Establishment of enzymatic kinetic assay of serum argininosuccinate lyase activity and its preliminary clinical application / 中华检验医学杂志

ABSTRACT

Objective To establish a continuous monitoring assay of serum argininosuccinate lyase (ASL) activity with automatic biochemistry analyzer, and perform methodology validation and preliminary clinical application.Methods According to the chemical reaction catalyzed by ASL and the working characteristics of automatic biochemistry analyzer, an enzyme coupled reaction system with high specificity was set up, and the methodology validation was performed.Three hundred and nine patients with various liver diseases, 269 non-liver disease patients and 40 healthy controls were enrolled in this study.Serum ASL, ALT, and AST level were determined in all subjects.Results A new kinetics assay of ASL activity was set up with automatic biochemistry analyzer.The methodological validation demonstratod that inter-assay and intra-assay coefficient of variation were 4.0% and 5.9% respectively and the mean recovery was 100.5%.The linear range was 0-167.7 U/L.The lowest detection limit was approximately 0 U/L.The interference test showed that there is no significant interferences while the concentration of bilirubin is less than 342 μmoL/L or commonly used anticoagulants is employed at their routine concentrations.However,interference was significant when Hb level is more than 0.06 g/L.Preliminary study of clinical application showed that there was no significant difference of serum ASL level between non-liver disease group and healthy group ( q = 0.027, P = 0.979 ), but there was significant differences for both serum ALT and AST levels (ALTq =6.461,P =0.000;ASTq =6.481,P =0.000).Conclusions A continuous monitoring assay for the determination of serum ASL activity is successfully established. Serum ASL may be a good biomarker for liver injury.