ALBERT

Description: Hematopoietic stem and progenitor cells (HSPC) fate is tightly regulated by their bone marrow (BM) microenvironment (ME). BM transplantation (BMT) frequently requires irradiation pre-conditioning to ablate endogenous hematopoietic cells. Whether the stromal ME is damaged and how it recovers following irradiation is unknown. We report that BM mesenchymal stromal cells (MSC) undergo massive damage to their mitochondrial function following irradiation. Donor healthy HSPC transfer functional mitochondria to the stromal ME, thus improving mitochondria activity in recipient MSC. Mitochondrial transfer to MSC is cell-contact dependent and mediated by HSPC connexin-43 (Cx43). Hematopoietic Cx43 deficient chimeric mice show reduced mitochondria transfer, which was rescued upon re-expression of Cx43 in HSPC or culture with isolated mitochondria from Cx43 deficient HSPCs. Increased intracellular ATP levels activate the purinergic receptor P2RX7 and lead to AMPK reduced activity in HSPC, dramatically increasing mitochondria transfer to BM MSC. Host stromal ME recovery and donor HSPC engraftment were augmented following mitochondria transfer. Deficiency of Cx43 delayed mesenchymal and osteogenic regeneration while in vivo AMPK inhibition increased stromal recovery. As a consequence, the hematopoietic compartment reconstitution was improved due to the recovery of the supportive stromal ME. Our findings demonstrate that healthy donor HSPC not only reconstitute the hematopoietic system following transplantation but also support and induce the metabolic recovery of their irradiated-damaged ME via mitochondria transfer. Understanding the mechanisms regulating stromal recovery following myeloablative stress are of high clinical interest to optimize BMT procedures and underscore the importance of accessory, non-HSC to accelerate hematopoietic engraftment.

Description: An activating mutation of Janus kinase 2 (JAK2-V617F) was previously described in chronic myeloproliferative disorders (MPD). In previously published studies, the frequency of the JAK2-V617F mutation was determined to be 80–90 % for patients with polycythemia vera (PV) and 40–70 % for essential thrombocythemia (ET). In this study, we analyzed the relationship between the JAK2-V617F mutation and clinical-hematological parameters in Egyptian patients with MPD and compared these findings with published studies from other geographic regions and previous studies in EGYPT. A total of 56 patients were studied; of which, 32 were diagnosed with PV and 24 with ET. The mutation status of JAK2 was determined using allele-specific oligonucleotide (ASO) PCR assay. We found that 53% of the PV group and 79% of the ET group were positive for the JAK2-V617F mutation. When all patients were analyzed; patient age, levels of WBCs, levels of hemoglobin, levels of platelets and splenomegaly were significantly different in patients with the JAK2-V617F mutation (p 〈 0.05). The JAK2-V617F mutation is frequently detected in the Egyptian patients with MPD, and especially in patients with ET. Hence, it would be useful to include JAK2 mutation screening in the initial evaluation of patients suspected to have MPD especially ET. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction: Oxidative stress plays a central role in the pathogenesis of morbidities in β-thalassemia. Peroxiredoxin-2 (PRDX2) is the third most abundant cytoplasmic protein in red cells and is able to reduce and detoxify a vast range of organic peroxides, H2O2, and peroxynitrite. PRDX2 has been demonstrated to be induced by oxidative stress and that cells overexpressing PRDX2 are more resistant to the oxidative stress. Vitamin E is a fat-soluble vitamin and an anti-oxidant which is often depleted in thalassemia patients as a result of iron overload. Aim: This randomized prospective trial aimed to investigate the efficacy and safety of vitamin E as an adjuvant therapy to the three used iron chelators in moderately iron overloaded young vitamin E-deficient β-thalassemia major (β-TM) patients in relation to tissue iron overload and examine its potential corrective value to markers of oxidative stress and to the level of PRDX2 as a novel protective marker of oxidative stress. Methods: Inclusion criteria were β-TM patients aged 6-18 years, vitamin E deficient, serum ferritin (SF) 〉1000-2500 μg/L and cardiac T2* 〉 10 ms and ejection fraction 〉 56 %. A total of 245 β-TM patients were screened for eligibility, 180 were enrolled while 35 did not meet inclusion criteria and 30 were excluded. The 180 β-TM vitamin E-deficient patients were equally enrolled into 3 groups (each; n=60) and received