ALBERT

Description: Introduction: We have recently reported that the evaluation CD25 expression on leukemic blasts at the time of disease onset could be an alternative non-molecular tool for predicting transplant outcomes in patients with cytogenetically intermediate acute myeloid leukemia (AML). We herein focus on patients with refractory or relapsed AML and examine the clinical correlation of the surface CD25 expression measured by flow cytometry at the time of transplantation and subsequent transplant outcomes. Patients and methods: A total of 60 AML samples with primary induction failure (n = 32), first relapse (n = 23) or second relapse (n = 5) were analyzed by means of flow cytometric CD25 antigen expression on leukemic blasts at the time of transplantation. Survival outcomes were compared with regard to the CD25 expression. Overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan-Meiyer. Factors associated with at least borderline significance (p〈 0.10) on univariate analyses were subjected to multivariate analysis using backward stepwise proportional hazard modeling. Multivariate analysis was performed using the Cox proportional hazards regression model. Results: CD25 antigen expression (〉10%) on leukemic blasts was observed in 24 patients (40%). There was no significant difference between CD25 positive and negative groups in terms of clinical characteristics including cytogenetic risk, WHO classification, marrow or peripheral blasts % at transplantation, comorbidity, conditioning regimen, donor source or interval between diagnosis and transplantation. Although more early relapse cases within 180 days were observed in the CD25 positive group (p = 0.01), cumulative incidence of relapse, non-relapse mortality, acute or chronic graft-versus-host disease were not different between 2 groups. However, there was a significant difference in OS or PFS between 2 groups: 2-years OS; 8.3% vs. 34.0%, p=0.004 (Fig 1A), 2-years PFS; 8.3% vs. 26.3%, p=0.003 (Fig 1B). Moreover, multivariate analysis showed that CD25 expression was an independent adverse factor for OS (hazard ratio: 2.01, 95% confidence interval: 1.10-3.67, p = 0.02). Conclusion: Our cohorts with total 60 patients with refractory or relapsed AML showed that CD25 endowed these patients with an adverse prognostic impact, which might not be overcome even by transplantation. AML patients with residual CD25+ blasts at the time of transplantation might require additional therapy before or after transplantation for better survival. However, our small experience clearly desires larger series patients for evaluating the real impact of CD25 expression. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Description: Introduction In allogeneic stem cell transplantation (allo-SCT), recent reports have shown that post-transplant microbial diversity of the gastrointestinal tract is closely associated with clinical outcomes. Furthermore, pre-transplant microbial status has also been associated with the development of acute graft-versus-host disease (GVHD). These results indicate that pre-transplant microbial ecosystem may influence the immune system after allo-SCT, induce alloimmune response such as GVHD, and may finally affect the transplant outcome. Thus, we evaluate the association between pre-transplant microbial diversity and transplant outcomes. Patients and Methods Between April 2013 and March 2015, fecal samples were obtained from 107 patients in Komagome hospital. Fecal samples were collected within 2 weeks before conditioning. Microbial analysis was performed using 16S rRNA gene (hypervariable V1-2 region) sequencing. Operational taxonomic units (OTU)-based microbial diversity was estimated by calculating the Shannon index. Patients were classified into 3 groups based on the diversity index: low (3) diversity group, and we evaluated transplant outcomes such as survival, non-relapse mortality, and the cumulative incidence of GVHD, in these 3 groups. Results Among the 107 patients, there were 18 (16.8%) patients in the low diversity group, 48 (44.9%) in the intermediate diversity group, and 41 (38.3%) in the high diversity group. The median age of all patients was 49 (range: 16-72) years. The median follow-up period for survivors was 597 days (range, 23-1,046 days). We found no significant differences among 3 groups in terms of age, gender, underlying disease, disease status, performance status, hematopoietic cell transplantation comorbidity index, GVHD prophylaxis, conditioning regimen, stem cell sources, and human leukocyte antigen disparity. However, the patients in the low diversity group received intravenous antibiotics just before the conditioning more frequently compared to the patients in the intermediate /high diversity groups. The patients in the low diversity group showed poor survival (p=0.37, Figure 1a), higher non-relapse mortality (p=0.25, Figure 1b) and higher incidence of grade II-VI gastrointestinal GVHD (p=0.77, Fgiure 1c) compared with the patients in the intermediate /high diversity group although these results were not statistically significant. The cumulative incidence of relapse was similar between 3 groups. When compared between patients with and without acute GVHD, the composition of microbiota did not differ significantly between these patients. Discussion and conclusion Our results indicate that pre-transplant microbial diversity did not affect transplant outcomes. Furthermore, in contrast to previous report, the microbial composition was also irrelevant to the development of GVHD. Bacterial translocation after allo-SCT is a key trigger for the development of acute GVHD. Thus, microbial status in this period would be more important than that before allo-SCT. However, the patients in the low diversity group tended to show poor survival, higher incidence of non-relapse mortality and GVHD. Thus, further evaluation with larger sample size might be necessary to confirm the association between pre-transplant microbial ecosystem and transplant outcomes. Disclosures No relevant conflicts of interest to declare.

