Lymphocyte subsets and soluble forms of MIC-A and MIC-B are prognostic factors in non-Hodgkin lymphoma patients.

MIC-A and MIC-B are the natural ligands for NKG2D, an activator receptor expressed in NK cells. Soluble isoforms of MIC-A and MIC-B (sMICA, sMICB) have been identified in different malignancies, affecting NK cells' cytotoxicity. The study was performed to determine the levels of sMICA, sMICB, the expression of MIC-A, and MIC-B on tumor tissues, and lymphocyte subpopulations (CD4 + , CD8 + , NK, NKT, Tγδ cells, B cells, monocytes) in 94 patients with non-Hodgkin's lymphoma (NHL) and 72 healthy donors.The most frequent lymphoma was diffuse large B cell lymphoma (48%). Patients with NHL had decreased numbers of CD4 T cells, CD8 T cells, B cells, monocytes, NK cells, type 1 dendritic cells, γδ T cells, and increased iNKT cells. Patients showed higher levels of sMIC-A and similar serum levels of sMIC-B.Survival was poorer in patients having higher LDH values and lower numbers of CD4 T cells, type 1 dendritic cells, gamma-delta T cells, and high levels of sMIC-A.In conclusion, high levels of sMIC and decreased numbers in circulating lymphocyte subsets are related to poor outcomes in NHL.

Soluble MIC-A, IPI, and response to treatment strongly predict survival in patients with germinal center diffuse large B cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most frequent lymphoma. MIC-A and MIC-B are the natural ligands for NKG2D, a receptor expressed in NK cells. MIC-A soluble isoforms (sMICA) have been described in different malignancies. OBJECTIVES: To analyze lymphocyte subsets and sMIC-A in germinal center DLBCL. MATERIALS AND METHODS: sMICA, sMICB, and peripheral blood lymphocyte subsets (CD4+, CD8+, NK, NKT, γδ T cells, and dendritic cells) were analyzed in 59 patients and 60 healthy donors. RESULTS: Patients had decreased numbers of type 1 and type 2 dendritic cells, NK, iNKT, CD4 T, and CD8 T cells, and higher levels of sMIC-A. The 2-year PFS for high IPI scores and high sMIC-A was 24% and 28%, respectively. The 2-year OS for high IPI scores and high sMIC-A was 42% and 33%. The 2-year PFS and OS for patients not achieving response to treatment were 0% and 10%, respectively. The MICPI score (one point each for high IPI score and high sMIC-A) showed that those patients summing two points had worse PSF and OS. CONCLUSIONS: Patients with DLBCL have decreased numbers of peripheral lymphocyte subsets and high levels of sMIC-A. The addition of sMIC-A to IPI could improve its prognostic relevance.

Poor Survival in COVID-19 Associated with Lymphopenia and Higher Neutrophile-Lymphocyte Ratio.

BACKGROUND: Immune cell counts in blood in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection may be useful prognostic biomarkers of disease severity, mortality, and response to treatment. OBJECTIVES: To analyze sub-populations of lymphocytes at hospital admission in survivors and deceased from severe pneumonia due to coronavirus disease-2019 (COVID-19). METHODS: We conducted a cross-sectional study of healthcare workers confirmed with SARS-CoV-2 in convalescents (control group) and healthy controls (HC) diagnosed with severe COVID-19. Serum samples were taken at hospital admission and after recovery. Serum samples ≥ 25 days after onset of symptoms were analyzed for lymphocyte subpopulations through flow cytometry. Descriptive statistics, Kruskall-Wallis test, receiver operating characteristic curve, calculation of sensitivity, specificity, predictive values, and Kaplan-Meier analysis were performed. RESULTS: We included 337 patients: 120 HC, 127 convalescents, and 90 severe COVID-19 disease patients (50 survivors, 40 deceased). For T cells, total lymphocytes ≥ 800/µL, CD3+ ≥ 400/µL, CD4+ ≥ 180/µL, CD8+ ≥ 150/µL, B cells CD19+ ≥ 80/µL, and NK ≥ 34/µL subsets were associated with survival in severe COVID-19 disease patients. All subtypes of lymphocytes had higher concentrations in survivors than deceased, but similar between HC and convalescents. Leukocytes ≥ 10.150/µL or neutrophils ≥ 10,000/µL were associated with increased mortality. The neutrophil-to-lymphocyte ratio (NLR) ≥ 8.5 increased the probability of death in severe COVID-19 (odds ratio 11.68). CONCLUSIONS: Total lymphocytes; NLR; and levels of CD3+, CD4+, CD8+, and NK cells are useful as biomarkers of survival or mortality in severe COVID-19 disease and commonly reach normal levels in convalescents.