desferrioxamine (DFO), deferiprone (DFP) and deferasirox (DFX). Patients in each group were further randomized either to receive vitamin E supplementation (400 IU daily) or not (n=30). All patients received vitamin E (group A) or no vitamin E (group B) were followed-up for one year with assessment of transfusion index, hemoglobin, serum ferritin (SF), liver iron content (LIC) and cardiac magnetic resonance imaging (MRI) T2*. Malondialdehyde (MDA), as an index for lipid peroxidation, and antioxidants including reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase and PRXD2 were assessed. Results: Baseline vitamin E was negatively correlated to SF, LIC and MDA while it was positively correlated to GSH, GPX, catalase and PRXD2. No significant difference was found as regards the studied variables at baseline and study end in patients who did not receive vitamin E (group B). After vitamin E therapy, transfusion index, SF, and LIC were significantly decreased in group A patients while hemoglobin and cardiac MRI T2* were elevated compared with baseline levels or those in group B without vitamin E. MDA levels were decreased while all the studied antioxidants were increased post-vitamin E supplementation compared with baseline levels or those in group B without vitamin E. The same improvement was found among DFP-treated patients post-vitamin E compared with baseline data. DFP-treated patients had the highest hemoglobin and antioxidant levels with the lowest SF and LIC compared with DFO or DFX subgroups. Conclusions: Vitamin E as an adjuvant therapy possibly potentiates the efficacy of DFP more than DFO and DFX in reducing iron burden and reduces oxidative stress in the moderately iron overloaded vitamin E-deficient β-TM patients, with no adverse events. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 4909 Introduction: Previous work has shown that the function and number of lymphocytes are vital for the patient's immune system to mount an effective response against cancer cells. Multiple recent studies have demonstrated the prognostic value of absolute lymphocyte count (ALC) in a wide range of malignancies. In children with acute lymphoblastic leukemia (ALL), ALC during induction chemotherapy have been shown to be an independent predictor of adverse outcome, even in the era of minimal residual disease (MRD). Most of the previous studies used Children Oncology Group (COG) based regimens with 3 or 4 drugs induction. We hypothesized that with more intensive induction regimens with 5 or 7 drugs, ALC would lose its prognostic value due to more intensive chemotherapy induced leukopenia. Patients/methods: We reviewed 136 Jordanian pediatric patients (Arabic ethnicity) with newly diagnosed ALL, age 1–18 years, from 2007 to 2009. The patients were treated at a single institution on modified St. Jude total XIII and VX protocols, with a median follow up of 35 months (range: 2–54 months). The induction phase was composed of 7 drugs regimen. Variables analyzed included ALC at diagnosis, day15, day 36 end of induction chemotherapy and at time of post induction marrow recovery, white blood cells at diagnosis, age at diagnosis, gender, immunophenotype, cytogenetics, risk group and MRD status at end of induction. ALC at each time-point was evaluated for prognostic ability by univariate and multivariate analysis. Results: We found that ALC at day15, day 36 end of induction chemotherapy and at time of post induction marrow recovery failed to have any prognostic effect on event-free survival (EFS) or overall survival (OS). We analyzed ALC as continuous and dichomatous variable, but without any prognostic significance. In contrast to our hypothesis, children with ALL intensive induction regimen did not have profound lymphopenia, with ALC day15 median of 1260 cells/ml (range: 0–9450), ALC day36 median of 866 (range: 100–3476), and ALC (post induction marrow recovery) median of 1145 cells/ml (range: 85–9676). Our cohort confirmed several known prognostic factors in childhhod ALL. For EFS outcome we found MRD35, age, phenotype and risk group to have a significant prognostic effect with P values of (0.016, 0.005, 0.006, 0.001) respectively. For OS outcome we found both age and phenotype to have a significant prognostic P value of (0.006 and

