Contribution of Molecular Biology in the Diagnosis and Follow-Up of Chronic Myeloid Leukemia

Abstract

Background: The advent of tyrosine kinase inhibitors and the evolution of molecular biology techniques have revolutionized the management and outcome of patients with chronic myeloid leukemia, it is currently considered a model of carcinogenesis and successful targeted therapy. Methods: Our study was retrospective, descriptive and observational, carried out within the hematology laboratory of the Avicenna Military Hospital in Marrakech, spread over a period of 6 years and included a total of 10 patients from the department of clinical hematology. The aim of our study was to highlight the impact of molecular biology, in particular the GeneXpert technique, on the diagnosis and monitoring of Chronic myeloid leukemia (CML), and to discuss afterwards the different techniques as well as their contribution. Results: Regarding the diagnostic data; all of our patients underwent a complete blood count, myelogram, and bone marrow karyotype. The complete blood count (CBC) showed leukocytosis in 100% of cases, thrombocytosis and anemia in 80% of cases. The myelogram showed a medullary blastosis with a rate <10% in 90% of the cases, thus classifying them in the chronic phase. At karyotype, all patients had the translocation (9; 22). Concerning molecular biology, quantification of the BCR-ABL transcript by GeneXpert was performed in 60% of patients, only 20% of cases benefited from both the quantitative study by GeneXpert and the qualitative study by multiplex PCR. During treatment, 80% of our patients were put on hydroxyurea pending confirmation of the diagnosis. Later on, all of our patients were treated with first-line imatinib, of which 3 (30%) had treatment failure requiring to be put on second-linenilotinib. Of these, 2 were treated with third-line dasatinib. GeneXpert was used for follow-up, a major molecular response (MMR) was achieved in 70% of the cases with an average delay of 9 months. The profiling of patients who obtained an MMR showed a male predominance ...........