Adoptive immunotherapy with double-bright (CD56bright /CD16bright ) expanded natural killer cells in patients with relapsed or refractory acute myeloid leukaemia: a proof-of-concept study.

Patients with acute myeloid leukaemia (AML) have a five-year survival rate of 28·7%. Natural killer (NK)-cell have anti-leukaemic activity. Here, we report on a series of 13 patients with high-risk R/R AML, treated with repeated infusions of double-bright (CD56bright /CD16bright ) expanded NK cells at an academic centre in Brazil. NK cells from HLA-haploidentical donors were expanded using K562 feeder cells, modified to express membrane-bound interleukin-21. Patients received FLAG, after which cryopreserved NK cells were thawed and infused thrice weekly for six infusions in three dose cohorts (106 -107 cells/kg/infusion). Primary objectives were safety and feasibility. Secondary endpoints included overall response (OR) and complete response (CR) rates at 28-30 days after the first infusion. Patients received a median of five prior lines of therapy, seven with intermediate or adverse cytogenetics, three with concurrent central nervous system (CNS) leukaemia, and one with concurrent CNS mycetoma. No dose-limiting toxicities, infusion-related fever, or cytokine release syndrome were observed. An OR of 78·6% and CR of 50·0% were observed, including responses in three patients with CNS disease and clearance of a CNS mycetoma. Multiple infusions of expanded, cryopreserved NK cells were safely administered after intensive chemotherapy in high-risk patients with R/R AML and demonstrated encouraging outcomes.

An Experimental Study Comparing the Expansion of Peripheral Blood Natural Killer (NK) Cells Cultured with Artificial Antigen-Presenting Cells, in the Presence or Absence of Bone Marrow Mesenchymal Stem Cells (MSCs).

NK cells have been seen as potential agents in adoptive immunotherapy for cancer. The main challenge for the success of this approach is to obtain a great quantity of activated NK cells for adoptive transfer. The present study had aimed to evaluate the effect of a feeder layer of irradiated MSCs in the in vitro expansion of NK cells. MSCs were obtained from the bone marrow (BM) cells remaining in the bag and filter used in the transplantation of hematopoietic stem cells. NK cells were obtained from peripheral blood (PB) of healthy volunteers. NK expansion and activation were stimulated by culture with artificial antigen-presenting cells (aAPCs) and IL-2, in the presence or absence of BM-MSCs. NK cell proliferation, phenotypic expression and cytotoxic activity were evaluated. Both culture conditions showed high NK purity with predominance of NK CD56brightCD16+ subset post expansion. However, cultures without the presence of MSCs showed higher NK proliferation, expression of activation markers (CD16 and NKG2D) and related cytotoxic activity. In this experimental study, the presence of a feeder layer of irradiated BM-MSCs interfered negatively in the expansion of PB-NKs, limiting their growth and activation. Further investigation is needed to understand the mechanisms of NK-MSC interaction and its implications.

Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil.

BACKGROUND: Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome. OBJECTIVE: To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center. RESULTS: Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality. CONCLUSIONS: In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil

ABSTRACT Background: Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome. Objective: To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center. Results: Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality. Conclusions: In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

Effects Of Hypoxia in Long-Term In Vitro Expansion of Human Bone Marrow Derived Mesenchymal Stem Cells.

Mesenchymal stem cells (MSC) are considered multipotent stromal, non-hematopoietic cells with properties of self-renovation and differentiation. Optimal conditions for culture of MSC have been under investigation. The oxygen tension used for cultivation has been studied and appears to play an important role in biological behavior of mesenchymal cells. The aim is characterize MSC in hypoxia and normoxia conditions comparing their morphological and functional characteristics. Bone marrow-derived mesenchymal stem cells obtained from 15 healthy donors and cultured. MSC obtained from each donor were separated into two cultivation conditions normoxia (21% O2 ) and hypoxia (three donors at 1%, three donors at 2%, five donors at 3%, and four donors at 4% O2 ) up to second passage. MSC were evaluated for proliferation, differentiation, immunophenotyping, size and cell complexity, oxidative stress, mitochondrial activity, and autophagy. Culture conditions applied did not seem to affect immunophenotypic features and cellular plasticity. However, cells subjected to hypoxia showed smaller size and greater cellular complexity, besides lower proliferation (P < 0.002). Furthermore, cells cultured in low O2 tension had lower mitochondrial activity (P < 0.03) and a reduced tendency to autophagy, although oxidative stress did not vary among groups (P < 0.39). Oxygen tension seems to be a key regulator of cellular adaptation in vitro, and metabolic effects underlying this variable remain undescribed. Heterogeneity or even lack of results on the impact of oxygen concentration used for expanding MSC highlights the need for further research, in order to optimize conditions of cultivation and expansion and achieve greater safety and therapeutic efficacy. J. Cell. Biochem. 118: 3072-3079, 2017. © 2017 Wiley Periodicals, Inc.

