An Extended Flow Cytometry Evaluation of ex Vivo Expanded NK Cells Using K562.Clone1, a Feeder Cell Line Manufactured in Brazil.

Natural killer (NK) cells play a crucial role in the immune system's response against cancer. However, the challenge of obtaining the required quantity of NK cells for effective therapeutic response necessitates the development of strategies for their ex vivo expansion. This study aimed to develop a novel feeder cell line, K562.Clone1, capable of promoting the ex vivo expansion of NK cells while preserving their cytotoxic potential. he K562 leukemic cell line was transduced with mbIL-21 and 4-1BBL proteins to generate K562.Clone1 cells. NK cells were then co-cultured with these feeder cells, and their expansion rate was monitored over 14 days. The cytotoxic potential of the expanded NK cells was evaluated against acute myeloid leukemia blasts and tumor cell lines of leukemia and glial origin. Statistical analysis was performed to determine the significance of the results. The K562.Clone1 co-cultured with peripheral NK showed a significant increase in cell count, with an approximate 94-fold expansion over 14 days. Expanded NK cells demonstrated cytotoxicity against the tested tumor cell lines, indicating preservation of their cytotoxic characteristics. Additionally, the CD56, CD16, inhibitory KIRs, and activation receptors were conserved and present in a well-balanced manner. The study successfully developed a feeder cell line, K562.Clone1, that effectively promotes the expansion of NK cells ex vivo while maintaining their cytotoxic potential. This development could significantly contribute to the advancement of NK cell therapy, especially in Brazil.

Association of CD38+ Immunophenotyping Biomarker With a Better Prognosis in Elderly Acute Myeloid Leukemia Patients.

BACKGROUND/AIM: The relevance of cytogenetic markers as prognostic risk factors has been demonstrated in a vast number of studies, with many prognostication tools utilizing these factors to determine treatment approaches. Patients aged above 60 years represent an important subgroup of acute myeloid leukemia (AML) patients, especially because they usually exhibit a poorer cytogenetic landscape and are less suitable for intensive treatments. The importance of evaluating prognostic parameters in AML, especially in low-income countries, prompted an investigation into CD38 expression and its effects. PATIENTS AND METHODS: Medical records of AML patients aged above 60 years from three hospitals in Brazil's northwest region were analyzed. A total of 67 patients were evaluated in terms of overall survival and factors predicting worse outcomes. The risk stratification was performed based on the European LeukemiaNet 2022 guidelines. The analysis of immunophenotyping markers was conducted using multi-parametric flow cytometry. RESULTS: The overall survival of CD38-positive AML patients was higher than that of patients with CD38-negative AML, with survival rates of 15.6 months versus 4 months, respectively (p-value=0.026). The impact of CD38 positivity was relevant also in multivariable Cox proportional hazards regression, demonstrating a positive effect on overall survival, with a hazard ratio of 0.33 (95%CI=0.13-0.79; p-value=0.014). CONCLUSION: Expression of CD38 in patients with AML was associated with better overall survival and serves as a relevant predictor of improved outcome in patients aged above 60 years.

[Circulating populations of CD4+ CD25+ CD127- regulatory t lymphocytes in peripheral blood of allergic asthmatic children]. / Determinación de poblaciones circulantes en sangre periférica de linfocitos T, reguladores CD4+ CD25+ CD127-, en niños asmáticos alérgicos.

OBJECTIVE: To carry out a preliminary analysis on the Treg lymphocyte counts present in the peripheral blood of allergic asthmatic children from the city of Cartagena, Colombia, compared to healthy controls. METHODS: We compared cytometry counts of ten asthmatic patients (age 7-16 years) and seven healthy controls (6-12 years), recruited in the city of Cartagena. Peripheral blood samples were stained using Cytek's 14-color cFluor Immunoprofiling kit (Cytek® cFluor® Immunoprofiling Kit 14 Color RUO kit), and analyzed on a Northern Lights™ spectral cytometer (Cytek® Biosciences, Fremont, CA, USA), to read 50.000 events per sample. The data obtained were analyzed in SpectroFlo® and FlowJo. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405). RESULTS: The frequency of CD3+, CD4+, CD25+, CD127- Tregs was 11% of all CD4+ T cells, with a range of minimum 8,1% and maximum 17,7%. There was no significant difference in the proportion of Tregs between allergic asthmatic patients and healthy controls (P = 0,2). CONCLUSIONS: With this preliminary sample size, no significant differences were found in the Treg lymphocyte population between allergic asthmatic patients and healthy controls. The 14-color multiplexed panel is a useful tool not only to count CD3+ and CD4+ populations, but also to obtain the percentage of regulatory T cells using cell surface markers.

