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Sarcopenia is a prognostic factor for cancer. Because creatinine is formed from creatine phosphate in muscle tissue, urinary creatinine excretion (UCE) serves as an index of muscle volume. However, as of yet, there are no studies assessing the clinical impact of UCE or weight- adjusted urinary creatinine excretion (WA-UCE) on allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. We analyzed the association between pre-transplant WA-UCE and transplant outcomes among 164 adult patients with acute myeloid leukemia in complete remission who underwent their first allo-HSCT at our center. The patients were classified into a high (

Fludarabine with intravenous busulfan (6.4 mg/kg; FB2) and fludarabine with intermediate-dose melphalan (140 mg/m2; FM140) are the most widely used reduced-intensity conditioning (RIC) regimens for allogeneic hematopoietic stem cell transplantation. FM140 generally has a lower relapse rate and higher non-relapse mortality (NRM), resulting in overall survival (OS) comparable to that seen with FB2. To evaluate the effect of reducing the melphalan dose, we retrospectively compared transplant outcomes in 156 patients who received FB2 (n = 103) or FM80 (n = 53) at our center (median age: 63 years; range 27–72 years). All patients received 4-Gy total body irradiation. Three-year OS, the cumulative incidence of relapse, and NRM were comparable between groups (FB2 vs. FM80, 58% vs. 47%, p = 0.24; 30% vs. 36%, p = 0.57; 17% vs. 21%, p = 0.44, respectively). There was no significant difference in the cumulative incidence of graft-versus-host disease (GVHD) at day 100, chronic GVHD at 3 years, or the 3-year GVHD-free/relapse-free survival rate. In the high-risk disease group, patients receiving FM80 tended to have lower 3-year OS (FB2 vs. FM80, 48% vs. 17%, p = 0.06). In summary, transplant outcomes following FB2 or FM80 were comparable except in patients with high-risk disease.

Autologous hematopoietic cell transplantation (HCT) is an effective therapy for patients with relapsed acute promyelocytic leukemia (APL). However, it remains unclear whether this procedure is equally effective for certain groups of patients. To address this question, we analyzed 296 patients with APL who had undergone autologous HCT during second or subsequent complete remission (CR2+) between 2006 and 2019. Among them, 24 patients were ≥65 years old, and 17 underwent autologous HCT during third or subsequent CR. Of the 286 patients whose measurable residual disease (MRD) data were available, 21 showed detectable MRD. The 5-year probabilities of relapse-free survival (RFS), overall survival, relapse, and nonrelapse mortality for the entire cohort were 85%, 88%, 9%, and 6%, respectively. The multivariate analysis revealed that the duration of first CR (

A 60-year-old woman with myelodysplastic syndrome/myeloproliferative neoplasm-unclassifiable underwent unrelated bone marrow transplantation from a human leukocyte antigen (HLA) 8/8 allele-matched male donor. Neutrophil engraftment was achieved on day 29. Fluorescence in situ hybridization of sex chromosomes demonstrated complete donor chimerism. The red blood cell and platelet transfusion dependence continued, and the neutrophil count decreased gradually. Despite prolonged administration of broad-spectrum antibiotics for febrile neutropenia, blood cultures on days 46 and 58 returned positive for Stenotrophomonas maltophilia (SM). Contrast-enhanced computed tomography revealed multiple nodules of septic emboli in the lungs and kidneys, suggesting a disseminated SM infection. Antibiotic therapy was conducted based on antimicrobial susceptibility testing. However, the blood cell count failed to normalize and a secondary graft failure was diagnosed. A HLA-haploidentical peripheral-blood stem-cell transplantation from the patient's son was performed on day 134 after the initial transplantation. Neutrophil engraftment was achieved on day 11. Red blood cells and platelets were also engrafted. After the resolution of the SM bacteremia, the patient was discharged on day 63. The prognosis of the SM bacteremia with neutropenia is poor. Antibiotic treatment based on antimicrobial susceptibility testing and a second transplant from an HLA-haploidentical donor likely contributed to the successful outcome in this patient.

