ALBERT

Description: 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

Description: Introduction: The development of next-generation sequencing has made it feasible to interrogate the entire genome or exome (coding genome) in a single experiment. Accordingly, our knowledge of the somatic mutations that cause cancer has increased exponentially in the last years. MPNs and MDS/MPD are chronic myeloid neoplasms characterized by an increased proliferation of one or more hematopoietic cell lineages, and an increased risk of transformation to acute myeloid leukemia (AML). MPNs and MDS/MPDs are heterogenous disorders, both in clinical presentation and in prognosis. We sought to determine the genetic landscape of Ph-negative MPNs and MDS/MPD through next-generation sequencing. Methods: Paired DNA (sorted CD66b-granulocytes/skin biopsy) from 102 patients with MPNs or MDS/MPD was subjected to whole exome sequencing on a Illumina HiSeq 2000 platform using Agilent SureSelect kit. Diagnosis included primary myelofibrosis (MF; N=42), essential thrombocythemia (ET; N=28), polycythemia vera (PV; N=12), chronic myelomonocytic leukemia (CMML; N=10), systemic mastocytosis (MS; N=6), MDS/MPD-Unclassified (N=2) and post-MPN AML (N=2). Tumor coverage was 150x and germline coverage was 60x. Somatic variants calls were generated by combining the output of Somatic Sniper (Washington University), Mutect (Broad Institute) and Pindel (Washington University). The combined output of these 3 tools was further filtered by in-house criteria in order to reduce false-positive calls (minimum coverage at both tumor/germline ≥8 reads; fraction of reads supporting alternate allele ≥10% in tumor and ≤10% in germline; ratio of allele fraction tumor:germline 〉2; excluding mutations seen in SNP databases). All JAK2 and CALR mutations were validated through Sanger sequencing. Validation of other somatic mutations is currently underway. Analysis of driver mutations was made with the Intogen web-based software, using the Oncodrive-FM and Oncodrive-cluster algorithms (www.intogen.org). Significantly mutated genes were considered as those with a q-value of

Description: Abstract 4531 Introduction: Cytomegalovirus (CMV) is one of the most common viral pathogens post-allogeneic stem cell transplantation (SCT). However, CMV reactivation and disease are relatively uncommon events after autologous stem cell transplantation (ASCT), with a reported incidence of 2–9%. There are few studies describing risk factors for development of CMV reactivation post-ASCT. Objective: To describe the incidence and risk factors for CMV reactivation post-ASCT in our institution and its impact on survival. Methods: The charts of patients who underwent ASCT at our institution from January 2005 until July 2009 were manually reviewed. CMV reactivation was detected by antigenemia assay and/or real-time PCR. Variables associated with CMV in a univariate analysis with a p

Description: Despite improvements in treatment for T-Acute Lymphoblastic Leukemia (T-ALL), only 70-80% of children and 40% of adults achieve long-term remission. To discover novel targets for the development of molecular therapeutics, we conducted a dominant genetic modifier screen to identify genes whose inactivation delays the onset of leukemia. We have generated a Myc-driven zebrafish model of T-ALL that recapitulates its human counterpart genetically and pathologically. Utilizing this zebrafish model of T-ALL, we conducted a genetic screen that identified a gene encoding dihydrolipoamide S-succinyltransferase (DLST), whose heterozygous loss significantly delays the onset of leukemia in zebrafish. DLST is the E2 component of α-ketogluterate dehydrogenase complex (KGDHC), a key enzyme in the TCA cycle that converts α-ketogluterate (α-KG) to Succinyl CoA. Western blot analysis revealed that DLST was upregulated in zebrafish tumor cells, T-ALL cell lines and primary human T-ALL samples. Zebrafish T-ALL cells with heterozygous inactivation of dlst have decreased cell size and slowed cell cycle progression, compared to T-ALL cells without dlst inactivation. To demonstrate that DLST is a relevant target in human T-ALL, we used two structural analogs of α-KG (α-keto-n-valeric acid sodium salt (KV) and α-keto-β-methyl-n-valeric acid (KMV)) to inhibit the KGDHC activity. Inhibition of KGDHC by both KV and KMV decreased cell viability and promoted apoptotic cell death in a panel of human T-ALL cell lines. Genetic inactivation of DLST, via shRNA knockdown, also decreased cell viability in MOLT16 human T-ALL cell line, confirming the therapeutic potential of DLST in human T-ALL treatment. In vivo treatment of our zebrafish T-ALL model with KV promoted tumor regression within seven days of treatment. Taken together our findings indicate that DLST is an important contributor to T-ALL pathologenesis, and suggest that DLST is a potential target for further therapeutic development to treat human T-ALL. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 3495 Poster Board III-432 Background It is well known that patients with hemophilia (both A and B) have a lower incidence of coronary artery disease (CAD). However, patients with hemophilia may develop atherosclerosis, and with increases in life expectancy it is possible that the incidence of CAD may increase in these patients. There are no studies analyzing the prevalence of CAD in patients with hemophilia and possible risk factors. Aims To determine the prevalence of CAD in patients with hemophilia treated in Brazil. Methods All patients with hemophilia in Brazil receive therapy with Factor VIII or Factor IX at government-designed hemophilia centers. We thus contacted all centers in Brazil by e-mail and information from databases concerning health information for all patients was reviewed by the responsible physician at each center. A questionnaire about risk factors for CAD and history of coronary events was sent to patients that had a positive history of CAD. Results There are 6,881 patients registered with a diagnosis of hemophilia A and 1,291 patients with a diagnosis of hemophilia B in Brazil. Fifty-six percent of hemophilia centers answered the query, and information on 71.7% of patients with hemophilia A (4,934 patients) and 61.4% of patients with hemophilia B (792 patients) was reviewed. There were only 3 patients (0.05%) with a positive history of CAD. Their clinical characteristics are summarized in Table 1. During surgical treatment for CAD, replacement with Factor VIII and Factor IX was done by continuous infusion to increase Factor activity to 80-100%. Antiplatelet therapy was used in all patients at some point, and one patient (#1) developed hemarthrosis after two months of ASA. Patient #3 did not start antiplatelet therapy after CABG, and developed thrombosis of the graft. ASA and clopidogrel were started after percutaneous coronary angioplasty. Conclusion We found a very low incidence of CAD in hemophiliac patients, even after doing a nationwide survey that included more than 5,000 patients. No information about risk factors can be gleaned due to the small number of patients. Surgical treatment after increasing factor activity appears to be safe in such patients. Despite a theoretical risk for increased bleeding, therapy with antiplatelet agents appears to be necessary in hemophiliac patients with CAD. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 4960 Introduction: Transfusion dependent anemia and iron overload are associated with reduced survival in patients with MDS. Increased iron absorption at the gastrointestinal tract may also contribute to iron overload. Serum ferritin is the most common method of assessing body iron content, but it can be elevated in patients with inflammatory conditions, and may not correlate with iron overload in specific organs such as the heart. T2* MRI is a non-invasive method for detecting iron overload in patients with transfusion-dependent anemia, and its efficacy has been validated in patients with thalassemia major. There are few studies reporting on the efficacy of T2* MRI for detection of iron overload in patients with MDS. Objective: To evaluate the efficacy of T2* MRI in detection of iron overload in patients with MDS, the prevalence of iron overload in this disease and correlate MRI findings with iron indexes (ferritin, transferrin and non-transferrin bound iron [NTBI]). Methods: Patients with MDS or chronic myelomonocytic leukemia (CMML), independent of transfusion requirements, were recruited into a prospective, single center trial to assess the efficacy of T2* MRI for detection of iron overload in this scenario. Patients receiving iron chelation therapy were excluded. Iron indexes were measured at the time of T2* MRI evaluation. Hepatic iron overload was considered in patients with a hepatic iron concentration (HIC) ≥ 2 g/mg. Cardiac iron overload was considered in patients with a T2* value 〈 20 milliseconds. Mann-Whitney and Fischer exact tests were used to compare baseline continuous and categorical variables among patients with and without iron overload as assessed by HIC. Correlation between HIC and iron indexes was assessed with Spearman correlation. Results: A total of 37 patients with MDS and one patient with CMML were recruited. Three patients were not evaluated by MRI due to claustrophoby, so 35 patients remain for the analysis. Median age was 68 years (range 18–84). MDS subtypes by the WHO classification include refractory anemia (N=3), refractory anemia with ring sideroblasts (N=5), 5q- syndrome (N=3), refractory cytopenias with multilineage dysplasia (N=13), refractory anemia with excess blasts-I (N=6) and –II (N=3) and unclassifiable MDS (N=1). Information about transfusion requirement was available for 28 patients, and 14 (50%) were transfusion dependent. Twenty-two patients could be classified by the WHO Prognostic Score System (WPSS) and were categorized as very low-risk (N=6), low-risk (N=3), intermediate risk (N=6) and high risk (N=7). Median ferritin, transferrin saturation and NTBI values were 1079.6 ng/mL (range 21.8–12738 ng/mL), 63% (range 6–100%) and 0.34 microM (range 0–12.93 microM), respectively. Median cardiac T2* value was 45.3 ms (range 19.7–70.1 ms), and only one patient had a T2* value indicative of cardiac iron overload. Median HIC value was 3.31 g/mg (range 0.2–9.97 g/mg), and 66% of patients had hepatic iron overload. Patients with hepatic iron overload had higher ferritin levels (1181 ng/mL vs. 131 ng/mL, p=0.007) and transferrin saturation (64% vs. 39%, p=0.02), but no differences in NTBI (0.29 microM vs. 0.22 microM, p=0.42). Patients with elevated HIC had a higher prevalence of transfusion dependency but the difference was not significant (50% vs. 33%, p=0.67). Ferritin levels and transferrin saturation correlated with HIC (r = 0.552, p=0.001 [ferritin]; r = 0.609, p=0.001 [transferrin saturation]). Conclusion: T2* MRI can detect iron overload in patients with MDS. Iron overload in MDS cannot be solely explained by transfusion dependent anemia. The study is currently ongoing and updated results will be presented at the meeting. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction KIT mutations, particularly the D816V mutation, are frequently found in patients with SM and play a central role in the pathogenesis of the disorder. A recent publication demonstrated pre-clinical evidence that inhibition of JAK-STAT signaling may inhibit KITD816V-mediated cell growth (Pardanani A et al, Leukemia 2010, 24:1378-1380), but there is no clinical data on the efficacy of JAK inhibitors in patients with MS. Objective To describe the case of a patient with KIT-mutated SM associated with myelofibrosis that was successfully treated with the JAK1/JAK2 inhibitor ruxolitinib Case Description A 67-years old male patient was referred to our center with an outside diagnosis of primary myelofibrosis (PMF). His main complaints included fatigue and pruritus. On physical examination, liver was enlarged 2 cm from right costal margin (RCM) and spleen was enlarged 8 cm from left costal margin (LCM). His complete blood count (CBC) showed Hb 13.9 g/dL, white blood cell count (WBC) was 22.41x109/L, and a platelet count of 702x109/L. His bone marrow (BM) biopsy was compatible with the diagnosis of PMF. He was found to be negative for the JAK2V617F-mutation. The patient was started on ruxolitinib at a dose of 20 mg twice daily. Four weeks from start of therapy, his spleen had decreased to 3 cm from LCM. The CBC at 4 weeks showed Hb 16 g/dL, WBC 12.8x109/L, platelets 459x109/L. After 16 weeks of therapy, the patient was feeling much better, and his spleen was down to

Description: Introduction The role of the endothelial cell in the pathogenesis of Ph-negative MPNs is still not elucidated. Some have reported the presence of the JAK2V617F mutation in endothelial colony forming cells (ECFC) isolated from peripheral blood in patients with Ph-negative MPNs (Teofili L et all, Blood 2011). Others, however, did not find such an association (Piaggio G et al, Blood 2009). In patients with Budd-Chiari Syndrome (BCS), the JAK2V617F mutation has been found in endothelial cell (ECs) isolated by micro dissection from liver biopsies in patients both with and without MPN (Sozer S et al, Blood 2009). Besides the JAK2V617F mutation, other mutations (e.g. ASXL1, TET2, DNMT3A, SRSF2) have been described in patients with Ph-negative MPNs, but their presence has not been evaluated in patients with BCS who carried the JAK2V617F mutation. Objectives 1. To evaluate the presence of the JAK2V617F mutation in CECs from patients with BCS both with and without concomitant Ph-negative MPNs; 2. To determine the mutational landscape of granulocytes in patients with BCS who harbored the JAK2V617F mutation but did not have the clinical diagnosis of a Ph-negative MPN. Methods We identified 10 patients from our institution who had a diagnosis of BCS and harbored the JAK2V617F mutation in granulocytes. Three patients died from hepatic failure before they could be evaluated by bone marrow biopsy, so 7 patients remain for the analysis. All patients were investigated for the presence of Ph-negative MPNs with bone marrow trephine biopsy. ECs assays were performed according to the method of Hill. Briefly, Ficoll-Paque density gradient–isolated mononuclear cells were plated on fibronectin coated 6-well dishes with EndoCult medium (Stem Cell Technologies) for 48 hours, when non adherent cells were recovered and re-plated in a new dish at 106/mL concentration. After an additional 5 days, adherent cells were plucked and analyzed by flow cytometry. The ECs population was sorted using a FACS