Pathophysiology of Alloimmunization.

INTRODUCTION: Alloimmunization is caused by exposure to erythrocytes from a donor that expresses blood group antigens other than those of the recipient and is related to processes that alter the balance of the immune system. Knowing the pathophysiology of alloimmunization process is essential to understand clinical complications associated with this process. PATIENTS AND METHODS: From October 2016 to April 2017, irregular antibody screening was performed in 1,434 polytransfused (compatible with the ABO and D system) patients by means of agglutination techniques using erythrocytes of a known phenotype of 44 patients with a positive alloantibody screening. Non-alloimmunized (control) subjects were matched for age, gender, pathology, and treatment group with alloimmunized patients. The subsets of B, T, and Treg lymphocytes were determined by flow cytometry. RESULTS: The results of screening for alloantibodies in patients by specificity of antibodies were as follows: nonspecific (30%), followed by anti-Dia (13%), anti-e (9%), anti-S (9%), anti-I (7%), anti-K (7%), and anti-P (7%). A lower percentage of CD4+ T lymphocytes and an increase of CD8+ T lymphocytes were observed in alloimmunized patients, as well as a low CD4/CD8 ratio (0.7 vs. 1.6, p = 0.003), a higher percentage of B lymphocytes versus the control group (30 vs. 20%, p = 0.003), and a decrease of Treg CD4+ lymphocytes versus the control group (3 vs. 12 cells/µL, p = 0.043). These observations suggest that alloimmunized patients have important alterations in the number of some lymphocyte subsets that can be translated into clinical immune dysregulation. CONCLUSION: A decreased CD4/CD8 ratio, increased B lymphocytes, and Treg lymphocyte deficiency are the most significant changes observed in alloimmunized patients.

Maternal obesity associated with increase in natural killer T cells and CD8+ regulatory T cells in cord blood units.

BACKGROUND: One of the major limitations of umbilical cord blood (UCB) as hematopoietic stem cell source is its restricted cell number. In mothers who are candidates for stem cell donation, there are variables that affect the quantity and quality of UCB units. The aim of this study was to determine if obstetric, maternal, and fetal factors modify the number of lymphocyte subsets in UCB units. STUDY DESIGN AND METHODS: This was a prospective, observational study. In UCB units, the numbers of CD34, NK, NKT, iNKT, Type 1 dendritic cells (DCs), Type 2 DCs, T γδ, T CD4+, T CD8+ lymphocytes, CD4+CD25+FoxP3+, and CD8+CD25+FoxP3+ T regulatory (Treg) cells were quantified by flow cytometry. RESULTS: Fifty-four UCB units were included; the donors' mean weight was 75 kg (range, 52 to 102 kg) and they had a mean body mass index (BMI) of 30 kg/m(2) (range 22 to 40 kg/m(2) ), of which 12 (22%) had a normal BMI, 14 (26%) were overweight, and 28 (52%) were obese. The mean number of CD34+ cells was 4.45 × 10(6) (range, 0.7 × 10(6) to 20.5 × 10(6) ). The number of NKT, CD3+, CD4+, CD8+, and CD8+CD25+FoxP3+ Treg cells was significantly higher in overweight or obese mothers; CD34+ cells were decreased in the same group. The number of iNKT and CD34+ cells was decreased in newborns weighing above the average. CONCLUSIONS: Maternal factors such as BMI, and fetal factors such as weight at birth, should be added to the selection criteria of UCB donors.