Description: [Background] Philadelphia chromosome positive (Ph+) leukemia is characterized by highly proliferative nature and clone instability that evokes the emergence of mutated clones, including BCR-ABL1 T315I mutated clone. Established evidence on the use of tyrosine kinase inhibitors (TKIs) after allogeneic hematopoietic stem cell transplantation (HSCT) is still lacking. The use of second-generation TKIs as a maintenance treatment after HSCT has been studied, and it is expected that their use would improve the prognosis by suppressing recurrence. The advent of ponatinib (PON), a potent inhibitor of tyrosine kinase including T315I mutated BCR-ABL1, is expected to improve clinical outcome of Ph+leukemia. However, there are few reports of a maintenance treatment using PON after HSCT. [Methods] We retrospectively reviewed data of 13 patients (pts) who received PON for Ph+leukemia after HSCT while in hematological complete remission (CR) between April 1, 2016 and July 15, 2019. Prophylactic treatment (Pro) was defined as post-transplant administration of PON while in minimal residual disease (MRD) negative CR. Pre-emptive treatment (Pre) was defined as starting PON when the bcr-abl transcript was detected by either quantitative or nested qualitative PCR after HSCT. ABL1 mutation was analyzed through the direct sequencing method. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Events version 5.0. Overall survival (OS) was estimated using Kaplan-Meier method. Non-relapse mortality (NRM) and cumulative incidence of hematological relapse (CIR) were calculated using Gray's test. This study protocol was approved by the ethics committee of Tokyo Metropolitan Komagome Hospital. [Results] Underlying diseases were Ph+ALL in 8 pts (5 in CR, 3 in non-CR at HSCT), CML in 5 (all in second chronic phase). ABL1 mutations were analyzed in 12 pts and T315I mutation was detected in 4 pts with Ph+ALL and 2 with CML. Furthermore, compound mutations (CMs) in BCR-ABL1 were detected in 4 pts before HSCT. PON was used in 6 only after HSCT, and in 7 both before and after HSCT. During the median observation after HSCT of 584 days (range, 116-1,110) for survivors, no vascular occlusion event occurred. With regard to adverse events (AEs), grade 3 AEs occurred in 2 pts (15.4%) and no grade 4 AE was observed. Two had liver dysfunction and one of them discontinued PON due to grade 3 abnormalities in liver function tests. One suffered from grade 3 thrombocytopenia. Four had skin rashes lower than grade 3 that were indistinguishable from skin graft-versus-host disease, and all of them resolved through topical steroid therapy. Of all, 6 were in Pro group and 7 were in Pre group. The initial dose of PON was median 15mg (range 45mg/twice a week - 15mg/day) in Pro and median 30mg (range, 15-45mg) in Pre. The median days from HSCT to the start of PON was 107 days (range, 32-174) in Pro and 208 days (range, 50-364) in Pre. The median duration of PON treatment was 297 days (range, 20-699) in Pro and 188 days (range, 5-608) in Pre. At final observation in Pro group, 2 pts relapsed and died during the salvage therapy, 1 pt discontinued PON due to hepatic adverse event, and 3 pts were still on PON. Meanwhile, in Pre group, 5 pts achieved MRD negative CR after PON administration (1 pt also received donor lymphocyte infusion and stop PON due to liver dysfunction, 1 discontinued PON by the patient's request, and 3 of them were still on PON). One pt with CM relapsed but achieved CR through salvage therapy and 1 pt with low performance status (KPS 60) died at home of unknown cause six days after taking PON 30mg daily. For all the 13 pts receiving PON maintenance therapy, OS was 74.6% (95%CI; 39.8-91.1), CIR was 23.1% (95%CI; 5.1-48.5), and NRM was 7.7% (95%CI; 0.4-30.6) at 1 year after transplant (Figure 1). Two out of 4 pts with CMs (V299L/F317L and E255K/T315I/F317L) remains in MRD negative CR. The other 2 with CMs (E255K/T315I and D276G/T315I) had progressed to hematological relapse, suggesting the resistance to PON. In contrast, only one out of 9 without CMs relapsed on PON treatment. [Conclusion] Our results suggested that post-transplant maintenance treatment using PON was tolerable in the majority of patients with Ph+leukemia, although the optimal dose or the initiation strategy (Pre or Pro) are still undetermined. Furthermore, some patients with T315I-inclusive CMs seemed to be resistant to PON. The longer observation in a larger cohort is warranted. Disclosures No relevant conflicts of interest to declare.

