Analysis of major BCR-ABL1 mRNA by digital polymerase chain reaction is useful for prediction of international scale

Background Major BCR-ABL1 mRNA in patients with chronic myeloid leukemia (CML) has generally been analysed by real-time polymerase chain reaction (PCR). Application of the international scale (IS) for the quantification of major BCR-ABL1 mRNA has been recommended in several sets of guidelines, including those of the European LeukemiaNet. The aim of this study was to clarify the efficacy of digital PCR technology for the IS of BCR-ABL1 mRNA in the patients with CML by comparing with real-time PCR. Methods The analysis of BCR-ABL1 mRNA was carried out by the Ipsogen ® BCR-ABL1 Mbcr IS-MMR DX Kit (Qiagen), and the QuantStudio 3D Digital PCR System (Thermo Fisher Scientific‎) using 20 peripheral blood samples obtained from the 9 patients with CML at Sapporo Medical University Hospital. Results The correlation between the data obtained by digital PCR and by real-time PCR was really high at R = 0.96. The detection limit of digital PCR was up to 0.003% and was equal to IS with 0.01% or less in comparison with real-time PCR. Conclusions Digital PCR technology is promising for predicting the IS value with similar efficacy to real-time PCR and should be useful for simple monitoring of the effects of tyrosine kinase inhibitor (TKI) treatments.