Introduction. Monoclonal B-cell lymphocytosis generally precedes chronic lymphocytic leukemia, affecting about 12% of the healthy adult population. This frequency increases in relatives of patients with chronic B-cell lymphoproliferative disorders.
Objective. To determine the frequency of monoclonal B-cell lymphocytosis in relatives of patients with chronic B-cell lymphoproliferative disorders, their immunophenotypic/cytogenetic characteristics, a possible relationship with infectious agents, and short-term follow-up in the Colombian population.
Materials and methods. Fifty healthy adults with a family history of chronic B-cell lymphoproliferative disorders were studied using multiparametric flow cytometry,
cytogenetic/serological testing, lifestyle survey, and 2-year follow-up.
Results. The frequency of monoclonal B-cell lymphocytosis found was 8%, with a predominance of female gender and advanced age, increasing to 12.5% for individuals with
a family history of chronic lymphocytic leukemia. Three out of four individuals presented chronic lymphocytic leukemia-type immunophenotype, all with low counts. In turn, a significantly higher number of cells/μl is observed in these individuals in T lymphocyte subpopulations, together with a greater predisposition to the disease. The described clonal populations increase over time in a non-significant manner.
Conclusions. The frequency and behavior of monoclonal B-cell lymphocytosis in patients with family history of chronic B-cell lymphoproliferative disorders are like those found in related studies, which suggests that there is no involvement of more relevant genes that can trigger uncontrolled clonal proliferation, but that generates immunological deregulation that could justify a greater risk of serious infection in these individuals.

In the mouse, the first hematopoietic cells are generated in the yolk sac from the primitive, erythro-myeloid progenitor (EMP) and lymphoid programs that are specified before the emergence of hematopoietic stem cells. While many of the yolk sac-derived populations are transient, specific immune cell progeny seed developing tissues, where they function into adult life. To access the human equivalent of these lineages, we modeled yolk sac hematopoietic development using pluripotent stem cell differentiation. Here, we show that the combination of Activin A, BMP4, and FGF2 induces a population of KDR+CD235a/b+ mesoderm that gives rise to the spectrum of erythroid, myeloid, and T lymphoid lineages characteristic of the mouse yolk sac hematopoietic programs, including the Vδ2+ subset of γ/δ T cells that develops early in the human embryo. Through clonal analyses, we identified a multipotent hematopoietic progenitor with erythroid, myeloid, and T lymphoid potential, suggesting that the yolk sac EMP and lymphoid lineages may develop from a common progenitor.
© 2021 Atkins et al.

When examining datasets of any dimensionality, researchers frequently aim to identify individual subsets (clusters) of objects within the dataset. The ubiquity of multidimensional data has motivated the replacement of user-guided clustering with fully automated clustering. The fully automated methods are designed to make clustering more accurate, standardized and faster. However, the adoption of these methods is still limited by the lack of intuitive visualization and cluster matching methods that would allow users to readily interpret fully automatically generated clusters. To address these issues, we developed a fully automated subset identification and characterization (SIC) pipeline providing robust cluster matching and data visualization tools for high-dimensional flow/mass cytometry (and other) data. This pipeline automatically (and intuitively) generates two-dimensional representations of high-dimensional datasets that are safe from the curse of dimensionality. This new approach allows more robust and reproducible data analysis,+ facilitating the development of new gold standard practices across laboratories and institutions.

B cell lymphomas' (BCL) current diagnosis is usually based on a combination of morphology, immunophenotype, recurrent cytogenetic aberration and clinical features. However, even with these diagnostic tools, a definitive diagnosis can be difficult to achieve. Therefore, the aim of this study was to assess the profile of CD39, CD43, CD81, and CD95 expressions in diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and Burkitt lymphoma (BL) cases.
To address this issue, we investigated the expression of CD39, CD43, CD81, and CD95 by eight-color flow cytometry in retrospective cases from 2014 to 2016.
The study included 27 adult patients diagnosed with DLBCL, FL, and BL during the study period. Four patients were diagnosed with germinal center B cell-like DLBCL (GCB DLBCL), seven with non-GCB DLBCL, nine with FL, and seven with BL. CD39 seems to be especially relevant to differentiate non-GCB DLBCL from BL and from FL. BL showed stronger expression of CD43 when compared to FL and GCB DLBCL. Moreover, CD43 may help to distinguish non-GCB DLBCL from GCB DLBCL. CD81 expression was much stronger in BL when compared to the other three groups of patients. Lastly, CD95 may also help to distinguish BL from the other subtypes, as BL cells expressed this antigen at low levels.
In combination, CD39, CD43, CD81, and CD95 expressions appear to be helpful to distinguish CD10+ BCL, particularly BL. Phenotypic distinction between FL and GCB DLBCL remains challenging and requires further studies. © 2017 International Clinical Cytometry Society.
© 2017 International Clinical Cytometry Society.

Autotransplantation of cryopreserved ovarian cortex can be associated with a risk of cancer cell reseeding. This issue could be eliminated by grafting isolated preantral follicles. Collagenase NB6 is an enzyme produced under good manufacturing practices (GMP) in compliance with requirements for tissue engineering and transplantation in humans and thus can be used to isolate preantral follicles from ovarian tissue in the framework of further clinical applications. Multicolor flow cytometry is an effective tool to evaluate the potential contamination of follicular suspensions by leukemic cells.
The efficiency of collagenase NB6 was evaluated in comparison to collagenase type IA and Liberase DH, in terms of yield, morphology and viability. A short-term in vitro culture of follicles isolated with collagenase NB6 was conducted for 3 days in a fibrin matrix. A modelization procedure was carried out to detect the presence of leukemic cells in follicular suspensions using multicolor flow cytometry (MFC).
No statistical differences were found between collagenase NB6, Liberase DH (p = 0.386) and collagenase type IA (p = 0.171) regarding the number of human preantral follicles isolated. The mean diameter of isolated follicles was significantly lower with collagenase NB6 (p < 0.0001). The survival rate of isolated follicles was 93.4% (n = 272) using collagenase NB6 versus 94.9% (n = 198) with Liberase DH and 92.6% (n = 298) using collagenase type IA. Even after 3 days of in vitro culture in a fibrin scaffold, most of the isolated follicles were still alive after using collagenase NB6 (90.7% of viable follicles; n = 339). The rate of isolated Ki67-positive follicles was 29 ± 9.19% before culture and 45 ± 1.41% after 3 days. In 23 out of 24 follicular suspensions analyzed, the detection of leukemic cells by MFC was negative. The purification had no significant impact on follicle viability.
The isolation and purification of human preantral follicles were performed following good manufacturing practices for cell therapy. Multicolor flow cytometry was able to confirm that final follicular suspensions were free from leukemic cells. This safe isolation technique using collagenase NB6 can be considered for future clinical applications.