Frequent somatic mutations in epigenetic regulators in newly diagnosed chronic myeloid leukemia.

Although tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of chronic myeloid leukemia (CML), the ability of TKIs to eradicate CML remains uncertain and patients must continue TKI therapy for indefinite periods. In this study, we performed whole-exome sequencing to identify somatic mutations in 24 patients with newly diagnosed chronic phase CML who were registered in the JALSG CML212 study. We identified 191 somatic mutations other than the BCR-ABL1 fusion gene (median 8, range 1-17). Age, hemoglobin concentration and white blood cell counts were correlated with the number of mutations. Patients with mutations ⩾6 showed higher rate of achieving major molecular response than those<6 (P=0.0381). Mutations in epigenetic regulator, ASXL1, TET2, TET3, KDM1A and MSH6 were found in 25% of patients. TET2 or TET3, AKT1 and RUNX1 were mutated in one patient each. ASXL1 was mutated within exon 12 in three cases. Mutated genes were significantly enriched with cell signaling and cell division pathways. Furthermore, DNA copy number analysis showed that 2 of 24 patients had uniparental disomy of chromosome 1p or 3q, which disappeared major molecular response was achieved. These mutations may play significant roles in CML pathogenesis in addition to the strong driver mutation BCR-ABL1.

Impact of combinatorial dysfunctions of Tet2 and Ezh2 on the epigenome in the pathogenesis of myelodysplastic syndrome.

Somatic inactivating mutations in epigenetic regulators are frequently found in combination in myelodysplastic syndrome (MDS). However, the mechanisms by which combinatory mutations in epigenetic regulators promote the development of MDS remain unknown. Here we performed epigenomic profiling of hematopoietic progenitors in MDS mice hypomorphic for Tet2 following the loss of the polycomb-group gene Ezh2 (Tet2KD/KDEzh2Δ/Δ). Aberrant DNA methylation propagated in a sequential manner from a Tet2-insufficient state to advanced MDS with deletion of Ezh2. Hyper-differentially methylated regions (hyper-DMRs) in Tet2KD/KDEzh2Δ/Δ MDS hematopoietic stem/progenitor cells were largely distinct from those in each single mutant and correlated with transcriptional repression. Although Tet2 hypomorph was responsible for enhancer hypermethylation, the loss of Ezh2 induced hyper-DMRs that were enriched for CpG islands of polycomb targets. Notably, Ezh2 targets largely lost the H3K27me3 mark while acquiring a significantly higher level of DNA methylation than Ezh1 targets that retained the mark. These findings indicate that Ezh2 targets are the major targets of the epigenetic switch in MDS with Ezh2 insufficiency. Our results provide a detailed trail for the epigenetic drift in a well-defined MDS model and demonstrate that the combined dysfunction of epigenetic regulators cooperatively remodels the epigenome in the pathogenesis of MDS.

A randomized controlled trial of cyclosporine and tacrolimus with strict control of blood concentrations after unrelated bone marrow transplantation.

Previous studies have suggested that tacrolimus (TAC) is more potent than cyclosporine (CSA) for prophylaxis against acute GVHD after allogeneic hematopoietic stem cell transplantation (HSCT). However, the target blood concentrations of these drugs in these studies were not consistent with the current recommendations. Therefore, we performed a randomized controlled trial to compare CSA and TAC with target blood concentrations of 500 and 15 ng/ml, respectively, to prevent acute GVHD after unrelated HSCT. A total of 107 patients were randomized into a CSA group (n=53) or a TAC group (n=54). During the first 4 weeks after HSCT, more than 90% of the patients achieved a mean blood concentration of between 80 and 120% of the target concentration. The incidences of grade II-IV and grade III-IV acute GVHD were 39.6 and 7.5% for the CSA group and 33.3 and 9.4% for the TAC group, respectively (P=0.41 and P=0.76). Other clinical outcomes, including overall survival, disease-free survival and the incidences of relapse, non-relapse mortality, and organ toxicities, were also equivalent. We concluded that the combinations of CSA and TAC with strict dose adjustment showed similar efficacies and toxicities as prophylaxis against acute GVHD after unrelated HSCT.

