lalistat 2 inhibited hrLAL with 1% residual activity at 1μM inhibitor but had no effect on hPL up to 10μM. LAL activity in DBS samples obtained from normal controls (n=140) was 0.50–2.30nmol/punch/h and in patients with CESD was