A 22-year-old man with a history of mediastinal germ cell tumor, which was diagnosed at age 20 and remained disease-free after chemotherapy, was diagnosed with acute myeloid leukemia (AML) M2 in January 2020. Karyotype analysis of bone marrow (BM) specimen at diagnosis detected 47,XXY, inv (16) in all cells. Following induction treatment, he achieved complete remission with a remarkable decrease in the minimal residual disease marker. Although considered related to therapy, the AML had a prognostically favorable karyotype, and the initial treatment response was very good. He had no human leukocyte antigen-matched sibling donor candidate. Thus, allogeneic hematopoietic stem cell transplantation was not scheduled at the first complete remission. After three cycles of consolidation therapy, he remained disease-free for over one year. Karyotype analysis of BM during remission revealed that all analyzed cells harbored 47,XXY, and Klinefelter syndrome (KS) was diagnosed. Although the patient experienced an adjustment disorder on KS diagnosis, he had overcome the difficulty with the assistance of psycho-oncologists, clinical psychologists, and genetic counselors. Herein, we report this rare case of KS that manifested after AML diagnosis following mediastinal germ cell tumor treatment.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients are at high risk of developing invasive pneumococcal disease (IPD) with substantial morbidity and mortality. Pneumococcal polysaccharide vaccine (PPSV23) and pneumococcal conjugate vaccine (PCV13) are the primary prevention strategy. The difference between the Japanese and international guidelines is limited except when to start PCV13. However, Japanese data regarding the incidence of IPD after allo-HSCT that include vaccination status are limited. Therefore, we aimed to study the clinical characteristics of patients with IPD following allo-HSCT, focusing on unvaccinated patients. We retrospectively reviewed allo-HSCT recipients between April 2005 and December 2018 at Komagome Hospital. Among 1,091 recipients, 11 (1008/100,000 recipients) developed 13 episodes of IPD. The median period from the first allo-HSCT to the first IPD episode was 686 days (10-3040 days). Ten patients developed IPD before vaccination, and seven of these unvaccinated patients with late-onset IPD were ineligible for vaccination based on domestic guidelines. Although appropriate treatments resulted in a good short-term prognosis, most episodes of IPD developed in unvaccinated allo-HSCT recipients. Our data support the promotion of better adherence to the current guidelines and the importance of pneumococcal vaccination even years after allo-HSCT to protect against late-onset IPD.

Idiopathic CD4+ lymphocytopenia (ICL) is the depletion of CD4+ lymphocytes to 3 without human immunodeficiency virus infection or other causes of lymphocytopenia. ICL causes fatal infections; its etiology remains unclear and it lacks consensus regarding therapeutic options. We report the first patient with ICL who had a successful clinical course following a cord blood transplant (CBT). A 45-year-old woman was diagnosed with ICL and underwent partial hepatectomy for an abscess caused by the Mycobacterium avium complex. No specific gene alterations were detected through next generation sequencing-based evaluation. Following a reduced-intensity conditioning (RIC) regimen consisting of fludarabine, busulfan, and 4 Gy total body irradiation, a single-unit CBT was performed. Neutrophils were engrafted on day +14. CD4+ lymphocyte counts increased to over 300 cells/mm3 on day +436. After 75 months, she was alive without any sequelae. CBT with an RIC regimen could be a curable treatment option for ICL.

Cytomegalovirus (CMV) infection is a major complication in allogeneic stem cell transplantation. The utility of CMV prophylaxis with letermovir has been reported; however, the specific applications remain unclear. In this study, we retrospectively analyzed large-scale registry data (N = 10 480) to clarify the risk factors for nonrelapse mortality (NRM) in connection with CMV reactivation. First, we identified risk factors for CMV reactivation using multivariate analysis and developed a scoring model. Although the model effectively stratified reactivation risk into 3 groups (43.7% vs 60.9% vs 71.5%; P < .001), the 3-year NRM was significantly higher in patients with CMV reactivation, even in the low (20.9% vs 13.0%, P < .001), intermediate (21.4% vs 15.6%; P < .001), and high (29.3% vs 18.0%; P < .001) reactivation risk groups. Next, survival analysis considering competing risks, time-dependent covariates, and interaction terms for exploring the heterogeneous impact of CMV reactivation on NRM in the training cohort revealed that chronic myeloid leukemia (CML) (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.05-2.96; P = .033), good performance status (PS) (HR, 1.42; 95% CI, 1.04-1.94; P = .028), HLA-matched donor (HR, 1.34; 95% CI, 1.06-1.70; P = .013), and standard-risk disease (HR, 1.28; 95% CI, 1.04-1.58; P = .022) were associated with increased NRM. In the test cohort, CMV reactivation was significantly associated with increased 3-year NRM among patients with 2 to 4 factors (22.1% vs 13.1%; P < .001) but was comparable among patients with 0 or 1 factor (23.2% vs 20.4%; P = .62). We propose that CMV prophylaxis should be determined based on reactivation risk, as well as these other factors.

To elucidate the impact of infused CD34+ cell doses on transplant outcome, we retrospectively analyzed 851 adult patients who received peripheral blood stem cell transplantation (PBSCT) from human leukocyte antigen (HLA)-matched related donors. The patients were divided into high- and low-CD34 groups at the cutoff value of 4.5 × 106/kg. Overall, the high CD34 group showed early neutrophil and platelet recovery. Stratification of disease risks demonstrated that among the patients with low-risk diseases, the high-CD34 group showed better disease-free survival (DFS) (64.9% vs. 55.5%, P = 0.0415) than did the low-CD34 group, without any increase in graft-versus-host disease (GVHD). Meanwhile, a higher CD34+ cell dose had no impacts on the outcomes of patients with high-risk diseases. Multivariate analyses for the patients with low-risk diseases revealed that a high CD34+ cell dose (hazard ratio [HR] 0.72, P = 0.048) and development of grade III-to-IV acute GVHD (HR 1.64, P = 0.018) were significantly associated with DFS. An excessive dose of CD34+ cells (>8.0 × 106/kg) led to an increase in acute GVHD. By stratification of disease risk, a CD34+ cell dose between 4.5 and 8.0 × 106/kg can be suggested for patients with low-risk diseases who undergo PBSCT from HLA-matched related donors.

