Development of Reverse Transcription Loop-Mediated Isothermal Amplification for Simple and Rapid Detection of Promyelocytic Leukemia-Retinoic Acid Receptor α mRNA

Acute promyelocytic leukemia (APL) is a disease characterized by expression of α ( α) chimeric mRNA. Although APL is curable, early death due to hemorrhage is a major problem. Here, we report the development of a simple and rapid diagnostic method for APL based on reverse transcription loop-mediated isothermal amplification (RT-LAMP). An RT-LAMP primer set was designed to detect three types of α mRNA in a single reaction. Serial dilutions of plasmid DNA containing bcr1, bcr2, or bcr3 α sequences and RNA extracted from bone marrow aspirates of 6 patients with APL were used to compare the results of RT-LAMP and nested PCR assays. Plasmid DNA was amplified by RT-LAMP, for which the reaction time was > 4 h shorter and the lower detection limit was higher than for nested RT-PCR. Six of 7 samples tested positive by both methods. We developed an RT-LAMP assay for simple and rapid α mRNA detection that may be clinically useful for point-of-care testing and APL diagnosis.