Description: Objective: Juvenile Idiopathic Arthritis (JIA) is commonly associated with different types of anemia. The diagnosis and treatment of IDA is a medical necessity; being a well-recognized cause of both short and long term morbidity plus being strongly related to poor disease outcome. In the presence of concomitant chronic illness or inflammation, the diagnosis of iron deficiency using the conventional laboratory parameters is a major medical challenge. Therefore, the utility of two recent iron status parameters; hepcidin-25 "active form of iron metabolism negative regulator" and reticulocyte hemoglobin content (CHr) "functional anemia indicator" was compared to that of two conventional ones; transferrin saturation (TSAT) and red cell distribution width percentages (RDW%) in diagnosing iron deficiency anemia in patients with JIA. Methods: Blood samples were obtained from 43 JIA patients whose ages ranged from 3 to 16 years and 20 age and sex matched healthy children as control group. Three different types of anemia; iron deficiency anemia (IDA), anemia of chronic disease (ACD) and combined anemia (IDA/ACD) were identified within the studied patients using iron profile, ESR and C-reactive protein. Serum hepcidin-25 was assessed by ELISA technique; CHr, TSAT% and RDW% were all estimated using Siemens ADVIA 2120 analyzer in patients and the control group. Results: Anemia was identified in 22 (51.2%) patients. Serum hepcidin-25 and TSAT% were significantly lower in IDA than ACD & IDA/ACD patients (p= 0.032 and p=0.034 for hepcidin and p= 0.004 and p=0.012 for TSAT%). Significantly lower CHr and higher RDW% were found in IDA/ACD compared to ACD patients (p= 0.032 and p〈 0.001, respectively). Serum hepcidin ≤ 3.8ng/mL and TSAT% ≤ 5.8% differentiated IDA from both ACD and IDA/ACD with 80 and 100% sensitivity and 88.24% specificity. CHr ≤24.4pg and RDW % 〉 16.4% showed 80 and 90% sensitivity and 100% specificity; distinguishing IDA/ACD from ACD. Conclusion: Serum hepcidin and CHr were not superior to TSAT% and RDW%; discriminating among different types of anemia in JIA patients. Table 1. Comparison between anemia subgroups according to CHr and serum hepcidin IDA(n=5) ACD(n=6) Combined anemia(n=7) Control(n=20) p CHr (pg) 23.61 ± 3.80a 27.36 ± 2.30b 23.37 ± 3.18a 30.54 ± 1.99

Description: Purpose Despite advancements in diagnosis and treatment modalities for hematological malignancies, presently, there are no reliable blood tests for disease prognosis or prediction of patient’s response to particular treatments. Identification of such biomarkers for diagnostic or therapeutic response in clinical monitoring of hematologic diseases such as Chronic Myeloid Leukemia (CML) would be very useful. Experimental Design The ability to identify biomarkers in body fluids (i.e., plasma or serum) will not only involve minimally invasive procedures, but also more importantly, the potential for monitoring disease progression and effective response to therapy in relatively early stages. In this study, global proteome analysis of serum, plasma, and bone marrow samples from 28 patients with newly diagnosed chronic–phase CML were analyzed by using expression proteomics technology (label free quantitative liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The goal was to evaluate for early treatment response and discovery disease–specific /disease-associated proteins for prognostic monitoring and patient’s response to therapy at protein level. Results We identified a panel of 15 differentially expressed proteins (〉 2- °- fold change, p〈 0.001) to accurately discriminate between CML patients that achieved Major Molecular Response (MMR) vs. No-Major Molecular Response (NoMMR) at 6 months (Figure 1 & Table 1). Six (6) of the 15 identified proteins were filtered and mapped as potential biomarkers using Ingenuity Pathway Analysis. Among the identified proteins implicated in hematological diseases include Group-specific component (vitamin D binding protein), haptoglobin and vitronectin. Others were inter-alpha-trypsin inhibitor heavy chain 1, leucine-rich alpha-2-glycoprotein 1 and metallophosphoesterase 1. We also observed most of these proteins to be located in extracellular space, acts as transporters and have been implicated as markers of hematological disease and inflammatory response. Our data indicates that multivariate analysis of quantitative proteome data can potentially be useful as a means of unsupervised artificial intelligence algorithm for classification and stratification of clinical CML patients. Conclusion Our results highlight the power of proteomics in the discovery of biomarkers for more accurate prediction of prognosis and monitoring treatment response in CML patients. These proteins might be valuable, once validated, to complement the currently existing parameters for reliable and objective prediction of disease progression, monitoring treatment response and clinical outcome of CML patients. Disclosures: No relevant conflicts of interest to declare.

