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The article presents several case studies related to flow Cytometry-based Detection of B-cell Lymphoproliferative Disorders in Patients with Mycosis Fungoides. Topics discussed a 61-year-old man was referred for evaluation of a non-pruritic rash that initially involved abdomen and later progressed to the back and limbs, and 59-year-old woman presented with a pruritic rash distributed over lateral aspects of her back and axilla with findings compatible with early-stage MF histopathologically.

Abstract: Automated morphological assessment of peripheral blood slides has become an important modality facilitating characterization and quantification of cells in a uniform, fast and robust manner. In this study, we evaluated the morphological diversity in peripheral blood films of 94 chronic lymphocytic leukemia (CLL) patients using the DM1200 CellaVision automated microscopy system. Aberrant lymphocytes and smudge cells were enumerated and correlated with CLL immunophenotype, chromosomal aberrations and prognostic parameters. Herein, we show that the percentages of aberrant and smudge cells was highly variable between patients and did not correlate with each other. Increased aberrant lymphocytes and fewer smudge cells were associated with an atypical immunophenotype including low expression of CD23, higher levels of FMC7 and bright surface levels of CD20. High fraction of aberrant lymphocytes also was associated with trisomy 12. These cells were predominantly of small/medium size, sometimes with cleft nuclei. No correlation was noted between aberrant or smudge cells and clinical stage, CD38, ZA70 or time to first treatment. Taken together, automated morphological analysis of peripheral blood leukocytes emerged as a powerful and robust tool for the quantitative morphological stratification of CLL. Integration of the automated morphological features discriminates between different CLL phenotypes and distinct chromosomal aberrations. [Copyright &y& Elsevier]

Abstract: Peripheral absolute monocyte count (AMC) has been reported to correlate with clinical outcome in different types of cancers. This association may relate to alteration in circulating monocytic subpopulations and tumor infiltrating macrophages. In this study we evaluated the clinical significance of peripheral AMC in 80 treatment naive patients with CLL. Measurement of AMC was based on direct morphological enumeration, due to our findings that complete blood count data may yield incorrect monocytes enumeration values in CLL. The median AMC in patients with CLL was within normal limits, however the AMC range exceeded the values of healthy individuals. The AMC trichotomized patients into 3 distinct sub-groups with different characteristics and outcomes. High AMC patients were younger and had higher absolute lymphocytes count, while patients with low AMC had prominent immune dysregulation (lower serum IgA levels, susceptibility to infections and a tendency for positive direct anti-globulin test). The low and high AMC patients had a shorter time to treatment compared to the intermediates AMC subgroups, whereas low AMC was associated with increased mortality caused by infectious complications. In conclusion, AMC quantification during the disease course classifies CLL patients into subgroups with unique clinical features and outcomes. [Copyright &y& Elsevier]

Emerging data on intraclonal diversity imply that this phenomenon may play a role in the clinical outcome of patients with chronic lymphocytic leukemia (CLL), where subsets of the CLL clone responding more robustly to external stimuli may gain a growth and survival advantage. In this study, we report intraclonal diversity resolved by responses to CD 19 engagement in CLL cells, which can be classified into CD19-responsive (CD19-R) and -nonresponive subpopulations. Engagement of CD19 by anti-CD19 Ab rapidly induced cellular aggregation in the CD19-R CLL cells. The CD19-R CLL cells expressed higher surface levels of CD19 and c-myc mRNA, exhibited distinct morphological features, and were preferentially abolished in rituximab-treated patients. Both subpop-ulations reacted to slgM stimulation in a similar manner and exhibited similar levels of Akt and Erk phosphorylation, pointing to functional signaling divergence within the BCR. CD19 unresponsiveness was partially reversible, where nonresponding CD19 cells spontaneously recover their signaling capacity following incubation in vitro, pointing to possible in vivo CD19-signaling atten-uating mechanisms. This concept was supported by the lower CD19-R occurrence in bone marrow-derived samples compared with cells derived from the peripheral blood of the same patients. CLL patients with >15.25% of the CD19-R cell fraction had a shorter median time to treatment compared with patients with <15.25% of CD19-R cell fraction. In conclusion, divergence in CD19-mediated signaling unfolds both interpatient and intraclonal diversity in CLL. This signaling diversity is associated with physiological implications, including the location of the cells, their responses to anti-CLL therapeutics, and disease progression. [ABSTRACT FROM AUTHOR]

