ALBERT

Description: Introduction: Stenotrophomonas maltophilia is an important nosocomial pathogen, particularly in immunocompromised patients, especially in patients with hematologic diseases. Methods: We reviewed the clinical characteristics and prognosis of patients with S. maltophilia bacteremia over a five-year period from January 2010 to December 2014. Species identification was performed using the automated Vitek 2 compact system (bioMe rieux). Results: The incidence of S. maltophilia bacteremia was 25.1 per 10 000 admissions in our study. Thirty-four patients (median age: 34 years; 64.7% males) with S. maltophilia bacteremia were analyzed. The S. maltophilia bacteremia related 30-day mortality was 44.1%. Risk factors associated with mortality in patients with S. maltophilia infection in the univariate and multivariate analysis were represented in Tables I and II. In the univariate analysis, risk factors included T〉39.0¡æ, septic shock, respiratory failure and non-remission after treatment for primary hematological diseases (P 39.0¡æ 75% 16.7% 2.490 1.318-4.704 0.005 Septic shock 90.0% 25.0% 2.544 1.473-4.393 0.001 Respiratory failure 100% 20.8% 4.672 2.366-9.225 0.000 Treatment outcome for hematological diseases Remission 10.0% 85.7% 0.247 0.116-0.526 0.000 HR, hazard ratio; CI, confidence interval; HSCT, Hematopoietic stem cell transplantation Table 2. Multivariate analysis of prognostic factors associated with mortality from S. maltophilia bacteremia Factor HR 95%CI P-value Respiratory failure 2.688 1.297-5.569 0.008 Remission after treatment for hematological diseases 0.367 0.153-0.879 0.025 HR, hazard ratio; CI, confidence interval Table 3. Susceptibility pattern of the 34 patients with Stenotrophomonas maltophilia bacteremia Antimicrobial agents S (%) I (%) Ceftazidime 24(70.6%) 1(2.9%) Cefoperazone 19(44.1%) 6(17.6%) Sulbactam and Cefoperazone 20(58.8%) 5(14.7%) Piperacillin 7(20.6%) 6(17.6%) Piperacillin-Tazobactam 11(32.3%) 7(20.6%) Amikacin 6(17.6%) 0(0%) Ciprofloxacin 28(82.4%) 1(2.9%) S, susceptible; I, intermediately susceptible. Disclosures No relevant conflicts of interest to declare.

Description: Background: Relapse remains the main cause of treatment failure post transplantation. Relapse prevention is an important strategy for acute myeloid leukemia (AML) patients. M ethods: We retrospectively analyzed the results of21 high risk AML patients who received a median number of 3 courses (range, 2 - 8) of decitabine (DAC) maintenance treatment (20mg/m2/d ×5d every 3 months for 1 year). Meanwhile, another 63 high risk AML patients without any prophylactic treatment after transplantation were included as a control group for 1:3 pair matched study. Results: With median follow-up of 23 months, 20 out of 21 (95.2%) patients maintained complete molecular remission (CMR) in DAC group, while 35 out of 63 (55.6%) patients maintained CMR in control group. Comparing with control group, the patients of DAC group had higher 3-year overall survival (OS) rates and 3-year leukemia free survival (LFS) rates (92.9% vs 51.8%, P =0.003; 94.1% vs 54.7%, P=0.002 respectively). Moreover, DAC maintenance was well tolerated in all patients and grade 3/4 or 4/4 hematological toxicities were observed in 11 of 21 (52.4%) patients. Conclusion: Our results suggested that DAC maintenance therapy was an effective and safe treatment option to prevent relapse after transplantation for high risk AML patients. Disclosures No relevant conflicts of interest to declare.

