Use of Droplet Digital Polymerase Chain Reaction for Detecting Minimal Residual Disease: A Prospective Multi-Institutional Study

Abstract

Background/Aim: Droplet digital polymerase chain reaction (ddPCR) is an exact method of measuring nucleic acids. The aim of this prospective study was to evaluate minimal residual disease (MRD) using ddPCR in chronic myeloid leukemia (CML) patients. Patients and Methods: Between May 2013 and November 2014, CML patients treated with nilotinib were enrolled in our study. BCR/ABL1 transcripts levels were evaluated using ddPCR at the first time of complete molecular response (CMR). We enrolled 15 patients from 7 Institutions. The treatment period and median follow-up period were 45 months and 47 months, respectively. Results: Patients with a high level of BCR/ABL1 transcript had a greater tendency to lose the CMR during the follow-up period (p=0.095). In addition, patients with a low level of BCR/ABL1 transcript showed a longer duration of CMR compared to those with a high level (p=0.032). Conclusion: We found that ddPCR is a sensitive method for detecting MRD and that MRD could affect the duration of the treatment response. Chronic myeloid leukemia (CML) is cytogenetically characterized by the translocation of t(9; 22) (q34;q11.2), which produces the BCR/ABL1 fusion oncogene (1). Since the success of imatinib, the first targeted agent in human history, more effective tyrosine kinase inhibitors (TKIs), such as dasatinib and nilotinib have been introduced to the frontline treatment of CML and show a 76-82% major molecular response rate (2, 3). CML is now thought to be a lifelong disease with a 5-year overall survival rate>90% (4). Previous reports have demonstrated that achievement of an early molecular response is a strong predictive marker of improved outcomes (5). Therefore, the European LeukemiaNet 2273 This article is freely accessible online.

Transferring measurable residual disease measurement in pediatric acute lymphoblastic leukemia from quantitative real‐time PCR to digital droplet PCR

“…This enables precise detection of a PCR product and absolute quantification of MRD levels without any external standard curve. 4 In several studies, a comparable accuracy and sensitivity of ddPCR to qPCR was confirmed with high concordance between both methods for different lymphoproliferative disorders. [3][4][5][6][7][8] Della Starza et al recently examined the sensitivity of MRD quantification using ddPCR for pediatric ALL.…”

“…Even though different groups established ddPCR assays for various hematologic malignancies, they all concluded that ddPCR was well suited for MRD determination 3–27 . For a detailed overview about different ddPCR approaches for MRD detection, see Table 1.…”

“…In several studies, a comparable accuracy and sensitivity of ddPCR to qPCR was confirmed with high concordance between both methods for different lymphoproliferative disorders 3–8 . Della Starza et al recently examined the sensitivity of MRD quantification using ddPCR for pediatric ALL.…”

“…The ddPCR system from BioRad splits the sample to be measured into up to 20 000 droplets. This enables precise detection of a PCR product and absolute quantification of MRD levels without any external standard curve 4 …”

Exosome: From leukemia progression to a novel therapeutic approach in leukemia treatment

“…qPCR is another molecular‐based method for MRD identification 171 . A comparative study by Lenczowsk et al showed that dPCR method is more accurate than qPCR in MPN patients MRD detection 172–174 . The residuals of disease give disappointing results of allogeneic transplantation and increase the risk of recurrence 21 .…”