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THE BRAZILIAN SOCIETY FOR BLOOD AND MARROW TRANSPLANTATION (SBTMO) PRESENTS THE BRAZILIAN GUIDELINES ON HEMATOPOIETIC STEM CELL TRANSPLANTATION

THE BRAZILIAN SOCIETY FOR BLOOD AND MARROW TRANSPLANTATION (SBTMO) PRESENTS THE BRAZILIAN GUIDELINES ON HEMATOPOIETIC STEM CELL TRANSPLANTATION

Objective The objective of the present study is to evaluate the association of red blood cell distribution width with acute kidney injury in sepsis. Methods This is a retrospective study of 849 critically ill patients with sepsis in intensive care unit. Demographic data, renal function, inflammation, complete blood count, and acid-base parameters were compared between acute kidney injury and non-acute kidney injury groups. Therefore, a multivariate analysis was performed to observe independent predictive factors. Results Comparatively, higher levels of C-reactive protein, lactate, red blood cell distribution width, and Simplified Acute Physiology Score 3 were found in the acute kidney injury group. The study showed a higher frequency of women, hemoglobin (Hgb) concentration, platelets, bicarbonate and PaO2/FiO2 ratio in the non-acute kidney injury group. In addition, there was an independent association of comorbidity-chronic kidney disease [OR 3.549, 95%CI: 1.627-7.743; p

This study proposes an innovative way to evaluate the homing and tracking of hematopoietic stem cells from young and old mice labeled with SPIONNIRF-Rh conjugated with two types of fluorophores (NIRF and Rhodamine), and their grafting by bioluminescence (BLI) in a bone marrow transplant (BMT) model. In an in vitro study, we isolated bone marrow mononuclear cells (BM-MNC) from young and old mice, and analyzed the physical–chemical characteristics of SPIONNIRF-Rh, their internalization, cell viability, and the iron quantification by NIRF, ICP-MS, and MRI. The in vivo study was performed in a BMT model to evaluate the homing, tracking, and grafting of young and old BM-MNC labeled with SPIONNIRF-Rh by NIRF and BLI, as well as the hematological reconstitution for 120 days. 5FU influenced the number of cells isolated mainly in young cells. SPIONNIRF-Rh had adequate characteristics for efficient internalization into BM-MNC. The iron load quantification by NIRF, ICP-MS, and MRI was in the order of 104 SPIONNIRF-Rh/BM-MNC. In the in vivo study, the acute NIRF evaluation showed higher signal intensity in the spinal cord and abdominal region, and the BLI evaluation allowed follow-up (11–120 days), achieving a peak of intensity at 30 days, which remained stable around 108 photons/s until the end. The hematologic evaluation showed similar behavior until 30 days and the histological results confirm that iron is present in almost all tissue evaluated. Our results on BM-MNC homing and tracking in the BMT model did not show a difference in migration or grafting of cells from young or old mice, with the hemogram analysis trending to differentiation towards the myeloid lineage in mice that received cells from old animals. The cell homing by NIRF and long term cell follow-up by BLI highlighted the relevance of the multimodal nanoparticles and combined techniques for evaluation.

Cell therapy with T cells expressing chimeric antigen receptor (CAR-T) is a type of immunotherapy that involves the manipulation and reprogramming of immune cells (T lymphocytes) in order to recognize and kill tumor cells. For use in patients, CAR-T cells must be manufcatured inside a GMP facility according to a established procedure.

Advanced therapy products can be an alternative treatment for several disease. Manufacturing steps and product release are critical points to avoid unsafe use of products. Quality controls tests, manufacturing practice, safety testing and efficacy trials need to be properly accessed before releasing to patients. Regulatory system for cell therapy products determines guidelines for production, clinical trials and registration, considering risk-benefit ratios. This article aims to discuss main aspects of National Regulatory for advanced therapy products.

Manufacturing of customized gene or cell therapy products such as CAR-T cells is complex and depends on release tests and exams that can attest to a consistent quality standard for each product. The quality of CAR-T cell products is subject to donor variation, but also includes the manufacturing environment, as well as the quality and availability of materials and reagents. Quality must be carefully monitored and integrated into the manufacturing process.

Some patients with hematologic malignancies may benefit from chimeric antigen receptor-T (CAR-T) cell treatment. Usually, the manufacture of this cells is carried out by centralized and specialized cell therapy laboratories that cryopreserve the CAR-T cells in bags and send it for infusion in the patient treatment center. In this context, the thawing and infusion of the CAR-T cell products are critical steps in this custody chain. This article aims to discuss the most relevant points related with the CAR-T cell thawing and infusion and proposes a kind of standard operational protocol (SOP) for these processes.

Chimeric antigen receptor-T (CAR-T) cells have emerged as a treatment option for patients with hematologic malignancies. Usually, their manufacture has been carried out by specialized and centralized laboratories. A useful strategy, which allows a better logistical organization, is the peripheral blood mononuclear cells (PBMC) cryopreservation and transportation. This article aims to discuss the most relevant points related to the PBMC cryopreservation and transportation process. In addition, it proposes a kind of standard operational protocol (SOP) that can be very helpful for the cell processing labs.

