The Utility of the Multiplex Reverse Transcriptase-Polymerase Chain Reaction Assay in the Detection of Hematologic Malignancies

Dear Editor The new 2008 WHO classification of hemato-oncological diseases includes a new category for recurrent chromosomal abnormalities [1]. Recurrent gene rearrangements such as RUNX1/ RUNX1T1 (formerly AML1/ETO), CBFB/MYH11, or PML/RARA, provide additional information for the diagnosis of AML, regardless of the blast count. Chromosomal abnormalities and gene mutations are the most influential and/or prominent factors used for determining prognosis. Detection of recurrent genetic abnormalities has become important for the diagnosis, determination of prognosis, and detection of minimal residual disease. Many translocations can be detected through conventional cytogenetics, FISH, and reverse transcriptase-PCR (RT-PCR). Among these, RT-PCR is the most sensitive method and can also detect cryptic gene rearrangements that remain undetected by conventional cytogenetics [2]. Single RT-PCR has been the most commonly used method to detect gene rearrangements in Korea. However, this method is limited to the detection of only certain types of translocations. In the 2000s, multiplex RT-PCR became widely adopted in Korea, enabling rapid detection of a broader range of gene rearrangements. In this study, we compared the diagnostic utility of multiplex RT-PCR to single RT-PCR, and then compared both of them with conventional cytogenetics. Although a direct comparison was not available because of different sampling periods, we investigated the difference between single RT-PCR and conventional cytogenetics to provide a more robust assessment of the diagnostic utility of multiplex RT-PCR. Among patients who visited our institution from January 2005 to June 2012, we identified individuals who were diagnosed with hematologic malignancies. Single RT-PCR was used for the diagnosis of patients from January 2005 to May 2008, and multiplex RT-PCR from June 2008 to June 2012. Patients were considered to have a hematologic malignancy when the results indicated AML, ALL, mixed phenotype acute leukemia (MPAL), and CML. Cytogenetic analysis and FISH analysis were performed according to the manufacturer’s instructions. Single RTPCR was performed using 3 primers for PML/RARA, BCR/ABL1, and RUNX1/RUNX1T1. Multiplex RT-PCR was conducted by the HemaVision kit (DNA Technology, Aarhus, Denmark). Characteristics of patients diagnosed with hematologic malignancies by single RT-PCR and multiplex RT-PCR are shown in