Description: We report the establishment of a novel cell line from a patient with acute myelocytic leukemia. The initial growth of this cell line was dependent on the presence of the stromal cell and cytokine interleukine 3. Subsequently, a stroma and cytokine-independent cell line was established, named SH-2. The cell line has proliferated continuously in vitro for more than 24 months. The SH-2 cell line showed identical chromosomal alterations to that of the initial bone marrow aspiration specimen, demonstrated a t(16;17))(q24;q12) translocation accompanied by deletions of y and 17 and triple 19.Chromosome painting FISH and Multi-FISH conformed the karyotype.SH-2 cells expressed myeloid antigens CD13, CD33 and MPO, SH-2 co-expressed NK markers CD16 and CD56. The loss of one p53 allele were proven by chromosome painting, FISH. A point mutation of CAG to CAT at codon 576 of extron 5 in another p53 allele was found by direct sequencing of DNA. Neither Epstein-Barr virus nor mycoplasma was not detected in SH-2 cells. DNA fingerprinting confirmed the authenticity of the cell line. Cytokines of GM-CSF,IL-3,IL-6,SCF,IL-4 and IL-5 can improve the proliferation of SH-2. SH-2 has colony formality and tumorigenic capacity in nude mice. The breakpoints of chromosomes 16 and 17 were localized RP11-356C4(16q24.3)and between BAC clone RP1-161P9 and RP11-47L3 corresponding to 17q12. The establishment of an myelocytic leukemia cell line with t(16;17)(q24;q12) could be valuable for the study of leukemogenesis and for the research of cloning the new gene involved in the t(16;17)(q24;q12) translocation.

Description: Objective: To evaluate the efficacy of auto-HSCT and allo-HSCT in the treatment of high risk peripheral T cell lymphoma (PTCL). Methods: From July 2007 to July 2014, 60 cases of high risk PTCL were analyzed retrospectively. Results: All 60 patients were at high risk group (carried with IPI≥3), with a median age of 31 (13-55) years old. Of the 60 cases, 22 were PTCL-not otherwise specified (PTCL-NOS), 22 with ALK negative anaplastic large cell lymphoma (ALK-negative ALCL) and 16 with angioimmunoblastic T-cell lymphoma (AITL). Twenty-one (21/60) received allo-HSCT and thirty-nine patients (39/60) received auto-HSCT. Before receiving transplantation, 40/60 patients were in complete remission (CR), 2/60 patients were partial remission (PR) and 18/60 patients were not remission (NR). In the 40 CR patients before transplant, 10 patients received allo-HSCT and 30 patients received auto-HSCT. In the 20 PR/NR patients before transplant, 11 patients received allo-HSCT and 9 patients received auto-HSCT. After a median follow-up of 39 (range 1-96) months, the K-M analysis showed that the 5-year PFS for auto-HSCT and allo-HSCT were 61% and 60% (P = 0.724). The 5-year OS for auto-HSCT and allo-HSCT were 62% and 61% (P = 0.724). There were no statistically significant differences between the auto-HSCT and allo-HSCT. And the cumulative TRM of allo-HSCT and auto-HSCT were 16.5% and 0 (P=0.250) within 5-years after transplantation. At the end of the last follow-up, 7 patients relapsed in auto-HSCT group and 2 patients relapsed in allo-HSCT group, the 5-year cumulative recurrence rates of auto-HSCT and allo-HSCT transplantation were 37.2% and 10.1% (P=0.298), respectively. Conclusion: There was no significant difference in the long-term survival between auto-HSCT and allo-HSCT for high risk PTCL patients. The effect of allo-HSCT may be better for NR patients. Disclosures No relevant conflicts of interest to declare.

Description: Objective: DNMT3A mutations are frequent in cytogenetically normal acute myeloid leukemia (cn-AML) patients and associated with poor survival. The role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in DNMT3Amut cn-AML patients remains unclear. Methods: In this study, we retrospectively analyzed the prognostic impact of DNMT3A mutations and explored the role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 308 cn-AML patients who received consolidation of intensive chemotherapy or allo-HSCT in our center from March 2005 to May 2014. Results: In the whole cohort, the median age was 40 years (range: 16-68 years), and there are 144 males and 164 females. Based on French-American-British (FAB) criteria, there were 5 (1.6%) patients classified as M0, 55 (17.9%) as M1, 74 (24.0%) as M2, 53 (17.2%) as M4, 75 (24.4%) as M5, 16 (5.2%) as M6, 3 (1.0%) as M7, and 27 (8.8%) that were unclassified AML patients. The median blast in BM was 56.12%, and the median white cell counts was 25.22(0.5-355.9)*109/L. 63 patients (20.5%) were identified with DNMT3A exon 23 mutations and R882H was the most frequent variant. The median age of DNMT3A mutated patients was elder than that of the control group (p