BACKGROUND Although Hematopoietic Stem Cells (HSC) donation through bone marrow (BM) and peripheral blood (PB) are usually safe procedures, adverse events are expected. One of the most common events especially among BM donors (BMD) is the development of anemia. To protect the BMD and preserve the hemoglobin levels, many centers collect autologous pre-procedure blood, but the actual benefits of this procedure is controversial. METHODS AND MATERIALS This study analyzed retrospectively data to observe what factors may influence the occurrence of post-donation anemia and also evaluate the relevance of autologous red blood cell pre procedure donation (PAD). RESULTS The development of immediately post donation anemia (IP) was higher in BMD than in PB donors (64.2% BMD and 10.7% PBD, P

The hematopoietic stem cell engraftment depends on adequate cell numbers, their homing, and the subsequent short and long-term engraftment of these cells in the niche. We performed a systematic review of the methods employed to track hematopoietic reconstitution using molecular imaging. We searched articles indexed, published prior to January 2020, in PubMed, Cochrane, and Scopus with the following keyword sequences: (Hematopoietic Stem Cell OR Hematopoietic Progenitor Cell) AND (Tracking OR Homing) AND (Transplantation). Of 2191 articles identified, only 21 articles were included in this review, after screening and eligibility assessment. The cell source was in the majority of bone marrow from mice (43%), followed by the umbilical cord from humans (33%). The labeling agent had the follow distribution between the selected studies: 14% nanoparticle, 29% radioisotope, 19% fluorophore, 19% luciferase, and 19% animal transgenic. The type of graft used in the studies was 57% allogeneic, 38% xenogeneic, and 5% autologous, being the HSC receptor: 57% mice, 9% rat, 19% fish, 5% for dog, porcine and salamander. The imaging technique used in the HSC tracking had the following distribution between studies: Positron emission tomography/single-photon emission computed tomography 29%, bioluminescence 33%, fluorescence 19%, magnetic resonance imaging 14%, and near-infrared fluorescence imaging 5%. The efficiency of the graft was evaluated in 61% of the selected studies, and before one month of implantation, the cell renewal was very low (less than 20%), but after three months, the efficiency was more than 50%, mainly in the allogeneic graft. In conclusion, our review showed an increase in using noninvasive imaging techniques in HSC tracking using the bone marrow transplant model. However, successful transplantation depends on the formation of engraftment, and the functionality of cells after the graft, aspects that are poorly explored and that have high relevance for clinical analysis.

