Subclassification of B-acute lymphoblastic leukemia according to age, immunophenotype and microenvironment, predicts MRD risk in Mexican children from vulnerable regions.

Introduction: The decisive key to disease-free survival in B-cell precursor acute lymphoblastic leukemia in children, is the combination of diagnostic timeliness and treatment efficacy, guided by accurate patient risk stratification. Implementation of standardized and high-precision diagnostic/prognostic systems is particularly important in the most marginalized geographic areas in Mexico, where high numbers of the pediatric population resides and the highest relapse and early death rates due to acute leukemias are recorded even in those cases diagnosed as standard risk. Methods: By using a multidimensional and integrated analysis of the immunophenotype of leukemic cells, the immunological context and the tumor microenvironment, this study aim to capture the snapshot of acute leukemia at disease debut of a cohort of Mexican children from vulnerable regions in Puebla, Oaxaca and Tlaxcala and its potential use in risk stratification. Results and discussion: Our findings highlight the existence of a distinct profile of ProB-ALL in children older than 10 years, which is associated with a six-fold increase in the risk of developing measurable residual disease (MRD). Along with the absence of CD34+ seminal cells for normal hematopoiesis, this ProB-ALL subtype exhibited several characteristics related to poor prognosis, including the high expression level of myeloid lineage markers such as MPO and CD33, as well as upregulation of CD19, CD34, CD24, CD20 and nuTdT. In contrast, it showed a trend towards decreased expression of CD9, CD81, CD123, CD13, CD15 and CD21. Of note, the mesenchymal stromal cell compartment constituting their leukemic niche in the bone marrow, displayed characteristics of potential suppressive microenvironment, such as the expression of Gal9 and IDO1, and the absence of the chemokine CXCL11. Accordingly, adaptive immunity components were poorly represented. Taken together, our results suggest, for the first time, that a biologically distinct subtype of ProB-ALL emerges in vulnerable adolescents, with a high risk of developing MRD. Rigorous research on potential enhancing factors, environmental or lifestyle, is crucial for its detection and prevention. The use of the reported profile for early risk stratification is suggested.

Consensus in acute myeloid leukemia in Mexico.

Acute myeloid leukemia (AML) comprises a heterogeneous group of hematopoietic cell neoplasms of myeloid lineage that arise from the clonal expansion of their precursors in the bone marrow, interfering with cell differentiation, leading to a syndrome of bone marrow failure. AML is a consequence of genetic and epigenetic changes (point mutations, gene rearrangements, deletions, amplifications, and arrangements in epigenetic changes that influence gene expression) in hematopoietic precursor cells, which create a clone of abnormal cells that are capable of proliferating but cannot differentiate into mature hematopoietic cells or undergo programmed cell death. The diagnosis requires more than 20% myeloid blasts in the bone marrow and certain cytogenic abnormalities. Treatment will depend on age, comorbidities, and cytogenetic risk among the most frequent.

La leucemia mieloide aguda (LMA) comprende un grupo heterogéneo de neoplasias de células hematopoyéticas de linaje mieloide que surgen de la expansión clonal de sus precursores en la médula ósea, interfiriendo con la diferenciación celular, lo que conlleva a un síndrome de falla medular. La LMA es una consecuencia de cambios genéticos y epigenéticos (mutaciones puntuales, rearreglos de genes, deleciones, amplificaciones y arreglos en cambios epigenéticos que influyen en la expression del gen) en las células hematopoyéticas precursoras, la cual crea una clona de células anormales que son capaces de proliferar, pero no se pueden diferenciar en células hematopoyéticas maduras ni sufrir una muerte celular programada. El diagnostic requiere más del 20% de blastos mieloides en médula ósea y ciertas anormalidades citogénicas. El tratamiento dependerá de la edad, comorbilidades, riesgo citogenético entre las más frecuentes.

Consenso de leucemia mieloide aguda en México / Mexican consensus in acute myeloid leukemia in Mexico

resumen está disponible en el texto completo

Abstract Acute myeloid leukemia (AML) comprises a heterogeneous group of hematopoietic cell neoplasms of myeloid lineage that arise from the clonal expansion of their precursors in the bone marrow, interfering with cell differentiation, leading to a syndrome of bone marrow failure. AML is a consequence of genetic and epigenetic changes (point mutations, gene rearrangements, deletions, amplifications, and arrangements in epigenetic changes that influence gene expression) in hematopoietic precursor cells, which create a clone of abnormal cells that are capable of proliferating but cannot differentiate into mature hematopoietic cells or undergo programmed cell death. The diagnosis requires more than 20% myeloid blasts in the bone marrow and certain cytogenic abnormalities. Treatment will depend on age, comorbidities, and cytogenetic risk among the most frequent.