Reconsideration of BCR ‐ ABL protein flow cytometric immunobead assay: how potent to diagnose and monitor chronic myeloid leukemia?

Summary Introduction Chronic myeloid leukemia ( CML ) is typically associated with the Philadelphia chromosome, resulting in the production of BCR ‐ ABL fusion oncoprotein with upregulated tyrosine kinase activity. We aimed to evaluate a new flow cytometric immunobead assay to detect BCR ‐ ABL protein in a group of patients with CML . Methods We enrolled 49 patients with CML , whose qRT ‐ PCR and/or cytogenetic analysis of Philadelphia chromosome aberration was available, including tyrosine kinase inhibitors ( TKI s)‐naïve and ( TKI s)‐treated patients with various levels of response. Twenty Philadelphia‐negative healthy individuals were also enrolled to obtain analytical negative controls. Peripheral blood samples were analyzed for BCR ‐ ABL fusion protein by flow cytometry. Results The BCR ‐ ABL fusion protein flow cytometric assay seemed efficacious to both diagnose the presence ( P ‐value <0.0001) and distinguish the levels ( P ‐value = 0) of the Philadelphia chromosome aberration. Groups of TKI ‐naïve and TKI ‐treated patients as well as levels of molecular/cytogenetic response to TKI ‐therapy were effectively discriminated ( P ‐value <0.01). The receiver operating characteristic ( ROC ) curve analysis indicated the diagnostic value of the assay as excellent ( AUC  = 0.95, P ‐value = 0). Conclusions The evaluated BCR ‐ ABL fusion protein assay might be useful for diagnosing and monitoring Philadelphia chromosome aberration.