Variants of the t (8;21) (q22;q22) involving chromosome 8, 21, and other chromosomes account for about 3% of all t (8;21) (q22;q22) in patients with acute myeloid leukemia (AML). However, the prognosis of AML with variant t (8;21) remains unknown due to the scarcity of reported cases. Herein we report a case of AML with t (6;21;8) (p23;q22;q22). Fluorescence in situ hybridization confirmed a RUNX1-RUNX1T1 fusion signal on the derivative chromosome 8. This is the first report on a variant of t (8;21) involving the breakpoint 6p23. After induction chemotherapy, our patient achieved complete remission and has been stable for four years.

Little information is available regarding whether unrelated cord blood transplantation (CBT) or an HLA 1-3 antigen-mismatched related donor peripheral blood stem-cell transplantation (PBSCT) using low-dose anti-thymocyte globulin (ATG) is superior as an alternative transplantation for patients who lack an HLA-matched sibling or unrelated donor. Therefore, we evaluated 7861 patients with hematologic malignancies (aged 0 to 70 years) who received either a CBT without ATG (CBT-no ATG, n = 7034) or an HLA 1-3 antigen-mismatched related donor PBSCT using low-dose ATG (PBSCT-ATG, n = 827). CBT-no ATG was associated with significantly better overall survival (OS) than the use of a PBSCT-ATG (hazard ratio [HR], 0.77; p .001), although PBSCT-ATG patients with an HLA 1 antigen-mismatch showed OS comparable to that in the CBT-no ATG group. Neutrophil and platelet engraftment was significantly delayed, whereas the incidences of nonrelapse mortality, and severe graft-versus-host disease (GVHD) were significantly lower in the CBT-no ATG group. The incidences of relapse and chronic GVHD were comparable between these donors. In conclusion, CBT-no ATG may be a better alternative than HLA-mismatched related donor PBSCT using low-dose ATG. Notably, HLA 2-3 antigen mismatch-related transplantation with low-dose ATG had significant adverse effects on transplantation outcomes.

Autologous hematopoietic cell transplantation (HCT) is an effective therapy for patients with relapsed acute promyelocytic leukemia (APL). However, it remains unclear whether this procedure is equally effective for certain groups of patients. To address this question, we analyzed 296 patients with APL who had undergone autologous HCT during second or subsequent complete remission (CR2+) between 2006 and 2019. Among them, 24 patients were ≥65 years old, and 17 underwent autologous HCT during third or subsequent CR. Of the 286 patients whose measurable residual disease (MRD) data were available, 21 showed detectable MRD. The 5-year probabilities of relapse-free survival (RFS), overall survival, relapse, and nonrelapse mortality for the entire cohort were 85%, 88%, 9%, and 6%, respectively. The multivariate analysis revealed that the duration of first CR ( or ≥2 years) was the sole factor associated with RFS (P = 0.002), but even those with CR1 duration2 years showed a 5-year RFS of 76%. The other factors such as age, disease status, and MRD status were not predictive for the survival outcomes. Our findings demonstrate very favorable long-term results when autologous HCT is conducted during CR2 + across the various subgroups of patients with relapsed APL.

The optimal treatment for Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) in first complete remission (CR1) has not been established in the high-intensity chemotherapy era. The outcomes of patients with Ph-negative ALL who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen-matched related or unrelated donor in CR1 (HSCT-MRD group and HSCT-MUD group) were obtained from a Japanese registry database. Patients aged 16–24 years and 25–65 years were analyzed separately, and their outcomes were compared to those of patients who continued high-intensity chemotherapy in CR1 in studies (202U group and 202O group) by the Japan Adult Leukemia Study Group (JALSG). In the HSCT-MRD group, patients younger than 25 years had lower overall survival (OS) than the 202U group, presumably due to the higher non-relapse mortality (NRM) in the HSCT-MRD group. Patients 25 years and older had similar OS to the 202O group. The lower relapse rate was counterbalanced by higher NRM in the HSCT-MRD group. In the HSCT-MUD group, patients in both age groups had similar OS to their corresponding groups in the JALSG studies. In conclusion, high-intensity chemotherapy may change the role of HSCT for Ph-negative ALL.