OBJETIVO: Realizar un análisis preliminar sobre los conteos de linfocitos Tregs presentes en sangre periférica de niños asmáticos alérgicos de la ciudad de Cartagena, comparado con controles sanos. MÉTODOS: Se compararon los conteos de citometría de diez pacientes asmáticos (entre 7 y16 años) y siete controles sanos (entre 6 y12 años), reclutados en la ciudad de Cartagena. La muestra de sangre periférica fue teñida empleando el kit de inmunofenotipo multiplexado de 14 colores de Cytek (Cytek® cFluor® Immunoprofiling Kit 14 Color), y analizada en un citómetro espectral Northern Lights™ (Cytek® Biosciences, Fremont, CA, USA), a lectura de 50.000 eventos por muestra. Los datos obtenidos fueron analizados en SpectroFlo® y FlowJo. El estudio fue aprobado por el Comité de Ética de la Universidad de Cartagena. RESULTADOS: El panel de tinción funcionó apropiadamente y dentro de los parámetros apropiados. Se obtuvo un promedio de células Tregs CD3+, CD4+, CD25+ y CD127- del 11% de todos los CD4+ en las muestras estudiadas, con un rango de mínimo de 8,1% y un máximo de 17,7%. No hubo diferencias significativas en la proporción de linfocitos Tregs entre los pacientes asmáticos alérgicos y los controles sanos (P = 0.2). CONCLUSIONES: Con este tamaño de muestra preliminar, no se encontraron diferencias significativas en la población de linfocitos Tregs entre los pacientes asmáticos alérgicos y los controles sanos. El panel multiplexado de 14 colores es una herramienta útil no solo para derivar las poblaciones CD3+ y CD4+, sino también para obtener el porcentaje de células T reguladoras empleando marcadores de superficie celular.

[Characterization of peripheral blood cellular populations in relation to Ascaris Lumbricoides infection in rural areas of Bolívar]. / Caracterización de poblaciones celulares en sangre periférica, con relación a la infección por Ascaris lumbricoides en zonas rurales de Bolívar.

OBJECTIVE: To compare the relative frequencies of immune cell populations in the peripheral blood according to A. lumbricoides infection status. METHODS: Peripheral blood samples were collected from participants infected (n = 35) and uninfected with A. lumbricoides (n=27) residing in different rural municipalities of Bolívar. Infection was diagnosed using two coprological examinations and the Kato-Katz technique. Immunophenotyping was performed using two panels of markers and staining in fresh blood. The flow cytometry reading was performed on a spectral cytometer (Northern Lights, Cytek, USA). The populations identified in the first panel (Figure 1) were T lymphocytes (CD45+ CD3+), CD4+ or CD8+, B lymphocytes (CD45+ SSClow CD3- CD19+), neutrophils (CD45+ SSChi CD3- CD16+), and eosinophils (CD45+ SSChi CD3- CD16low). Monocytes were identified in another panel (Figure 2): classical (CD14++ CD16 -), intermediate (CD14++ CD16+), and non-classical (CD14+ CD16++). Dendritic cells, including CD123 + + CD303 + (plasmacytoid), HLA-DR + + CD1c + (myeloid CD1c +), and CD14-CD141 + + (myeloid CD141 +), were also identified. The study received approval from the Ethics Committee of the University of Cartagena, and participants provided informed consent. Funding was provided by the Colombian Sistema General de Regalías under BPIN2020000100405 - BPIN2020000100364. RESULTS: No significant differences were observed in age [mean cases: 35.69 (SD: 17.7) vs. controls: 37.04 (SD: 15.6) years] or sex (cases: 62.9% vs. controls: 74.1%) (Table 1). All infections were mild, with a median of 96 eggs (IQR, 48-216). A marginally significant difference was observed only in the percentage of neutrophils (45.37% in cases vs. 54.79% in controls, p=0.041) (Figure 3). Although the frequency of eosinophils was higher in the cases (8.1% vs. 6%), this difference was not significant (p=0.138) (Figure 3). No significant differences were observed in the populations of monocytes or dendritic cells between cases and controls (Figure 4). CONCLUSION: Mild A. lumbricoides infection appears to affect the number of neutrophils in peripheral blood. The low infection intensity in the studied samples may explain the lack of a significant impact on other cellular populations.