Significant increase in MIC-A and MIC-B and soluble MIC-A and MIC-B in canine lymphomas.

Non-Hodkin's lymphoma (NHL) is the most frequent hematologic malignancy in humans and dogs. NKG2D is one of the most critical receptors on NK cells, recognizing their natural ligands on malignant cells such as A and B major histocompatibility complex-related proteins (MIC-A and MIC-B). Soluble molecules (sMIC-A and sMIC-B) can interfere with immune synapsis between NK cells and tumor cells, impeding NK cytotoxicity. The main objectives of this study were to analyze, in dogs with diffuse large B cell lymphoma, NK cell lymphoma, and reactive lymphadenopathies, the role of NK cells, their activating receptors NKG2D and NKp46, and their ligands MIC-A and MIC-B, as well as soluble molecules sMIC-A and sMIC-B. Thirty-six dogs with a possible diagnosis of NHL and eight healthy dogs were studied. NHL was diagnosed in 28 (78 %) dogs; in the other 8 (22 %), reactive lymphadenopathies were present. Most of the lymphomas corresponded to B cell NHL (82 %). The most predominant subtype was diffuse large B cell lymphoma (21, 71.5 %), followed by five cases (18 %) that were Non-B Non-T lymphomas (presumably NK cell lymphomas) and other B cell lymphomas (3, 10.5%). There were no cases of T cell NHL. MIC-A was positive in 7 of 27 (26 %) cases of NHL, and MIC-B in 20 of 27 (74 %) NHL. In non-malignant lymphadenopathies, three (37.5 %) dogs were positive for MIC-A, and five (62.5 %) expressed MIC-B. Dogs with lymphoma had higher numbers of NK cells than eight healthy dogs. In 15 dogs (12 cases with NHL and three cases with reactive adenopathies) and eight controls, there were no differences in the number of NK cells expressing NKP46 and NKG2D. NHL dogs had higher values of sMIC-A and sMIC-B. B-cell and NK cell lymphomas correspond to 86 % and 14 % of all canine lymphomas. MIC-A, MIC-B, and sMIC-A and sMIC-B were increased in canine lymphomas.

[Impact of hyperglycemia on the prognosis of patients hospitalized for severe pneumonia in COVID-19]. / Impacto de hiperglucemia en el pronóstico de hospitalizados por neumonía grave en COVID-19.

Background: Adequate glycemic control improves the prognosis of patients hospitalized for pneumonia associated with severe COVID-19. Objective: To evaluate the impact of hyperglycemia (HG) on the prognosis of patients hospitalized for severe pneumonia associated with COVID-19 in unvaccinated patients. Material and methods: Prospective cohort study. We included patients hospitalized from August 2020 to February 2021, with severe COVID-19 pneumonia, not vaccinated against SARS-CoV-2. Data was collected from admission to discharge. We used descriptive and analytical statistics according to the data distribution. ROC curves were used to determine the cut-off points with the highest predictive performance for HG and mortality, with the IBM SPSS program, version 25. Results: We included 103 patients, 32% women, 68% men, age 57 ± 13 years; 58% were admitted with HG (191, IQR 152-300 mg/dL) and 42% with normoglycemia (NG < 126 mg/dL). Mortality was higher in HG at admission 34 (56.7%) than in NG 13 (30.2%) (p = 0.008). HG was associated with diabetes mellitus 2 and neutrophilia (p < 0.05). The risk of death increases 1.558 times (95% CI 1.118-2.172) if HG is at admission and 1.43 times (95% CI 1.14-1.79) during hospitalization. Maintaining NG throughout the hospitalization contributed independently to survival (RR = 0.083 [95% CI 0.012-0.571], p = 0.011). Conclusion: HG significantly impacts prognosis by increasing mortality more than 50% during hospitalization for COVID-19.