Description: New hematopoietic cell transplant (HCT) approaches are urgently needed for patients with severe aplastic anemia (SAA) who lack an HLA-identical donor. Haploidentical HCT with post transplant cyclophosphamide (PTCy) represent a potential universal available option for almost all children with SAA. We present a novel conditioning regimen for haploidentical HCT in children with SAA in a center where horse ATG is not available. Conditioning regimen consists of rabbit ATG 2.5 mg/kg/day from day -9 to -7, Fludarabine 30 mg/kg/day from day -6 to -2, Cyclophosphamide 14.5 mg/kg/day from day -6 to -5, Thiotepa 5 mg/kg/day from day -4 to -3, and 4 Gy TBI on day -1 in in two fractions. GvHD prophylaxis consist of PTCy 50 mg/kg/day on days +3 and +4 along with Cyclosporine A and Mycophenolate mofetil (MMF) starting on day +5. Four consecutive children with SAA referred to our center for haploidentical HCT starting in 2018. Median age at HCT was 9 years (5-16) with 3 males and 1 female. All patients were heavily transfused with both blood and platelets prior to referral for HCT. Two patients had strong and one had weak positive anti-HLA antibodies (DSAs) and received desensitization with IVIG, Rituximab and plasmapheresis. One patient received buffy coat infusion on day -1 due to persistent strong DSAs despite desensitization. Median CD34+ dose received was 12 x 10e6, and median CD3+ dose was 29 x 10e6. Donors were all same blood group to patients. All patients successfully engrafted neutrophils at median of 13 days (12-14). Platelets engraftment in 3/4 patients at median of 7 days (5-10). All patients received peripheral blood as stem cell source. Three of four patients survived and doing well at last follow up. One patient had toxic death on day +38 due to chemotherapy related toxicity causing multi-organ failure. Chimerism analysis was full donor in all four patients at median follow up time of 11 months (2-12). Patients were sent home at median of 24 days post HCT. None developed grade 2-4 acute GvHD nor chronic GvHD. Acute GvHD of skin grade 1 stage 1 developed in 2 patient and managed with topical steroids. Viral reactivations consisted of CMV viremia and BK hemorrhagic cystitis in all patients, and have all resolved. No post transplant autoimmune complications. Haploidentical HCT with PTCy represents a quick and first line approach in heavily transfused children with SAA. Although yet limited number of patients, this regimen is feasible and appears to be safe. A great advantage of this regimen is the rapid engraftment of both neutrophils and platelets. Moreover, although using peripheral blood as a stem cell source, there was no severe acute or chronic GvHD. Disclosures No relevant conflicts of interest to declare.

Description: Background Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare subtype of HL for which optimal treatment is controversial. We retrospectively reviewed the files of patients with NLPHL diagnosed and followed up at our institution and describe clinical characteristics and outcome and explore prognostic factors for progression-free survival (PFS) and overall survival (OS). Methods We included consecutive patients diagnosed with NLPHL and followed at King Fahad Specialist Hospital, Damamm (KFSH-D), a referral center for the Eastern Province of Saudi Arabia. Primary aim of this study was to determine clinical outcomes (PFS and OS) according to treatment strategy, i.e. radiotherapy (+/- Rituximab) (RT) only, chemotherapy (+/- Rituximab) (CT), combined modality (+/- Rituximab) (CMT), Rituximab monotherapy (R), and active surveillance (AS). Secondary aim was an exploratory analysis of candidate prognostic factors for PFS and OS. PFS was defined as time (months) from date of diagnosis to disease progression or death from any cause. Event time distributions were estimated using the method of Kaplan-Meier and groups were compared using the log-rank test. We used univariable and multivariable PFS analyses for candidate prognostic factors. Results From 1/2006 to 12/2017 data on 49 patients treated at KFSH-D, aged 16 years (y) or older, with a diagnosis of NLPHL and with sufficient treatment and follow-up (F/U) were analyzed. Median age at diagnosis was 29y (range, 16-56), 76% were male. Histology was typical in 86% (n=42), variant in 8% (n=4), and with transformed histology at diagnosis in 6% (n=3) of cases. Disease characteristics: 63% (n=31) of patients were stage I/II and 37% (n=18) stage III/IV, B-symptoms 12%, extranodal disease 10%, splenic involvement 8%, bulky disease (≥5 cm) 12%, and bone marrow involvement 4% of patients. The German Hodgkin Study Group (GHSG) score was intermediate-risk and high-risk in 53% (n=26) and 24% (n=12) of patients, respectively. Management strategy (MS), depending on physician's preference, was RT (16%, n=8), CT (43%, n=21), CMT (27%, n=13), R (6%, n=3), and AS (8%, n=4). For patients induced with chemotherapy +/- RT, ABVD-like (+/- Rituximab) (n=25) or CHOP (+/- Rituximab) (n=9) were used in all cases. The overall response rate (ORR) for 45 patients who received treatment was 91% (complete responses (CR), 69%), 98% ORR when cases with transformed histology at diagnosis were excluded. Median F/U was 36 months (m), (range, 8-127). Overall, outcome was excellent, with 3- and 5-y PFS estimates of 80% and 75%, respectively (Figure). Overall survival was 100% with no deaths observed (Figure). The current PFS is 98%. Transformation at relapse/progression was observed in 2 patients at 36m and 45m, respectively, and remain disease free at 24m and 35m, respectively, following salvage treatment and auto-SCT. The 5-y cumulative risk