Effect of quality control cycle on reducing the false negative rate of minimal residual disease of flow cytometry in patients with acute myeloid leukemia

Abstract

Objective To analyze the application of quality control cycle (QCC) in reducing the false negative rate of minimal residual disease (MRD) of flow cytometry in patients with acute myeloid leukemia (AML). Methods In AML patients with abnormal fusion gene detected in hematology laboratory of Changhai Hospital during the year of 2014, the prevalence of AML-MRD detected both by flow cytometry (FCM) and real-time fluorescence quantitative polymerase chain reaction (FQ-PCR) were analyzed retrospectively. The possible causes of false negative rate of flow cytometric MRD referring to PCR were further deeply analyzed, and the improvement measures were adapted from January 2015 to December 2015 and further judged all according to the QCC methods. Results Pareto diagram showed that the dilution and coagulation of the specimen, the improper analysis strategy and the incomplete combination of the MRD index [composition ratio: 83.3% (60/72)] were the main factors leading to the leakage of FCM MRD in 2014. The QCC group devised measures to reduce the dilution probability of bone marrow and develop a standard operating procedures (SOP) for sampling and testing, strengthen the maintenance of the flow instrument and more importantly, focused on optimizing the antibody panels and gated strategies referring to the current two main kinds of MRD detection combination modes on the basis of the latest advances published in 2015. Finally, the undetected rate of AML-MRD was reduced by FCM from 14.8% (72/486) in 2014 to 2.6% (16/620) in 2015. Conclusions The QCC can effectively reduce the leakage rate of flow cytometric AML MRD, improve the ability of laboratory quality control and the ability to solve problems. Solving problems with QCC is thus worthy of being popularized. Key words: Leukemia, myeloid, acute; Minimal residual disease; Flow cytometry; Quality control cycle; Leakage rate