The role of matching human leukocyte antigen (HLA) haplotypes in unrelated allogeneic bone marrow transplantation (allo-BMT) remains unclear. Here, we imputed the HLA haplotypes of 3657 patients who received unrelated single HLA allele-mismatched allo-BMT, included from the Transplant Registry Unified Management Program (TRUMP) database, the Japanese registry program for hematopoietic transplantation, using mathematical methods. We successfully imputed the HLA haplotypes of both patients and donors in 1365 cases (37.3%) with ≥90% probability. Of the patients, 1326 (97.1%) and 39 (2.9%) were categorized into one-haplotype-matched and no-haplotype-matched groups, respectively. Disease-free survival was significantly worse in the no-haplotype-matched group. Multivariate analyses revealed that no-haplotype-match was an independent risk factor for reducing disease-free survival (hazard ratio, 1.54 [95% confidence interval: 1.01-2.36]; p = 0.047). However, the overall survival did not significantly differ between the groups. The incidence of grade III-IV acute and chronic graft-versus-host disease did not significantly differ between the groups. Furthermore, there were no significant differences in the cumulative incidences of relapse and non-relapse mortality between the groups. Our findings suggest that imputing haplotypes using a mathematical approach can help to avoid transplanting patients with donors who do not share matching haplotypes, thereby improving the outcome of allo-BMT.

Vacuolar myelopathy (VM) is known to be a neurological complication in patients with acquired immunodeficiency syndrome (AIDS). In autopsy-based studies, VM was reported in approximately 20-50% of patients with AIDS. It manifests in various says, mainly presenting as a painless spastic paraparesis with a sensory ataxia. We present a rare case of VM after bone marrow transplantation (BMT) in a patient without AIDS. A 50-year-old man developed weakness in the lower legs, leg muscle atrophy, and difficulty in walking 86 days after BMT. The patient died from septic shock on day 309. The autopsy revealed intralamellar vacuolation in the spinal white matter, which was compatible with VM.

Cytomegalovirus (CMV) infection is a major complication during allogeneic stem cell transplantation (allo-SCT). However, mechanisms of adaptive immunity that drive this remain unclear. To define early immunological responses to CMV after transplantation, we using next-generation sequencing to examine the repertoire of T-cell receptors in CD8+/CMV pp65 tetramer+ cells (CMV-CTLs) in peripheral blood samples obtained from 16 allo-SCT recipients with HLA-A*24:02 at the time of CMV reactivation. In most patients, TCR beta repertoire of CMV-CTLs was highly skewed (median Inverse Simpson’s index: 1.595) and, 15 of 16 patients shared at least one TCR-beta clonotype with ≥ 2 patients. The shared TCRs were dominant in 12 patients and, two clonotypes were shared by about half of the patients. Similarity analysis showed that CDR3 sequences of shared TCRs were more similar than unshared TCRs. TCR beta repertoires of CMV-CTLs in 12 patients were also analyzed after 2–4 weeks to characterize the short-term dynamics of TCR repertoires. In ten patients, we observed persistence of prevailing clones. In the other two patients, TCR repertoires became more diverse, major clones declined, and new private clones subsequently emerged. These results provided the substantive clue to understand the immunological behavior against CMV reactivation after allo-SCT.

Total body irradiation using intensity-modulated radiation therapy total body irradiation (IMRT-TBI) by helical tomotherapy in allogeneic hematopoietic stem cell transplantation (allo-HSCT) allows for precise evaluation and adjustment of radiation dosage. We conducted a single-center pilot study to evaluate the safety of IMRT-TBI for allo-HSCT recipients. Patients with hematological malignancies in remission who were scheduled for allo-HSCT with TBI-based myeloablative conditioning were eligible. The primary endpoint was the incidence of adverse events (AEs). Secondary endpoints were engraftment rate, overall survival, relapse rate, non-relapse mortality, and the incidence of acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively). Between July 2018 and November 2018, ten patients were recruited with a median observation duration of 571 days after allo-HSCT (range, 496–614). D80% for planning target volume (PTV) in all patients was 12.01 Gy. Average D80% values for lungs, kidneys and lenses (right/left) were 7.50, 9.03 and 4.41/4.03 Gy, respectively. Any early AEs (within 100 days of allo-HSCT) were reported in all patients. Eight patients experienced oral mucositis and gastrointestinal symptoms. One patient experienced Bearman criteria grade 3 regimen-related toxicity (kidney and liver). All cases achieved neutrophil engraftment. There was no grade III–IV aGVHD or late AE. One patient died of sinusoidal obstruction syndrome 67 days after allo-HSCT. The remaining nine patients were alive and disease-free at final follow-up. Thus, IMRT-TBI was well tolerated in terms of early AEs in adult patients who underwent allo-HSCT; this warrants further study with longer observation times to monitor late AEs and efficacy.