Patients with SARS-CoV-2 may be affected by the acute respiratory distress syndrome (ARDS), which has been associated with high mortality rate. As no specific drugs are available for ARDS, mesenchymal stem cells (MSC) seems to be a promising cell therapy due to immunomodulatory effects on reducing and healing inflammation-induced lung and other tissue injuries. The goal of this Phase I clinical trial was to explore the safety and efficacy of bone marrow-derived MSC (BM-MSC) infusions in patients with COVID-19 ARDS. The inclusions criteria were age between 18 to 70 years and PaO2/FiO2≤200mmHg. The BM-MSC infusions were as follow: one to 3 infusions intravenous doses of BM-MSC of 1x10 6 cells/kg; each dose could be administered with an interval between 3 to 7 days. The primary endpoint was safety (adverse events) within 6 hours; cardiac arrest or death within 24 hours post-infusion. The secondary endpoint includes patient survival at 30 days after the first infusion. Six patients were included in the trial and treated with at least one infusion of BM-MSC. The median age was 60,3 years (54 to 69), 5 were male. The median time between the worsening of respiratory distress and the BM-MSC infusion was 10 days (3 to 31 days). The median of PaO2/FiO2 before infusion was 151.86 (127.80-164.44) and median PaCO2 was 63,85 (39 to 117). One patient was treated with 3 MSC doses, two patients with 2 doses and 3 patients one dose. No serious adverse effects were observed within 24 hours post-infusion; only one death was observed following 30 days of cell administration. None of them showed adverse events during BM-MSC infusion. Only one patient showed signs of pulmonary infection one week after first BM-MSC infusion. This patient was at increased risk for infection due to prolonged intubation and a high dose of corticosteroid. Therefore, it was not possible to conclude its association with BM-MSC treatment. Only two patients showed clinical improvement after BM-MSC infusion. Patient 1 had BM-MSC infusion 72 hours after worsening of respiratory parameters, and thorax CT suggested the hypothesis of cryptogenic organizing pneumonia, which led to decision of using methylprednisolone 125mg I.V. for 3 days and carry on with MSC infusion. We observed a decrease in CRP levels from 126 to 67 mg/dL on day 1 after the first infusion, and PaO2/FiO2 ratio improved from 155 to 297 mmHg on day 5. He received the second dose within 7 days interval and by day 11 of the first infusion a new thorax TC showed complete resolution of alveolar consolidation areas in both lungs (Figure 1A and 1B). Patient 2 had BM-MSC administration 11 days after respiratory worsening and also presented improvement of PaO2/FiO2 ratio (148 to 215 mmHg after 2 days of infusion) and had thorax CT images suggesting cryptogenic organizing pneumonia with administration of methylprednisolone 250mg I.V. Nevertheless, the second dose was not administered due to ventilator-associated pneumonia and urinary infection. Four patients showed a non-sustained increase of PaO2/FiO2 ratio, with higher median PCO2 levels of 69,3 mmHg (range, 61,2 to 117) comparing to 39 and 47,3 mmHg of patients 1 and 2, respectively. PCO2 parameter could be a marker to indicate a worse response to MSC treatment, since it could point out chronic phases of COVID-19 disease. The patients died due to COVID-19 complications. No difference in inflammatory markers, such as interleukin 6, C-protein reactive test, procalcitonin, ferritin was observed before and after treatment. Inclusion criteria did not defined interval between respiratory worsening and first BM-MSC infusion. Four patients had chronic phase of COVID-19 without inflammatory markers and hypercapnia. It could be related to severity of pulmonary disease, such as reported in chronic obstructive pulmonary disease. Two patients were discharged after MSC treatment and they received methylprednisolone to treat cryptogenic organizing pneumonia. There are only a few clinical trials and observational studies evaluating the use of high-dose of glucocorticoid for severe COVID-19 pneumonia. Therefore, it is not possible to conclude that use of glucocorticoid has contributed to favorable outcomes. In conclusion, BM-MSC showed to be a secure therapeutic option for severe COVID-19 pneumonia, possibly with superior benefit in acute phases and lower PCO2 levels. Further studies involving a large cohort or randomized controlled trials are warranted. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Acute GvHD (aGvHD) is a life-threatening complication of hematopoietic stem cell transplantation. Frontline therapy for aGvHD consists of corticosteroid administration. However, ∼25% of the patients have a steroid-refractory disease, a sign of poor prognosis. An alternative therapy for steroid-refractory aGvHD is infusion of mesenchymal stromal cells (MSCs). Herein, we report the results of 46 patients treated with MSC infusion as salvage therapy for steroid-refractory aGvHD III/IV (78% grade IV). Patients received a median cumulative dose of MSCs of 6.81 × 106/kg (range, 0.98–29.78 × 106/kg) in a median of 3 infusions (range, 1–7). Median time between the onset of aGvHD and the first MSC infusion was 25.5 days (range, 6–153). Of the patients, 50% (23/46) presented clinical improvement. Of these, 3 patients (13%) had complete response, 14 (61%) had partial response and 6 (26%) had transient partial response. The estimated probability of survival at 2s year was 17.4%. Only 2 patients (4.3%) presented acute transient side effects (nausea/vomiting and blurred vision) during cell infusion. No patient had late or severe side effects because of MSC infusion. These results suggest that this therapeutic modality is safe and should be considered for steroid-refractory aGvHD, especially in countries where other second-line agents are less available.

Introduction Regular analysis of demographic, clinical and outcome data is indispensable for ensuring and maintaining quality in a hematopoietic stem cell transplant (HSCT) center. For this, data needs to be extracted accurately. Organization accreditations such as FACT (Foundation for the Accreditation of Cellular Therapy) require submission of data to the US (CIBMTR) or the European (EBMT) Registries correctly. Due to discrepancies found between medical charts data and the data submitted to CIBMTR in the first FACT accreditation cycle (2012), our HSCT center decided to hire a dedicated data manager. Objective We describe here the training and performance of the data manager in the process of collecting and transferring HSCT data to national and international registries. Methods The professional hired as data manager received internal and external training. Externally, she attended national and international congresses and visited the CIBMTR (2016). Internally, she first received training by the clinical team about the forms to be filled in. Together with the HSCT multi-professional team, they evaluated the data collection process and defined which data should appear in the medical records. Appropriate outcomes were defined for data analysis based on literature searches, the FACT requirements and the need of the clinical staff, and the data manager was trained in data analysis using R. The clinical team together with data manager developed templates appropriate for the clinical follow-up of patients, such as the Dentistry to collect data on mucositis. The quality nurse developed a regular internal auditing system. Results One of the results was the reduction of three hours in filling out the forms (TED 2400). From the structuring, organization and updating of the database, it was possible to obtain relevant indicators on survival and cumulative incidence of acute and chronic graft versus host disease, transplant-related mortality and disease relapse. These are used by the HSCT team in clinical rounds and in critical analyses of the program performance. In re-accreditations (2015 and 2018) after hiring and training, no non-compliance was identified in item B9, related to the insertion and submission of transplant data. In 2017, the clinical team designed, with the data manager, an ethically-approved multicenter study until 2027, about on transplant-related outcomes, currently with 19 centers in Brazil that sending data to CIBMTR. Conclusion Training of the data manager at our HSCT center (a profession not official in Brazil) allowed the development of strategies and tools that resulted in greater accuracy in data collection and analysis, and FACT-compliant.