Introducción: el adecuado control glucémico mejora el pronóstico de pacientes hospitalizados por neumonía asociada a COVID-19 grave. Objetivo: evaluar el impacto de la hiperglucemia (HG) sobre el pronóstico de pacientes hospitalizados por neumonía grave asociada a COVID-19 en no vacunados. Material y métodos: estudio de cohorte prospectivo. Se incluyeron pacientes hospitalizados de agosto de 2020 a febrero de 2021, con neumonía grave por COVID-19, no vacunados contra SARS-CoV-2. Los datos fueron recolectados desde el ingreso hasta el egreso. Se empleó estadística descriptiva y analítica de acuerdo con la distribución de datos. Se construyeron curvas ROC para determinar los puntos de corte de mayor rendimiento predictivo para HG y mortalidad, con el programa IBM SPSS, versión 25. Resultados: se incluyeron 103 pacientes, 32% mujeres, 68% hombres, edad 57 ± 13 años; 58% ingresaron con HG (191, IQR 152-300 mg/dL) y 42% en normoglucemia (NG < 126 mg/dL). La mortalidad fue mayor en HG al ingreso 34 (56.7%) que en NG 13 (30.2%) (p = 0.008). La HG se asoció con diabetes mellitus 2 y neutrofilia (p < 0.05). El riesgo de muerte se incrementó 1.558 veces (IC 95% 1.118-2.172) si la HG fue al ingreso y 1.43 veces (IC 95% 1.14-1.79) durante la hospitalización. Mantener NG durante todo el internamiento contribuyó de manera independiente a la sobrevida (RR 0.083 [IC 95% 0.012-0.571], p = 0.011). Conclusión: la HG impacta significativamente el pronóstico al incrementar en más de 50% la mortalidad durante la hospitalización por COVID-19.

CD133+CD34+ and CD133+CD38+ blood progenitor cells as predictors of platelet engraftment in patients undergoing autologous peripheral blood stem cell transplantation.

BACKGROUND: Hematopoietic stem cells (HSC) have been characterized by CD34+ expression and an adequate dose of CD34+ cells is associated with a complete engraftment. CD133 is a more specific marker of HSC. MATERIALS AND METHODS: We studied the relationship between graft content of CD34+, CD133+, and CD38+ cells and trilineage engraftment after autologous stem cell transplantation in patients with different hematological disorders. Blood samples were obtained before and after mobilization with recombinant granulocyte-colony stimulating factor (G-CSF, 16 µg/kg), from apheresis collections, and after transplantation. RESULTS: Cell subsets were quantified by flow cytometry, and the dose of each population infused was correlated with success of engraftment. G-CSF induced mobilization of CD133+CD38+ cells (12.6-fold) and CD133+CD34+ cells (14.7-fold). A correlation was observed between the infused dose of CD133+CD34+ and CD133+CD38+ cells and platelet engraftment. CONCLUSION: CD133+CD34+ and CD133+CD38+ cells were mobilized with G-CSF and these cell subsets were correlated with platelet engraftment.

Undifferentiated immunophenotypes and not expression of BCR-ABL can be associated in adult Mestizo Mexican patients with ALL.

INTRODUCTION: The BCR-ABL t(9;22)(q34;q11) translocation has been identified as a risk factor in de novo acute lymphoblastic leukemia (ALL), but there are other factors that may influence survival in patients not expressing this translocation. OBJECTIVE: To associate expression and non-expression of BCR-ABL with immunophenotype and other clinical features in adult patients with ALL from a Mexican mestizo population. MATERIAL AND METHODS; Peripheral blood samples from 35 adult patients with de novo ALL were used to detect BCR-ABL by reverse transcriptase polymerase chain reaction (RT-PCR) as well as immunophenotype by flow cytometry. RESULTS: In the group of BCR-ABL negative patients (74.28%) two subgroups were identified with the immature immunophenotypes CD34+/CD33+ and/or CD13+, and CD10-/CD34+. In the group of BCR-ABL positive patients (25.72%) leukemic blast cells with a more differentiated immunophenotype compared to the BCR-ABL negative group were found. As regards clinical and biological characteristics, we found survival in months to be very similar and a tendency to high initial leukocyte counts in both groups. CONCLUSIONS: This is the first study conducted on a Mexican mestizo population to report that BCR-ABL negative patients can present a high frequency of undifferentiated immunophenotypes and must therefore be considered as vulnerable as BCR-ABL positive patients.