We assessed the efficacy and safety of weekly cyclophosphamide-bortezomib-dexamethasone (CBD) induction prior to autologous stem cell transplantation (ASCT) in newly diagnosed Japanese patients with multiple myeloma (MM). This regimen consisted of four 28-day cycles of once-weekly oral cyclophosphamide (300 mg/m2), subcutaneous bortezomib (1.3 mg/m2), and oral dexamethasone (40 mg). Responding patients underwent stem cell collection followed by ASCT. The primary endpoint was the postinduction rate of achieving a near complete response (nCR) or better. Among the 38 enrolled patients, a complete response (CR), an nCR, a very good partial response (VGPR), and a partial response (PR) were achieved in 10.5, 2.6, 23.7, and 36.8% of cases, respectively. A grade 4 hematological adverse event (AE) was observed in 1 patient. Grade 3–4 infection, including febrile neutropenia, was observed in 4 patients (10.5%). Although 2 patients dropped out due to AE, 94.7% of the patients completed the induction phase. However, because of a poor response to induction chemotherapy (

A 76-year-old man presented with shortness of breath and the laboratory tests suggested anemia and reticulocytopenia. CBC showed only anemia, and the bone marrow aspiration smear demonstrated absence of erythroid hematopoietic cells. Consequently, pure red cell aplasia (PRCA) was diagnosed. Computed tomography (CT) showed mediastinal multiple lymph node enlargement and ground-glass opacity in both the lung fields. Biopsy specimens of the mediastinal lymph node showed mild follicular hyperplasia and polyclonal plasma cells proliferation in the interfollicular area. These findings suggest idiopathic multicentric Castleman disease plasma cell type (iMCD PC type). Ciclosporin (CyA) was administered but there was no clinical improvement after 6 weeks of therapy. Therefore, prednisolone (PSL) was started at 0.5 mg/kg/day and was very effective for the PRCA and MCD. A total of 3 cases of CD (2 cases of MCD PC type and 1 case of CD HV type) with PRCA have been previously reported. In the 2 cases of MCD PC type, anemia was improved using PSL combination therapy. However, in the single case of CD HV type, PSL was not effective and anemia was improved with CyA treatment. This case suggests the possibility of using PSL as the first-line drug for MCD PC type with PRCA.