Background: Membrane-assisted autologous chondrocyte transplantation is considered the gold standard surgical technique to treat greater than two millimetres diameter cartilage lesions in the knee in patients after conservative treatment failure. However, this technique is only available in developed countries of North America, Europe and Japan. According to Brazilian law, it is considered an advanced cell therapy product. There is currently no product of this type enabled for clinical use in Brazil. Following the request of the Brazilian regulatory agency (ANVISA), this phase 1 study was developed. The objective is to access feasibility and safety of a new membrane-assisted autologous chondrocyte product.Methods: Three participants with a larger than two millimetres articular cartilage lesion in the distal femur or the patella, which did not improve their symptoms with conservative treatment, will be submitted to an arthroscopically assisted cartilage biopsy. After isolation and expansion in a good manufacturing practices facility, chondrocyte seeded collagen membranes will be surgically inserted in the lesion and fixed with fibrin glue. The follow-up period will last 1 year. Primary outcome will be incidence and severity of complications according to NCI-CTCAE version 4.0. Secondary outcomes will be Western-Ontario McMaster Universities Osteoarthritis Index scale, International Knee Documentation Committee subjective scale and magnetic resonance observation of cartilage repair tissue magnetic resonance scale.Conclusions: This study, together with previous preclinical results and international experience, will allow patients in Latin America to have access to this advanced cell therapy.Trial Registration: Brazilian registry of clinical trials RBR-6fgy76 (http://www.ensaiosclinicos.gov.br/rg/RBR-6fgy76/). Ethical approval: CAAE: 73911617.2.0000.0071.

Background Autologous peripheral blood hematopoietic stem cell (PBSC) collection efficiency (CE) is reportedly affected by the patient's blood properties; however, studies to identify factors correlated with CE have shown inconsistent results. Additionally, variables such as stem cell graft granulocyte content and patient age, sex, and underlying disease, may be associated with hematopietic stem cell (HSC) infusion-related adverse reactions. In this study, we evaluated the correlation of preleukapheresis PB granulocyte count and PBSC harvest variables with CD34+ collection yield and efficiency, and thawed HSC infusion side effect occurrence. Patients and methods We evaluated data from 361 patients who had undergone autologous PBSC transplant. Large volume leukapheresis was the method for PBSC collection. Complete Blood Count and CD34+ cell enumeration were performed in the preapheresis PB and the apheresis product sample. The PBSC grafts were submitted to non-controlled rate freezing after addition of 5% DMSO plus 6% hidroxyethylstarch as a cryoprotectant solution. The cryopreserved graft was thawed in a 37°C water bath and then infused without further manipulation. Results The CD34+ yield was associated with preapheresis PB CD34+ count and immature granulocyte count. The PBSC CE was negatively correlated with preapheresis white blood cell (WBC), immature granulocyte and granulocyte count. The leukapheresis product total nucleated cell (TNC) and granulocyte content was correlated with the thawed graft infusion side effect occurrence. Conclusion This study has shown that preapheresis PB WBC and granulocyte counts were associated with leukapheresis CE. Additionally, the leukapheresis product TNC and granulocyte content was correlated with thawed graft infusion side effect occurrence.

Hematopoietic stem cell transplantation (HSCT) is an important treatment option for children with severe and refractory sickle cell disease (SCD) with debilitating clinical complications. HSCT with cells from the bone marrow of a HLA-identical sibling used in SCD has a low mortality risk, high cure rate, and high event-free survival rate after a median follow-up of 5-6 years. However, matched donors are found in only about 20% of the patients. A boy aged 8 years with SCD had a sister

Neonatal alloimmune thrombocytopenia is a serious disease, in which the mother produces antibodies against fetal platelet antigens inherited from the father; it is still an underdiagnosed disease. This disease is considered the platelet counterpart of the RhD hemolytic disease of the fetus and newborn, yet in neonatal alloimmune thrombocytopenia the first child is affected with fetal and/or neonatal thrombocytopenia. There is a significant risk of intracranial hemorrhage and severe neurological impairment, with a tendency for earlier and more severe thrombocytopenia in subsequent pregnancies. This article reports a case of neonatal alloimmune thrombocytopenia in the second pregnancy affected and discusses diagnosis, management and the clinical importance of this disease.

