Test Code LAB9762 BCR::ABL1 t(9;22) major (p210) IS, Quantitative
Performing Laboratory
Barnes-Jewish Hospital Laboratory
Methodology
The quantitative BCR::ABL1 assay specific for the p210 isoform is performed on the GeneXpert (Cepheid) platform. RNA is extracted, converted to cDNA, and BCR::ABL1 and ABL1 cDNA targets are quantified by real-time PCR amplification.
The analytical sensitivity of this assay is 0.0032% p210 BCR::ABL1. Due to assay non-linearity for % p210 values >10% or <0.0032%, if p210 is detected, those values will be reported as "Positive, >10%" or “Positive, below the lower level of quantitation”, respectively.
Note: Prior evidence of BCR::ABL1 fusion by FISH or PCR is required for testing. This test is not considered diagnostic and should only be used for monitoring patients known to have the p210 BCR::ABL1 fusion isoform or to identify the isoform following detection of BCR::ABL1 by FISH.
Specimen Requirements
Call Barnes-Jewish Hospital Molecular Diagnostics Laboratory at 314-454-8685 for collection instructions.
Forms: Molecular Diagnostics Requisition
Specimen Type: Whole blood
Container/Tube: Lavender top
Specimen Volume: Full tube
Specimen Minimum Volume: 5 mL
Collection Instructions: Invert several times to mix blood. Clotted blood is not acceptable.
Additional Information:
1. RNA is extremely liable and subject to degradation, delay in shipping may compromise RNA viability and results.
2. Specimen cannot be frozen.
Specimen Type: Bone marrow
Container/Tube: Lavender top (EDTA)
Specimen Volume: 2 mL
Specimen Minimum Volume: 1 mL
Collection Instructions: Invert several times to mix bone marrow. Clotted sample is not acceptable.
Addiontional Information:
1. RNA is extremely liable and subject to degradation, delay in shipping may compromise RNA viability and results.
2. Specimen cannot be frozen.
Day(s) Test Set Up
Monday through Friday
Cut-off time: 1500 on days test performed
Turnaround Time:
STAT: not available
Routine: 1 to 4 business days
Test Classification and CPT Coding
81206
Reference Values
An interpretive report will be provided.
Literature Reference:
Branford S, Fletcher L, Cross N, et al. Desirable performance characteristics for BCR-ABL measurement on an international reporting scale to allow consistent interpretation of individual patient response and comparison of response rate between clinical trials. Blood 2008;113:3330-3338.
White HE, Matejschuk P, Rigsby P, et al. Establishment of the first World Health Organization International Genetic Reference Panel for quantification of BCR-ABL mRNA. Blood 2010;116:e111-117.
Cross, N. Standardisation of molecular monitoring for chronic myeloid leukemia. (2009). Best Practice & Research Clinical Haematology, 22:355.
O’Brien, S.G., Guilhot, F., and Larson, R.A., et al. (2003). Imatinib compared with interferon and low-dose cytarabien for newly diagnosted chronic-phase chronic myeloid leukemia. N Eng J Med, 348:994.
Vigil, C.E., Griffiths, E.A., Wang, E.S., and Wetzler, M. (2011). Interpretation of cytogenetic and molecular results in patients treated for CML. Blood Reviews, 25:139.
Winn-Deen, E., Helton, B., Van Atta, R., et al. (2007). Development of an Integrated Assay for Detection of BCR-ABL RNA. Clinical Chemistry, 53:9
Specimen Transport Temperature
Samples must be sent at ambient or refrigerated temperatures. Do Not send frozen.
Additional Information
For BJH Laboratory Use Only
Analyte Stability:
Blood and bone marrow are stable up to 4 hours at ambient temperature and up to 120 hours refrigerated.
Laboratory Processing Instructions:
Test performed in BJH Molecular Diagnostics