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

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• 作者：John Hamilton ; ^{john.hamilton2@ggc.scot.nhs.uk} ; Iain Jones ; Rajeev Srivastava ; Peter Galloway
• 关键词：Lysosomal acid lipase ; Dried blood spot ; Method ; Lalistat 2 ; Wolman disease ; Cholesterol ester storage disease
• 刊名：Clinica Chimica Acta
• 出版年：2012
• 出版时间：16 August, 2012
• 年：2012
• 卷：413
• 期：15-16
• 页码：1207-1210
• 全文大小：351 K

文摘

Background

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.

Methods

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).

Results

Lalistat 2 inhibited hrLAL with 1 % residual activity at 1 ¦ÌM inhibitor but had no effect on hPL up to 10 ¦ÌM. LAL activity in DBS samples obtained from normal controls (n = 140) was 0.50-2.30 nmol/punch/h and in patients with CESD was < 0.03 nmol/punch/h (n = 11). Activity in carriers showed intermediate activity: 0.15-0.40 nmol/punch/h (n = 15).

Conclusions

Measurement of LAL using DBS is made difficult by the presence of other lipases in whole blood. Lalistat 2 is a specific inhibitor of LAL which allows the determination of LAL in DBS. Results show the method differentiates clearly between normal controls, carriers and affected cases.