Altered neutrophil immunophenotypes in childhood B-cell precursor acute lymphoblastic leukemia

An increasing number of evidences suggest a genetic predisposition in acute lymphoblastic leukemia (ALL) that might favor the occurrence of the driver genetic alterations. Such genetic background might also translate into phenotypic alterations of residual hematopoietic cells. Whether such phenotypic alterations are present in bone marrow (BM) cells from childhood B-cell precursor (BCP)-ALL remains to be investigated. Here we analyzed the immunophenotypic profile of BM and peripheral blood (PB) maturing/matured neutrophils from 118 children with BCP-ALL and their relationship with the features of the disease. Our results showed altered neutrophil phenotypes in most (77%) BCP-ALL cases. The most frequently altered marker was CD10 (53%), followed by CD33 (34%), CD13 (15%), CD15/CD65 (10%) and CD123 (7%). Of note, patients with altered neutrophil phenotypes had younger age (p = 0.03) and lower percentages of BM maturing neutrophils (p = 0.004) together with greater BM lymphocyte (p = 0.04), and mature B-cell (p = 0.03) counts. No significant association was found between an altered neutrophil phenotype and other disease features. These findings point out the potential existence of an altered residual hematopoiesis in most childhood BCP-ALL cases.This work was supported by the following grants: Bilateral Cooperation Program between Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES (Brasília/Brazil) and Dirección General de Políticas Universitárias – Ministério de Educación, Cultura y Deportes - DPGU (Madrid/Spain) (311/15) and RD12/0036/0048 from RETICS, (Instituto de Salud Carlos III, Ministerio de Economia y Competitividad, Madrid, Spain and Fondos FEDER); Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro of Brazil (E26/110.105/2014; E26/102.191/2013); Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPQ of Brazil (400194/2014–7). EO and DNRG were both supported by grants from CAPES (Brazil). NLD was partly supported by a grant from CNPQ (Brazil). TS and LS were supported by the internal grants from the Medical University of Silesia (Katowice, Poland).Peer Reviewe