Hematologic Diseases

Quantitative real-time polymerase chain reaction (PCR) is used to detect the t(9;22) BCR-ABL1 fusion transcripts that result in major (p210), minor (p190), or micro (p230) fusion proteins. Minimal residual disease monitoring results for the major breakpoint transcripts are reported and graphed on the International Scale (IS). Monitoring results for the minor and micro breakpoints transcripts are reported.

disease state indication(s)
Chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL)

clinical use
The BCR-ABL1 fusion gene is the hallmark finding in BCR-ABL1-positive chronic myelogenous leukemia (CML), but it can also be found in other hematologic neoplasms, including 25-30% of adult B-cell acute lymphoblastic leukemia (B-ALL), 3-5% of pediatric B-ALL, and rarely in acute myeloid leukemia (AML) and T-cell acute lymphoblastic leukemia (T-ALL). The major (p210) breakpoint transcript is the most common type found in CML, but minor (p190) and micro (p230) breakpoint transcripts can also found in rare cases of CML with atypical phenotype features. The minor (p190) breakpoint transcript is associated with increased monocytes, while the micro (p230) breakpoint BCR-ABL transcript is associated with prominent neutrophilic maturation and/or conspicious thrombocytosis. Monitoring treatment response to tyrosine kinase inhibitor (TKI) therapy is crucial in the management of patients with CML to assess response and detect resistance. The National Comprehensive Cancer Network (NCCN) currently recommends monitoring response to TKI therapy by quantitative PCR using the International Scale (IS).

methodology/product platform
Polymerase chain reaction (PCR)

specimen type and requirements
Peripheral blood: 2-3 mL in EDTA (purple-top) tube.
Bone marrow: 2-3 mL in EDTA (purple-top) tube.
Note: Use refrigerated cold pack for transport. Make sure cold pack is not in direct contact with specimen.

turnaround time
Global (TC & PC): 4 days

cpt code(s)
81206 (xN) major breakpoints
81207 (xN) minor breakpoints
81208 (xN) other breakpoints

medicare moldx cpt code
81479 (x1)

regulatory classification
Laboratory developed test (LDT)

ordering option
Global (TC & PC)