OBJETIVO: Comparar las frecuencias relativas de poblaciones de células inmunes en sangre periférica de acuerdo con el estado de infección por A. lumbricoides. MÉTODOS: Se recolectaron muestras de sangre periférica de participantes infectados (n=35) y no infectados con A. lumbricoides (n=27), residentes en distintos municipios rurales de Bolívar. La infección se diagnosticó por dos métodos coprológicos y la técnica de Kato-Katz. El inmunofenotipo se determinó con dos baterías de marcadores y tinciones en sangre fresca. La lectura fue realizada en un citómetro espectral (Northern Lights, Cytek, USA). Las poblaciones identificadas en la primera batería (Figura 1) fueron linfocitos T (CD45+ CD3+) CD4+ o CD8+, linfocitos B (CD45+ SSClow CD3- CD19+), neutrófilos (CD45+ SSChi CD3- CD16+), y eosinófilos (CD45+ SSChi CD3- CD16low). Los monocitos se identificaron en otra batería (Figura 2): clásicos (CD14++ CD16­), intermedios (CD14++ CD16+), y no clásicos (CD14+ CD16++). También se identificaron células dendríticas, tales como: CD123++ CD303+ (plasmocitoides), HLA-DR++ CD1c+ (mieloides CD1c+), y CD14- CD141++ (mieloides CD141+). El estudio recibió la aprobación del Comité de Ética de la Universidad de Cartagena, y los participantes otorgaron su consentimiento informado. La financiación fue proporcionada por el Sistema General de Regalías de Colombia, bajo el BPIN2020000100405 - BPIN2020000100364. RESULTADOS: No se observaron diferencias significativas en edad [media = casos: 35,69 (DE: 17,7) vs controles: 37,04 (DE: 15,6 años] o sexo (casos: 62,9% vs. controles: 74,1%). Todas las infecciones fueron leves con una mediana de huevos de 96 (RIC: 48 - 216). Solo se encontró diferencia significativa marginal en el porcentaje de neutrófilos (45,37% en los casos vs 54,79% en controles, p=0,041). Si bien la frecuencia de eosinófilos fue más alta en los casos (8,1% vs. 6%), esta diferencia no alcanzó la significancia (p=0,138). No se observaron diferencias significativas en las poblaciones de monocitos o células dendríticas entre casos y controles (Figura 4). CONCLUSIÓN: La infección leve por A. lumbricoides parece afectar el número de neutrófilos en sangre periférica. Es posible que por la baja intensidad de la infección en la muestra estudiada, no se detecte un impacto importante de la misma sobre el resto de las poblaciones celulares. Palabras claves: Helmintos; Ascaris lumbricoides; Citometría de flujo; Inmunofenotipado; Neutrófilos.

Isolation and Immunophenotyping of Leukocytes from the Human Maternal-Fetal Interface.

During human pregnancy, leukocytes that infiltrate the maternal-fetal interface play a major role in establishing a delicate balance between immune tolerance and functional response and setting the inflammatory process that leads to labor. Here we describe two methods for isolating immune cells from the chorioamniotic membranes (decidua parietalis) and placental blood (decidua basalis) that combine gentle enzymatic digestion, magnetic cell sorting, and density gradient. Isolated leukocytes can be immunophenotypified by flow cytometry, and both isolation methods are compatible with downstream cellular and molecular applications, such as cell culture, transcriptome, and proteome analyses.

CD4+ Th1 and Th17 responses and multifunctional CD8 T lymphocytes associated with cure or disease worsening in human visceral leishmaniasis.

Introduction: In VL, a proinflammatory phenotype is typically associated with enhanced phagocytosis and a Th1 mediated immune response resulting in infection control. In contrast, an anti-inflammatory phenotype, associated with a predominant regulatory response, typically enables intracellular multiplication of Leishmania parasites and disease progression. Methods: To investigate the impact of chemotherapy on Th2 and Th17 immune responses in patients with visceral leishmaniasis (VL), we assessed all combinations of intracellular expression of IFN-γ, IL-10, IL-4 and IL-17 in the CD4+ and CD8+ T cell populations of peripheral blood mononuclear cell (PBMC) samples from patients, after antigenic stimulation with Leishmania lysate, throughout treatment and follow-up. As increases in spleen and liver sizes and decreases in hematocrit, hemogloblin, erythrocytes, monocytes, leukocytes and platelets levels are strongly related to the disease, we studied the correlations between the frequencies of T cells producing the afore mentioned cytokines, individually and in combination, and these variables, as markers of disease or cure. Results: We found that the frequency of IFN-γ-producingCD4+ T cells increased until the end of chemotherapy with Glucantime® or AmBisome ®, while IL-10, IL-4 and IL-17-producing CD4+ T cells peaked on day 7 following the start of treatment. Although the frequency of CD4+IL-17+ cells decreased during treatment an increase was observed after clinical cure. The frequency of CD4+ T cells producing only IFN-γ or IL-17 correlated with blood monocytes levels. Frequencies of double-producers of IFN-γ and IL-10 or IL-4 correlated positively with eosinophils and platelets levels. Together, this suggest that IFN-γ drives the immune response towards Th1 at cure. In contrast, and associated with disease or Th2 response, the frequency of CD4+ IL-10+ cells correlated positively with spleen sizes and negatively with circulating monocyte levels, while the frequency of CD4+ producing both IL-4 and IL-10 correlated negatively with platelets levels. The frequency of CD8+ single-producers of IFN-γ increased from day 21 to 90 while that of single-producers of IL-10 peaked on day 7, of IL-4 on day 30 and of IL-17, on day 180. IFN-γ expression in CD8+ single- and double-producers of cytokines was indicative of an immune response associated with cure. In contrast, frequencies of CD8+ double-producers of IL-4 and IL-10, IL-4 and IL-17 and IL-10 and IL-17 and producers of three and four cytokines, were associated with disease and were low after the cure. Frequencies of CD8+ T cells producing IFN-γ alone or with IL-17 were positively correlated with platelets levels. In contrast, as markers of disease: 1) frequencies of single producers of IL-10 correlated negatively with leukocytes levels, 2) frequencies of double producers of IL-4 and IL-10 correlated negatively with platelet, leukocyte, lymphocyte and circulating monocyte levels, 3) frequencies of triple-producers of IFN-γ, IL-4 and IL-10 correlated negatively with platelet, leukocyte and neutrophil levels and 4) frequencies of producers of IFN-γ, IL-4, IL-10 and IL-17 simultaneously correlated positively with spleen size, and negatively with leukocyte and neutrophil levels. Discussion: Our results confirmed that the clinical improvement of VL patients correlates with the decrease of an IL-4 and IL-10 CD4+Th2 response, the recovery of CD4+ Th1 and Th17 responses and the frequency of CD8+ single-producers of IFN-γ and double producers of IFN-γ and IL-17.