Introduction Myelodysplastic syndromes (MDS), a heterogeneous group of acquired clonal hematopoietic stem cell disorders, is characterized by peripheral cytopenia and has a high tendency to progress to acute myeloid leukemia (AML). Serum ferritin (SF) level is a well-known indicator of iron stores and inflammation. Elevated SF levels is common in patients with MDS and appear to be largely related to regular red blood cell (RBC) transfusions. However, some patients with MDS showed high SF levels at the time of diagnosis, even before receiving RBC transfusions, although the exact mechanisms is unclear. The impact of SF elevation without RBC transfusion has not been well characterized. In this study, we assessed cytogenetic, molecular, and clinical characteristics of patients with MDS and SF elevation. Methods Patients with newly diagnosed MDS who visited our hospital between Jan 2011 and Jan 2020 were included in this study. Patients were defined as high-SF-MDS when SF values were >350 ng/mL (patients with Results Among the 112 patients with MDS, SF value were available for 87 patients. This study analyzed 28 women and 59 men with a median age of 69 years (range: 28-87 years). The median follow-up period was 540 days (range: 3-3618 days). A total of 17 patients died during the observational period (until Apr 2021). Patients were diagnosed with MDS with single lineage dysplasia (MDS-SLD, n = 9), MDS with multilineage dysplasia (MDS-MLD, n = 26), MDS with ring sideroblasts with SLD (MDS-RS-SLD, n = 5), MDS-RS-MLD (n = 6), MDS with excess blasts 1 (MDS-EB1, n = 25), MDS-EB2 (n = 13), MDS with isolated del(5q) (n=1), and MDS, unclassifiable (MDS-U, n = 2). The median SF value was 263 ng/mL (range: 3-1,245 ng/mL); 31 patients were classified as high-SF-MDS and 56 were classified as low-SF-MDS. The Proportion of MDS subtypes differed significantly between the groups (P=0.004, Table1). Compared to low-SF-MDS, MDS-EB1/2 (51.6% vs. 39.3%) and MDS-RS-SLD/MLD (22.6% vs. 1.8%) was more common in high-SF-MDS. In the laboratory data analysis, high-SF-MDS patients showed low Hb levels, high RBC distribution width values, and high bone marrow RS percentages. In patients with high-SF-MDS, as well as MDS-RS, the presence of bone marrow RS was also observed in seven out of 11 patients with MDS-EB1/2 (median 8%, range 2-19%). Complex karyotype ( was more common in patients with high-SF-MDS (46.4% vs. 16.0%, P=0.007) than those with low-SF-MDS. Trisomy 8 and del (5q) were also frequently detected among those with high-SF-MDS. Patients with high-SF-MDS had worse 2-year overall survival (OS) than those with low-SF-MDS. To clarify the molecular characteristics of high-SF-MDS in more detail, NGS analysis was performed on 11 patients with high-SF-MDS whose samples were available. Ten gene mutations were detected in eight patients. Interestingly, five among 11 patients harbored TP53 mutation; the median variant allele frequency was 53.9% (range, 39.7-64.1%). Subsequently, SF3B1 gene mutation was detected in three patients; and two of them also harbored TP53 mutation. Other gene mutations, RUNX1, STAG2, SRSF2, ASXL1, ATM, DNMT3A, BCOR, and DDX41 were detected in one patient each. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Background: Additional cytogenetic abnormalities (ACA), the most frequent form of cytogenetic changes, are considered as a result of genetic instability and clonal evolution of leukemia cells. Recently, we described that ACA at the first relapse was associated with the significantly lower second complete remission (CR2) rate and poor survival in adult acute myeloid leukemia (AML) patients (Hematol Oncol. 2018;36:252-257). However, the prognostic impact of ACA after allogeneic stem cell transplant (allo-SCT) has not been elucidated in adult AML patients. Patients and methods: Of the 145 adult AML patients who underwent the first allo-SCT in CR2 between 1997 and 2019, 98 patients whose cytogenetic abnormality data both at diagnosis and at the first relapse were available were included in this study. Cytogenetic changes between at diagnosis and the first relapse were classified into four groups: (1) no change, (2) ACA was acquired at the first relapse, (3) cytogenetic abnormalities observed at diagnosis were reduced or had disappeared at the first relapse, and (4) cytogenetic abnormalities observed at diagnosis were reduced or had disappeared, and completely different ACA was acquired at the first relapse. In this study, groups 2 and 4 were defined as ACA acquisition. Overall survival (OS) was defined as the interval from the date of transplant to the date of death. Fisher's exact test was used to compare binary variables. The cumulative incidence (CI) of non-relapse mortality (NRM) and relapse were evaluated with Gray's test, considering relapse and NRM as a competing risk, respectively. OS was estimated with the Kaplan-Meier method and compared using the log-rank test. Factors associated with at least borderline significance (p < 0.20) in univariate analyses were subjected to multivariate analysis. The Cox and Fine-Gray proportional hazard model were used for multivariate analysis of prognostic and risk factors, respectively. Values of p < 0.05 were considered to indicate statistical significance. Results: Of the 98 patients included in this study, 57 were male, and 41 were female. The median age at transplant was 45 years (range, 17-71 years). The median duration of CR1 was 12.4 months (range, 1.3-70.3 months) and cytogenetic risk groups were good, intermediate, and poor in 26 (27%), 70 (71%), and two patients (2%), respectively. Donor types were related, unrelated, and cord blood in 23 (24%), 59 (60%), and 16 patients (16%), respectively, and 86 (87%) and 61 patients (62%) were conditioned with myeloablative and total body irradiation-containing regimens, respectively. According to the definition described above, 20 patients (20%) acquired ACA at the first relapse. There was no significant difference in baseline characteristics and transplant procedures between patients with and without ACA acquisition. The OS rates were not significantly different between two groups (55% vs. 72% at three years after transplant; p = 0.28). The CI of relapse was significantly higher in patients with ACA acquisition than those without ACA acquisition (59% vs. 15%; p < 0.01), while the CI of NRM were not significantly different between two groups (5% vs. 19%; p = 0.17). Multivariate analysis for OS revealed that age over 50 years (hazard ratio [HR] = 2.4; p < 0.01), but not ACA acquisition, was identified as an independent prognostic factor. ACA acquisition (HR = 4.7; p < 0.01) was extracted as an independent risk factor of relapse, while use of reduced intensity conditioning regimens (HR = 3.1; p = 0.03) and more than or equal to 1 of performance status at transplant (HR = 2.7; p = 0.04) showed independent risks of NRM. The similar OS rates between two groups might resulted from an offset of the lower relapse rate with the higher NRM rate in patients without ACA acquisition despite not reaching statistical significance. This increasing NRM rates in those without ACA acquisition was potentially associated with use of reduced intensity conditioning regimens in larger proportion (0% vs. 15%; p = 0.12). Conclusion: These findings suggested that ACA acquisition at the first relapse was associated with a higher risk of relapse even after allo-SCT in CR2 in adult AML patients. As AML cells with ACA acquisition was resistant to not only chemotherapy but also graft-versus-leukemia effect, innovative therapeutic strategy is warranted. Disclosures Handa: Janssen: Honoraria; Kyowa Kirin: Research Funding; Takeda: Honoraria, Research Funding; BMS: Honoraria; Chugai: Research Funding; Ono: Honoraria; Sanofi: Honoraria, Research Funding; Abbvie: Honoraria; MSD: Research Funding; Shionogi: Research Funding; Celgene: Honoraria, Research Funding; Daiichi Sankyo: Research Funding.

