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The diagnosis of juvenile myelomonocytic leukaemia (JMML) is based on clinical, laboratory and molecular features but immunophenotyping [multiparametric flow cytometry (MFC)] has not been used routinely. In the present study, we describe the flow cytometric features at diagnosis with special attention to the distribution of monocytic subsets and the relation between MFC and molecular subgroups. MFC was performed with an eight-colour platform based on Euroflow. We studied 33 JMML cases. CD34 + /CD117 + /CD13 + cells >2% was found in 25 cases, and 51·5% presented an aberrant expression of CD7. A decrease of CD34 + /CD19 + /CD10 + cells was seen in eight cases and in four they were absent. The granulocytic population had a decreased side scatter in 29 cases. Bone marrow monocytic precursors were increased in 28 patients, with a decrease in classical monocytes (median 80·7%) and increase in CD16 + (intermediate and non-classical). A more pronounced increase in myeloid CD34 + cells was seen in patients with Neurofibromatosis type 1 (NF1) and tyrosine-protein phosphatase non-receptor type 11 (PTPN11), with aberrant CD7 expression in four of six and 10/12 patients respectively. Thus, JMML shows an immunophenotypic profile similar to myelodysplastic syndromes, and a different monocyte subset distribution when compared with chronic MML. MFC proved to be an important diagnostic tool that can help in differential diagnosis with other clonal diseases with monocytosis., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

Our aim was to evaluate the cost-effectiveness of a minimal lymphocyte subset quantification (LSQ) by flow cytometry as the first screening in children with clinically suspected primary immunodeficiency (PID). Two hundred sixty-eight Brazilian patients (0-21 years old) were studied. They were divided by clinical and phenotypical features into those fulfilling criteria for PID (PID phenotype) according to the 2017 International Union of Immunological Societies (IUIS) classification and those not fulfilling these criteria (non-PID phenotype). We evaluated how many patients had values below the 10th percentile for five lymphocyte subsets in peripheral blood, (suggestive of PID) according to reference values for Brazil, Italy and USA. Three lymphocyte subsets (T CD3/CD4, B CD19 and NK CD16/CD56) had p-value < 0.05 and Odds Ratio (OR) indicating a risk at least two times higher for the diagnosis of a PID phenotype. The application of Kappa coefficient (k) on Brazilian vs Italian and Brazilian vs US data sets resulted in k compatible with strong or excellent level of agreement between the three classification systems. The authors conclude that a number of CD3 + /CD4 + , CD19 + and CD16 + /CD56 + (NK) cells in peripheral blood <10th percentile represented a significant risk for the diagnosis of PID in this cohort. Natural killer (NK) deficiency is quite rare and has a very specific clinical profile. So, the analysis of these cells could be requested only in some cases, saving even more costs. The minimal immunophenotyping, with quantification of T CD4 + , CD19 + and in some cases CD16 + /CD56 + cells, may be a useful tool for the first screening of PID, saving costs, especially in developing countries., (© 2019 APMIS. Published by John Wiley & Sons Ltd.)

Multiparameter flow cytometry is a highly sensitive, fast, and specific diagnostic technology with a wide range of applicability in hematology. Although well-established eight-color immunophenotyping panels are already available, most Brazilian clinical laboratories are equipped with four-color flow cytometer facilities. Based on this fact, the Brazilian Group of Flow Cytometry (Grupo Brasileiro de Citometria de Fluxo, GBCFLUX) for standardization of clinical flow cytometry has proposed an antibody panel designed to allow precise diagnosis and characterization of acute leukemia (AL) within resource-restricted areas. Morphological analysis of bone marrow smears, together with the screening panel, is mandatory for the primary identification of AL. The disease-oriented panels proposed here are divided into three levels of recommendations (mandatory, recommendable, and optional) in order to provide an accurate final diagnosis, as well as allow some degree of flexibility based on available local resources and patient-specific needs. The proposed panels will be subsequently validated in an interlaboratory study to evaluate its effectiveness on the diagnosis and classification of AL. (Assoc editor comm. 2)., (© 2015 International Clinical Cytometry Society.)

Background: Immunophenotyping is a valuable ancillary technique for the differential diagnosis between myelodysplastic syndromes (MDS) with low bone marrow (BM) blast counts and a normal karyotype, and reactive peripheral (PB) cytopenias. Our aim was to search for the most important variables for this purpose. We also analyzed the age variation of BM B-cell precursors (BCP) and its differences in reactive and clonal cytopenias., Methods: Immunophenotypic analyzes were performed in BM of 54 patients with MDS (76% with BM blasts <5%) and 35 cases of reactive cytopenias. Healthy allogeneic BM transplantation donors (n = 41) were used as controls. We used a four-color panel of antibodies analyzing 9 granulocytic, 8 monocytic and 6 CD34(+) cell features., Results: Asynchronous shift to the left in maturing granulocytes and increase in CD16(+) monocytes were also found in reactive PB cytopenias, but the most important aberrancies in MDS were seen in myeloid CD34(+) cells. Decrease in BCP, that is a hallmark of MDS, could also be found in reactive cytopenias, especially in patients >55 years. % BM BCP could be calculated by the formula: (-7.97 × log age) + (4.24 × log % CD34 (+) cells) - (0.22 x nr. alterations CD34 (+) cells) + 0.577. Corrected R(2) = 0.467., Conclusion: Analysis of myelomonocytic precursors and CD34(+) cells was satisfactory for the differential diagnosis between reactive PB cytopenias and MDS. The most specific alterations were found in CD34(+) cells. Comparison of the values obtained with those of normal age-matched controls is recommended., Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1975931809154663.

