BCR-ABL1 Transcript Detection for Chronic Myelogenous Leukemia (CML) and Acute Lymphocytic Leukemia (ALL), Quantitative

Whole blood, bone marrow, or cell pellet

3 to 5 mL whole blood or 1 to 2 mL bone marrow

1 mL bone marrow or 3 mL whole blood (Note: This volume does not allow for repeat testing.)

Lavender-top (EDTA) tube, green-top (sodium heparin) tube, yellow-top (ACD-A) tube, tan-top (K2-EDTA) tube or pink-top (K2-EDTA) tube

This assay can detect three different types of BCR-ABL1 fusion transcripts associated with CML, ALL, and AML:e13a2 (previously b2a2) and e14a2 (previously b3a2) (major breakpoint, p210), as well as e1a2 (minor breakpoint, p190). The e13a2 and e14a2 transcript values are titrated to the current International Scale (IS). The standardized baseline is 100% BCR-ABL1 (IS) and major molecular response (MMR) is equivalent to 0.1% BCR-ABL1 (IS) corresponding to a 3-log reduction. Results should be correlated with appropriate clinical and laboratory information as indicated.

In vitro studies have indicated that this assay has an analytical detection sensitivity of 4.5 log below the standard baseline (<0.0032%). A negative result does not rule out the presence of low levels of BCR-ABL1 transcript below the level of detection of this assay, or the presence of rare BCR-ABL1 transcripts not detected by the assay.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Total RNA is isolated from the sample and subject to a real-time, reverse transcriptase polymerase chain reaction (RT-PCR). The PCR primers and probes are specific for BCR-ABL1 e13a2, e14a2 and e1a2 fusion transcripts. The ABL1 transcript is amplified as the control for cDNA quantity and quality. Serial dilutions of a validated positive control RNA with known t(9;22) BCR-ABL1 are used as reference for quantification of BCR-ABL1 relative to ABL1. The numeric BCR-ABL1 level is reported as % BCR-ABL1/ABL1 and the detection sensitivity is 4.5 log below the standard baseline (<0.0032%).