Background: B-lymphoblastic leukemia (B-ALL) is the most common childhood malignancy, and its diagnosis requires immunophenotypically demonstrating blast B cell lineage differentiation. Expression of myeloperoxidase (MPO) in B-ALL is well-described and it has been recognized that a diagnosis of mixed phenotype acute leukemia should be made cautiously if MPO expression is the sole myeloid feature in these cases. We sought to determine whether MPO expression in pediatric B-ALL was associated with differences in laboratory, immunophenotypic, or clinical features.

Methods: We reviewed clinical, diagnostic bone marrow flow cytometry, and laboratory data for all new B-ALL diagnoses at our pediatric institution in 5 years. Cases were categorized as MPO positive (MPO+) or negative (MPO-) using a threshold of ≥20% blasts expressing MPO at intensity greater than the upper limit of normal lymphocytes on diagnostic bone marrow flow cytometry.

Results: A total of 148 cases were reviewed, 32 of which (22%) were MPO+. MPO+ B-ALL was more frequently hyperdiploid and less frequently harbored ETV6-RUNX1; no MPO+ cases had KMT2A rearrangements or BCR-ABL1. Although not significantly so, MPO+ B-ALL was less likely than MPO- B-ALL to have positive end-of-induction minimal residual disease studies (9.4 and 24%, respectively), but relapse rates and stem cell transplantation rates were similar between groups. Aberrant expression of other more typically myeloid markers was similar between these groups.

Conclusion: In our study cohort, MPO+ B-ALL showed minimal residual disease persistence less often after induction chemotherapy but otherwise had similar clinical outcomes to MPO- B-ALL, with similar rates of additional myeloid antigen aberrancy.

Download full-text PDF

Source
http://dx.doi.org/10.1002/cyto.b.21966DOI Listing

Publication Analysis

Top Keywords

mpo+ b-all
12
b-all
9
expression pediatric
8
b-lymphoblastic leukemia
8
mpo expression
8
diagnostic bone
8
bone marrow
8
marrow flow
8
mpo- b-all
8
minimal residual
8

Similar Publications

Myeloperoxidase (MPO) is the most specific marker of the myeloid lineage, essential for diagnosing acute myeloid leukemia and mixed phenotype acute leukemia with myeloid components. In this regard, we present a unique case of B-acute lymphoblastic leukemia (B-ALL) with isolated MPO expression in bone marrow blasts detected by flow cytometry and immunohistochemistry, while peripheral blood blasts were negative for MPO expression. In this report, our discussion encompasses diagnostic pitfalls from a laboratory testing perspective in similar cases and includes a literature review.

View Article and Find Full Text PDF

In this retrospective cohort study, we evaluated the level of biomarkers of inflammation like phagocyte-related S100 proteins and a panel of cytokines in 128 children with pre-B ALL and 22 with T-ALL. The biomarkers were evaluated at diagnosis and during antileukemic therapy (day 29 and after six months) and we evaluated their correlation with basic laboratory values. Further, for the children with pre-B ALL, we evaluated whether the biomarkers could predict the outcome of ALL expressed as minimal residual disease (MRD), relapse, and death.

View Article and Find Full Text PDF

Introduction: Myeloperoxidase (MPO) is considered a specific marker of myeloid/non-monocytic lineage in the diagnosis of mixed phenotype acute leukemia (MPAL). However, the clinical significance of isolated dim MPO expression in otherwise typical B lymphoblastic leukemia (B-ALL; referred to as B/myeloid MPAL ) in adult patients is unknown.

Methods: We compared flow cytometric immunophenotype and clinicopathological findings among cases of B/myeloid MPAL (n = 13), other MPAL subtypes (n = 10, B/myeloid and T/myeloid MPAL), B-ALL (n = 64), and acute myeloid leukemia (AML, n = 58), using the 2016 WHO classification.

View Article and Find Full Text PDF

Lineage switches in acute leukemia occur rarely, and the underlying mechanisms are poorly understood. Herein, we report the case of an elderly patient with leukemia in which the leukemia started as B-cell acute lymphoblastic leukemia (B-ALL) and later changed to B- and T-cell mixed phenotype acute leukemia (MPAL) and acute myeloid leukemia (AML) during consecutive induction chemotherapy treatments. A 65-year-old woman was initially diagnosed with Philadelphia chromosome-negative B-ALL primarily expressing TdT/CD34/HLA-DR; more than 20% of the blasts were positive for CD19/CD20/cytoplasmic CD79a/cytoplasmic CD22/CD13/CD71.

View Article and Find Full Text PDF

Introduction: Recently, isolated myeloperoxidase expression (isoMPO) has been documented in B-acute lymphoblastic leukemia (B-ALL) and several contradictory studies addressed its clinical significance in pediatric patients.

Aim: In this study, isoMPO was evaluated in bone marrow biopsies (BMB) from adults with B-ALL using immunohistochemistry (IHC) in relation to a number of risk-stratification factors and patients' outcomes.

Methods: Sixty B-ALL adult patients were selected upon electronic database search.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!