Multicolor flow cytometry immunophenotyping and characterization of aneuploidy in pediatric B-cell precursor acute lymphoblastic leukemia

Abstract

the aim of this study was to assess the incidence of dna aneuploidy in Polish children with B-cell precursor acute lymphoblastic leukemia (BcP-all) and the relationship between aneuploidy and immunological phenotype, age, leukocyte count, s-phase fraction (sPF) and early response to induction chemotherapy assessed by the percentage of residual blast cells in bone marrow aspirates. the study group consisted of 267 patients. dna content and immunophenotype were assessed in the bone marrow before treatment using multicolor flow cytometry (Fc). dna aneuploidy was detected in 50/267 (19%) patients. high hyperdiploidy was found to be associated with lower leukocyte count (p = 0.006) and common all immunophenotype. Flow cytometry analysis revealed that high hyperdiploid BcP-all patients showed significantly higher expression of cd9, cd20, cd22, cd58, cd66c, cd86 and cd123 antigens as compared to other groups of ploidy. in contrast, cd45 showed decreased expression. the percentage of leukemic blasts at diagnosis was lower in high hyperdiploid BcP-all cases than in diploid (79% vs. 85.7%, p = 0.001). the difference in minimal residual disease (Mrd) levels on day 15 and 33 of induction therapy between analyzed groups was not significant.this study showed that high hyperdiploidy is associated with lower wBc count and specific immunological phenotype. Flow cytometric evaluation of expression of selected antigens can be used for fast identification of markers of aneuploidy in pediatric BcP-all, before genetic tests results are available. understanding the biological significance of aneuploidy in leukemia can potentially be exploited therapeutically using targeted therapies against specific blast cell subclones.

Immunophenotypic portrait of leukemia‐associated‐phenotype markers in B acute lymphoblastic leukemia

“…When comparing the different WHO subgroups of B ALL patients with recurrent cytogenetic abnormalities (see Figure S3B), we observed a significant higher expression of CD9 at the surface of hyperdiploid B lymphoblasts in comparison with other subgroups of recurrent cytogenetic alterations (Figure 1b, p = 0.0032), confirming the results obtained by Pierzyna‐Switala et al (2021). We also observed a significant lower expression of CD9 at the surface of B lymphoblasts with a t(9;22)(BCR‐ABL) in comparison with hyperdiploid B lymphoblasts and with B lymphoblasts without any recurrent cytogenetic alteration (Figure 1b, p = 0.0020 and p = 0.0317, respectively).…”

“…When comparing the different WHO subgroups of B ALL patients with recurrent cytogenetic abnormalities (see Figure S4C), we observed a significant overexpression of CD58 in cases with hyperdiploidy ( p = 0.0007, Figure S4D), as already known in the literature (Pierzyna‐Switala et al, 2021). In addition, we also observed an overexpression of this marker in cases with t(1;19) when compared with B lymphoblasts with other recurrent cytogenetic abnormalities ( p = 0.0300), or without any recurrent alteration ( p = 0.0002, Figure 3), an observation that needs to be confirmed in others cohorts with a larger number of patients.…”

Common Genetic Abnormalities and Phenotypic Scoring in Saudi Patients with Acute B-Lymphoblastic Leukemia

“…have been studied previously as discriminative markers for the HD group. 17 . Overexpression of CD123 was recently correlated to HD, but this marker did not prove to have valuable expression in our cohort.…”

Flow Cytometric Ploidy Analysis in Acute Lymphoblastic Leukemia and Plasma Cell Myeloma

“…11,36 However, further literature regarding the relevance of SPF in pediatric patients with ALL is sparse and has not claimed any prognostic relevance. 18,37,38 Due to the emergence of more robust risk assessment modalities, SPF is no longer used as a prognostic tool in any present-day pediatric ALL treatment protocols.…”