Description: Introduction Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curable treatment for various hematological malignancies, some serious comorbidities are still problematic, and acute graft-versus-host disease (aGVHD) is a major cause of morbidity and mortality. The gut microbiota and its metabolites have been reported to play pivotal roles in both intestinal inflammation and the immune system. Also in allo-HSCT, it is increasingly evident that imbalance in the gut microbiota (dysbiosis) related to the development of aGVHD. Short chain fatty acids (SCFAs), which are produced as fermentation products by gut microbiota, are among the most studied metabolites. Of them, butyrate has been reported to strengthen the mucosal barrier, induce the differentiation of colonic regulatory T cells (Natue. 2013; 504: 446-450). Actually, both butyrate and butyrate high-producing bacteria mitigate aGVHD in a mouse model (Nat Immunol. 2016; 17: 505-513) and furthermore, some dietary ingredients are known to increase SCFAs in the colon. Resistant starch (RS) is the starch portion that is not absorbed in the small intestine but is fermented in the large intestine, and converted into butyrate. GFO is an enteral supplement comprising glutamine, fiber, and oligosaccharides, and has been reported to be alleviate the mucosal injury in HSCT (Case Rep Oncol. 2014; 7: 692-699). Based on these results, we conduct a prospective study to evaluate the clinical impact of these prebiotics on transplant outcomes. Methods Forty-nine patients who underwent allo-HSCT in our hospital were enrolled in this study (prebiotics group). As a control group, 142 patients were selected because both the clinical and micorobial data were available. We used commercially available RS (Amylofiber SH®, J-Oil Mills Inc., Tokyo, Japan) and GFO (GFO®, Otsuka Pharmaceutical Factory Inc., Tokushima, Japan). Amylofiber SH® is corn starch which contains 70% of RS. Eight grams of RS were provided for patients at lunch and dinner, and one pack of GFO®, which contains 3 g of glutamine, 4.7 g of polydextrose , 1.45 g of oligosaccharides, was provided at breakfast. Patients ingested RS and GFO® from the start of conditioning regimen to +day 28. To evaluate the efficacy of prebiotics, the incidence of aGVHD, and severity of oral mucositis and diarrhea were compared. Moreover, sequencing of 16s ribosomal RNA gene was performed using feces samples before and day 28 after allo-SCT in both groups. Results The patient characteristics of the two groups were no significant differences except for the rate of female to male transplantation (4 % vs 17 % p=0.028). Median intake of prebiotics was 51%; 45% in RS and 68% in GFO, respectively. There was clear positive correlation between RS and GFO intakes. No adverse events obviously attributable to intake of prebiotics were observed. The cumulative incidence of all grade (63.3% vs. 75.4%, p=0.02) and Grade II-IV aGVHD (32.9% vs 47.9% p=0.03) was significantly lower in the prebiotics group compared with the control group. Interestingly, the incidence of skin aGVHD was significantly lower in the prebiotics group compared with the control group (53.8% vs 64.8% p=0.04 in all grade; 12.7% vs. 26.9% p=0.03 in ≥stage 3).In a multivariate analysis, prebiotics intake was associated with a decreased risk of grade II-IVaGVHD (p=0.04, HR: 0.58[95% CI: 0.35-0.97]).Oral mucositis was significantly less severe in prebiotics group in the