Although the indications for allogeneic hematopoietic stem cell transplantation (allo-HSCT) as a treatment for T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) and Philadelphia chromosome (Ph)-negative B-cell acute lymphoblastic leukemia (B-ALL) are similar, few studies have compared its outcomes for T-ALL/LBL and Ph-negative B-ALL. The clinical data of 28 patients with T-ALL, 16 with T-LBL, and 99 with Ph-negative B-ALL who underwent the first allo-HSCT from 2000 to 2019 were retrospectively analyzed. Complete remission (CR) rates at allo-HSCT were 79 %, 63 %, and 75 % for T-ALL, T-LBL, and B-ALL, respectively; the 3-year overall survival (OS) rates were 55.7 %, 56.2 %, and 58.6 %, respectively (p = 0.92). Univariate analysis revealed that disease subtypes were not significantly associated with OS (B-ALL vs. T-ALL: hazard ratio [HR]=0.89, p = 0.70; T-LBL vs. T-ALL: HR=0.87, p = 0.75), and CR at allo-HSCT was the only prognostic factor for OS (HR=0.25, p < 0.001). Multivariate analysis demonstrated that CR at allo-HSCT was the only predictor of OS (HR=0.24, p < 0.001). In all three disease subtypes, patients in CR at allo-HSCT tended to have a lower cumulative incidence of relapse than did those in non-CR (T-ALL: 13.6 % vs. 50.0 %, p = 0.10; T-LBL: 20.0 % vs. 50.0 %, p = 0.21; B-ALL: 10.0 % vs. 56.0 %, p < 0.01). Thus, the outcomes of allo-HSCT for T-ALL/LBL were comparable to those of Ph-negative B-ALL. Irrespective of the disease subtypes, achieving CR before allo-HSCT was associated with a favorable OS. Further advances in chemotherapy before allo-HSCT and defining the optimal timing of allo-HSCT would improve the prognosis of patients with T-ALL/LBL.

To elucidate the impact of infused CD34

The major limitation of cord blood transplantation (CBT) for adults remains the delayed hematopoietic recovery and higher incidence of graft failure, which result in a higher risk of early mortality in CBT. We evaluated early overall survival (OS), non-relapse mortality (NRM), neutrophil engraftment, acute graft-vs-host disease, and cause of early death among 9678 adult patients who received single-unit CBT in Japan between 1998 and 2017. The probability of OS at 100 days was 64.4%, 71.7%, and 78.9% for the periods 1998 to 2007, 2008 to 2012, and 2013 to 2017, respectively (P < .001). The cumulative incidences of NRM at 100 days during the same period were 28.3%, 20.8%, and 14.6%, respectively (P < .001). The cumulative incidences of neutrophil engraftment were also improved during the same period (P < .001). The most common cause of death within 100 days after CBT was bacterial infection in 1998 to 2007 and primary disease in the latter two time periods. Across the three time periods, the proportions of deaths from bacterial and fungal infection, graft failure, hemorrhage, sinusoidal obstructive syndrome, and organ failure decreased in a stepwise fashion. Landmark analysis of OS and NRM after 100 days showed that OS did not change over time in the multivariate analysis. Our registry-based data demonstrated a significant improvement of early OS after CBT for adults over the past 20 years. The landmark analysis suggested that improvement of early mortality could lead to an improvement of long-term OS after CBT.