Introduction Currently the ideal stem cell donor is a fully matched HLA sibling; nonetheless, an elderly patient has a high probability of an also aging donor. Age has been related to worse transplant outcomes, mainly due to the higher incidence of acute and chronic GVHD and higher mortality rates when compared to patients performing transplantation with younger donors, in addition to possible comorbidities that may make them ineligible for donation. Objectives Considering the excellent results of transplants with haploidentical donors, which are comparable to those obtained with fully matched donors, the present study aims at assessing which would be the best donor for the patient witch has a fully matched sibling of 50 years of age and older and a younger haploidentical child. Methods This is a consecutive retrospective descriptive observational epidemiological study involving all patients who underwent hematopoietic progenitor cell transplantation with a fully matched or partially matched (haploidentical) related donor during the period from January 2010 to October 2017. Overall survival of patients aged 50 years or older was the primary outcome of the study. Results An amount of 47 patients was included in the study. In 72% the diagnosis was acute myelogenous leukemia or myelodysplastic syndrome.Regarding the compatibility, in 31 (65.9%) of the procedures the donor was fully matched and in 16 (34.1%) the donor was haploidentical. The mean age of the patients was 63 years in both groups, but the mean age of donors was significantly higher among the fully matched donors, who were on average 60 years with a range between 32 and 82. All of these donors were siblings of the receptor. About the haploidentical donors, the mean age was 37 years, ranging from 21 to 66 years, and 87% were children of the recipient. We did not observe a statistically significant difference in overall survival between patients whose donor was fully matched or haploidentical. The age of the donor ( The time of hospitalization of patients submitted to haploidentical transplantation was greater than that patients whose donor was fully matched (69.6 days and 36.7 days respectively, p = 0.001). Conclusion The results obtained in the study demonstrate the non-inferiority of the donor haploidentico in relation to the fully matched donor for patients aged 50 years or more.

Background Accurate prediction of stem cell yield is important for planning leukapheresis procedures. A formula has been published (Pierelli et al., Vox Sang 2006;91:126-34) to estimate the CD34+ dose collected on the first day of leukapheresis that was based on the preapheresis peripheral blood (PB) CD34+ counts, the blood volume processed, and the donor's weight. The aim of this study was to assess the predictive value of this formula. Study design and methods Data were retrospectively collected on 1126 consecutive PB stem cell harvests conducted at five institutions. Information on age, sex, diagnosis, weight, preapheresis absolute peripheral CD34+ count, total blood volume processed, and CD34+ cells harvested per kilogram of body weight on the first day of apheresis was collected. Results Among donors at least 18 years old, Pearson's correlation coefficient (r) between actual yield (AY) and predicted yield (PY) was 0.76. To characterize this correlation, AY and PY were classified as being within the conventionally acceptable CD34+ doses (>2 × 10(6) -5 × 10(6) cells/kg), below this range (≤2 × 10(6) cells/kg), or above it (>5 × 10(6) cells/kg). The positive predictive value (PPV) of PY was estimated considering the distribution of AY as the "gold standard." PPV was relatively high for PY of more than 5 × 10(6) cells/kg (85%), moderate for PY of not more than 2 × 10(6) cells/kg (72%), and low for PY more than 2 × 10(6) to 5 × 10(6) cells/kg (56%). A consistent pattern was observed within institutions. Conclusion The formula of Pierelli et al. is associated with a PPV that is high, moderate, and relatively low for the corresponding predicted CD34+ doses.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only treatment that enhances survival and stabilizes neurologic symptoms in X-linked adrenoleukodystrophy (X-ALD) with cerebral involvement, a severe demyelinating disease of childhood. Patients with X-ALD who lack a well-matched HLA donor need a rapid alternative. Haploidentical HSCT using post transplant cyclophosphamide (PT/Cy) has been performed in patients with malignant and nonmalignant diseases showing similar outcomes compared to other alternative sources. We describe the outcomes of transplants performed for nine X-ALD patients using haploidentical donors and PT/Cy. Patients received conditioning regimen with fludarabine 150 mg/m2, cyclophosphamide 29 mg/kg and 2 Gy total body irradiation (TBI) with or without antithymocyte globulin. Graft-vs.-host disease prophylaxis consisted of cyclophosphamide 50 mg/kg/day on days +3 and +4, tacrolimus or cyclosporine A and mycophenolate mofetil. One patient had a primary graft failure and was not eligible for a second transplant. Three patients had secondary graft failure and were successfully rescued with second haploidentical transplants. Trying to improve engraftment, conditioning regimen was changed, substituting 2 Gy TBI for 4 Gy total lymphoid irradiation. Eight patients are alive and engrafted (17–37 months after transplant). Haploidentical HSCT with PT/Cy is a feasible alternative for X-ALD patients lacking a suitable matched donor. Graft failure has to be addressed in further studies.

