Development and evaluation of LAMP, CPA and IMSA methods for rapid detection of the AML1/ETO fusion gene in acute myeloid leukemia

The objective of the present study was to determine whether the loop-mediated isothermal amplification (LAMP), cross-priming amplification (CPA), and/or isothermal multiple-self-matching-initiated amplification (IMSA) methods can provide rapid detection of the runt related transcription factor 1/runt related transcription factor 1 translocation partner 1 (AML1/ETO) fusion gene in acute myeloid leukemia (AML). According to the sequence of the AML1/ETO fusion gene available in GenBank and the principles of the LAMP, CPA and IMSA methods, specific primers were designed to bind a conserved region of the AML1/ETO gene in each assay. Following optimization of the conditions for the LAMP, CPA and IMSA assays, the specificity and sensitivity of the assays were examined and compared. In addition, 41 clinical samples were assayed using the three methods. It was observed that a ladder-like pattern of DNA products was produced in AML1/ETO-positive samples in all three assays, whereas no DNA product was generated with the controls. The detection limit of the LAMP and CPA assays was 50 copies/tube, and for the IMSA assay was 10 copies/tube. This sensitivity was consistent, and improved in the latter case, compared with that of the reverse transcription-polymerase chain reaction (RT-PCR) assay. Furthermore, the detection rate for bone marrow or peripheral blood samples was 9.76%, and the agreement among the LAMP, CPA, IMSA and RT-PCR methods was 100%. Therefore, the LAMP, CPA and IMSA methods optimized in the present study provided rapid detection of the AML1/ETO fusion gene for an initial clinical diagnosis of AML. In addition, the LAMP, CPA and IMSA assays are straightforward to perform and do not require specialized instruments. Therefore, these three isothermal methods may be used to perform field tests or assays at resource-limited hospitals.