early period (day 0 to +9) of allo-HSCT. With regard to diarrhea, the duration of diarrhea in the prebiotics group was shorter than that in the control group (median 7 days vs. 9 days, p=0.049). In microbial analysis, the diversity of the gut microbiota was well conserved, or improved in some cases, in the prebiotics group compared to that in the control group. Conclusions Our results indicate that prebiotics treatment could reduce post-transplant complications, including GVHD by conserving the intestinal microbial diversity in transplant patients. Further evaluation will be needed to confirm them. Disclosures No relevant conflicts of interest to declare.

Description: Background: The introduction of tyrosine kinase inhibitor (TKI) has reduced the indications for allogeneic hematopoietic stem cell transplants (HSCT) in patients with chronic myeloid leukemia (CML). In children and adolescents/young adults (AYA), however, the long-term side effects of TKI and financial burden could become a future issue. Thus, the role of HSCT with reduced intensity conditioning (RIC) as an alternative to TKI especially in the first chronic phase (CP1) should be defined for children and AYA with CML. However, less is well-known about the efficacy of RIC regimens on children and AYA with CML, in chronic phase (CP) as well as advanced phase. Aims: To describe the long-term outcomes of children and AYA with all phases of CML treated with a RIC HSCT and to define potential prognostic factors for outcome. Patients and Methods: We retrospectively analyzed 3796 patients with CML using data from the Transplant Registry Unified Management Program of the Japan Society of Hematopoietic Cell Transplantation and included children and AYA under 30 years old at HSCT who underwent allo-HSCT between 2001 and 2014 and received TKI before HSCT. The myeloablative conditioning regimen was defined as TBI ≥ 8 Gy, busulfan 〉 8mg/kg, or melphalan 〉 180 mg/m2. Result: The characteristics of patients are summarized in Table 1. RIC was selected preferentially in patients with better status. The median follow-up of survivors was 64 months (3 - 171 months). There was no significant difference in 5-year overall survival (OS) among CP (124 cases), accelerated phase (AP) (23 cases) and blastic phase (BP) (53 cases) at diagnosis, 83%, 71% and 73%, respectively. In CP at diagnosis, 5-year OS was significantly higher in CP1 (89 cases) at HSCT than in CP2≤/AP/BP (35 cases) (89% versus 66%, p = 0.0004), and in CP1 at HSCT, there was no difference in 5-year OS between myeloablative conditioning (MAC) (58 cases) and RIC (31 cases) (both 89%) (Figure 1). However, 5-year OS in RIC was significantly higher in children (0-14 years old, 23 cases) than in AYA (15-29 years old, 8 cases) (95% versus 75%, p = 0.0495). Two of eight AYA patients with CP1 died after RIC HSCT due to grade IV acute GVHD-related complications without disease relapse, suggesting that the indications for RIC in AYA with CP1 should be carefully judged. In AP/BP at diagnosis, 5-year OS was significantly higher in the second chronic phase (CP2) (48 cases) at HSCT than in the third chronic phase (CP3)≤/AP/BP (28 cases) (82% versus 56%, p = 0.0073). However, the rate of major cytogenetic response (MCyR) at HSCT was significantly higher in CP2 than in CP3≤/AP/BP, and when focusing only on MCyR at HSCT in AP/BP at diagnosis, there was no difference in 5-year OS between CP2 at HSCT (40 cases) and CP3≤/AP/BP (13 cases) (83% versus 78%). On condition of MCyR at HSCT in AP/BP at diagnosis, regardless of the phase at HSCT, there was no difference in 5-year OS between MAC (46 cases) and RIC (7 cases: 2 in children and 5 in AYA) (79% versus 100%) (Figure 2), suggesting that even in AP/BP at diagnosis, RIC could be indicated for the patients with good response to TKI. On multivariate analysis, disease phase at HSCT and time from diagnosis to HSCT were independent predictors of OS in CP at diagnosis (Table 2), and cytogenetic response at HSCT and stem