Características clínicas de neoplasia de células dendríticas plasmocitoides blásticas en Chile: reporte de 10 casos

Introducción: La neoplasia de células dendríticas plasmocitoides blásticas (NCDPB) es una hemopatía maligna poco frecuente y de mal pronóstico, con reportes de casos aislados en la realidad nacional. Produce compromiso cutáneo y de médula ósea y frecuentemente es confundida con otras patologías al diagnóstico. El presente trabajo tiene como objetivo describir las características clínicas de 10 pacientes diagnosticados en centros asistenciales chilenos. Material y Métodos: Se obtuvo en forma retrospectiva información clínica e inmunofenotípica de pacientes diagnosticados de NCDPB en los centros participantes en el periodo 2013-2021. Resultados: Se identificaron 10 pacientes, el 80% de sexo masculino, con una mediana de edad de 66 años (15-81). Los diagnósticos iniciales de derivación más frecuentes fueron linfoma T (4/10) y leucemia aguda mieloblástica (3/10). La mayoría presentó afección cutánea (7/10) y compromiso de médula (7/10) y en menor frecuencia adenopatías, esplenomegalia y hepatomegalia. En el hemograma se observó anemia y leucopenia, con blastos en frotis en 5/10. Se indicó CHOP en 8/10 casos con remisión en 5/8 y en un caso HyperCVAD seguido de trasplante alogénico de médula ósea. La mediana de sobrevida fue de 10 meses (IC 95% 4,2-15,8 meses) con 9/10 fallecidos. Se documentó recaída en sistema nervioso central en 2 casos. Conclusiones: La NCDPB es una patología poco frecuente que se presenta en la realidad nacional de forma similar a lo descrito en la literatura. Es susceptible de responder a quimioterapia inicial asociada a terapia intratecal.

Background: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare malignant tumor with a dismal prognosis, with isolated case reports in Chile. The BPDCN can present skin and bone marrow compromise, and its diagnosis is frequently confused with other pathologies. This study aimed to evaluate the clinical and immunophenotypical features of BPDCN in the Chilean population. Methods: We performed a retrospective study from 2013 to 2021 in clinical records of 2 public Chilean referral hospitals, including ten patients, 80% male, with a median age of 66 years (15-81). Results: The most frequent initial referral diagnoses were T-cell lymphoma (4/10) and acute myeloblastic leukemia (3/10). Seven patients presented skin and bone marrow involvement; we found a lower frequency of adenopathies (5/10), splenomegaly (2/10), and hepatomegaly (2/10). The complete blood count revealed anemia and leukopenia, with blasts in 5/10. Nine patients received induction therapy. CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) was indicated in 8/10 cases with remission in 5/8, and 1 patient received HyerCVAD (cyclophosphamide, vincristine, doxorubicin and dexamethasone, methotrexate, cytarabine) and an allogeneic bone marrow transplant. The median survival was 10 months (95% CI 4.2-15.8 months) with 9/10 deaths. Relapse in the central nervous system was documented in 2 cases. Conclusions: Our study found that BPDCN, a rare pathology in the Chilean population, shows a similar clinical presentation compared to previous studies. It is susceptible to respond to initial systemic and intrathecal chemotherapy.

Association between Immunophenotypic Parameters and Molecular Alterations in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is a hematologic malignancy that occurs due to alterations such as genetic mutations, chromosomal translocations, or changes in molecular levels. These alterations can accumulate in stem cells and hematopoietic progenitors, leading to the development of AML, which has a prevalence of 80% of acute leukemias in the adult population. Recurrent cytogenetic abnormalities, in addition to mediating leukemogenesis onset, participate in its evolution and can be used as established diagnostic and prognostic markers. Most of these mutations confer resistance to the traditionally used treatments and, therefore, the aberrant protein products are also considered therapeutic targets. The surface antigens of a cell are characterized through immunophenotyping, which has the ability to identify and differentiate the degrees of maturation and the lineage of the target cell, whether benign or malignant. With this, we seek to establish a relationship according to the molecular aberrations and immunophenotypic alterations that cells with AML present.

