Assessment of minimal residual disease in patients with B-cell acute lymphoblastic leukemia using EuroFlow: Relation to other prognostic factors

Purpose: Presence of post-therapeutic leukemia cells in the bone marrow is defined as minimal residual disease (MRD) in acute lymphoblastic leukemia. Purpose of monitoring MRD is to determine the response to treatment and the risk of leukemia relapses. Materials and methods: This is a retrospective study of 66 B-cell acute lymphoblastic leukemia patients treated at King Fahad Specialist Hospital-Dammam from November 2018 to December 2020. We tested MRD results on day-29 of treatment from bone marrow aspiration and correlated the relationship of MRD found to other prognostic factors such as patient age, gender, hematological parameters at diagnosis such as white blood count (WBC), hemoglobin level, absolute neutrophil count, platelets, percent blast cell in the bone marrow and blast cell in peripheral blood at diagnosis, aberrant markers of immunophenotype of blasts at diagnosis, and cytogenetic abnormalities. Results: On day 29, a significant correlation between WBC and MRD status was discovered. Also, a significant correlation between peripheral blood blast percentage and MRD status was determined on day 29. Also, hemoglobin, neutrophils, and platelets are not significantly associated with MRD status. Similarly, cytogenetic variables and risk stratification are not significantly associated with MRD status. Furthermore, CDw65+ and CD15+ are the only aberrant markers significantly associated with MRD status, even though they are not commonly expressed in patients. Conclusion: CD22, TdT, cyCD79a, CD81, and CD9 were other immunophenotype markers expressed by most participants. Hyperdiploidy was the most common karyotype.