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[Correlation and interconversion between erythrocyte cholinesterase values obtained by the Michel and the EQM
1Grupo de Malaria, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia. jaimecarmonaf@hotmail.com
Biomedica : Revista Del Instituto Nacional De Salud
|February 24, 2007
Summary
Linear equations were developed to convert red cell cholinesterase measurements between Michel and EQM methods. This facilitates data comparison for clinicians and epidemiologists using these cholinesterase tests.
Area of Science:
- Biochemistry
- Clinical Chemistry
- Occupational Health
Background:
- Multiple assays exist for measuring red blood cell cholinesterase.
- Evaluating concordance between different measurement techniques is crucial for reliable data interpretation.
Purpose of the Study:
- To formulate a linear equation for transforming reference values between Michel and EQM cholinesterase activity assays.
- To enable standardized comparison of cholinesterase activity data across different laboratory methods.
Main Methods:
- A descriptive, cross-sectional, and prospective study design was employed.
- A representative sample of 827 healthy adults (aged 18-75) from northwestern Colombia was recruited.
- Quantitative erythrocyte cholinesterase tests (Michel and EQM) were performed.
Main Results:
- Quantitative erythrocyte tests (Michel and EQM) showed moderate correlation (r=0.67, R2=44%).
- Linear regression models were established to interconvert Michel (delta pH/hour) and EQM (U/g oxy-hemoglobin) units.
- Adjusted equations, after outlier removal, improved the correlation coefficient to r=0.72.
Conclusions:
- A system of linear equations was successfully developed for interconversion of Michel and EQM cholinesterase units.
- This facilitates direct comparison of clinical and epidemiological data obtained using these distinct cholinesterase measurement methods.
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