Brazilian guidelines on hematopoietic stem cell transplantation in acute myeloid leukemia.

INTRODUCTION/OBJECTIVES: Acute myeloid leukemia (AML) accounts for 90% of all cases of acute leukemia in adults. In Brazil, the mortality from myeloid leukemia is 1.74/100 000 men and 1.37/100 000 women. Our aim was to review and update guidelines of the Brazilian Society of Bone Marrow Transplantation on indications of hematopoietic stem cell transplantation (HSCT) for the treatment AML. CONCLUSIONS: (i) Allo-HSCT is recommended for high-risk AML (IA); (ii) allo-HSCT is recommended for AML of intermediate risk (IA); (iii) allo-HSCT is recommended for AML relapsed/refractory (C4); (iv) auto-HSCT is recommended for AML after 1 consolidation (C4); (v) auto-HSCT is recommended for AML in CR1 (higher than QT in the Brazilian experience) (C4); (vi) auto-HSCT is accepted for AML M3 in second molecular complete remission (2B); (vii) peripheral blood instead of Bone Marrow HSC for advanced disease (2A); (viii) recommended conditioning protocols: Bu-Cy/Bu-Mel, Bu-Flu, TBI-Cy. In umbilical cord HSCT, consider ATG-based protocols (2A); (ix) allogeneic HSCT for the treatment of AML can be used in patients between 60 and 80 yr with good performance status and the absence of significant comorbidities (C4).

Mesenchymal stem cell therapy and acute graft-versus-host disease: a review.

Mesenchymal stem cells (MSCs) are being widely studied as potential cell therapy agents due to their immunomodulatory properties, which have been established by in vitro studies and in several clinical trials. Within this context, mesenchymal stem cell therapy appears to hold substantial promise, particularly in the treatment of conditions involving autoimmune and inflammatory components. Nevertheless, many research findings are still contradictory, mostly due to difficulties in characterization of the effects of MSCs in vivo. The purpose of this review is to report the mechanisms underlying mesenchymal stem cell therapy for acute graft-versus-host disease, particularly with respect to immunomodulation, migration, and homing, as well as report clinical applications described in the literature.

Assessment of regulatory T cells in childhood immune thrombocytopenic purpura.

This study had the objective to assess the frequency of Tregs in children newly diagnosed with ITP and ascertain whether an association exists between Tregs and platelet counts, by means of a comparison with healthy controls. This case-control study included 19 patients newly diagnosed with ITP-whose blood samples were collected at four points in time: before any therapy and 1, 3, and 6 months after diagnosis-and 19 healthy controls. Tregs (CD4(+) CD25(+)Foxp3 T cells) were evaluated by flow cytometry. There was a statistically significant difference in platelet count between the case and control groups. There were no significant differences in Treg counts between cases and controls at any point during the course of the study and no difference in Treg counts between the chronic and nonchronic groups and no significant correlation between Tregs and platelet counts in the case and control groups. The findings of this study did not show any statistically significant correlation between Tregs and number of platelets in the case and control groups. Treg cells did not play a role in the regulation of autoimmunity in children with ITP.

High prevalence of anemia in children and adult women in an urban population in southern Brazil.

This population-based study was designed to detect the prevalence of anemia in a healthy population of children (18 months to 7 years) and women (14 to 30 years) tested in 2006-2007 in the state of Rio Grande do Sul, Brazil as part of an effort to tackle this massive problem that still affects so many people in the XXI century. Anemia was defined according to the WHO. Capillary blood was measured and socioeconomic status was determined according to the Brazilian Association of Market Research Agencies. The median prevalence of anemia in 2198 children was 45.4% and in 1999 women 36.4%. Anemia decreased with age during childhood; although significantly more prevalent in lower classes individuals, it was also high in the upper classes. There are indirect evidences that the lack of iron supplementation and/or iron fortified food may play a role in it. Professionals and society wise measures of education have to be implemented in order to address possible biologic factors involved in childhood psychosocial development in southern Brazil.