Background Associations between aplastic anemia and numerous drugs, pesticides and chemicals have been reported. However, at least 50% of the etiology of aplastic anemia remains unexplained. Design and Methods This was a case-control, multicenter, multinational study, designed to identify risk factors for agranulocytosis and aplastic anemia. The cases were patients with diagnosis of aplastic anemia confirmed through biopsy or bone marrow aspiration, selected through an active search of clinical laboratories, hematology clinics and medical records. The controls did not have either aplastic anemia or chronic diseases. A total of 224 patients with aplastic anemia were included in the study, each case was paired with four controls, according to sex, age group, and hospital where the case was first seen. Information was collected on demographic data, medical history, laboratory tests, medications, and other potential risk factors prior to diagnosis. Results The incidence of aplastic anemia was 1.6 cases per million per year. Higher rates of benzene exposure (≥30 exposures per year) were associated with a greater risk of aplastic anemia (odds ratio, OR: 4.2; 95% confidence interval, CI: 1.82–9.82). Individuals exposed to chloramphenicol in the previous year had an adjusted OR for aplastic anemia of 8.7 (CI: 0.87–87.93) and those exposed to azithromycin had an adjusted OR of 11.02 (CI 1.14–108.02). Conclusions The incidence of aplastic anemia in Latin America countries is low. Although the research study centers had a high coverage of health services, the underreporting of cases of aplastic anemia in selected regions can be discussed. Frequent exposure to benzene-based products increases the risk for aplastic anemia. Few associations with specific drugs were found, and it is likely that some of these were due to chance alone.

Since 2004, when a case report describing the use of human mesenchymal stem cells (hMSCs) infusion as a therapy for GVHD after bone marrow transplantation, a new perspective in MSC function emerged. Since then hMSCs immunomodulatory potential became the target of several studies. Although great progress has been made in our understanding of hMSCs, their effect on T cell remains obscure. Our study has confirmed the already described effect of hMSCs on lymphocytes proliferation and survival. We also show that the impairment of lymphocyte proliferation and apoptosis is contact-independent and occurs in a prostaglandin-independent manner. A potential correlation between IL-7 and hMSCs effect is suggested, as we observed an increase in IL-7 receptors (CD127) on lymphocyte membrane in MSC presence. Additionally, blocking IL-7 in hMSCs-lymphocytes co-cultures increased lymphocytes apoptosis and we also have demonstrated that hMSCs are able to produce this interleukin. Moreover, we found that during Th1/Th17 differentiation in vitro, hMSCs presence leads to Th1/Th17 cells with reduced capacity of INF-y and IL-17 secretion respectively, regardless of having several pro-inflammatory cytokines in culture. We did not confirm an increment of Treg in these cultures, but a reduced percentage of INF-y/IL-17 secreting cells was observed, suggesting that the ratio between anti and pro-inflammatory cells changed. This changed ratio is very important to GvHD therapy and links hMSCs to an anti-inflammatory role. Taken together, our findings provide important preliminary results on the lymphocyte pathway modulated by MSCs and may contribute for developing novel treatments and therapeutic targets for GvHD and others autoimmune diseases.

Accurate prediction of stem cell yield is important for planning leukapheresis procedures. A formula has been published (Pierelli et al., Vox Sang 2006;91:126-34) to estimate the CD34+ dose collected on the first day of leukapheresis that was based on the preapheresis peripheral blood (PB) CD34+ counts, the blood volume processed, and the donor's weight. The aim of this study was to assess the predictive value of this formula.Data were retrospectively collected on 1126 consecutive PB stem cell harvests conducted at five institutions. Information on age, sex, diagnosis, weight, preapheresis absolute peripheral CD34+ count, total blood volume processed, and CD34+ cells harvested per kilogram of body weight on the first day of apheresis was collected.Among donors at least 18 years old, Pearson's correlation coefficient (r) between actual yield (AY) and predicted yield (PY) was 0.76. To characterize this correlation, AY and PY were classified as being within the conventionally acceptable CD34+ doses (2 × 10(6) -5 × 10(6) cells/kg), below this range (≤2 × 10(6) cells/kg), or above it (5 × 10(6) cells/kg). The positive predictive value (PPV) of PY was estimated considering the distribution of AY as the "gold standard." PPV was relatively high for PY of more than 5 × 10(6) cells/kg (85%), moderate for PY of not more than 2 × 10(6) cells/kg (72%), and low for PY more than 2 × 10(6) to 5 × 10(6) cells/kg (56%). A consistent pattern was observed within institutions.The formula of Pierelli et al. is associated with a PPV that is high, moderate, and relatively low for the corresponding predicted CD34+ doses.

Objective: To evaluate factors affecting peripheral blood hematopoietic stem cell yield in patients undergoing large-volume leukapheresis for autologous peripheral blood stem cell collection. Methods: Data from 304 consecutive autologous peripheral blood stem cell donors mobilized with hematopoietic growth factor (usually G-CSF), associated or not with chemotherapy, at Hospital Israelita Albert Einstein between February 1999 and June 2010 were retrospectively analyzed. The objective was to obtain at least 2 × 106 CD34+ cells/kg of body weight. Pre-mobilization factors analyzed included patient's age, gender and diagnosis. Post mobilization parameters evaluated were pre-apheresis peripheral white blood cell count, immature circulating cell count, mononuclear cell count, peripheral blood CD34+ cell count, platelet count, and hemoglobin level. The effect of pre and post-mobilization factors on hematopoietic stem cell collection yield was investigated using logistic regression analysis (univariate and multivariate approaches). Results: Pre-mobilization factors correlating to poor CD34 + cell yield in univariate analysis were acute myeloid leukemia (p = 0.017) and other hematological diseases (p = 0.023). Significant post-mobilization factors included peripheral blood immature circulating cells (p = 0.001), granulocytes (p = 0.002), hemoglobin level (p = 0.016), and CD34+ cell concentration (p < 0.001) in the first harvesting day. However, according to multivariate analysis, peripheral blood CD34+ cell content (p < 0.001) was the only independent factor that significantly correlated to poor hematopoietic stem cell yield. Conclusion: In this study, peripheral blood CD34+ cell concentration was the only factor significantly correlated to yield in patients submitted to for autologous collection.