cell source in AP/BP at diagnosis (Table 3). There was no significant difference of OS between MAC and RIC. Conclusion: In HSCT for CML after TKI administration, the indications for RIC in children under 15 years old with CP1 are appropriate. In RIC HSCT for AYA patients under 30 years old with CP1, caution should be exercised in transplant-related mortality rather than disease progression. Furthermore, even in AP/BP at diagnosis, RIC could be indicated for children and AYA patients with MCyR at HSCT. Disclosures Ichinohe: Astellas Pharma: Research Funding; Chugai Pharmaceutical Co.: Research Funding; CSL Behring: Research Funding; Eisai Co.: Research Funding; Kyowa Hakko Kirin Co.: Research Funding; Ono Pharmaceutical Co.: Research Funding; Pfizer: Research Funding; Nippon Shinyaku Co.: Research Funding; MSD: Research Funding; Otsuka Pharmaceutical Co.: Research Funding; Repertoire Genesis Inc.: Research Funding; Sumitomo Dainippon Pharma Co.: Research Funding; Taiho Pharmaceutical Co.: Research Funding; Takeda Pharmaceutical Co.: Research Funding; Zenyaku Kogyo Co.: Research Funding; Alexion Pharmaceuticals: Honoraria; Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; JCR Pharmaceuticals: Honoraria; Janssen Pharmaceutical K.K.: Honoraria; Mundipharma: Honoraria; Novartis.: Honoraria.

Description: Background: Sarcopenia, the loss of muscle mass, has been recognized as a prognostic factor for cancer patients. For example, low body mass index (BMI) was reported to be a risk of poor overall survival (OS) among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. However, low BMI was not associated with high non-relapse mortality (NRM) rate, and BMI may not directly reflect the physical condition. (Bone Marrow Transplant. 2014;49:1505-12). To evaluate the clinical impact of the muscle volume on the prognosis of allo-HSCT recipients, other biomarkers that directly reflect muscle mass may be warranted. Urinary creatinine excretion (UCE) has been reported to estimate muscle mass and have prognostic value for kidney transplant patients (Transplantation. 2008;86:391-8.). There is no report to evaluate clinical impact of UCE on the prognosis of allo-HSCT recipients. Therefore, we retrospectively analyzed the association between pre-transplant UCE and the transplant outcomes. Methods: We included 173 adult patients with acute myeloid leukemia (AML) in complete remission (CR) who underwent first allo-HSCT from 2006 to 2017 at our institute and measured UCE before allo-HSCT. Concerned the possibility of urine storage failure, two patients with low total daily urine volume (

Description: Introduction Cardiac diastolic dysfunction plays a crucial role in the development of heart failure. The ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e') reflects left ventricular end-diastolic pressure and is used in the diagnosis of diastolic heart failure. Although cardiac complication is one of the most serious problems in hematopoietic stem cell transplantation (HSCT), the impact of diastolic dysfunction on clinical outcomes after allogeneic HSCT is unclear. Thus, we investigated the effects of diastolic dysfunction on HSCT using E/e'. Patients and Methods We retrospectively reviewed the records of 102 evaluable patients who underwent their first allogeneic HSCT at our hospital between November 2010 and July 2012, and investigated whether elevated E/e' would affect the clinical outcomes such as incidence of cardiac complications, overall survival (OS) and non-relapse mortality (NRM). Patients were classified into high- E/e' group if E/e' was ≥9 and classified into low- E/e' group if E/e' was