Detection of minimal residual disease by flow cytometry for patients with multiple myeloma submitted to autologous hematopoietic stem cell transplantation.

The treatment strategy in multiple myeloma (MM) is to get complete remission followed by high-dose chemotherapy and autologous Hematopoietic Stem Cell Transplantation (HSCT). Neoplastic Plasma Cells (NPCs) are CD45(-/dim), CD38(+high), CD138(+), CD19(-), and CD56(+high) in most cases. The description of this immunophenotype is of major importance as it leads to the correct identification of minimal residual disease (MRD). Samples from 44 Patients were analyzed prospectively in this study. We analyzed if the presence of MRD at three months after HSCT was predictive of relapse or death. There were 40 evaluable patients of whom 16/40 patients had MRD at three moths after HSCT and there were none in cytological relapse. The mean overall survival (OS) was 34 months and disease-free survival (RFS) was 28 months after HSCT. There was no significant difference in the log rank analysis comparing OS and the presence of MRD (P = 0,611) and RFS (P = 0,3106). Here, we demonstrate that three color flow cytometry (FCM) is more sensitive for MDR evaluation than cytological analyzes. However, based in our data we can not affirm that MRD is a good predictor of MM relapse or death. In conclusion, our results could be attributed to a short followup, small sample size, and over most to the inability of a three-color FCM to detect the NPC population.

Validation of the EBMT Risk Score for South Brazilian Patients Submitted to Allogeneic Hematopoietic Stem Cell Transplantation.

Background. Allogeneic hematopoietic stem cell transplantation (HSCT) is still associated with a high transplant-related mortality rate. In 2009, the EBMT risk score was validated as a simple tool to predict the outcome after allogeneic HSCT for acquired hematological disorders. Objectives. The aim of this study was to validate the applicability of the EBMT risk score for allogeneic HSCT on South Brazilian patients. Methods. A retrospective observational study was performed based on patients' records and data base at Hospital de Clínicas de Porto Alegre, including all allogeneic transplants for malignant and severe aplastic anemia from 1994 to 2010. Patients were categorized according to EBMT risk score and overall survival (OS). Nonrelapse mortality (NRM) and relapse rate (RR) were analyzed. Results. There were 278 evaluable patients. OS, NRM, and RR at five years median followup were 48.7%, 40.7%, and 30.7%, respectively. The OS was 81.8% for risk score 0 and 0% for score 6 (P < 0.001), and NRM was 13.6% and 80% for risk scores 0 and 6, respectively (P = 0.001). Conclusion. The EBMT risk score can be utilized as a tool for clinical decision making before allogeneic HSCT for malignant hematological diseases and severe aplastic anemia at a single center in Brazil.

DNMT3A Mutations in Patients with Acute Myeloid Leukemia in South Brazil.

Acute myeloid leukemia (AML) is a complex and heterogeneous hematopoietic tissue neoplasm. Several molecular markers have been described that help to classify AML patients into risk groups. DNA methyltransferase 3A (DNMT3A) gene mutations have been recently identified in about 22% of AML patients and associated with poor prognosis as an independent risk factor. Our aims were to determine the frequency of somatic mutations in the gene DNMT3A and major chromosomal translocations in a sample of patients with AML. We investigated in 82 samples of bone marrow from patients with AML for somatic mutations in DNMT3A gene by sequencing and sought major fusion transcripts by RT-PCR. We found mutations in the DNMT3A gene in 5 patients (6%); 3 were type R882H [corrected]. We found fusion transcripts in 19 patients, namely, AML1/ETO (n = 5; 6.1%), PML/RARα (n = 12; 14.6%), MLL/AF9 (0; 0%), and CBFß/MYH11 (n = 2; 2.4%). The identification of recurrent mutations in the DNMT3A gene and their possible prognostic implications can be a valuable tool for making treatment decisions. This is the first study on the presence of somatic mutations of the DNMT3A gene in patients with AML in Brazil. The frequency of these mutations suggests a possible ethnogeographic variation.