Introduction: Busulfan (Bu) is used in the conditioning regimen for hematopoietic stem cell transplantation (HSCT). Therapeutic drug monitoring (TDM) of Bu with subsequents adjustments doses based on a “target” therapeutic concentration may reduce toxicity after HSCT. Objectives: To evaluatethe impact of TDM of Bu and clinical outcomes in patients with acute leukemia that underwent to allogeneic matched related donor (MRD) and allogeneic matched unrelated donor (MUD) HSCT. Patients and methods: From January 2009 to January 2014, we prospectively analyzed 42 patients with diagnosis of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) who underwent TDM of Bu (IV or oral) before transplantation (test dose) and TDM on 1st day of conditioning regimen. Samples were collected at 0, 30’, 60’ and subsequently every hour until 6 hours after administration of busulfan. The plasma was extracted by HPLC (High Performance Liquid Chromatography). All the patients that were submitted to TDM had a test dose 15 days to 48 hours before transplantion. The dose of Bu was adjusted during the first day of the conditioning regimen based on test dose. At the same time we analyzed 21 patients in the retrospective group who did not underwent TDM (from 2004 to 2010). Results: In the retrospective group (n=21), all of them underwent to MRD transplantation. Six (46.2%) were in first complete remission (CR1), 18(85.7%) patients received Bu and cyclophosphamide (BuCy) and the mean of age was 38 years (18-55 Yo). The median of CD34+ cells was 5.4 x 106/kg. The second group consisted by patients that received oral Bu (n= 21): 7 (33.3%) underwent to MUD transplantation, 14 (66.6%) to MRD transplantation, 8 (44.4%) patients were second complete remission (CR2), 4 (22.2%) had active disease status with a mean age of 32.7 years (14-58 Yo). Fifteen (71.4%) received BuCy and 16 (76.2%) received cells from peripheral blood. The median of CD34+ cells was 5.8 x106/kg. The median area under the curve (AUC) in 24 hours was 4950 μMol.min (3196.6- 8212 μMol.min). The third group was IV Bu (n= 21): 7 (33.3%) patients underwent MRD and 14 (66.6%) MUD transplantation, 7 (33.3%) patients were CR1, 7 (33.3%) had active disease or prior HSCT with a mean of age 52.7 years (20-74 Yo). The majority of patients received fludarabine and Bu (n=18; 85.7%) as conditioning and bone marrow was the main source. Immunosuppression was based on FK-506 and methotrexate (90.5% of patients). The median of AUC in 24 hours was 5690 μMol.min (3539.6- 8881.8 μMol.min). The cumulative incidence (CI) of sinusoidal obstructive syndrome (SOS) in the retrospective group and IV Bu were 9.5% for both, while in the group oral Bu it was at 19% (p = 0.566). The median AUC of Bu received during conditioning for those who died of SOS was lower in oral Bu than IV Bu (4872 uMol.min vs 5732 uMol.min respectively). The CI of acute graft-versus-host disease (aGVHD) at D+100 was 38.1% in the retrospective group, 40.6% in oral Bu and 42.9% in IV Bu. Chronic GVHD was 13.6% in oral Bu, 34% in IV Bu and 42.9% in the retrospective group (p = 0.142). The CI of relapse at D+100 was 19% in IV Bu, 4.8% in the retrospective group and oral Bu did not have this event. The IC of death at D+100 was 34.9% in group oral Bu, 9.5% in IV Bu and 14.3% in the retrospective (p = 0.102). The CI of relapse at 1.5 years was 35.8% in the IV Bu, 34.8% in oral Bu and 14.3% in the retrospective group. The CI of death at 1.5 years was 9.5% in group IV Bu, 53.5% in oral Bu and 34.3% in the retrospective (p = 0.015). Among patients who died until D+100, the median of AUC was 5732 μMol.min (5578.5-6818.5 μMol.min) during the conditioning for IV Bu and 4872 μMol.min (3448-8212 μMol.min) for oral Bu. The range between the AUC was large and there was no correlation with patients who died. Conclusion: In acute leukemia SOS had an impact on mortality at D+100 after HSCT (p Disclosures No relevant conflicts of interest to declare.