Cellular and Humoral Immune Responses to Vaccination for COVID-19 Are Negatively Impacted by Senescent T Cells: A Case Report.

BACKGROUND: Herein, we aimed to follow up on the cellular and humoral immune responses of a group of individuals who initially received the CoronaVac vaccine, followed by a booster with the Pfizer vaccine. METHODS: Blood samples were collected: before and 30 days after the first CoronaVac dose; 30, 90, and 180 days after the second CoronaVac dose, and also 20 days after the booster with the Pfizer vaccine. RESULTS: Whilst the positivity to gamma interferon-type cellular response increased after the first CoronaVac dose, neutralizing and IgG antibody levels only raised 30 days after the second dose, followed by a drop in these responses after 90 and 180 days. The booster with the Pfizer vaccine elicited a robust cellular and humoral response. A higher number of double-negative and senescent T cells, as well as increased pro-inflammatory cytokines levels were found in the participants with lower humoral immune responses. CONCLUSION: CoronaVac elicited an early cellular response, followed by a humoral response, which dropped 90 days after the second dose. The booster with the Pfizer vaccine significantly enhanced these responses. Furthermore, a pro-inflammatory systemic status was found in volunteers who presented senescent T cells, which could putatively impair the immune response to vaccination.

Multiparametric flow cytometry directing the evaluation of CRLF2 rearrangements and JAK2 status in pediatric B cell precursor acute lymphoblastic leukemia.

INTRODUCTION: This study aimed to determine whether cytokine receptor-like factor 2 (CRLF2) antigen expression evaluated using multiparametric flow cytometry (MFC) could predict the genotype of CRLF2 and Janus kinase 2 (JAK2) status for application in the diagnosis of pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). METHODS: A total of 321 BCP-ALL bone marrow samples were collected, 291 at diagnosis and 13 at first relapse, while 17 samples were excluded due to low cellular viability. The CRLF2 antigen expression was evaluated using flow cytometry (percentage of positivity and median fluorescence intensity [MFI]). The CRLF2 transcript levels were assessed via quantitative reverse transcription polymerase chain reaction using SYBR Green. The CRLF2 rearrangements (CRLF2-r) were identified using the CRLF2 break-apart probe via fluorescence in situ hybridization. Sanger sequencing was performed to identify the JAK2 exon 16 mutations. RESULTS: We observed that 60 of the 291 cases (20.6%) presented CRLF2 antigen positivity, whereas the CRLF2 transcript overexpression was found in 19 of 113 cases (16.8%). The JAK2 mutation was found in four out of 116 cases (3.4%), all of which had CRLF2 ≥10% of positive cells and intermediate or high MFI (p < 0.0001). In addition, in the 13 cases with the CRLF2-r, a positive correlation was found with the CRLF2 antigen intermediate (61.5%) MFI (p = 0.017). Finally, the CRLF2-positive antigen was identified in the BCP-ALL subclones. CONCLUSION: The identification of the CRLF2 antigen using the MFC, based on the percentage of positivity and MFI values, is a useful tool for predicting JAK2 mutations and CRLF2-r.

Epidemic history and evolution of an emerging threat of international concern, the severe acute respiratory syndrome coronavirus 2

This comprehensive review focuses on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its impact as the cause of the COVID-19 pandemic. Its objective is to provide a cohesive overview of the epidemic history and evolutionary aspects of the virus, with a particular emphasis on its emergence, global spread, and implications for public health. The review delves into the timelines and key milestones of SARS-CoV-2's epidemiological progression, shedding light on the challenges encountered during early containment efforts and subsequent waves of transmission. Understanding the evolutionary dynamics of the virus is crucial in monitoring its potential for adaptation and future outbreaks. Genetic characterization of SARS-CoV-2 is discussed, with a focus on the emergence of new variants and their implications for transmissibility, severity, and immune evasion. The review highlights the important role of genomic surveillance in tracking viral mutations linked to establishing public health interventions. By analyzing the origins, global spread, and genetic evolution of SARS-CoV-2, valuable insights can be gained for the development of effective control measures, improvement of pandemic preparedness, and addressing future emerging infectious diseases of international concern.

Application of mass cytometry to characterize hematopoietic stem cells in apheresis products of patients with hematological malignancies.