Introduction: Cord blood (CB) is becoming a valuable source for stem cells utilized in a variety of cell therapy applications, as well as for newborn diagnostics. Some parameters of the CB cellular components can be provided by automated analyzers, while others, such as immature or aberrant cells, require blood film morphological assessment. The objectives of the study were to establish normal CB morphology and to determine the prevalence of morphologically aberrant leukocytes in CB. Methods: We performed a comprehensive morphological analysis of 100 CB samples taken from healthy term and appropriate-for-gestational-age neonates born to healthy mothers, preterm neonates, neonates of diabetic mothers, and small-for-gestational-age neonates. Blood counts were assessed, and manual morphological analyses were performed by laboratory specialists. Results: The manual differential count of normal CB samples established the following values: 47.8 ± 10.7% neutrophils, 31.2 ± 9.8% lymphocytes, 10.0 ± 4.0% monocytes, and 3.0 ± 2.5% eosinophils, with no significant sex-related differences. Blasts were observed in 44/100 samples with an average of 0.5 ± 0.7% per sample, and only a minor left shift was observed. There were significant populations of large granular lymphocytes (19.1 ± 10.6% of the total lymphocytes) and morphologically aberrant lymphocytes (12.4 ± 5.4% of the total lymphocytes) in the samples, irrespective of neonatal status. The differentials of preterm CB samples differ significantly from normal term CB samples, including the reverse of neutrophils/lymphocytes ratio, and the lack of basophils. Conclusions: Normal values and unique morphological features in the CB of neonates are described. The abundant morphologically aberrant lymphocytes in CB may represent an immature state of the immune system at birth. [ABSTRACT FROM AUTHOR]

Simple Summary: Chimeric Antigen Receptor T-cell (CAR T) therapy has become the preferable therapeutic approach in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Detection of CAR Ts in peripheral blood smear (PBS) is challenging due to the low sensitivity of current morphological technologies. We provide herein a morphological analysis of CAR Ts during the production process and in consecutive PBS obtained from DLBCL patients undergoing CAR T therapy, employing a novel, highly sensitive microscopy platform. We found that activated morphology was attributed predominantly to transduced cells following engagement with target cells. The average number of day 5 CAR Ts, and their sustained presence, were significantly higher in patients obtaining complete response. Also, a high number of CAR Ts was associated with longer cytokine storm release syndrome. These data indicate that CAR T morphological surveillance in PB might serve as a simple, fast and inexpensive method to provide clinically relevant insights. Chimeric Antigen Receptor T-cell (CAR T) therapy has become the preferable treatment in relapsed/refractory diffuse large B-cell lymphomas (DLBCL) patients. Detection of CAR Ts in peripheral blood smear (PBS) is challenging due to insufficient data regarding their morphology and low sensitivity. The morphological evolution of CAR Ts along their production process, and in patients, was established by Full-Field Morphology (FFM), a novel digital microscopy approach that provides highly sensitive PBS analysis. At day 8 of production, 42.7 ± 10.8% of the CAR T transduced cells exhibited activated morphology compared with 9.3 ± 3.8% in untransduced cells. Moreover, engagement of transduced CAR Ts with target cells resulted in further morphological transformation into activated morphology (83 ± 5.6% of the cells). In patients, the average number of day 5 CAR Ts, and their sustained presence, were significantly higher in patients obtaining complete response. A high number of activated morphology CAR Ts at day 14 was associated with prolonged cytokine release storm. Overall, CAR Ts exhibited heterogeneous morphology, with the activated morphology attributed predominantly to transduced cells following engagement with target cells. Post-transfusion CAR T detection was associated with increased complete responses. FFM CAR T surveillance in PBS may serve as a simple inexpensive method to provide clinically relevant insights into this treatment modality. [ABSTRACT FROM AUTHOR]

