Real-time RT-PCR for quantitative detection of the t(15;17) PML-RARA fusion transcript. Both long and short isoforms of the fusion transcript are detected. Positive results identify the isoform and quantify it as a ratio with the amount of transcript from a normal control gene. Analytical sensitivity is 1 tumor cell in 10,000 normal cells.
The (15;17) translocation occurs in nearly all cases of acute promyelocytic leukemia (APL, or AML subtype M3). The translocation is associated with a high rate of complete remission due to sensitivity of leukemic cells to all trans-retinoic acid (ATRA). This assay is recommended for diagnostic confirmation and initiation of ATRA therapy, for monitoring minimal residual disease, and for detection of relapse
Bone marrow (preferred): 2 mL in EDTA tube. Peripheral blood (acceptable): 5 mL in EDTA tube.
Use cold pack for transport, making sure cold pack is not in direct contact with specimen. Ship same day as drawn whenever possible; specimens <72 hours old preferred.