Aria BD Biosciences sorter according to the following phenotype: CD45-PerCP-negative, CD31-FITC-positve, VEGFR2-PE-positive, CD34-PECy7-positive, CD133-APC-negative. The presence of the JAK2V617F mutation was investigated by allele-specific PCR. Paired DNA (sorted CD66b-granulocytes/skin biopsy) from 3 patients with JAK2V617F-positive BCS without a clinical diagnosis of Ph-negative MPN was subjected to whole exome sequencing on a Illumina HiSeq 2000 platform using Agilent SureSelect kit. Tumor coverage was 150x and germline coverage was 60x. Somatic variants calls were generated by combining the output of Somatic Sniper (Washington University), Mutect (Broad Institute) and Pindel (Washington University), followed by in-house filters to reduce false positive calls. Results We were able to obtain CECs from all 7 patients. The purity of the CECs populations obtained was over 96% in all cases. Among the 7 patients with BCS, five did not have any clinical feature of a Ph-negative MPN, with a normal bone marrow biopsy. Results are summarized in the table. The JAK2V617F mutation was positive in the CECs from 5 cases, including 3 patients who only had BCS. In one patient with BCS solely the reaction did not work, and in another the JAK2 was wild-type in the ECs. The mutation was positive in CECs from both patients with myelofibrosis and BCS. Three patients with BCS solely were evaluated by whole exome sequencing. The only known pathogenic abnormality found was the JAK2V617F mutation, albeit at a low allele fraction (5%, 6% and 12.6%). Conclusion The presence of the JAK2V617F mutation in CECs from patients with BCS who did and did not have a diagnosis of Ph-negative MPN suggest that the mutation plays an important role in the development of vascular complications in these patients. Further studies with a larger number of patients are needed to precisely define the importance of CECs in the pathogenesis of MPNs. The sole presence of the JAK2V617F mutation in circulating granulocytes at a very low allele fraction in patients with BCS without Ph-negative MPNs suggest that these patients have a pre-malignant clone that would probably remain undiagnosed had it been not for the development of hepatic venous thrombosis. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF) are myeloproliferative neoplasms (MPN) with similar driver mutations. The three hallmark molecular alterations in these diseases are JAK2, MPL and CALR mutations. Patients with myelodysplastic/myeloproliferative (MPN/ MDS) neoplasms such as refractory anemia with ring sideroblasts and thrombocytosis (RARS-T) also present with the same hallmark genetic changes. Nevertheless, roughly 10% of these patients do not present mutations in neither of these genes. Recent data suggest that triple negative patients have a more aggressive clinical course. While the molecular alterations present in patients with MPN have been extensively studies, the genomic profile of triple negative TE/PMF/RARS-T has not been described. To better characterize these patients we performed whole exome / genome sequencing of paired granulocytes and skin from 15 triple negative MPN patients Methods: A total of 15 patients with triple negative MPN or MPN/ MDS [PMF (N=6)/TE (N=8)/RARS-T (N=1)] were analyzed. DNA was extracted from CD66b+ magnetic bead selected granulocytes (EasySep, Stem Cell Technologies) and matched skin biopsies with QiaAmp DNA Mini kit (Qiagen). Whole-exome targeted capture was carried out on 3 μg of genomic DNA, using the SureSelect Human Exome Kit 51Mb version 4 (Agilent Technologies, Inc., Santa Clara, CA, USA). The exome library was sequenced with 100 bp paired-end reads on an Illumina HiSeq2000. Somatic variants calls were generated by combining the output of Somatic Sniper (Washington University), Mutect (Broad Institute) and Pindel (Washington University). Tumor coverage was 150x and germline coverage was 60x. The combined output of these 3 softwares was further filtered by in-house criteria in order to reduce false-positive calls (minimum coverage at both tumor/germline ≥8 reads; fraction of reads supporting alternate allele ≥5% in tumor and ≤10% in germline; ratio of allele fraction tumor:germline 〉2). All JAK2 and CALR mutations were validated through Sanger sequencing. Validations of other somatic mutations are under way at this point. Results: First we asked whether other hematopoietic related genes could be responsible for the pathogenesis of the triple negative cases. With that goal we searched for high confidence mutations in genes that are mutated in at least 1% of patients with hematopoietic tumors on COSMIC (catalog of somatic mutations in cancer) database and also genes known to be recurrently mutated in myeloid malignancies. Only 6 out of 15 patients presented mutations in other myeloid related genes. The diagnosis of these patients were PMF=4, TE=2. The