Successful treatment of cytomegalovirus enteritis after unrelated allogeneic stem cell transplantation by the infusion of ex vivo-expanded CD4+ lymphocytes derived from the recipient's peripheral blood donor cells.

Adoptive immunotherapies have been developed for antiviral agent-refractory cytomegalovirus (CMV) disease after stem cell transplantation (SCT). However, the application of such strategies is limited, particularly in terms of need for donor cooperation regarding blood sampling and inaccessibility in the setting of cord blood transplantation. Herein, we describe the first successful treatment of antiviral agent-refractory CMV enteritis after allogeneic SCT by the infusion of ex vivo-expanded donor-derived CD4(+) lymphocytes obtained from the recipient's peripheral blood.

Vascular endothelial growth factor as a predictive marker for POEMS syndrome treatment response: retrospective cohort study.

OBJECTIVE: POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes) syndrome is a rare multisystem disease characterised by plasma cell dyscrasia and overproduction of vascular endothelial growth factor (VEGF). VEGF is assumed to be useful in monitoring disease activity, because VEGF levels usually decrease after treatment. However, there is no study to investigate whether the extent of decrease in VEGF correlates with clinical outcome. We tested the predictive efficacy of serum VEGF levels in POEMS syndrome. METHOD: This was an institutional review board approved retrospective observational cohort study of 20 patients with POEMS monitored regularly for more than 12 months (median follow-up, 87 months) after treatment onset using our prospectively accumulated database of POEMS from 1999 to 2015. Patients were treated by autologous peripheral blood stem cell transplantation or thalidomide administration. Serum VEGF was measured by ELISA. Outcome measures included clinical and laboratory findings and relapse-free survival. RESULTS: Serum VEGF levels decreased rapidly after treatment, and stabilised by 6 months post treatment. Patients with normalised serum VEGF levels (<1040 pg/mL) at 6 months showed prolonged relapse-free survival (HR=12.81, 95% CI 2.691 to 90.96; p=0.0001) and greater later clinical improvement. The rate of serum VEGF reduction over the first 6 months post treatment correlated with increased grip strength, serum albumin levels, and compound muscle action potential amplitudes at 12 months. CONCLUSIONS: Serum VEGF level at 6 months post treatment is a predicative biomarker for disease activity and prognosis in POEMS syndrome. Serum VEGF could be used as a surrogate endpoint for relapse-free survival or clinical or laboratory improvement of POEMS syndrome for clinical trials.

Favorable survival after allogeneic stem cell transplantation with reduced-intensity conditioning regimens for relapsed/refractory follicular lymphoma.

Allogeneic stem cell transplantation (allo-SCT) is a curative option for patients with relapsed follicular lymphoma (FL). Prospective studies of reduced-intensity conditioning (RIC) have revealed that chemosensitivity at allo-SCT is the most reliable predictor of outcome; however, limited data are available for progressive/refractory disease. We report here a retrospective analysis of RIC allo-SCT for patients with FL. The purpose of this study was to elucidate the role of allo-SCT for patients with relapsed/refractory FL. We analyzed 46 patients-11 (24%) transplanted in CR, 6 (13%) transplanted in PR and 29 (63%) with progressive/refractory disease. The estimated 5-year overall survival rate was 71.6% (95% confidence interval (CI), 51.5-84.5%). According to the disease status at transplantation, the 5-year survival rate was 80.7% (95% CI, 37.7-95.4%) in the patients with CR or PR and 66.1% (95% CI, 41.5-82.3%) in those with progressive/refractory disease (P=0.29). There were no differences in relapse/progression and non-relapse mortality between the patients with chemosensitive disease and progressive/refractory disease. Allo-SCT may be a valuable treatment option, even for patients with progressive/refractory FL.

Patient-reported quality of life after allogeneic hematopoietic cell transplantation or chemotherapy for acute leukemia.

