Evaluation of a new method for cholinesterase determination

Area of Science:

• Biochemistry
• Clinical Chemistry
• Enzymology

Background:

• Serum cholinesterase (ChE) activity is a clinically significant biomarker.
• Accurate and reliable ChE determination is crucial for diagnosing various medical conditions.
• Existing ChE assays may have limitations in terms of substrate specificity or assay conditions.

Purpose of the Study:

• To evaluate a new commercially available assay system for serum cholinesterase catalytic activity.
• To adapt and apply this new assay to a centrifugal fast analyzer for high-throughput analysis.
• To establish reference ranges for serum cholinesterase activity in a healthy population.

Main Methods:

• Serum cholinesterase activity was determined at 30°C using para-hydroxybenzoylcholine as the substrate.
• The assay employed a coupled enzymatic reaction utilizing para-hydroxybenzoate hydroxylase and monitoring NADPH absorbance decrease at 340 nm.
• Kinetic measurement of enzyme activity was performed using a centrifugal fast analyzer.

Main Results:

• The new assay demonstrated precision and good correlation with established methods using different substrates (propionylthiocholine, butyrylthiocholine, benzoylcholine).
• Reference ranges for 700 healthy subjects were determined as 140-345 U/L (95% central range).
• Significant differences in serum cholinesterase activity were observed between males (155-353 U/L) and females (134-323 U/L).

Conclusions:

• The evaluated assay system is a precise and reliable method for determining serum cholinesterase activity.
• The assay is suitable for application on centrifugal fast analyzers, enabling efficient clinical laboratory testing.
• Established reference ranges provide valuable data for interpreting serum cholinesterase levels in clinical practice.