Chronic lymphocytic leukemia (CLL) cells depend on their microenvironment for proliferation and survival. Ectonucleotidase CD39 has anti-inflammatory properties as it hydrolyzes proinflammatory extracellular ATP, generates anti-inflammatory adenosine, and also protects regulatory T cells from ATP-induced cell death. In this study, we investigated the clinical significance of CD39 expression on CD4 T cells in 62 patients with CLL as well as its compartmental regulation and explored the possible mechanisms for its induction. Compared to healthy individuals, CD4CD39 lymphocytes were increased in the peripheral blood of patients with CLL and correlated with the advanced stage of disease. CD4CD39 cells were also higher in patients with CLL, who needed therapeutic intervention, and in those who had unmutated immunoglobulin heavy chain variable region gene, were ZAP70 or had β2-microglobulin levels of >3 g/L. There were more CD4CD39 lymphocytes in the bone marrow compartment than in the peripheral blood, and in vitro studies showed that CD39 can be induced on CD4 cells by exposure to ATP or indirectly, following B cell receptor engagement. This may support the notion that the leukemic cells contribute to create an immune-subversive environment, and perhaps to a poorer prognosis. CD39 may also serve as a future target for the development of novel therapies with immune-modulating antitumor agents in CLL. [ABSTRACT FROM AUTHOR]

Severe neutropenia and protracted thrombocytopenia remain serious clinical problems following cord blood transplantation (CBT) due to the paucity of stem and progenitor cells in the grafts. Administration of ex-vivo expanded megakaryocyte progenitor cells may facilitate platelet production. We propose a novel strategy to expand these rare cells ex-vivo, from a small portion of the cord blood (CB) unit, using fibronectin (FN), a major component of hematopoietic niches, combined with cytokines, including thrombopoietin and the hematopoietic stress-associated acetylcholinesterase readthrough peptide (ARP). Application of multiple gates and high definition flow cytometry enabled clear resolution of expanded hematopoietic stem/precursor cells (HSPC) and megakaryocyte progenitors (Mk-p) and their early subsets while eliminating positively stained non-relevant cells. FN increased viability, expansion of all CD34+ HSPC populations and Mk-p. The combination of FN + thrombopoietin + ARP maintained and expanded very early myeloid and thrombopoietic precursors, increased the proliferation of megakaryocyte, granulocyte-macrophage and multilineage colony-forming progenitors and supported Mk maturation as measured by ploidy and glycoprotein IIb/IIIa expression by quantiative reverse transcription polymerase chain reaction. This approach, which involves expanding HSPC and Mk precursors from a small portion of the CB unit, without sacrificing the coveted stem cells, may lead to improved cell therapy modalities to facilitate earlier myelopoiesis and platelet production post-CBT. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the use of allogeneic stem cell transplantation (allo-SCT) in the treatment of chronic lymphocytic leukemia (CLL).