Description: Background Myelodysplastic syndromes (MDS), commonly seen in elderly patients, represent a heterogeneous group of clonal hematopoietic stem cell disorders caused by the accumulation of gene mutations. By contrast, congenital bone marrow failure syndromes and genetic predispositions associated with MDS are known in pediatric patients. However, little is known about the pathogenesis of MDS in adolescent and young adult (AYA) patients. Previous reports showed the patients with MDS aged under 40 or 41.5 years at allo-HSCT were associated with good survival compared to those among the older population (N Engl J Med. 2017;376:536-547, Blood. 2017;129:2347-2358). However, AYA-MDS is rare, and its clinical features and genetic abnormalities have not been analyzed enough. It is suspected that the clinical and genetic features of AYA-MDS patients might be different from those of elderly patients or pediatric patients. Therefore, we investigated the gene abnormalities of AYA-MDS patients and aimed to elucidate the genetic characteristics associated with the good outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT). We analyzed the patients younger than 50 years of age in order to reduce the variation of patient-related factors. Methods We analyzed the outcomes of all consecutive patients aged under 50 years who were diagnosed with MDS or acute myeloid leukemia evolving from MDS in our hospital between January 2005 and July 2018. The study was approved by the institutional review board, and patients gave written informed consent for the study, according to the Declaration of Helsinki. Cytogenetic analysis and genomic DNA extraction were carried out using diagnostic bone marrow samples. We performed targeted next-generation sequencing to identify mutations in 68 driver genes using AmpliSeq for Illumina Myeloid Panel and On-Demand Panel on the MiniSeq system (Illumina). Gene variants were detected by in-house analysis pipeline. Overall survival (OS) was analyzed for all patients, and the Kaplan-Meier survival curve was used to assess OS using the log-rank test. Additionally, the cumulative incidence of relapse (CIR) was analyzed for patients who underwent allo-HSCT. Gray's test was used to evaluate the CIR. Results A total of 85 patients with MDS aged under 50 years (U40 between 15 and 39 years old: N=37, 40s between 40 and 49 years old: N=48) were analyzed. The median follow-up time of survivors was 2,041 days (range 176-5,085). There were no significant differences in patient characteristics between U40 and 40s. The 3-year OS of U40 were superior to 40s (79.9% vs. 58.1%, P=0.018), especially lower risk IPSS categories (3-year OS, 95.5% vs. 50.8%, P=0.002). In total, 69 of 85 patients (U40: N=31, 40s: N=38) had undergone allo-HSCT. U40 patients had lower percentage of bone marrow blasts at just before HSCT than 40s patients (over 10%, 12.9% vs. 36.8%, P=0.048), and better 3-year OS from HSCT in lower-IPSS (88.8% vs. 53.8%, P=0.024); but not in higher-IPSS (45.0% vs. 43.2%, P=0.834). In this cohort, at least one driver mutation was detected in 61% of allo-HSCT recipients. Frequently mutated genes (more than 10%) were ASXL1 and RUNX1; however, both of the genes did not have significant impact on the outcomes. While, only one patient in 40s had TP53 mutation. We detected 0.8 (range 0-3) and 1.8 (range 0-6) mutations at average in U40 and 40s, respectively (P=0.06). The proportions of the patients without any gene mutations were 52% in U40 and 30% in 40s. Transplanted patients with 0 or 1 mutation showed lower relapse rate than those with 2 or more mutations (3-year CIR, 23.3% vs. 45.2%, P=0.049). Conclusions The clinical outcomes of U40 patients with MDS were favorable than those in the 40s, especially in lower disease risk. The number of driver mutations in U40 tended to be lower than that in 40s. MDS in adult is regarded as a stem-cell aging disease with gene mutations; however, MDS-associated mutations were not detected in the half of U40. Moreover, TP53 mutation that is associated with extremely poor posttransplant survival was not detected in U40 patients. MDS patients with less than 2 mutations showed lower relapse rate, which maybe indicate genetic mutations have a great impact on transplant outcomes between 15 and 49 years old. Disclosures No relevant conflicts of interest to declare.