Serum calcium is an independent prognostic factor of overall survival in Mexican patients with multiple myeloma.

OBJECTIVE: To evaluate the impact of different prognostic factors that has been suggested to be useful in predicting the survival of patients with multiple myeloma (MM). MATERIALS AND METHODS: A longitudinal prospective study was conducted on 24 adult Mexican patients diagnosed with primary MM. The levels of expression of CD38, CD138 and cyclin D1 were analyzed in plasma cells (PCs) from patients and mononuclear cells from healthy donors. Serum levels of lactate dehydrogenase, creatinine, calcium, beta2 microglobulin and interleukin-6 (IL-6) as well as hemoglobin and platelet count were taken into consideration. RESULTS; CD138 and cyclin D1 levels in absolute numbers were significantly overexpressed in malignant PCs. A positive correlation was noted between cyclin D1 and CD38 expression levels in malignant PCs. IL-6 and serum calcium were also positively correlated in MM patients. Cyclin D1 overexpression was not associated with better overall survival (OS). Normal calcium levels were associated with better overall survival (OS). Serum calcium was the only variable correlating with better OS in Cox regression analysis. CONCLUSION: Serum calcium is an independent prognostic factor of OS in a population of Mexican patients with MM.

Important decrease in invariant natural killer T, CD4+ regulatory T cells, CD8+ regulatory T cells, gamma-delta T cells, and CD4+ T lymphocytes in HIV-negative patients with hemophilia.

Hereditary hemophilias are X-linked inherited bleeding disorders defined as deficiencies of the coagulation factors VIII or IX. They are characterized by easy to provoke or spontaneous bleeding. HIV infection in hemophilic patients is a risk factor for the reduction of CD4+ T cells. There is no information regarding the cellular immune function in HIV-negative patients with hemophilia. To evaluate the number of lymphocyte subsets in adult patients with hemophilia A or B as compared with healthy donors. 39 Adult hemophilics and 27 healthy donors were included. Lymphocyte subsets [CD4 and CD8 T cells, natural killer cells, natural killer T (NKT) cells, invariant NKT (iNKT) cells, gamma-delta T (γδT) cells, type 1 and 2 dendritic cells, CD14 monocytes, CD4 and CD8 regulatory T cells (Tregs), and B cells], were analyzed by flow cytometry. A significant decrease of CD4+ T lymphocytes, γδT cells, iNKT cells, CD4+ and CD8+ Tregs was observed in patients with hemophilia. Those patients having factor VIII inhibitor had the lowest CD4+ Treg and CD8+ Treg counts. CD14 monocytes were increased, as well as iNKT and type 2 dendritic cells in obese-overweight hemophilics. CD4+ lymphocytes, iNKT, γδT cells, and Tregs (CD4+ and CD8+), are significantly decreased in patients with hemophilia. Depletion of Tregs is more important in patients with factor VIII inhibitor. Physicians caring for hemophilia patients should realize that, even when they are not suffering infections frequently, may have early evidence of cellular immunodeficiency.

Clinical relevance of NKT cells and soluble MIC-A in Hodgkin lymphoma.

Previous studies demonstrated that the majority of Hodgkin lymphoma (HL) patients achieve response after treatment, while 5% become refractory. Studies analyzing the role of lymphocyte subsets in peripheral blood are limited. This investigation sought to evaluate peripheral blood lymphocyte subsets and soluble MHC class I chain-related proteins A and B (sMIC-A/B) and their correlation with survival in patients with newly diagnosed HL. The study recruited 36 patients and 72 healthy donors. HL patients showed a decrease in CD4, B, monocytes, NK, and NKT cells; and an increase in γ-δ T cells and soluble MIC-A serum levels. Higher values of s-MIC-A  >100 ng/mL and NKT cells >40 µL correlated with poor overall survival (OS). In conclusion, in HL peripheral blood CD4 T and B cells, monocytes, NK, and NKT cells were decreased, while s-MIC-A and γ-δ T cells increased. Higher values of s-MIC-A and NKT cells correlated with poor survival.