Objectives: Reliable diagnosis of heparin‐induced thrombocytopenia and thrombosis (HIT) is mandatory for patient management, yet prompt determination of pathogenic antibodies remains an unmet clinical challenge. Common immunoassays carry inherent limitations and functional assays which detect antibody‐mediated platelet activation are not usually readily available to routine laboratories, especially the serotonin release assay (SRA), being technically demanding, time consuming, and requires high level expertise. To overcome some of these limitations, we have developed a practical functional flow cytometric assay (FCA) for routine clinical use. Methods: A simple FCA is described which avoids platelet manipulation, is highly specific and sensitive compared with SRA, and provides rapid results. Results: Of the 650 consecutive samples, from HIT‐suspected patients, 99 (15.3%) were positive by the PaGIA Heparin/PF4 immunoassay and 31 (4.8%) by FCA. Average platelet activation was 11‐fold higher in PaGIA+/FCA+ vs PaGIA−/FCA− samples. Of 21 SRA‐positive samples, 19 were FCA‐positive (relative sensitivity 90.5%), and of 42 SRA‐negative samples, 40 were FCA‐negative (relative specificity 95.2%). The FCA showed significantly higher correlation with the clinical presentation of HIT (4Ts score) performed on 182 patients, compared with PaGIA Heparin/PF4 (ROC‐plot analysis, AUC 0.93 vs 0.63, P < 0.001). At a 92% sensitivity, the assay specificity was 96%. Conclusions: The present FCA is practical for routine testing, providing prompt reliable results for initial diagnosis and confirmation, to effectively assist in HIT patient management. [ABSTRACT FROM AUTHOR]

Endurance, marathon-type exertion is known to induce adverse changes in the immune system. Increased airway hyper-responsiveness and airway inflammation are well documented in endurance athletes and endurance exercise is considered a major risk factor for asthma in elite athletes. Yet, the mechanisms underlying this phenomenon are still to be deduced. We studied the effect of strenuous endurance exercise (marathon and half-ironman triathlon) on CD4+ lymphocyte sub-populations and on the balance between effector and regulatory CD4+ lymphocytes in the peripheral blood of trained athletes, Endurance exercise induced a significant increase in Th17 cells and a sustained decrease in peripheral blood regulatory T cells (Tregs). While interleukin (IL)-2 levels remained undetectable, post-race serum IL-6 and transforming growth factor (TGF) β levels were significantly elevated. Treg levels in sedentary controls' decreased in vitro after incubation with athletes' post-exercise serum, an effect that was attenuated by supplements of IL-2 or anti IL-6 neutralizing antibodies. Our data suggest that exercise-induced changes in serum cytokine levels promote alterations in Tregs and Th17 cell populations, which may divert the subtle balance in the immune system towards inflammation. This may explain allergic and autoimmune phenomena previously reported in endurance athletes and contribute to our understanding of exercise-related asthma. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding a study on the correlation between Th17 cell counts and Tregs peripheral blood lymphocytes in patients with early stage chronic lymphocytic leukemia (CLL).

Abstract: Multiple myeloma is characterized by the malignant growth of immunoglobulin producing plasma cells, predominantly in the bone marrow. The effects of primary human mesenchymal stromal cells on the differentiation phenotype of multiple myeloma cells were studied by co-culture experiments. The incubation of multiple myeloma cells with bone marrow-derived mesenchymal stromal cells resulted in significant reduction of the expression of the predominant plasma cell differentiation markers CD38 and CD138, and cell surface immunoglobulin light chain. While the down-regulation of CD138 by stromal cells was completely dependent on their adhesive interactions with the multiple myeloma cells, interleukin-6 induced specific down-regulation of CD38. Mesenchymal stromal cells or their conditioned media inhibited the growth of multiple myeloma cell line, thereby reducing the overall amounts of secreted light chains. Analysis of primary multiple myeloma bone marrow samples reveled that the expression of CD38 on multiple myeloma cells was not affected by adhesive interactions. The ex vivo propagation of primary multiple myeloma cells resulted in significant increase in their differentiation markers. Overall, the data indicate that the bone marrow-derived mesenchymal stromal cells revert multiple myeloma cells to less differentiated phenotype by the combined activities of adhesive interactions and interleukin-6. [Copyright &y& Elsevier]

The front cover image is based on the Original Article* I Pathogenic heparin-induced thrombocytopenia and thrombosis (HIT) antibodies determined by rapid functional flow cytometry i by Michal Cipok** et al., https://doi.org/10.1111/ejh.13277 GRAPH. [Extracted from the article]