of transformation (excluding cases with transformed histology at diagnosis) was 6%. Two secondary cancers were observed. Exploratory univariate analysis revealed high-risk GHLG score (P=0.001), bulky disease (P=0.001), splenic involvement (P=0.01), transformed histology at diagnosis (P=0.02), and non-RT MS (P=0.001) as risk factors for shorter PFS. In the final multivariate model, the GHLG score (P=0.01) and non-RT MS (P=0.004) were the only a risk factor for shorter PFS. In pairwise comparison, excluding patients with transformed histology at diagnosis and patients on AS, for patients with stage I/II disease, RT-based therapy was associated with improved 5-y PFS rates compared to CT-based therapy, (P = 0.02). For patients with stage III/IV disease 5-year PFS rates did not differ between RT-based and CT-based therapy (P= 0.4). For patients treated with CT, ABVD +/- Rituximab (n=13) vs CHOP +/- Rituximab (n=8) induction produced similar PFS rates at 5-years (P=0.9). Conclusion In this single center retrospective study, NLPHL had an excellent outcome. MS had an impact on PFS but not OS. High-risk GHLG score and omission of upfront RT were adversely prognostic factors for PFS. Large prospective trials are warranted to determine the optimal treatment approach for this rare B-cell lymphoma. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

Description: Bone marrow (BM) residing hematopoietic stem and progenitor cells (HSPC) replenish the blood with mature cells with a finite life span on a daily basis while maintaining the reservoir of undifferentiated stem cells. We recently showed that light/darkness onset induce two different BM HSPC peaks. Morning-induced norepinephrine and TNF secretion metabolically facilitate HSPC differentiation and egress to replenish the circulation with new mature leukocytes. Night augmented BM melatonin renews BM CD150+ hematopoietic stem cell (HSC) reservoir and their long-term repopulation potential (Golan et al, Cell Stem Cell, In Press). How melatonin primes BM HSPC to change their phenotype and function to re-acquire an undifferentiated and primitive state, is poorly understood. The hormone melatonin is an important mediator of bone formation and mineralization, and ultimately regulates the balance of bone remodeling (Cardinali DP et al, J. Pineal Res., 2003). The cross talk between HSPC and their BM stromal microenvironment is tightly regulated and determines HSPC fate. Therefore, we examined whether melatonin plays a role in regulation of murine BM mesenchymal stem and progenitor cells (MSPC, CD45-/Sca-1+/PDGFRα+), known to support HSPC maintenance in their BM niches. Mice treated with melatonin for 5h during the morning had increased levels of BM MSPC endowed with higher colony-forming unit fibroblast (CFU-F) potential in vitro. Interestingly, the metabolic state of these progenitor cells was altered by melatonin demonstrating reduced glucose uptake ability and lower mitochondria content. To test if differences in stromal cells content exist between day and night, we examined BM MSPC and found increased levels at 11PM, the time of melatonin BM peak, with higher Sca-1high surface expression levels, as compared to daylight 11AM. These changes were associated with augmented CFU-F levels by MSPC harvested at 11PM and accompanied by reduced glucose uptake levels and mitochondria content. Our preliminary results suggest that melatonin at night increases BM MSPC levels and reduces their metabolic activity to maintain them in a primitive and undifferentiated state. Moreover, we found that melatonin-elevated HSPC at 11PM also share lower glucose uptake ability with reduced mitochondria content and lower mitochondrial membrane potential (evaluated by TMRE). We hypothesize that melatonin reprograms the metabolic state of both HSPC and their stromal MSPC microenvironment to renew and maintain a primitive state of both populations at night. One of the factors inhibited by melatonin is the bioactive lipid Sphingosine 1-Phosphate (S1P), which in turn inhibits melatonin production. We found that mice with low S1P levels (S1Plow) due to lack of the SPHK1 enzyme have high BM melatonin levels also during the day in contrast to wild type (WT) mice. S1Plow mice had higher levels of primitive stromal progenitor cells including CFU-F and lower levels of differentiating osteoblast precursors compared to WT mice. In addition, these mice had less BM Reactive Oxygen Species (ROS)high committed hematopoietic progenitor cells, but more primitive ROSlow EPCR+ HSC endowed with higher long-term repopulation capacity in both primary and serially transplanted recipients. Next, we examined how light/dark cues affect the homing of transplanted BM HSPC into the BM of irradiated hosts 18h after transplantation. We found that donor HSPC harvested at 11PM have elevated homing ability compared to 11AM harvested cells. Importantly, MSPC also better homed to the BM of irradiated recipients when we transplanted donor BM cells obtained at 11PM compared with 11AM. As a result, accelerated BM repopulation kinetics was documented one week post transplantation in mice transplanted with BM cells harvested at 11 PM. Taken together, our results reveal that in vivo melatonin renews and maintains the BM reservoir and function of primitive MSPC and HSPC by metabolically reprogramming these cells during the night on a daily basis. Since the primed HSPC and MSPC at night showed improved function and BM homing potential, these features might be mimicked by human BM cells in order to harness them for improved clinical transplantation protocols. Disclosures No relevant conflicts of interest to declare.

