BCR/ABL - PHILADELPHIA CHROMOSOME (IS - INTERNATIONAL SCALE) QUANTITATIVE

BCR/ABL - Philadelphia Chromosome (IS - International Scale) Quantitative is an advanced molecular biology test used to detect and measure the amount of BCR-ABL fusion gene transcripts in blood or bone marrow samples. The test is performed using highly sensitive real-time quantitative PCR technology and reports results according to the International Scale (IS), allowing standardized monitoring of treatment response in patients with Chronic Myeloid Leukemia (CML) and other Philadelphia chromosome-positive leukemias.

The Philadelphia chromosome is a genetic abnormality formed by a translocation between chromosomes 9 and 22, resulting in the BCR-ABL fusion gene. This abnormal gene produces an uncontrolled tyrosine kinase protein that drives the development of leukemia. Quantitative monitoring of BCR-ABL levels plays a critical role in diagnosis, treatment planning, and long-term disease management.

Benefits of the Test

• Accurately quantifies BCR-ABL fusion gene transcripts.
• Supports diagnosis of Philadelphia chromosome-positive leukemias.
• Monitors response to targeted therapy.
• Provides standardized International Scale (IS) reporting.
• Detects minimal residual disease (MRD).
• Assists in treatment adjustment decisions.
• Helps assess disease progression or relapse.
• Supports long-term leukemia management.

Why Doctors Recommend This Test

Doctors recommend this test for patients diagnosed with Chronic Myeloid Leukemia (CML), Philadelphia chromosome-positive Acute Lymphoblastic Leukemia (Ph+ ALL), or other BCR-ABL-positive hematological malignancies. The test is essential for monitoring treatment effectiveness, evaluating molecular response, detecting residual disease, and identifying disease recurrence.

Regular quantitative monitoring allows healthcare providers to assess whether targeted therapies such as tyrosine kinase inhibitors are working effectively.

Preparation Before Test

• No fasting is generally required.
• A blood sample or bone marrow specimen may be collected.
• Inform your doctor about ongoing leukemia treatment.
• Provide previous BCR-ABL test reports if available.
• Follow all sample collection instructions provided by healthcare professionals.
• Ensure timely transportation of the specimen to the laboratory.

Normal Reporting Time

Most BCR/ABL - Philadelphia Chromosome (IS - International Scale) Quantitative reports at Focus Diagnostics are available within 2–3 hours for sample processing and molecular workflow initiation. Final quantitative PCR results are generally available within a few working days depending on laboratory procedures and quality control requirements.

Who Should Take This Test?

This test may be recommended for:

• Patients diagnosed with Chronic Myeloid Leukemia (CML).
• Individuals with Philadelphia chromosome-positive leukemia.
• Patients receiving tyrosine kinase inhibitor therapy.
• Individuals requiring molecular response monitoring.
• Patients undergoing leukemia follow-up evaluation.
• People at risk of disease recurrence.
• Patients requiring minimal residual disease assessment.
• Individuals undergoing long-term leukemia management.

Detailed Information

The Philadelphia chromosome is one of the most important genetic abnormalities in hematologic oncology. It results from a reciprocal translocation between chromosomes 9 and 22, designated as t(9;22)(q34;q11). This chromosomal rearrangement creates the BCR-ABL fusion gene, which encodes an abnormal tyrosine kinase protein that continuously stimulates uncontrolled growth and proliferation of white blood cells.

BCR-ABL is present in the vast majority of patients with Chronic Myeloid Leukemia (CML) and in a subset of patients with Acute Lymphoblastic Leukemia (ALL). Detection and quantification of this molecular marker have transformed leukemia diagnosis and management, particularly with the introduction of targeted therapies such as tyrosine kinase inhibitors (TKIs).

BCR/ABL - Philadelphia Chromosome (IS - International Scale) Quantitative testing utilizes real-time quantitative Polymerase Chain Reaction (RT-qPCR) technology to measure the amount of BCR-ABL transcript present in a patient's sample. The International Scale (IS) standardization allows consistent comparison of results across different laboratories and treatment centers worldwide.

Serial monitoring of BCR-ABL levels is essential for evaluating treatment response. A decreasing transcript level generally indicates effective therapy, while rising levels may suggest treatment resistance, disease progression, or relapse. The test is also highly valuable for detecting minimal residual disease (MRD), even when no leukemia cells are visible under a microscope.

Current clinical guidelines recommend regular BCR-ABL monitoring at defined intervals during treatment. Results help physicians determine whether patients are achieving optimal molecular milestones and whether modifications to therapy may be required.

Because treatment decisions in CML are heavily dependent on molecular response measurements, accurate and standardized testing is critical for achieving the best possible clinical outcomes. The International Scale has become the global standard for reporting BCR-ABL quantitative results.

At Focus Diagnostics, BCR/ABL - Philadelphia Chromosome (IS - International Scale) Quantitative testing is performed using advanced molecular diagnostic platforms, highly sensitive real-time PCR technology, and stringent quality assurance protocols to provide accurate, reliable, and clinically meaningful leukemia monitoring results.