When discussing treatment options for patients with acute leukemia, it is important to acknowledge the impact of allogeneic hematopoietic cell transplantation (allo-HCT) or chemotherapy on quality of life (QOL). We performed a cross-sectional questionnaire study that administered SF-36, FACT-Leukemia and EuroQOL5D to 524 acute leukemia survivors, to compare patient-reported QOL between chemotherapy and allo-HCT, and to elucidate predictors of QOL. Patients who received chemotherapy alone had a better physical QOL than those who received allo-HCT. On the other hand, the allo-HCT group reported a better mental QOL. In the comparison of QOL in the allo-HCT patients according to the presence of GVHD at survey, patients who had GVHD symptoms experienced statistically and clinically significantly worse QOL than those who did not. In the allo-HCT patients without GVHD, the physical QOL was comparable to that in the chemotherapy patients, and they experienced significantly better mental and general QOL than the chemotherapy patients. GVHD and immunosuppressive drugs at survey were strongly associated with worse QOL after allo-HCT. In the chemotherapy group, a shorter time between treatment completion and survey was significantly associated with worse QOL. Further evaluation of QOL by a longitudinal assessment with quantitative and qualitative analyses are warranted.

Clinical significance of pretransplant serum ferritin on the outcome of allogeneic hematopoietic SCT: a prospective cohort study by the Kanto Study Group for Cell Therapy.

This prospective study aimed to investigate the influence of pretransplant serum ferritin levels on the outcomes of allogeneic hematopoietic SCT (HSCT). In total, 190 patients with acute leukemia or myelodysplastic syndrome were consecutively enrolled. The patients were divided into two groups: low-ferritin group (<1000 ng/mL) and high-ferritin group (⩾1000 ng/mL). The primary end point was the cumulative incidence of infection within 100 days after HSCT, which was similar between the two groups: bloodstream infection, 35 vs 38%, P=0.65; bacterial infection, 44 vs 41%, P=0.68; and fungal infection, 6 vs 8%, P=0.71. The 1-year adjusted probability of OS of the high-ferritin group was significantly lower than that of the low-ferritin group (76 vs 63%, P=0.017). Using receiver operating characteristic curve, the threshold of pretransplant serum ferritin levels for bloodstream infection was 1400 ng/mL; the threshold for OS, EFS and non-relapse mortality was 1349 ng/mL. In conclusion, pretransplant serum ferritin levels of ⩾1000 ng/mL did not influence the incidence of infection but adversely affected OS after HSCT. A higher threshold of pretransplant serum ferritin levels may predict HSCT outcomes.

Comprehensive analysis of genetic alterations and their prognostic impacts in adult acute myeloid leukemia patients.

To clarify the cooperative roles of recurrently identified mutations and to establish a more precise risk classification system in acute myeloid leukemia (AML), we comprehensively analyzed mutations in 51 genes, as well as cytogenetics and 11 chimeric transcripts, in 197 adult patients with de novo AML who were registered in the Japan Adult Leukemia Study Group AML201 study. We identified a total of 505 mutations in 44 genes, while only five genes, FLT3, NPM1, CEBPA, DNMT3A and KIT, were mutated in more than 10% of the patients. Although several cooperative and exclusive mutation patterns were observed, the accumulated mutation number was higher in cytogenetically normal AML and lower in AML with RUNX1-RUNX1T1 and CBFB-MYH11, indicating a strong potential of these translocations for the initiation of AML. Furthermore, we evaluated the prognostic impacts of each sole mutation and the combinations of mutations and/or cytogenetics, and demonstrated that AML patients could be clearly stratified into five risk groups for overall survival by including the mutation status of DNMT3A, MLL-PTD and TP53 genes in the risk classification system of the European LeukemiaNet. These results indicate that the prognosis of AML could be stratified by the major mutation status in combination with cytogenetics.

Allogeneic transplantation for primary myelofibrosis with BM, peripheral blood or umbilical cord blood: an analysis of the JSHCT.

