Background: Detection and quantitation of BCR-ABL1 transcripts are crucial for managing patients with chronic myeloid leukemia (CML). Although real-time quantitative polymerase chain reaction (RT-qPCR) can be measured on an International Scale (IS), this has not become fully universal. By using a WHO international standard panel established for calibrating secondary standards based on the IS, we have previously developed an RT-qPCR kit, ODK-1201, for quantification of major BCR-ABL1.
Results: In this study, the reliability of kit-specific conversion factor 1.12 was validated by exchanging patients' samples between three local clinical laboratories and a reference laboratory. The mean bias of the local method after IS conversion was 1.6 fold lower than the reference method. The clinically-useful sensitivity of the kit was further evaluated for monitoring patients with deep molecular response. Based on the correlation of the IS values between ODK-1201 and the reference laboratory method, the detection level of the kit was estimated as 0.0032 % BCR-ABL1 (IS).
Conclusions: ODK-1201 is a highly sensitive one-step RT-qPCR system for detecting BCR-ABL1 on the IS in 2 h after RNA extraction, thus contributing to standardization of molecular monitoring in CML.
Keywords: BCR-ABL1; Chronic myeloid leukemia; Conversion factor; International Scale; Real-time quantitative PCR.