Interlaboratory survey of enzyme analyses. I. Preliminary

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Biochemical Analysis

Background:

• Accurate enzyme analysis is crucial for diagnosing various medical conditions.
• Interlaboratory variability in enzyme measurements can impact patient care.
• Standardized survey specimens are needed to evaluate laboratory performance.

Purpose of the Study:

• To develop and validate enzyme survey specimens for assessing laboratory performance.
• To establish a method for statistically analyzing laboratory data from enzyme surveys.
• To evaluate the performance of laboratories in analyzing enzymes such as lactate dehydrogenase (LDH) and creatine phosphokinase (CPK).

Main Methods:

• Preparation of serum pools spiked with creatinine, urea, and five enzymes (LDH, CPK, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase).
• Creation of admixtures with original serum to establish linear interspecimen relationships.
• Distribution of liquid and lyophilized specimens to multiple laboratories for analysis using diverse methods and instruments.

Main Results:

• The admixture technique successfully established linear relationships for creatinine and urea nitrogen.
• Survey specimens were prepared with six concentrations of each enzyme.
• Data analysis methods were developed to assess laboratory performance in enzyme analyses.

Conclusions:

• Statistically analyzing data from these survey specimens provides meaningful assessments of laboratory performance.
• The developed methodology allows for the evaluation of laboratory accuracy across different analytical conditions.
• This approach contributes to improving the reliability of enzyme measurements in clinical laboratories.