INTRODUCTION: Hematopoietic stem cell transplantation (HSCT) is a widely used therapy, but its success largely depends on the number and quality of stem cells collected. Current evidence shows the complexity of the hematopoietic system, which implies that, in the quality assurance of the apheresis product, the hematopoietic stem cells are adequately characterized and quantified, in which mass cytometry (MC) can provide its advantages in high-dimensional analysis. OBJECTIVE: This research aimed to characterize and enumerate CD45dim/CD34+ stem cells using the MC in apheresis product yields from patients with chronic lymphoid malignant diseases undergoing autologous transplantation at the Abu Dhabi Stem Cells Center. METHODS: An analytical and cross-sectional study was performed on 31 apheresis products from 15 patients diagnosed with multiple myeloma (n = 9) and non-Hodgkin lymphomas (n = 6) eligible for HSCT. The MC was employed using the MaxPar Kit for stem cell immunophenotyping. The analysis was performed manually in the Kaluza and unsupervised by machine learning in Cytobank Premium. RESULTS: An excellent agreement was found between mass and flow cytometry for the relative and absolute counts of CD45dim/CD34+ cells (Bland-Altman bias: -0.029 and -64, respectively), seven subpopulations were phenotyped and no lineage bias was detected for any of the methods used in the pool of collected cells. A CD34+/CD38+/CD138+ population was seen in the analyses performed on four patients with multiple myeloma. CONCLUSIONS: The MC helps to characterize subpopulations of stem cells in apheresis products. It also allows cell quantification by double platform. Unsupervised analysis allows results completion and validation of the manual strategy. The proposed methodology can be extended to apheresis products for purposes other than HSCT.

Extreme lymphocytosis in a dog with T-zone lymphoma.

Background: Canine T-zone lymphoma (TZL) is recognized as an indolent CD45-T cell lymphoma, with low aggressiveness and high overall survival. The diagnosis is obtained by histopathology and immunohistochemistry, but also by cytological examination of the lymph node associated with immunophenotyping. Lymphocytosis is commonly identified as around 10,000 cells/µl and may reach 30,760 cells/µl. Case Description: The present report describes a case of a female Golden Retriever, nine years old, with generalized lymphadenopathy. In the cytological examination of the superficial cervical lymph node, a monomorphic population of small, "clear cells" and "hand mirror" lymphocyte shape was suggestive of TZL. The leukogram showed intense leukocytosis (160,050 cells/µl) due to small clear cell lymphocytosis (152,048 cells/µl). The myelogram showed a myeloid:erythroid ratio of 2:3; with a pyramidal distribution of cell types and the presence of 22.8% of lymphocytes in the differential count. Bone marrow, peripheral blood, and lymph node immunophenotyping resulted in lymphocyte gates with 97.3% to 99.5% CD5+, predominantly CD4-, CD8-, and CD45- confirming the diagnosis of TZL with associated leukemia. Treatment with chlorambucil and prednisolone was started. During the first month, the lymphocytosis remained above 200,000 cells/uL. After four months of treatment, there was a decrease in lymphocytes, which progressively reached a count of 10,800 cells/ul in the eleventh month. Conclusion: In the literature, lymphocytosis above 30,760 cells/µl has not been observed in TZLs. Thus, it is believed that this is the first report of extreme lymphocytosis with a slow response to chemotherapy.

Multiparametric flow cytometry directing the evaluation of CRLF2 rearrangements and JAK2 status in pediatric B cell precursor acute lymphoblastic leukemia

Asbtract Introduction This study aimed to determine whether cytokine receptor-like factor 2 (CRLF2) antigen expression evaluated using multiparametric flow cytometry (MFC) could predict the genotype of CRLF2 and Janus kinase 2 (JAK2) status for application in the diagnosis of pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Methods A total of 321 BCP-ALL bone marrow samples were collected, 291 at diagnosis and 13 at first relapse, while 17 samples were excluded due to low cellular viability. The CRLF2 antigen expression was evaluated using flow cytometry (percentage of positivity and median fluorescence intensity [MFI]). The CRLF2 transcript levels were assessed via quantitative reverse transcription polymerase chain reaction using SYBR Green. The CRLF2 rearrangements (CRLF2-r) were identified using the CRLF2 break-apart probe via fluorescence in situ hybridization. Sanger sequencing was performed to identify the JAK2 exon 16 mutations. Results We observed that 60 of the 291 cases (20.6%) presented CRLF2 antigen positivity, whereas the CRLF2 transcript overexpression was found in 19 of 113 cases (16.8%). The JAK2 mutation was found in four out of 116 cases (3.4%), all of which had CRLF2 ≥10% of positive cells and intermediate or high MFI (p < 0.0001). In addition, in the 13 cases with the CRLF2-r, a positive correlation was found with the CRLF2 antigen intermediate (61.5%) MFI (p= 0.017). Finally, the CRLF2-positive antigen was identified in the BCP-ALL subclones. Conclusion The identification of the CRLF2 antigen using the MFC, based on the percentage of positivity and MFI values, is a useful tool for predicting JAK2 mutations and CRLF2-r.