Description: Background Although the outcome after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) for the patients with acute myeloid leukemia (AML) in complete remission has been improved, the prognosis of patients with active disease is still dismal, generally with 20 - 30% of overall survival (OS) at 2 years. Prognostic value of gene mutations detected by the next generation sequencing (NGS) for this extremely poor group remains to be evaluated. Methods A total of 120 patients with AML not in hematological remission who received the first allo-HSCT at our institute between April 2005 and December 2017 were enrolled. For each patient, genomic DNA was extracted from the frozen bone marrow sample harboring leukemic blasts which was preserved at the nearest available date before the initiation of conditioning regimen. Sequencing was performed using TruSight Myeloid Sequencing Panel® on the MiniSeq system (Illumina). Gene variants were detected by in-house analysis pipeline. Charts were retrospectively reviewed on survival, relapse, and non-relapse mortality (NRM). The Kaplan-Meier method was used to assess OS using the log-rank test. Univariate and multivariate analysis were performed to identify potential prognostic factors. The Cox proportional hazards method was used for the multivariate analysis to assess OS. Gray's test and the Fine-Gray test were used to assess the cumulative incidence of relapse (CIR). Competing risks were relapse and NRM. Results Median follow-up of survivors was 1345 days (235 - 4888 days). Median age at transplant was 51 (range 21 - 71). Grafts were from bone marrow (n = 67, 55.8%), peripheral blood (n=42, 35.0%) and cord blood (n=11, 9.2%). Refined disease risk index (Blood. 2014;123:3664-71) scored high (n=61, 51.3%) and very high (n=58, 48.7%). OS at 2 years of the whole cohort was 27.3% (95% confidence interval [CI], 19.4% - 35.7%). There was no significant difference in OS between patients in primary induction failure and in relapse (OS at 2 years: 26.5% [n=50] vs 28.7% [n=70], p= 0.293). NGS analysis revealed TP53 loss-of-function mutation in 23 (19.2%) patients. Among all detected gene mutations, TP53 mutation was the most powerful predictor of poor OS after allo-HSCT (OS at 2 years: 13.5% vs 30.5% for TP53+ [n=23] vs TP53- [n=97], p= 0.0184). Consistent with previous reports, monosomal karyotype (MK, J Clin Ocnol 2010:26;4791-7) was significantly associated with positive TP53 mutation (13.3% of non-MK vs 37.9% of MK, p=0.006). Of note, all the patients (n=11) positive for both prognostic factors died within 1 year after allo-HSCT, whereas OS of the patients without either factor (n=78) was 33.6% at 2 years. Multivariate analysis on OS revealed MK, TP53 mutation, de novo AML (no prior history of MDS), ECOG performance status score 2 or more, C reactive protein 1.0 mg/dL or more, peripheral blood blast frequency of 1% or more at the initiation of conditioning regimen were independent prognostic factors for poor OS. Among them, to determine the prognostic factors critical for deciding the indication of allo-HSCT, we chose pre-transplant factors which were available around one months before transplant. From this point of view, multivariate analysis revealed independent prognostic factors for poor OS after allo-HSCT including MK (Hazard ratio [HR] 2.05; 95% confidence interval [CI] 1.30 - 3.25, p=0.00217), TP53 mutation (HR 1.72; 95% CI 1.04 - 2.86, p=0.035), and de novo AML (HR 1.67; 95% CI 1.04 - 2.86, p=0.036). Because the HR of these three factors were comparable, a score of 1 was assigned to each factor. OS at 2 years was 49.7%, 26.5% and 13.1% for patients with low (score 0, n=23), intermediate (score 1, n=63) and high (score 2 or 3, n=34) risk, respectively (p