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 ( We used receiver operating characteristics curve in order to determine the cutoff value of the WA-UCE and classified the patients into the high and low WA-UCE group. We evaluated transplant outcomes such as OS, progression-free survival (PFS), NRM, and cumulative incidence of relapse (CIR) between two groups. Results: The median age at allo-HSCT was 52 (range, 18-73) and there were more male patients (n=111) than female patients (n=60). Regarding cytogenetic risk, 15 (9.1%), 112 (65.8%), and 38 (23.0%) were categorized as favorable, intermediate, and poor risk, respectively (There were five patients without cytogenetic data). The median follow-up period of survivors was 704 (range, 9 to 3,857) days. We defined the cutoff value of the weight adjusted UCE as 148 μmol/kg/day in male and 128 μmol/kg/day in female. Among 171 patients, 90 patients (male = 59, female = 31) were in the high WA-UCE group and 81 patients (male = 52, female = 29) were in the low WA-UCE group. We found no significant differences between two groups in terms of the number of relapse before allo-HSCT, cytogenetic risks, conditioning regimens, hematopoietic cell transplantation comorbidity index, donor-recipient HLA matching, donor source, or estimated glomerular filtration rate. On the other hand, patient's age at allo-HSCT was significantly younger (low vs. high WA-UCE group: median, 53 [range, 18 - 73] vs. 48 [range, 19 - 68] years, P = 0.02) and BMI was lower (low vs. high WA-UCE group: median, 22.3 [range, 15.4 - 38.8] vs. 21.9 [range, 15.4 - 29.3] kg/m2, P = 0.003) in high WA-UCE group. In univariate analysis, we observed a significant difference in OS, PFS, and NRM between two groups (low vs. high WA-UCE group: 1-year OS, 60.1% vs. 80.9%, P < 0.01; 1-year PFS, 54.1% vs. 70.9%, P = 0.02; 1-year NRM, 24.8% vs. 12.3%, P = 0.02) (Figure1). On the other hand, there was no significant difference in 1-year CIR between two groups (low vs. high WA-UCE group: 21.1% vs. 16.8%, P = 0.63). In our cohort, the low BMI (< 18.5 kg/m2) was not significantly associated with OS, PFS, CIR, and NRM (low vs. high BMI group: 1-year OS, 77.6% vs. 69.9%, P = 0.51; 1-year PFS, 74.1% vs. 60.9%, P = 0.45; 1-year CIR, 14.8% vs. 19.5%, P = 0.02, 1-year NRM, 11.1% vs. 19.5%, P = 0.70) In multivariate analysis, the low WA-UCE was an independent risk factor for OS (Hazard ratio (HR) [95% confidence interval (CI)]; 2.29 [1.38 - 3.80], P < 0.01), PFS (HR [95% CI]; 1.76 [1.11 - 2.79], P = 0.02), and NRM (HR [95% CI]; 2.22 [1.13 - 4.36], P = 0.02) (table1). Conclusion: In allo-HSCT adult recipients with AML in CR, low WA-UCE before transplantation was associated with poor prognosis, which related to high NRM within 1 year. WA-UCE can be an independent, objective, simple, and reliable biomarker for evaluating muscle mass and predicting transplant outcome. Disclosures No relevant conflicts of interest to declare.

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.

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.

[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.

[Background] Cytomegalovirus (CMV) disease is a major complication after allogeneic stem cell transplantation (SCT). However, mechanisms of adoptive immunity against CMV are not fully elucidated. Recently, high-throughput next-generation sequencing (NGS) technology made it possible to shed light on the detailed and comprehensive landscape of T-cell receptor (TCR) repertoire. In this study, we analyzed TCR repertoire of CMV-specific cytotoxic T-cells (CMV-CTLs) in patients who suffered from CMV reactivation after SCT to clarify the diversity and dynamics of CMV-specific T-cell immunity. [Methods] We sequentially collected peripheral blood mononuclear cells from patients with HLA-A*24:02 who received SCT in our institution. Samples were collected weekly or every two weeks from their neutrophil engraftment until approximately 100 days after SCT. CMV reactivation was evaluated weekly with CMV antigenemia test. CD8 and CMV pp65 tetramer positive cells were sorted and unbiased next-generation sequencing-based analyses of TRBV/TRBJ gene segments were performed at the timing of CMV reactivation in 16 patients, and TRA gene segments were also analyzed in 10 patients. In addition, TCR beta repertoires after 2-4 weeks were analyzed in 12 patients. In the 12 patients, the dynamics of TCR repertoire diversity and proportional changes of each clone were assessed. We evaluated the diversity by Shannon-Weber index, and we defined TCR beta clonotypes found in two or more patients using the same TRBV/TRBJ gene segments and CDR3 amino acid sequences as public. This study was approved by the ethics committee of Tokyo Metropolitan Komagome Hospital. [Results] Among 16 patients, 11 received bone marrow, 3 received peripheral blood stem cells, and 2 received cord blood transplant. Underlying diseases were acute myeloid leukemia in 7, acute lymphoblastic leukemia in 7, and myelodysplastic syndromes in 2 patients. Median age at SCT was 50 years old (range: 20-71). Median duration from SCT to first CMV reactivation was 39 days (range: 16-55) and 7 patients (43.8%) were administered systemic corticosteroid at the time of reactivation (prednisolone 10-30mg/day). Median peripheral blood CMV-CTLs count at that time was 29.47/uL (range: 4.65-229.6). In most patients TCR beta repertoire of CMV-specific CTLs when CMV reactivated was highly skewed (median Shannon-Weber index was 1.44 [range: 0.542-3.164]). TCR alpha and beta were analyzed together in 10 patients and their diversity correlated well (p [Conclusion] TCR repertoire of CMV-CTLs at the time of CMV reactivation after SCT is highly oligoclonal and frequently shared among different patients, but can dynamically change in a short period in some patients. Functional analyses of the dominant TCRs to understand their reactivity against CMV epitope and elucidation of the clinical significance and developmental mechanisms of clone shift are strongly warranted. Figure Disclosures Kitaura: Repertoire Genesis Inc.: Employment. Suzuki:Repertoire Genesis Inc.: Equity Ownership.