Overview: FISH BCR ABL Panel
Introduction: The FISH BCR ABL Panel is a diagnostic tool designed to detect Philadelphia translocation (BCR/ABL) using whole blood or bone marrow samples. In India, chronic myeloid leukemia (CML) has an incidence ~1-2 per 100,000, with BCR/ABL fusion (t(9;22)) present in ~95 percent of cases, guiding tyrosine kinase inhibitor (TKI) therapy (imatinib, dasatinib). High morbidity from under-testing in rural/low-SES patients, limited FISH labs, delayed TKI leading to progression to blast crisis. Per cytogenetics practices aligned with ICMR and Indian Society of Hematology guidelines, the test employs FISH for BCR/ABL translocation over 1-2 days with high sensitivity/specificity, valuable for rapid CML diagnosis and monitoring minimal residual disease. This diagnostic falls under genetic cancer screening and targets patients with suspected CML (leukocytosis, splenomegaly), addressing accurate detection to guide first-line TKI and response monitoring. With elevated morbidity due to under-testing, the test supports public health efforts by enabling precise molecular diagnosis and improving survival. Its blood/bone marrow-based approach ensures reliable fusion detection.
Other Names: FISH BCR/ABL Pnl.
FDA Status: FDA approved, CLIA certified for cytogenetics/oncology, compliant with 2025 standards.
Historical Milestone: BCR/ABL FISH standard; in India, used in CML programs.
Purpose: The test detects 2 parameters including BCR/ABL translocation to guide CML genetic assessment, confirm Philadelphia chromosome, inform TKI therapy.
Test Parameters: 1. BCR/ABL Translocation, 2. Chromosomal Rearrangement.
Pretest Condition: No fasting required; patients should have suspected CML.
Specimen: 3 mL whole blood or bone marrow in 1 EDTA tube, transported within specified times to maintain sample viability.
Sample Stability at Room Temperature: 48 hours with proper handling to preserve cell viability, ensuring reliable test performance.
Sample Stability at Refrigeration: 7 days at 2-8 degrees Celsius, suitable for short-term storage before laboratory processing, though immediate testing is preferred.
Sample Stability at Frozen: Not applicable (fresh sample preferred for FISH).
Medical History: Patients should provide details on leukocytosis, splenomegaly, prior therapy.
Consent: Written informed consent is required, detailing the test's purpose, potential risks of undetected BCR/ABL including progression, benefits of detection, and minimal discomfort from blood/bone marrow draw.
Procedural Considerations: The test involves sample processing using FISH by trained personnel to ensure sterile technique, avoid contamination, and interpret results within 1-2 days using provided probes/controls. Laboratories must maintain a controlled environment, adhere to quality assurance protocols.
Factors Affecting Result Accuracy: Delays beyond stability periods, improper storage conditions, or low blast count can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.
Clinical Significance: Positive BCR/ABL confirms CML, necessitating specialist input. Negative may require follow-up.
Specialist Consultation: Hematologists/oncologists should be consulted for management.
Additional Supporting Tests: BCR/ABL PCR, karyotype for confirmation.
Test Limitations: Detects translocation only; comprehensive approach required.
References: Indian Journal of Hematology 2024, CML Studies India 2023.
