Test Code LAB9762 BCR::ABL1 t(9;22) major (p210) IS, Quantitative
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.
Performing Laboratory
Barnes-Jewish Hospital Laboratory
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.
Specimen Transport Temperature
Samples must be sent at ambient or refrigerated temperatures. Do Not send frozen.
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
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
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