Background Umbilical cord blood transplantation is seen as an alternative source of hematopoietic support for patients who lack suitable HLA-matched donors. Disadvantages of this method include the relatively low cellularity, late engraftment and consequently restrictive use to pediatric patients, due to the low number of hematopoietic progenitors. Transplantation of two cord blood units has been seen as a strategy to overcome the low yield, often leading to the long-term establishment of hematopoiesis supported by a single cord blood unit. Predictive factors of the predominant unit are still unclear. Total nucleated cell count, CD34+, CD3+ dose were independent factors associated with unit predominance, although this is still a controversial issue. Methods This retrospective study included 21 patients with hematologic malignancies and immunodeficiencies who underwent double unit cord blood transplantation. We analysed HLA mismatch, ABO group, total nucleated cell count (TNC), CD34+ dose and post-thaw viability and their correlation with the prevalent unit. Transplantations were performed from 2007 to 2013. Six patients were excluded due to incomplete information and another three died before engraftment. Results Median NC and CD34+ doses were similar between engrafted and non-engrafted units. Nine transplantations (60%) resulted in engraftment of the higher TNC unit. TNC dose in the predominant units varied between 2.02-3.05x107/kg (median dose: 2.651x107/kg), and in the non-engrafted units between 1.69x107/kg-4.39x107/kg (median dose: 2.44x107/kg), which was not statistically significant (p= 0.65). Sixty percent of the transplantations (9 patients) also resulted in engraftment of the unit with higher CD 34+ (median dose: 2.05x106/kg), compared to 40% (6 patients) in which the lower dose unit prevailed (median dose: 1.95 x106), also not statistically significant (p= 0.861). As for ABO, 26% of the units were ABO matched with the recipient, while the majority was HLA mismatched (93%). Conclusion Multiple factors related to the unit and patient influence UCB predominance. In the sample studied, no particular variant played a specific role, probably due to the limited sample size. Current evidence suggests that immunologic-related mechanisms (CD34+ and CD3+ dose) are involved, yet further studies are necessary for a better understanding of which factors lead to unit engraftment. Disclosures: No relevant conflicts of interest to declare.

Abstract 4047 Stem Cell collection via apheresis is the preferred method of collecting stem cells for hematopoietic stem cell transplantation. Accurate prediction of stem cell yield is important for the planning of apheresis procedures and for the collection of adequate stem cells. Pierelli et. al. (Vox Sanguinis 2006, 91; 126) proposed a mathematical formula to estimate the CD34+ dose collected on 1st day of apheresis based on the peripheral blood (PB) CD34+ concentration pre-apheresis and the blood volume processed (BVP). Patients and Methods : We tested the predictive value of this formula in a multicenter sample of 1608 apheresis procedures performed at 5 centers (SCSP n=85, CAS n=195, HIAE n=305, China n=172, MDACC n=851). A 50% randomly selected sample of the MDACC study population was included in this analysis. Each contributing institution selected all consecutive apheresis procedures performed over a designated time frame. Baseline patient characteristics were collected including age, gender, diagnosis, mobilization regimen, complete blood counts on day of collection, and the absolute PB CD34+ counts within 24 hours of the first apheresis procedure. Subjects who did not have data on the PB CD34+ counts were not included in the analysis. Information on total BVP and CD34+ cells collected/kg was also collected. There were 694 males (59%), median age was 50 years. To facilitate comparison of results, we used the same statistical methods reported by Pierelli et. al. to assess the correlation between the actual (ay) and predicted (py) CD34+ yields, including assessment of the linear correlation between these measures and the distribution of the ay/py ratio. Results: Data on both actual and predicted yields were available for 1148 (97%) records. Overall, Pearson's correlation coefficient (r) between ay and py was 0.67, ranging from 0.67 for MDACC to 0.86 for China and CAS. Median ay/py ratio was 1.1 (0.02–433) ranging from 0.99 for HIAE to 1.5 for China and CAS. To characterize the correlation between ay and py and facilitate the clinical application of our findings, we classified the actual and predicted yields as falling below (5) the conventionally acceptable collected CD34+ doses (x106/Kg). Positive predictive value (PPV) of py was estimated considering the distribution of ay as the “gold standard”. PPV was relatively high for py >5 [85% (95% CI 81–89%)], average for py 5, exceeding 80% at all institutions except SCSP. Overall, 13% of cases predicted to have a CD34+ yield between 2 and 5, had an actual yield 5, acceptable PPV for doses533%33%38%27%39%28%Predicted Day 1 CD34+ dose (× 106/Kg), (median, range)2.40.02–2112.60.3–242.20.1–730.960.02–253.20.1–672.40.1–211527%30%19%20%38%23%Ratio CD34+ dose collected/predicted1.10.02–4331.10.2–111.50.03–6.31.50.02–4330.990.04–121.10.1–9.9Pearson's correlation coefficient0.670.830.860.860.770.67Pearson's within Predicted Day 1 dose50.560.770.810.70.630.6 Disclosures: No relevant conflicts of interest to declare.