A 3-year-old girl is confirmed to have ALL by immunophenotyping.The patient is positive for the CALLA antigen.Cytogenetic analysis results indicate the presence of the Philadelphia chromosome.What does this mean for the patient?

Question

Quizplus · Accepted Answer

The presence of the Philadelphia chromosome is associated with poor prognosis in patients with ALL. This abnormality is caused by a translocation involving chromosomes 9 and 22, leading to the formation of a BCR-ABL fusion gene. The BCR-ABL protein has constitutive tyrosine kinase activity, promoting uncontrolled cell proliferation, survival, and resistance to therapy. While the use of tyrosine kinase inhibitors (TKIs) has significantly improved outcomes in patients with Philadelphia-positive ALL, the presence of this genetic abnormality still carries a worse prognosis than Philadelphia-negative disease. The CALLA (CD10) antigen is commonly expressed in ALL, especially in precursor B-cell ALL (which is the most common subtype in children), and is used in immunophenotyping to help identify the specific lineage and stage of the disease.

A 3-Year-Old Girl Is Confirmed to Have ALL by Immunophenotyping