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Normal B lymphoid maturation occurs in bone marrow (BM) throughout life, but immature B‐cell progenitors (BCPs) are more numerous in children than in adults. To assess the normal values according to age became important as BCPs are decreased in myelodysplastic syndromes and have been considered an important diagnostic and prognostic feature in these clonal disorders. in a multicenter retrospective study from the Brazilian Group of Flow Cytometry we analyzed the variation of BCPs in normal BM according to age and technical peculiarities of each laboratory. We analysed of 45 BM donors and 89 cases examined for elucidation of transitory reactive cytopenias presenting a normal BM immunophenotyping. BCPs were enumerated as CD19+/CD34+/CD45dim/CD10+cells (panel 1) or CD19+/CD34+/CD45dimcells (panel 2) among the total nucleated non‐erythroid cells and as percentage of CD34+cells. we included 134 cases. Panel 1 was applied in 88 cases and panel 2 was used in 46. Age range: 10 months to 89 years. In a multiple regression, % BCPs/total nucleated cells was an exponential function of age. Age explained alone 49.4% of the variance, while ‘panel used’ explained 1.8% and ‘laboratory’ explained 0.7%. Age explained only 24.9% of the variance of BCPs/CD34+cells. in normal individuals, BM B‐cell precursors varied mainly according to age, but were also dependent on technical peculiarities of operators and equipments. Analysis by phenotype and as percentage of total nucleated cells was more accurate and less susceptible to variation than evaluating % BCPs/total CD34+cells. © 2017 International Clinical Cytometry Society

Multiparametric flow cytometry (MFC) is a powerful tool for the diagnosis of hematological malignancies and has been useful for the classification of chronic lymphoproliferative disorders (CLPD) according to the WHO criteria. Following the purposes of the Brazilian Group of Flow Cytometry (GBCFLUX), the aim of this report was to standardize the minimum requirements to achieve an accurate diagnosis in CLPDs, considering the different economic possibilities of the laboratories in our country. Most laboratories in Brazil work with 4‐fluorescence flow cytometers, which is why the GBCFLUX CLPD Committee has proposed 4‐color monoclonal antibody (MoAb) panels. Panels for screening and diagnosis in B, T and NK lymphoproliferative disorders were developed based on the normal differentiation pathways of these cells and the most frequent phenotypic aberrations. Important markers for prognosis and for minimal residual disease (MRD) evaluation were also included. The MoAb panels presented here were designed based on the diagnostic expertise of the participating laboratories and an extensive literature review. The 4‐color panels presented to aid in the diagnosis of lymphoproliferative neoplasms by GBCFLUX aim to provide clinical laboratories with a systematic, step‐wise, cost‐effective, and reproducible approach to obtain an accurate immunophenotypic diagnosis of the most frequent of these disorders. © 2016 International Clinical Cytometry Society

HIV infection is associated with numerous abnormalities affecting both the myeloid and lymphoid lineages. We studied the features associated with peripheral cytopenias as the first sign of HIV infection in children. Peripheral blood (PB) counts, PB and bone marrow (BM) lymphocyte subsets, as well as viral load and serum levels of ferritin, vitamin B12, and folic acid were determined. Five children were naïve of treatment (Group 1) and three were under HAART (Group 2). In Group 1 all patients had anemia of chronic disease. One had a bone marrow culture positive for Mycobacterium avium intracellulare and pancytopenia. Besides this, neutropenia and thrombocytopenia were seen in one patient each. In Group 2 anemia was found in all, neutropenia in one, and thrombocytopenia in two patients. Peripheral blood cytopenias were due to HAART toxicity in one patient. In the other two they were due to iron or folate deficiency. Bone marrow cytology showed cell abnormalities mainly in granulocytic precursors and megakaryocytes. All except two (taking HAART) patients had a high viral load. There was a straight correlation between viral load in PB and bone marrow. Viral load was correlated with peripheral CD4 but not with CD8 lymphocytes. A decrease in bone marrow B lymphocytes was seen in all patients. The introduction of HAART improved peripheral cytopenias. Bone marrow examination was useful for determining the etiology of the cytopenias and for detection of opportunistic infection. Hemopoietic cell abnormalities were similar to those seen in adults and indicative of HIV infection.