Description: Abstract 2544 Somatic mutation of the EZH2 gene is seen in myelodisplastic syndrome, myelofibrosis, and chronic myelomonocytic leukemia patients. The prevalence and prognostic impact of somatic mutations of EZH2 in patients with acute myelogenous leukemia (AML) remains unknown. In this study, we sought to determine the incidence and clinical implications of somatic EZH2 mutations in 714 patients with de novo AML by PCR amplification of the entire coding region followed by direct bidirectional DNA sequencing. EZH2 mutations were identified in 13/714 (1.8%) of AML patients and occurred almost exclusively in males (11/13, P=0.033). In univariate analysis, the presence of EZH2 mutations was significantly associated with lower blast percentage (21–30%) in bone marrow (P=0.0001) and −7/del(7q) (P=0.025). There was no difference in the incidence of mutations in 13 genes, including ASXL1, CBL, c-KIT, DNMT3A, FLT3, IDH1, IDH2, MLL, NPM1, NRAS, RUNX1, TET2, and WT1, between patients with and without EZH2 mutations. Complete remission, event-free survival or overall survival was similar between AML patients with and without EZH2 mutation (p〉0.05). These results demonstrated EZH2 mutation as a recurrent genetic abnormality associated with lower blast percentage in BM and −7/del(7q) in de novo acute myeloid leukemia. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 4599 Background: POEMS syndrome is a multisystem disorder associated with plasma cell dyscrasias which characterized by polyneuropathy (P), organomegaly (O), endocrinopathy (E), serum M-protein (M), and skin changes (S). Recently, we successfully treated two POEMS syndrome patients by using bortezomib-based regimen(VDD) and followed by autologous peripheral blood stem cell transplantation (APBSCT) with bortezomib combined with high-dose melphalan(Mel) conditioning regimen. Methods: According to the latest Mayo Clinic criteria, two patients’ diagnosis of POEMS syndrome could be comfirmed. Both of them had no response to the classical treatments, but achieved near complete remission(CR) after 4 cycles and 1 cycle of VDD respectively(Bortezomib 1.3–1.6 mg/m2/w×4 weeks; 40 mg of Liposomal doxorubicin on the fourth day of the first week; and 10 mg of dexamethasone during the initial 4 days of first cycle. Each course was at 21 days interval). Then, autologous peripheral blood stem cell collection was performed sucessfully (2.16×106/kg and 3×106/kg respectively) after mobilization by cyclophosphamide (3g/m2/d for 1 day) with subcutaneous G-CSF. APBSCT were performed approximately 1 month after stem cell collection. Two patients were conditioned with Bortezomib 1.6mg/m2(d-13,d-6,d+1,d+7)+Mel 200mg/m2(d-3)and Bortezomib 1.3 mg/m2(d-8,d-1,d+6,d+13)+ Mel 200mg/m2(d-2) respectively. Results: No toxic death or serious adverse effects occurred during APBSCT. Neutrophil and platelet recoveried at +10d, +27d and +7d, +20d respectively. Only case 1 patient developed mild hypoxemia during neutrophil engraftment period, but was successfully treated with corticosteroid and antibiotic therapy. The case 2 presented mucositis, diarrhea and nausea during neutropenic peroid. A follow-up period were 12 and 6 months respectively. Both of them achieved continuous CR. There was a dramatic improvement in clinical symptoms and serum VEGF levels in all two patients post VDD treatment including organomegaly (splenomegaly), M-protein, pericardiac/pleural effusion,ascites and polyneuropathy. Conclusion: This is the first report of POEMS patients treated by APBSCT with bortezomib and high dose Melphalan conditioning regimen. Our results suggest that Bortezomib is a new effective and relative safe therapeutic option for POEMS syndrome not only in the conventional treatment but also in APBSCT procedure. Disclosures: No relevant conflicts of interest to declare.