Immunophenotypic characterization of acute leukemias in Bahia, Brazil

ABSTRACT Objective To characterize the immunophenotypic profile of acute leukemias in the population of the state of Bahia, Brazil. Methods This is a descriptive, retrospective study. From 2014 to 2018, 796 new cases of acute leukemia were evaluated. The data were obtained from analysis of reports and records of tests performed by flow cytometry immunophenotyping. All individuals of all age groups diagnosed as acute lymphoblastic leukemia or acute myeloid leukemia were included in the study. Demographic variables and expression of leukemia antigens were evaluated. Results Most cases were diagnosed as acute myeloid leukemia and 42.7% as acute lymphoblastic leukemia. Significant differences were found in expression of markers in acute leukemias when age groups were compared, as well as in demographic characteristics. B-cell acute lymphoblastic leukemia was more prevalent than cases of T-cell origin. Assessing the aberrant markers in acute myeloid leukemias, the non-acute promyelocytic leukemia group presented expression of CD7 and CD56 as the most frequent ones. In B-cell acute lymphoblastic leukemia, the most frequent aberrant markers were CD66c, CD13 and CD33. Conclusion Significant differences were found as to several antigens when comparing adults and children, and these findings may contribute to future studies correlating the phenotypic profile to genetic characteristics and therapeutic response, including specific antigen therapies, which may be better targeted.

The Characterization of Cardiac Explants Reveals Unique Fibrosis Patterns and a Predominance of CD8+ T Cell Subpopulations in Patients with Chronic Chagas Cardiomyopathy.

AIM: The present study aimed to characterize the histopathological findings and the phenotype of inflammatory cells in the myocardial tissue of patients with end-stage heart failure (ESHF) secondary to CCC in comparison with ESHF secondary to non-Chagas cardiomyopathies (NCC). METHODS: A total of 32 explanted hearts were collected from transplanted patients between 2014 and 2017. Of these, 21 were classified as CCC and 11 as other NCC. A macroscopic analysis followed by a microscopic analysis were performed. Finally, the phenotypes of the inflammatory infiltrates were characterized using flow cytometry. RESULTS: Microscopic analysis revealed more extensive fibrotic involvement in patients with CCC, with more frequent foci of fibrosis, collagen deposits, and degeneration of myocardial fibers, in addition to identifying foci of inflammatory infiltrate of greater magnitude. Finally, cell phenotyping identified more memory T cells, mainly CD8+CD45RO+ T cells, and fewer transitioning T cells (CD45RA+/CD45RO+) in patients with CCC compared with the NCC group. CONCLUSIONS: CCC represents a unique form of myocardial involvement characterized by abundant inflammatory infiltrates, severe interstitial fibrosis, extensive collagen deposits, and marked cardiomyocyte degeneration. The structural myocardial changes observed in late-stage Chagas cardiomyopathy appear to be closely related to the presence of cardiac fibrosis and the colocalization of collagen fibers and inflammatory cells, a finding that serves as a basis for the generation of new hypotheses aimed at better understanding the role of inflammation and fibrogenesis in the progression of CCC. Finally, the predominance of memory T cells in CCC compared with NCC hearts highlights the critical role of the parasite-specific lymphocytic response in the course of the infection.

Mieloma múltiple con IgM de superficie precedido por síndrome mielodisplásico en paciente anciana / Surface membrane IgM multiple myeloma preceded by myelodysplastic syndrome in an elderly patient

Introducción: El mieloma múltiple con expresión de inmunoglobulina M de superficie constituye una enfermedad rara cuya causa es desconocida y se caracteriza por una alta tasa de anormalidades genéticas en las células plasmáticas o sus precursores. Objetivo: Determinar las características clínicas y sus asociaciones con la expresión inmunofenotípica de inmunoglobulina M de superficie e inmunohistoquímica de CD20 en una paciente afectada de mieloma múltiple precedido por síndrome mielodisplásico. Presentación del caso: Paciente femenina, 68 años de edad. Admitida en el Servicio de Hematología Clínica. Al momento del diagnóstico presentó palidez, trombocitopenia, hipercalcemia y lesiones óseas. Inicialmente, mediante citometría de flujo se detectaron patrones aberrantes para granulocitos, neutrófilos, monocitos y serie eritroide, sugerentes de síndrome mielodisplásico. Posteriormente se observó aumento de las células plasmáticas del 18 % en el frotis de médula ósea, exhibiendo una morfología similar a linfocitos. Se reportó una población patológica de 6 % de la celularidad total, mostrando positividad para CD38, CD117 e inmunoglobulina M de superficie, negatividad para CD19 y CD45, fenotipo coherente con células plasmáticas anormales. Adicionalmente resultados de inmunohistoquímica relataron tinción difusa de CD20 en biopsia de médula ósea. La paciente logró recuperarse luego de un trasplante autólogo de células progenitoras hematopoyéticas. Conclusión: Los resultados resaltan la importancia de diagnosticar y monitorear casos únicos que permitan un tratamiento oportuno del paciente.