hematopoietic related genes mutated in these patients were: ASXL1 (n=4), CUX1 (n=3), NRAS (n=2) and ATM, CBL, CSFR3, CREBBP, DNMT3A, ETV6, EZH2, JARID2, MLL2, PHF6, SRSF2, STAG2, TET2, GNAS, U2AF1 (n=1). Noteworthy, we have found one known oncogenic mutation in CSFR3, an alteration supposed to be specific for chronic neutrophilic leukemia and atypical CML, in a patient with ET, and an oncogenic mutation in GNAS in a patient with PMF. In addition, the patient with RSRA-T had a putative oncogenic mutation in PTPN11 Remarkably, the average number of hematopoietic related mutations in these patients was 5, significantly higher than the total number of mutations found in another cohort of patients with either JAK2 (average = 1.7) or CALR mutations (average = 1.9). Although our numbers are small, we may speculate that the high incidence of ASXL1 mutations (28%) associated with a high number of prognostically detrimental mutations can partially explain the worse outcomes associated with triple negative MPN. Noteworthy is also the high prevalence of CUX1 mutations in this subset of patients (21%) when compared to other myeloid malignancies in general. Regarding the other 9 patients for whom no hematopoietic mutations could be identified, 6 patients had ET, 2 patients PMF and one patient had RARS-T. Conclusion: We have shown that: i-patients with triple negative MPN are molecularly heterogeneous, with one group presenting a high number of hematopoietic related mutations, ii-the most common mutations present in these patients are ASXL1, CUX1 and NRAS, iii-The majority of these patients do not present mutations in hematopoietic related genes, what suggests that non-described molecular mechanisms are operating in these patients. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Hematopoietic stem cell transplantation (HSCT) was offered primarily as a therapeutic option for severe sickle cell disease in the context of myeloablative matched sibling donor transplants over the last two decades and helped to establish the benefits of transplantation for this disorder. In recent years, the transplant community has set out to explore ways to make stem-cell transplantation more available to patients with the disease, define indications and better timing, and offset toxicities with novel approaches to conditioning and better supportive care. In this context, neurological complication such as stroke disease and blood flow alteration in medial cerebral artery constitute the main indications of HSCT but neurological complications are the main causes of TRM in D+100 and is important to find ways to prevent this problem. Objective: Describe early neurological complications in sickle patients undergoing related HSCT on single specialized center and its following after the early diagnosis. Material and Methods: Seven patient were undergone related HSCT for sickle disease from 2011 to 2013. All patients filled inclusion criteria in the study and signed agreement term. Results: Seven HSCT were developed in the period, being four males. The average age was 13 years old (7-24). The HSCT indications were previous stroke, cerebral flow alteration on Doppler, acute chest syndrome and alloimunization. All patient were on blood transfusion therapy. The conditioning regimen was BuCy + ATG and the GVHD prophylaxis was MTX and CSA. Related donors were chosen with 10/10 HLA match and graft source marrow. The median of the neutrophil engraftment was D+ 25 and the platelets engraftment was in D+60. Two patient died, one by intestinal and liver GVHD on D+120, and another with sagittal sinus thrombosis and hemorrhagic stroke on D+3. Other two patients showed PRES syndrome related to cyclosporine use. The patients showed generalized seizures with tomographic neurological alteration. After the imunossupressor change to tacrolimus and the change of Phenytoin to Lamotrigine, the patient had total resolution of neurological complications without development of neurological sequelae. Patients who used Lamotrigine since the beginning of the conditioning have not shown neurological alterations. Conclusion: The PRES Syndrome and Stroke are two of the main causes of mortality related to the use of calcineurin inhibitors. Patients with sickle disease have shown endothelial and cerebral microcirculation changes, which made them highly susceptible to neurological complication. The control of blood pressure, maintenance of 50.000 platelets level and the use of Lamotrigine as prophylaxis of seizures seems to decrease the risk of neurological complications. Prospective studies with lamotrigine as primary prevention of PRES Syndrome must be performed. Patients with severe neurological alteration as vessels stenosis more than 90% and Moya-Moya Syndrome must be better evaluated before the conditioning because of high TRM risk. Disclosures No relevant conflicts of interest to declare.