Changes to BCR-ABL Quantitation; Testing Now Available
in the Molecular Pathology Laboratory

Effective: Tuesday, October 30, 2012, BCR-ABL quantitation by reverse transcription quantitative polymerase chain reaction (RT-qPCR) will be provided by the Molecular Pathology Laboratory at the Department of Pathology and replace the mail-out test to Molecular MD.

The BCR-ABL translocation [t(9;22)(q34;q11)] is present in greater than 95% of chronic myelogenous leukemia (CML), 20-40% of adult acute lymphoblastic leukemia (ALL) and a subset of pediatric ALL. Molecular assessment for the BCR-ABL RNA fusion transcript has become the standard for monitoring CML patients undergoing tyrosine kinase inhibitor therapy and translocation positive ALL. A major molecular response (MMR) is equivalent to 0.1% of International Scale (IS) or a 3-log reduction from a standardized baseline value as determined from the International Randomized Interferon versus STI571 (IRIS) study. The UIHC BCR-ABL RNA Quantitation assay has been calibrated to the International Scale.

Specimen type: Whole blood (EDTA anti-coagulated; pink or lavender top tube) or bone marrow aspirates (EDTA anti-coagulated; pink or lavender top tube).

Method: The BCR-ABL RNA Quantitation assay (Asuragen, Inc. Austin, TX) uses multiplex reverse transcription in combination with real-time PCR technology. The major and minor BCR/ABL1 translocations b2a2 (e13a2), b3a2 (e14a2) and e1a2 along with the ABL1 normalization control are simultaneously detected and quantified. A correction factor of 0.38 was determined by calibration to the International Scale.  The assay can reliably detect 1 tumor cell in a background of 15,000 normal cells with detection limits of 30 BCR-ABL copies and 0.02% IS. The specific breakpoint is determined by sizing the BCR-ABL fusion transcript PCR products by fluorescence-based capillary electrophoresis. This test is not designed for the identification of the e19a2 fusion transcript associated with the p230 product.

Results Reported: International Scale Percent Ratio (IS%) of BCR-ABL fusion transcript to ABL1 copies
Percent Ratio of BCR-ABL fusion transcript to ABL1 copies (Raw %)
BCR-ABL fusion transcript in copies if present.
ABL1 copy number for specimen adequacy.

For patients with a new diagnosis of CML or ALL, the breakpoint for the BCR-ABL fusion transcript will be reported.

Please use Epic order code LAB7393 for blood specimens, code LAB7773 for bone marrow specimens. The Cerner Code for blood is BCRQNT. The Cerner code for bone marrow is BCRQTBM.

Questions concerning testing can be directed to Aaron Bossler, MD, PhD (ext. 4-9566), Deqin Ma, MD, PhD (ext. 4-5700) or Jonathan Heusel, MD, PhD (ext. 6-8217).