Description: In spite its established prognostic role in ALL and being a powerful method for patient stratification, Minimal residual disease in AML is still an area of research need to be investigated to decide its value in AML treatment. In this is a retrospective study, 388 adult AML patients from period 2009-2014 in NCI Cairo University were included, comparing minimal residual disease to other prognostic factors to determine its value as an independent prognostic factor to stratify AML patients and to assess possibility of treatment tapering according MRD. We divided patients in to 3 groups according cytogenetics: favorable, intermediate, poor risk. (We considered patients having negative MRD: those having day 28 and day 42 BMA free for MRD less than 0.01) All patients with FLT3 were excluded prior start this study because we proved by other study its grave prognosis and it outweigh MRD as independent prognostic factor, and eventually those patients will relapse within a short period of time. 5 years disease free survival First group patient with favorable cytogenetics: included 156 patients. We found that 76 patients who become MRD negative post first cycle induction had significantly better disease free survival 64% and overall survival 61.7% compared to those having persistence MRD ( 80 patient) post first cycle of induction 24%, 14% respectively with p value 0.02. Out of 76 patients had negative MRD, 29 patients just took 2 cycles of chemotherapy one induction chemotherapy and one consolidation. Those patients continued to maintain CR in spite receiving 2 cycles of chemotherapy which confirm powerful prognostic impact of MRD with DFS : 61, OS 59.3% which showed no significant difference from those who completed their chemotherapy (p value : 0.07) Those patients didn't continue treatment due to medical problems or non compliance or insurance coverage problems. Those who had persistence MRD post first cycle of induction had prognosis resembling those of poor cytogenetics. Out of 80 patients having persistent MRD, 9 died prior relapse due to medical problems. 64 relapsed and took salvage chemotherapy then kept under follow up. 23 patient did allogenic bone marrow transplantation, 9 were in CR and were done due to persistence MRD and 14 patient did due to relapse and transplantation were done in second CR. patients who had did allogenic transplantation had better disease free survival and overall survival. Second group intermediate risk: 103 patients. We had 40 patients with negative MRD, whose DFS and OS were 59% and 55% respectively. Of those patients, 14 received only 2 cycles of chemotherapy and also showed favorable prognosis in spite being intermediate risk and retained CR. DFS : 57%, OS 55% with no statistical difference between those continued chemotherapy or not. 63 Patients had positive MRD, out of them 5 patients had lost follow up. DFS was13% and OS was 11%. 47 patients relapsed took salvage chemotherapy and kept under follow up out of which 16 patients did bone marrow transplantation. 11 patients did bone marrow transplantation due to persistence MRD and they had longer disease free survival compared to those had salvage chemotherapy and kept under follow up. Same disease free survival overall survival to those did BMT post second CR. Third group with poor risk cytogenetic included 127 patients. 32 patients got MRD negative (DFS: 38% OS: 8%). Out of which 9 didn't receive further chemotherapy post 2 cycles. Again with no significant p value between both groups (P: 0.08) We had 95 patients with persistent MRD post induction. 11 patients lost follow up. 65 relapsed and received salvage chemotherapy DFS 29% and OS: 5%. 19 patients did allogenic bone marrow transplantation. 8 patients did allogenic bone marrow transplantation due to persistence MRD. We found that poor risk cytogenetic outweighs MRD and only patients did BMT had favorable outcome regarding disease free survival 42% and overall survival 11%. Finally we conclude that minimal residual disease can be used as independent prognostic factor. Also MRD can be used as in stratifying patients and tailoring the treatment plan allowing the possibility to stop treatment at a less number of cycles and preventing further chemotherapy complications. Disclosures No relevant conflicts of interest to declare.