Description: Background: Nonmyeloablative conditioning with 2-Gy TBI alone or in combination with fludarabine (FLU/TBI) and HLA-matched related donor peripheral blood allografts followed by cyclosporine (CSP) and mycophenolate mofetil (MMF) for the prophylaxis of graft-versus-host disease (GVHD) is an effective therapy for many hematologic malignancies with reliable engraftment and moderate toxicity. The major causes of non-relapse mortality (NRM) are the development of acute and chronic GVHD. Several studies have demonstrated that tacrolimus may offer advantages compared with CSP for the prevention of GVHD in patients treated with myeloablative conditioning. The combination of tacrolimus and MMF, which has been used for GVHD prophylaxis after myeloablative hematopoietic cell transplantation (HCT), was well tolerated with low toxicity. Pilot data suggested an improved and perhaps superior GVHD prophylaxis with tacrolimus/MMF compared to our extensive historical experience using CSP/MMF with nonmyeloablative HCT. The purpose of this study is to evaluate the incidence of grade III-IV and II-IV acute GVHD, extensive chronic GVHD, along with the rate of NRM, relapse/progression, and overall survival after nonmyeloablative conditioning and post-grafting immunosuppression with tacrolimus and MMF. Methods: In a phase II multicenter clinical trial we evaluated the effect of post grafting immunosuppression with tacrolimus and MMF for the prophylaxis of GVHD following nonmyeloablative conditioning with 2-Gy TBI alone or in combination with 90mg/m2 FLU (FLU/TBI) for patients with hematologic malignancies. Patients at low risk of graft rejection (preceding autologous HCT within 6 months) received TBI alone (n=50) while the remaining patients received FLU/TBI conditioning (n=100). Tacrolimus was administered orally (0.06 mg/kg, Q12 hr) from days -3 to +56 and in the absence of GVHD tapered off by day +180. Tacrolimus was targeted to 15-20 ng/ml for the first 28 days and 10-20 ng/ml subsequently while on full dose. MMF was given orally (15 mg/kg, Q12 hr) from day 0 until day 27. Results: 150 patients were enrolled from 2004 to 2013 and received peripheral blood stem cells (median doses of 8.1×106 CD34+ cells/kg and 3.5×108 CD3+ cells/kg) from HLA-matched related donors. Diagnosis at transplant included AML (n=42), ALL (n=6), CLL (n=2), MDS/MPD (n=12), NHL (n=25), HL (n=8), and MM (n=55). Median patient age was 56 (range 19-74) years. Sixty-one percent of patients had an HCT comorbidity index (HCT-CI) score of greater than 2. Five percent of patients had failed a prior autologous HCT in FLU/TBI group. Median follow-up was 5.2 years. One graft failure was observed in the FLU/TBI group and no patients rejected their graft. The early NRM at day 100 was 1%. The cumulative incidences of grade II-IV and grade III-IV acute GVHD at 120 days were 26% (FLU/TBI 25%; TBI 28%) and 4% (FLU/TBI 2%; TBI 8%), respectively. Only one patient developed grade IV acute GVHD. Forty-eight percent of patients had chronic GVHD by 5 years (FLU/TBI 44%; TBI 54%). Five-year NRM was low at 12%. The overall cumulative incidence of relapse/progression at 5 years was 52%. Five-year overall and progression-free survivals were 51% and 37%, respectively. Conclusions: Post-grafting immunosuppression and GVHD prophylaxis with tacrolimus/MMF resulted in a low risk of acute and chronic GVHD, which compares favorably with our experience in a concurrent trial using CSP/MMF with FLU/TBI conditioning (46% grades II-IV acute and 72% chronic GVHD with CSP/MMF, respectively; BBMT, 2013, 19: 1340-1347). Furthermore, we recently reported that the active metabolite of MMF (MPA) concentration at steady state (MPA Css) was lower in patients who received concomitant CSP than patients receiving tacrolimus. Low total MPA Css was associated with an increased risk of severe acute GVHD following nonmyeloablative HCT (BBMT 2013, 19: 1159-1166). Together these data warrant consideration of a randomized phase III trial to investigate the role of tacrolimus/MMF versus CSP/MMF in nonmyeloablative HCT. Figure 1. Cumulative incidences of grade II to IV acute GVHD (A) and chronic GVHD (B) Figure 1. Cumulative incidences of grade II to IV acute GVHD (A) and chronic GVHD (B) Disclosures Maloney: Seattle Genetics: Honoraria; Juno Therapeutics: Research Funding; Janssen Scientific Affairs: Honoraria; Roche/Genentech: Honoraria.