Introduction: Multiple Myeloma with expression of surface immunoglobulin M is a rare entity, whose cause is unknown, and is characterized by a high rate of genetic abnormalities in plasma cells or their precursors. Objective: To determining the clinical characteristics and their associations with the immunophenotypic expression of surface immunoglobulin M and CD20 immunohistochemistry in a patient affected by Multiple Myeloma preceded by Myelodysplastic syndrome. Case presentation: A 68-year-old female patient is admitted to the Clinical Hematology Service. At the time of diagnosis, she presented pallor, thrombocytopenia, hypercalcemia, and bone lesions. Initially, flow cytometry detected aberrant patterns for neutrophilic granulocytes, monocytes, and the erythroid series suggestive of myelodysplastic syndrome. Subsequently, an 18% increase in plasma cells was observed in the bone marrow smear, exhibiting a lymphocyte-like morphology. A pathological population of 6% of the total cellularity was reported, showing positivity for CD38, CD117 and surface immunoglobulin M, negativity for CD19 and CD45, a phenotype consistent with abnormal plasma cells. Additionally, immunohistochemical results reported diffuse CD20 staining in bone marrow biopsy. The patient managed to recover after an autologous hematopoietic stem cell transplant. Conclusion: The results found highlight the importance of diagnosing and monitoring single cases that allow timely treatment of the patient.

Age-associated phenotypic imbalance in TCD4 and TCD8 cell subsets: comparison between healthy aged, smokers, COPD patients and young adults.

BACKGROUND: COPD is associated with an abnormal lung immune response that leads to tissue damage and remodeling of the lung, but also to systemic effects that compromise immune responses. Cigarette smoking also impacts on innate and adaptative immune responses, exerting dual, pro- and anti-inflammatory effects. Previously, we showed that COPD patients presented accelerated telomere shortening and decreased telomerase activity, while, paradoxically, cigarette-smokers exhibited preserved telomerase activity and slower rate of telomere shortening. RESULTS: Here, we evaluated the naive, CM, EM and TEMRA subsets of TCD4 and TCD8 cells according to the expression of CCR7/CD45RA. We compared age-matched COPD patients, cigarette-smokers without clinical-laboratory evidence of pulmonary compromise, and healthy individuals. They were additionally compared with a group of young adults. For each subset we analysed the expression of markers associated with late differentiation, senescence and exhaustion (CD27/CD28/CD57/KLRG1/PD1). We show that COPD patients presented a drastically reduced naive cells pool, and, paradoxically, increased fractions of naive cells expressing late differentiation, senescence or exhaustion markers, likely impacting on their immunocompetence. Pronounced phenotypic alterations were also evidenced in their three memory T-cell subsets compared with the other aged and young groups, suggesting an also dysfunctional memory pool. Surprisingly, our smokers showed a profile closer to the Healthy aged than COPD patients. They exhibited the usual age-associated shift of naive to EM TCD4 and TCD8 cells, but not to CM or TEMRA T-cells. Nonetheless, their naive T-cells phenotypes were in general similar to those of the Youngs and Healthy aged, suggesting a rather phenotypically preserved subset, while the memory T-cells exhibited increased proportions of cells with the late-differentiation or senescence/exhaustion markers as in the Healthy aged. CONCLUSION: Our study extends previous findings by showing that COPD patients have cells expressing a full range of late differentiated, senescent or exhausted phenotypes encompassing all TCD4 and TCD8 subsets, consistent with a premature immunosenescence phenotype. Surprisingly, the smokers group's results suggest that moderate to heavy chronic cigarette smoking did not accelerate the pace of immunosenescence as compared with the Healthy aged.

Immunophenotypic changes in juvenile myelomonocytic leukaemia after treatment with hypomethylating agent: Do they help to evaluate dept of response?

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.

Identification of immunophenotypes in esophageal squamous cell carcinoma based on immune gene sets.

PURPOSE: Esophageal squamous cell carcinoma (ESCC) is a malignant tumor with high heterogeneity. Research on molecular mechanisms involved in the process of tumor origination and progression is extremely limited to investigating mechanisms of molecular typing for ESCC. METHODS: After comprehensively analyzing the gene expression profiles in The Cancer Genome Atlas and Gene Expression Omnibus databases, we identified four immunotypes of ESCC (referred to as C1-C4) based on the gene sets of 28 immune cell subpopulations. The discrepancies in prognostic value, clinical features, drug sensitivity, and tumor components between the immunotypes were individually analyzed. RESULTS: The ranking of immune infiltration is C1 > C4 > C3 > C2. These subtypes are characterized by high and low expression of immune checkpoint proteins, enrichment and insufficiency of immune-related pathways, and differential distribution of immune cell subgroups. Poorer survival was observed in the C1 subtype, which we hypothesized could be caused by an immunosuppressive cell population. Fortunately, C1's susceptibility to anti-PD-1 therapy offers hope for patients with poor prognosis in advanced stages. On the other hand, C4 is sensitive to docetaxel, which may offer novel treatment strategies for ESCC in the future. It is worth noting that immunophenotyping is tightly bound to the abundance of stromal components and stem cells, which could explain the tumor immune escape to some extent. Ultimately, determination of hub genes based on the C1 subtypes provides a reference for the discovery of immunotarget drugs against ESCC. CONCLUSION: The identification of immunophenotypes in our study provides new therapeutic strategies for patients with ESCC.