Description: Background Constitutional partial trisomy 8 mosaicism (CT8M) is a congenital chromosomal abnormality with an estimated occurrence rate as one out of 25,000-50,000 pregnancies. CT8M has a wide variability in physical manifestation ranging from apparently normal to severe disablement. However, diagnosis of CT8M in adult without physical abnormality is difficult . Acquired trisomy 8, which is restricted to the malignant cells, is one of the most common chromosomal abnormalities in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), and clinical implication of carrying isolated trisomy 8 is considered as intermediate cytogenetic risk in MDS. However, isolated trisomy 8 without morphological dysplastic features is not definitive evidence for MDS. 15 to 20% of trisomy 8 in MDS are supposed to be derived from CT8M. We therefore diagnosed CT8M patients among patients with cytopenia and analyzed clinical and genetic features to uncover the association with MDS. Methods . Clinical features including cytogenetic analysis were analyzed regularly. Genomic DNA was extracted from whole PB cells or BM mononuclear cells. We performed targeted next-generation sequencing to identify mutations in 68 driver genes of myeloid neoplasms using AmpliSeq for Illumina Myeloid Panel and On-Demand Panel on the MiniSeq system (Illumina). Gene variants were detected by in-house analysis pipeline. The study was approved by the institutional review board and patients gave written informed consent for the study. Results We identified nine CT8M patients with cytopenia.They comprised 3 males and 6 females at a median age of 56 years (range 24-84 years) (Table). All the patients carried no physical abnormality nor conspicuous phenotypic features. Four patients (Patient #3, #4, #6 and #7) did not show apparent morphological dysplasia at the initial BM examination, and they were not diagnosed as MDS. Their cytopenia has not been exacerbated until now without any treatment, and the duration of stable cytopenia was from 2 to 12 years in these patients. By contrast, five patients with CT8M were diagnosed as MDS . Two patients (#5 and #8) were diagnosed as MDS-single lineage dysplasia (SLD), and their cytopenia has not become worse without any treatment for about 4 years. Other three patients diagnosed as MDS-multilineage dysplasia (MLD) showed various clinical courses. Patient #1 was treated with azacitidine and maintains complete hematological improvement after 34 courses of the treatment. Patient #2 was treated with erythropoietin stimulating agent and azacytidine but developed to AML 3 years after initial diagnosis but leukemic blasts has del(20), not +8. Patient #9 developed advanced pancytopenia in 3 months from initial diagnosis and received red blood cell transfusion regularly. Gene mutations were detected in five out of nine patients with CT8M. In three patients, gene mutations were detected at high (20 to 50%) variant allele frequency (VAF). Patient #2 who was analyzed at the AML phase had gene mutations of SRSF2, SF3B1, STAG2 and NOTCH1. BM sample from patient #9 showed ASXL1 mutation and two TET2 mutations. Patient #4 who did not show apparent myelodysplasia had a high VAF ASXL1 mutation, indicating clonal idiopathic cytopenias of undetermined significance. Two patients had low (2 to 5%) VAF mutations; patient #1 was analyzed after 34 courses of azacitidine had a TET2 mutation; patient #5 with MDS-SLD had a WT1 mutation and two PHF6 mutations. Four patients (#3, #6, #7 and #8) did not have any mutations. The clinical and genetic features showed that CT8M with cytopenia without MDS-related mutations were under 56 years old and did not develop to MDS or stayed at MDS-SLD. Patients with low VAF mutations were also stable. By contrast, patients with advanced diseases gained multiple MDS-related gene mutations with high VAF. One patient without dysplasia had a high VAF ASXL1 mutation. All the patients with gene mutations were age of 56 to 84 years. Conclusion Our results indicated that isolated trisomy 8 may cause cytopenia, but the cytopenia is not exacerbated without MDS-related driver gene mutations. CT8M patients with cytopenia might get gene mutations gradually with age, which leads to MDS or AML. Disclosures No relevant conflicts of interest to declare.