Development and Evaluation of a Set of Spike and Receptor Binding Domain-Based Enzyme-Linked Immunosorbent Assays for SARS-CoV-2 Serological Testing.

The implementation and validation of anti-SARS-CoV-2 IgG serological assays are reported in this paper. S1 and RBD proteins were used to coat ELISA plates, and several secondary antibodies served as reporters. The assays were initially validated with 50 RT-PCR positive COVID-19 sera, which showed high IgG titers of mainly IgG1 isotype, followed by IgG3. Low or no IgG2 and IgG4 titers were detected. Then, the RBD/IgG assay was further validated with 887 serum samples from RT-PCR positive COVID-19 individuals collected at different times, including 7, 14, 21, and 40 days after the onset of symptoms. Most of the sera were IgG positive at day 40, with seroconversion happening after 14-21 days. A third party conducted an additional performance test of the RBD/IgG assay with 406 sera, including 149 RT-PCR positive COVID-19 samples, 229 RT-PCR negative COVID-19 individuals, and 28 sera from individuals with other viral infections not related to SARS-CoV-2. The sensitivity of the assay was 99.33%, with a specificity of 97.82%. All the sera collected from individuals with infectious diseases other than COVID-19 were negative. Given the robustness of this RBD/IgG assay, it received approval from the sanitary authority in Mexico (COFEPRIS) for production and commercialization under the name UDISTEST-V2G®.

FLT3-ITD and CD135 Over-Expression are Frequent Findings of Poor Survival in Adult Patients with Acute Leukemias.

BACKGROUND: Fms-like tyrosine kinase 3 (FLT3) expression and mutation have been considered a poor prognostic factor in acute myeloid leukemia (AML). FLT3-ITD mutation is present in 30% of adult patients with AML and 2-5% in childhood acute lymphoblastic leukemia (ALL). The impact of these mutations on the prognosis of ALL patients, has not yet been established. Moreover, a limited number of publications regarding the level of expression of the FLT3 receptor (CD135) in both leukemias exist. This study aimed to analyze the clinical outcomes associated to the presence of FLT3-ITD mutation and the expression of CD135. METHODS: 82 adult patients with newly diagnosed acute leukemia (39 with AML and 43 with ALL) were included. Flow cytometry and RT-PCR were done to analyze the expression of CD135 and the presence of FLT3 ITD mutation, respectively. RESULTS: FLT3-ITD was present in 14 (36%) of AML and 15 (35%) of ALL patients. Disease free survival (DFS) and overall survival (OS) were lower in ALL patients having a CD135 expression >3000 cells/µL. There was a trend for poor OS in AML patients expressing FLT3 ITD. OS was worse in AML patients with high expression of CD135. CONCLUSION: A higher (35%) frequency of FLT3-ITD was found in adult ALL patients. The presence of FLT3-ITD was associated with a trend of poor OS in AML cases, and overexpression of CD135 was correlated with poor DFS in ALL cases and poor OS in both acute leukemias.

Granulocyte colony-stimulating factor produces a decrease in IFNgamma and increase in IL-4 when administrated to healthy donors.