The nitric oxide synthase (NOS) inhibitor, Nω‐nitro‐L‐arginine methyl ester (L‐NAME), inhibits both rat and human eosinophil chemotaxis in vitro. Here, the role of nitric oxide (NO) in human eosinophil cell surface integrin expression and function was investigated.Human peripheral blood eosinophils were treated with L‐NAME (0.01 – 1.0 mM) and their adhesion to human fibronectin and serum observed. Adhesion of cells to fibronectin and serum increased by 24.0±4.6 and 43.8±4.7%, respectively, when eosinophils were treated with 1.0 mML‐NAME. Increased adhesion by L‐NAME could be abolished when cells were co‐incubated with VLA‐4‐ and Mac‐1‐specific monoclonal antibodies (mAbs).The NO donor, sodium nitroprusside (2.5 mM), significantly inhibited eosinophil adhesion to fibronectin and serum by 34.3±4.5 and 45.2±5.6%, respectively. This inhibition was accompanied by a 4 fold increase in the levels of intracellular cyclic GMP.Flow cytometrical analysis demonstrated that L‐NAME induced an increased expression of CD11b (Mac‐1) on the eosinophil cell surface of 36.3±7.4%. L‐NAME had no effect upon CD49d (VLA‐4) expression.Treatment of human eosinophils, in vitro, with H‐[1,2,4] oxadiazolo quinoxalin‐1‐one (ODQ) (0.1 mM), an inhibitor of soluble guanylate cyclase, also significantly increased eosinophil adhesion to fibronectin and serum by 73.5±17.9 and 91.7±12.9%, respectively. This increase in adhesion could also be inhibited by co‐incubation with the Mac‐1 and VLA‐4‐specific mAbs.In conclusion, results indicate that NO, viaa cyclic GMP‐dependent mechanism, inhibits the adhesion of human eosinophils to the extracellular matrix (ECM). This inhibition is accompanied by a decrease in the expression and function of the eosinophil's adhesion molecules, in particular, the expression of the Mac‐1 integrin and the function of the VLA‐4 integrin.

AIM: Magnetic resonance imaging (MRI) of the femora was used to investigate the marrow cellularity during the evolution of non-transplanted aplastic anaemia (AA) and hypocellular myelodysplastic syndrome (h-MDS) in order to investigate the relationship between this cellularity and disease progression.

The aim of the present study was to analyze the nucleolar organizer region (AgNOR) pattern of granulopoietic precursors in chronic myeloid leukemia (CML) at diagnosis and during the course of the disease. Clusters of AgNORs and isolated dots were counted separately in 24 cases of CML at diagnosis, in 19 cases during the relapse of the chronic phase after treatment, and in 16 cases of blast crisis. For comparison, 20 cases of normal bone marrow were studied. Each cell type had its own characteristic AgNOR pattern, as has been described for normal bone marrow. There was no significant difference in the number of AgNORs between cells in the peripheral blood and bone marrow. Compared with normal granulopoiesis, myeloblasts in CML at diagnosis had lower numbers of clusters, which decreased further during relapse of chronic phase and in blast crisis. Promyelocytes and myelocytes showed significantly fewer dots. The number of AgNOR clusters correlates inversely with the duration of the cell cycle. Therefore, these findings are consistent with the progressive loss in proliferative activity of immature precursors described during the course of CML. As the number of dots indicates cellular maturation, their lower number in promyelocytes and myelocytes in CML favors the concept of a discordant maturation process described in this desease. The separate counting of clusters and dots provides a useful, simple, and cheap method of describing cytokinetic changes during the course of this myeloproliferative

Abstract:  Prolymphocytic leukemia (PLL) is a rare lymphoproliferative disorder that takes a rapidly progressive course and where therapeutic interventions are often unsuccessful. In this context, the new purine analogs may be a promising option. We report two cases of PLL treated with cladribine. The first patient had been resistant to polychemotherapy (COP) but responded well to two courses of 2-CdA. He achieved a partial remission, which he maintained for 15 months. The second patient had very advanced disease but obtained a partial response after three courses of 2-CdA, given as a first-line therapy in an ambulatory setting. These results, as well others reported in the literature, permit us to consider 2-CdA as a highly promising therapeutic option for PLL.