Description: Acute erythroid leukemia (AEL) is a distinct subtype of acute myeloid leukemia (AML) characterized by predominant erythropoiesis. Currently, only few studies using next-generation sequencing were reported in AEL. To decipher the somatic mutation spectrum and discover disease-driving genes responsible for the pathogenesis of AEL, we performed whole exome-sequencing (WES) in 6 AEL and validating using targeted next generation sequencing (NGS) and Sanger sequencing in 58 AEL. From August 2003 to October 2014, a total of 158 patients fulfilling the WHO criteria for AEL were identified, comprising 91 males and 67 females. Median age was 50 years. These patients were further subclassified into 3 groups: 37 AEL after MDS, 108 de novo AEL, and 13 AML with myelodysplasia-related changes. In total, we identified 52 genes with somatic mutations in at least 2 patients, including CEBPA in 4 patients and GATA2 in 2 patients. We identified high frequencies of mutations in CEBPA (40.0%, 22/55; about 1/4 are biallelic mutations), GATA2 (22.4%, 13/58), NPM1 (15.5%, 9/58), SETBP1 (12.1%, 7/58), and U2AF1 (12.1%, 7/58), followed by TP53 (5.2%, 3/58), RUNX1 (3.5%, 2/58), TET2 (3.5%,2/58), ASXL1 (3.5%, 2/58), DNMT3A (3.5%, 2/58), SRSF2 (1.7%, 1/58) and FLT3 (1.7%, 1/58). We did not detect alterations of some of commonly mutated genes associated with AML, including IDH1, IDH2 and RAS. The results are summarized in Figure 1. To further identify the prevalence of GATA2 mutations in hematologic malignancies, we amplified and sequenced the entire coding region of GATA2 gene in 253 non-AEL AML, 40 chronic myeloid leukemia in blast crisis (CML-BC), 55 B-cell acute lymphoblastic leukemia (B-ALL), and 38 T-cell acute lymphoblastic leukemia (T-ALL). We detected GATA2 mutations in 5.5% of non-AEL AML, 15% of CML-BC, and none of B-ALL or T-ALL. The GATA2 mutations in AEL are mainly localized in ZF1 domain (P304H, D309E, A318V/T, G320S/D, L321P, and R330X) and TAD domain (Q20H). To find out the implications of GATA2 mutations in the leukemogenesis of AEL, we overexpressed the mutants of GATA2 (P304H, L321P, and R330X) in 293T cells and demonstrate that GATA2 mutant led to reduced transcriptional activity. Whereas overexpression of GATA2 mutants in mouse myeloid progenitor cell line, 32D, has no effect on the proliferative or colony formation abilities, it caused increased expression of erythroid-related antigen Ter-119 (Figure 2), b-globin and bh1-globin. Furthermore, 32D cells transfected with GATA2 mutants showed increased positivity than control cells by Benzidine staining. Taken together, our findings demonstrate that the mutatome of AEL is different from other types of AML. AEL is associated with a high frequency of mutations in GATA2 and CEBPA. GATA2 mutations resulted in a decrease of transcriptional activity and erythroid development of mouse myeloid progenitors, suggest an important role of GATA2 mutations in AEL. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 4536 Objective To evaluate the safety profile and efficacy of umbilical cord-derived mesenchymal stem cell infusion in patients with steroid-resistant, severe, acute graft-versus-host disease (aGVHD). Methods A total of 19 patients with steroid-resistant severe aGVHD received mesenchymal stem cell infusion treatment. We analyzed the treatment response, transplantation-related mortality, events associated with infusion and relapse rate. Results Two patients with grade II, 5 patients with grade III and 12 patients with grade ‡W aGVHD received a total of 58 infusions of mesenchymal stem cell. The mean total dose of mesenchymal stem cell was 2.13×106 (range 0.6–7.2×106) cells per kg bodyweight. 7 patients received one infusion, 2 patients received two infusions, and 10 patients received three or more infusions. 11 patients had a complete response and 4 had a partial response and 4 had no response. No patients had side-effects during or immediately after infusions of mesenchymal stem cell and no ectopic tissue was detected to date. 11 patients survived and 8 died, 4 for aGVHD, 1 for infection and 2 for aGVHD with concomitant infection and 1 for underlying leukemia relapse. The cell viability of freshly prepared mesenchymal stem cell is 93% (92%-95%) by trypan blue staining. The cell viability of controlled-rate freezed and thawed cells mesenchymal stem cell is 72% (70%-74%). Conclusion Infusion of umbilical cord-derived mesenchymal stem cell expanded in vitro is an effective therapy for patients with steroid-resistant, severe aGVHD without negative impact on relapse. Freshly prepared mesenchymal stem cells are superior to freezed and thawed cells in terms of cell viability. Disclosures: No relevant conflicts of interest to declare.