Hematopoietic stem cells transplantation (HSCT) is the leading curative therapy for a variety of hematological and hereditary diseases; however, graft versus host disease (GVHD), an immunologic phenomenon that is favored by Th1 cytokines and cytotoxic cells from donors, is present frequently and is one of the most important causes of transplant related mortality. Peripheral blood HSCT is the preferred source of stem cells in almost 100% of the cases of autologous HSCT and in 70% of allogeneic transplants. The best mobilizing agent to get the stem cells out from the bone marrow is the Granulocyte-Colony Stimulating Factor (G-CSF). In this work, our main objective was to study a possible correlation between the graft cell dose and the patient's clinical outcome. We evaluated the immunologic changes produced by G-CSF in the lymphocyte and cytokine profiles in allogeneic HSC donors. HSC from twelve donors were mobilized with G-CSF at 16 microg/kg/day, for 5 days. Basal Peripheral Blood (BPB), Mobilized Peripheral Blood (MPB), and aphaeresis mononuclear cells (G-MNC) samples were taken from all donors. Using flow cytometry, we quantified CD19(+), CD3(+), CD3(+)CD4(+), CD3(+)CD8(+), NK, NKT, DC1, and DC2 cells. Cytokines were determined by ELISA in culture supernatants. CD19(+) (p = 0.001), DC1 (p < 0.002) and DC2 (p < 0.001) cells were increased in MPB with respect to BPB. An increase in Th2 cytokines such as (IL-4) and a decrease in Th1 cytokines (IFNgamma, IL-2) were also found in MPB samples. In conclusion, Th1 and Th2 cytokines are relevant in predicting the clinical outcome after allogeneic peripheral blood HSCT.

γδ T Cells Number, CD200, and Flt3 Expression Is Associated with Higher Progression Free Survival in Patients with Chronic Myeloid Leukemia.

BACKGROUND: Tumor immunoedition involves alterations in cells of immune system, which may play an important role in the immunosurveillance of patients with cancer diseases. AIM OF THE STUDY: To determine the association between the number of immune cells and the expression of surface markers in leukemic cells of patients with de novo CML who achieved molecular response. METHODS: A longitudinal study was conducted in 31 patients with de novo CML. Peripheral blood samples were obtained at diagnosis for quantification of immune cells and tumor cells expressing CD200, CD135, GpP, and Bcl-2. Results were compared with a group of 60 healthy donors. Lymphocyte subsets were analyzed during a 48 month follow-up period and molecular response to treatment was assessed simultaneously by QT-PCR. The group of patients with deep molecular response was compared with de novo CML patients; the cut-off value of cell count was determined by ROC analysis. Kaplan-Meier and Cox proportional hazard model were used to determine the significant association between the number of cells and progression-free survival. RESULTS: Differences in number of CD4, CD4Tregs, NK, γδT, monocytes, and pDC's, tumor-cells expressing CD200+, CD135+, GpP+, and Bcl-2+ were observed between patients and healthy donors. The number of γδT lymphocytes, CD200+, and CD135+ cells were associated with longer progression-free survival (p = 0.0112, p = 0.0012 and p = 0.0201 respectively). CONCLUSION: A γδT lymphocyte count <63 cel/uL, CD200+ <997 cel/uL, and CD135+ <23 317 cel/uL at diagnosis is associated with the maintenance of deep molecular response at 48 months in patients with de novo CML.

Toxoplasma gondii: effect of maternal infection in the development of lymphoid organs of BALB/c neonates.

Toxoplasmosis is one of the worldwide parasitic zoonoses. Alterations in the lymphopoietic system are still poorly studied. We analyzed lymphoid organs of BALB/c mice neonates from Toxoplasma gondii-intraperitoneally-infected mothers on 19th day of gestation, with 30 tachyzoites of strain RH. Normal non-infected pregnant females were used as controls. At 7 days after birth, animals were classified as neonates from infected (NIM) and neonates from non-infected mothers (NNIM). Weight of the thymus and number of thymic cells in NIM were decreased, percentage of apoptosis was significantly increased. Decrease in lymphocytes and monocytes and an increase of plasma cells were observed in bone marrow of NIM. Peripheral blood of NIM showed an increase of monocytes and neutrophils and a decrease in lymphocytes. Infection of the mother during the last day of gestation provokes in the neonates changes in the lymphoid organs that could explain survival of 75% of them.

Post-treatment improvement of NK cell numbers predicts better survival in myeloma patients treated with thalidomide-based regimens.

