Research and discussion on the evaluation scheme of reagent lot-to-lot differences in 16 chemiluminescence analytes, established by the EP26-A guidelines of the CLSI.

BACKGROUND

Verification of new reagent lots is a part of the crucial tasks in clinical laboratories. The Clinical and Laboratory Standards Institute (CLSI) EP26-A guideline provides laboratories with an evaluation method for reagent verification. The purpose of this study was to compare the performance of EP26-A with our laboratory reagent lot verification protocol and get the final scheme.

METHOD

16 chemiluminescence analytes including estradiol (E2), progesterone (P), ferritin (FER), cortisol (COR),carbohydrate antigen 153 (CA153), and free prostate-specific antigen (FPSA). were prospectively evaluated in two reagent lots. The laboratory's lot verification process included evaluating 5 patient samples with the current and new lots and acceptability according to a predefined criteria. For EP26-A, method imprecision data and critical differences at medical decision points were important factors affecting the sample size requirements and rejection limits.

RESULT

The number of samples required for EP26-A was 3 to 12, of which P, CA153, and FPSA had increased by more than 5 samples compared with the current protocol. Of the 16 chemiluminescence analytes, 11 had higher rejection limits when using EP26-A than the current laboratory scheme. Our current protocol and EP26-A were in agreement in 32 of the 32 (100%) paired verifications.

CONCLUSION

The EP26-A protocol is an important tool to find the differences between reagent lots, and it makes up for the loopholes in the statistical efficiency, sample concentration and quantity, and the selection of rejection limits in the current protocol.