Background: myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic clonal disorders. So, prognostic variables are important to separate patients with a similar biology and clinical outcome. We compared the importance of risk stratification in primary MDS of IPSS and WPSS with the just described revision of IPSS (IPSS-R), and examined if variables obtained by bone marrow immunophenotyping could add prognostic information to any of the scores., Methods: In this prospective study of 101 cases of primary MDS we compared the relation of patients' overall survival with WHO types, IPSS, IPSS-R, WPSS and phenotypic abnormalities of hematopoietic precursors. We examined aberrancies in myelomonocytic precursors and CD34(+) cells. Patients were censored when receiving chemotherapy or BM transplantation. Survival analysis was made by Cox regressions and stability of the models was examined by bootstrap resampling., Results: MEDIAN AGE: 64 years (15-93). WHO types: 2 cases of 5q- syndrome, 7 of RA, 64 of RCDM and 28 of RAEB. In the univariate Cox analysis, increasing risk category of all scores, degree of anemia, higher percentage of BM blasts, higher number of CD34(+) cells and their myeloid fractions besides increasing number of phenotypic abnormalities detected were significantly associated with a shorter survival. In the multivariate analysis comparing the three scores, IPSS-R was the only independent risk factor. Comparing WPSS with phenotypic variables (CD34(+)/CD13(+) cells, CD34(+)/CD13(-) cells and "total alterations") the score and "CD34(+)/CD13(+) cells" remained in the model. When IPSS was tested together with these phenotypic variables, only "CD34(+)/CD13(+) cells", and "total alterations" remained in the model. Testing IPSS-R with the phenotypic variables studied, only the score and "CD34(+)/CD13(+) cells" entered the model., Conclusions: Immunophenotypic analysis of myelomonocytic progenitors provides additional prognostic information to all clinical scores studied. IPSS-R improved risk stratification in MDS compared to the former scores.

Summary: 5‐Azacitidine has been used before stem cell transplantation in juvenile myelomonocytic leukaemia (JMML) patients. Recently, we have described immunophenotypic features in JMML at diagnosis. Here, our aim was to examine the changes in the immunophenotypic features during azacitidine treatment, correlating it with clinical response. Patients treated with 5‐azacitidine were evaluated at diagnosis and after three and six cycles of medication. Among 32 patients entering the study, 28 patients were examined after three cycles and 25 patients after six. Patients showed a reduction in CD34/CD117+ cells: median 3.35% at diagnosis, 2.8% after three cycles and 1.63% after six. B‐cell progenitors were decreased at diagnosis and decreased after treatment. Monocytes decreased: 11.91% to 6.4% and 4.18% respectively. Complete response was associated with increase in classical monocytes. T lymphocytes, reduced at diagnosis, increased in patients responding to 5‐azacitidine. Immunophenotypic aberrancies including expression of CD7 in myeloid progenitors remained after treatment. This feature was associated with a worse response to treatment, as well as presence of NF1. Immunophenotyping was feasible in all patients. Clinical response was associated with a decrease of myeloid progenitors and monocytes and a rise in T lymphocytes although phenotypic aberrancies persisted. The largest effect was observed after three cycles. [ABSTRACT FROM AUTHOR]

Background: Acute promyelocytic leukemia is a cytogenetically well defined entity. Nevertheless, some features observed at diagnosis are related to a worse outcome of the patients. Methods: In a prospective study, we analyzed peripheral (PB) leukocyte count, immunophenotype, methylation status of CDKN2B, CDKN2A and TP73; FLT3 and NPM1 mutations besides nuclear chromatin texture characteristics of the leukemic cells. We also examined the relation of these features with patient's outcome. Results: Among 19 cases, 4 had a microgranular morphology, 7 presented PB leukocytes >10x109/l, 2 had FLT3-ITD and 3 had FLT3-TKD (all three presenting a methylated CDKN2B). NPM1 mutation was not observed. PB leukocyte count showed an inverse relation with standard deviation of gray levels, contrast, cluster prominence, and chromatin fractal dimension (FD). Cases with FLT3-ITD presented a microgranular morphology, PB leukocytosis and expression of HLA-DR, CD34 and CD11b. Concerning nuclear chromatin texture variables, these cases had a lower entropy, contrast, cluster prominence and FD, but higher local homogeneity, and R245, in keeping with more homogeneously distributed chromatin. In the univariate Cox analysis, a higher leukocyte count, FLT3-ITD mutation, microgranular morphology, methylation of CDKN2B, besides a higher local homogeneity of nuclear chromatin, a lower chromatin entropy and FD were associated to a worse outcome. All these features lost significance when the cases were stratified for FLT3-ITD mutation. Methylation status of CDNK2A and TP73 showed no relation to patient's survival. Conclusion: in APL, patients with FLT3-ITD mutation show different clinical characteristics and have blasts with a more homogeneous chromatin texture. Texture analysis demonstrated that FLTD-ITD was accompanied not only by different cytoplasmic features, but also by a change in chromatin structure in routine cytologic preparations. Yet we were not able to detect chromatin changes by nuclear texture analysis of patients with the FTLD-TKD or methylation of specific genes. [ABSTRACT FROM AUTHOR]