Quantitative assessment of PML-RARa and BCR-ABL by two real-time PCR instruments: multiinstitutional laboratory trial.

The recent introduction on the market of instruments for real-time PCR has prompted the development of quantitative assays for the most common fusion transcripts detectable in hematologic malignancies. However, because the ABI PRISM apparatus (ABI; Applied Biosystems) was the first available instrument for real-time PCR, most of the methods developed for the ABI PRISM use TaqMan probe chemistry (1)(2)(3). With the introduction of other real-time PCR instruments, such as the LightCycler (LC; Roche), other methods have been described (4)(5)(6)(7). The instruments differ in several respects, including the light sources and the approach to acquisition of fluorescence data. Few reports have compared the results obtained with different types of real-time PCR instruments (8). To the best of our knowledge, no such multicenter studies with common calibrators and common methods have been reported. In the present study we analyzed the results obtained with two of the more widely used instruments for real time PCR, i.e., the ABI and LC, for amplifying two rearrangements frequently detectable in human leukemia, the BCR-ABL and PML-RARa fusion genes. For BCR-ABL several quantitative methods have been established for both instruments (3)(4)(5)(6)(7), whereas for PML-RARa most of the quantitative methods have been developed for the ABI PRISM (1). The quantification of BCR-ABL transcripts is clinically relevant for monitoring patients with chronic myeloid leukemia undergoing allogeneic hematopoietic stem cell transplantation (4)(9) or treatment with interferon-a or imatinib mesylate (9)(10)(11). For example, low numbers of BCR-ABL transcripts after 2 weeks of imatinib treatment predict a good response to imatinib after 4 weeks (9). With respect to PML-RARa , recent reports have shown that …