Multiple myeloma (MM) is a disease characterized by antitumoral immune dysfunction. The objective of the present study was to determine lymphocyte subsets (B, T, NK, NKT, iNKT, dendritic cells, and regulatory T cells) in 68 newly diagnosed patients and 113 healthy donors. Lymphocyte subsets were studied in the same patients 6 months after treatment. Pre-treatment values of CD4+ T cells, NK cells, type 2 dendritic cells, and B cells in MM patients were lower than in healthy donors. Forty patients (59%) received MPT treatment and 28 (41%) thal-dex. Patients with no response to treatment, exhibited a decrease in CD4+ T cells and NK cells, as well as an increase in Treg cell numbers. Median DFS and OS was lower in patients not achieving response, in patients having low numbers of NK cells, and higher values of LDH. The number of CD4 T cells, NK, DC2, and B cells at diagnosis is lower in patients with MM. Non-responder patients had lower CD4 and NK, but higher Treg cell values. Patients in which response is not achieved, and those holding lower values of NK cells and higher levels of LDH, have poor DFS and OS.

Description of CD8+ Regulatory T Lymphocytes and Their Specific Intervention in Graft-versus-Host and Infectious Diseases, Autoimmunity, and Cancer.

Gershon and Kondo described CD8+ Treg lymphocytes as the first ones with regulating activity due to their tolerance ability to foreign antigens and their capacity to inhibit the proliferation of other lymphocytes. Regardless, CD8+ Treg lymphocytes have not been fully described-unlike CD4+ Treg lymphocytes-because of their low numbers in blood and the lack of specific and accurate population markers. Still, these lymphocytes have been studied for the past 30 years, even after finding difficulties during investigations. As a result, studies have identified markers that define their subpopulations. This review is focused on the expression of cell membrane markers as CD25, CD122, CD103, CTLA-4, CD39, CD73, LAG-3, and FasL as well as soluble molecules such as FoxP3, IFN-γ, IL-10, TGF-ß, IL-34, and IL-35, in addition to the lack of expression of cell activation markers such as CD28, CD127 CD45RC, and CD49d. This work also underlines the importance of identifying some of these markers in infections with several pathogens, autoimmunity, cancer, and graft-versus-host disease as a strategy in their prevention, monitoring, and cure.

Cell proliferation and inhibition of apoptosis are related to c-Kit activation in leukaemic lymphoblasts.

Receptor tyrosine kinase (RTK) activity may contribute to carcinogenesis. The c-Kit receptor, a member of the RTK family, is expressed in immature haematopoietic system cells. Acute lymphoblastic leukaemia (ALL) presents incompletely differentiated lymphoblasts, and consequently, c-Kit expression can be detected in these cells. The BCR-ABL kinase, which is usually present in both ALL and chronic myeloid leukaemia, can trigger signalling pathways with neoplastic effects. However, a certain number of ALL patients and chronic myeloid leukaemia patients do not express this kinase, raising the question of which other proteins that intervene in signalling pathways may be involved in the development of these diseases. OBJECTIVES: To test whether c-Kit has proliferative effects and affects the inhibition of apoptosis of leukaemic lymphoblasts that do not express BCR-ABL. METHODS: We cultured RS4:11 lymphoblasts and analysed the expression and activation of c-Kit by immunofluorescence, and flow cytometry, evaluation of cell proliferation, apoptosis, cyclin D1 and Bak expression were carried out by flow cytometry; activation of AKT and survivin expression were tested by immunoblot. RESULTS: The c-Kit receptor was found to induce proliferation and to increase the expression of cyclin D1 via the PI3K/AKT/NF-kB signalling pathway. Additionally, the c-Kit/PI3K/AKT pathway increased the inhibition of apoptosis and survivin expression. Similarly, c-Kit was observed to reduce the expression of the pro-apoptotic Bak protein. CONCLUSION: These results suggest that, in leukaemic lymphoblasts, c-Kit triggers a signalling pathway with proliferative and anti-apoptotic effects; information to this effect has not yet been reported in the literature.