To determine whether a difference in donor source affects the outcome of transplantation for patients with primary myelofibrosis (PMF), a retrospective study was conducted using the national registry data on patients who received first allogeneic hematopoietic cell transplantation (HCT) with related BM (n=19), related PBSCs (n=25), unrelated BM (n=28) or unrelated umbilical cord blood (UCB; n=11). The 5-year OS rates after related BM, related PBSC and unrelated BM transplantation were 63%, 43% and 41%, respectively, and the 2-year OS rate after UCB transplantation was 36%. On multivariate analysis, the donor source was not a significant factor for predicting the OS rate. Instead, performance status (PS) ≥2 (vs PS 0-1) predicted a lower OS (P=0.044), and RBC transfusion ≥20 times before transplantation (vs transfusion ≤9 times) showed a trend toward a lower OS (P=0.053). No advantage of nonmyeloablative preconditioning regimens in terms of decreasing nonrelapse mortality or increasing OS was found. Allogeneic HCT, and even unrelated BM and UCB transplantation, provides a curative treatment for PMF patients.

Severe hyponatremia caused by syndrome of inappropriate secretion of antidiuretic hormone developed as initial manifestation of human herpesvirus-6-associated acute limbic encephalitis after unrelated bone marrow transplantation.

Severe hyponatremia is a critical electrolyte abnormality in allogeneic stem cell transplantation (allo-SCT) recipients and >50% of cases of severe hyponatremia are caused by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Here, we present a patient with rapidly progressive severe hyponatremia as an initial sign and symptom of human herpesvirus-6-associated post-transplantation acute limbic encephalitis (HHV-6 PALE) after allo-SCT. A 45-year-old woman with acute lymphoblastic leukemia received unrelated bone marrow transplantation from a one locus-mismatched donor at the DR locus. On day 21, she developed a generalized seizure and loss of consciousness with severe hyponatremia, elevated serum antidiuretic hormone (ADH), and decreased serum osmolality. A high titer of HHV-6 DNA was detected in cerebrospinal fluid. Treatment with foscarnet sodium and hypertonic saline was started with improvement of neurological condition within several days. Although an elevated serum ADH, low serum osmolality, and high urinary osmolality persisted for 2 months, she had no other recurrent symptoms of encephalitis. Our experience suggests that hyponatremia accompanied by SIADH should be recognized as a prodromal or concomitant manifestation of HHV-6 PALE, and close monitoring of serum sodium levels in high-risk patients for HHV-6 PALE is necessary for immediate diagnosis and treatment initiation.

Allogeneic hematopoietic stem cell transplantation for adult AML patients with granulocytic sarcoma.

We recently reported that adult acute myeloid leukemia (AML) patients with granulocytic sarcoma (GS) possessed unique clinical features and poor prognosis. However, the optimal therapeutic strategy for this entity has not been established. Therefore, the aim of this study was to assess the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the management of AML with GS. We retrospectively analyzed 503 consecutive adult AML patients (median age, 44 years; range, 15-73 years) who received allo-HSCT. A total of 44 patients (8.7%) had GS before transplantation. Patients with GS achieved comparable survival to those without GS (5-year overall survival (OS), 47% vs 44%, respectively, P=0.621). In patients with GS, excellent outcomes were seen in those that underwent allo-HSCT while in complete remission, whereas nine out of ten patients with GS at the time of transplant experienced a relapse within 6 months after allo-HSCT. Local irradiation for GS prior to allo-HSCT and acute and chronic graft-versus-host disease did not affect survival significantly. Multivariate analysis identified age, disease status and the use of myeloablative conditioning as independent prognostic factors for OS. These data suggest that better control of GS prior to allo-HSCT is crucial to improve the outcome of transplantation for those with GS.

Secondary solid tumors after allogeneic hematopoietic SCT in Japan.

To evaluate the incidence and risk factors for secondary solid tumors in Japan after allogeneic hematopoietic SCT (allo-HSCT), 2062 patients who had received allo-HSCT between 1984 and 2005 were retrospectively analyzed. Twenty-eight patients who developed 30 solid tumors were identified a median of 5.6 years after transplantation. The risk for developing tumors was 2.16-fold higher than that of the age- and sex-adjusted general population. The cumulative incidence of solid tumors at 10 years after allo-HSCT was 2.4%. The risk was significantly higher for tumors of the skin, oral cavity and esophagus (standard incidental ratio 40.23, 35.25 and 10.73, respectively). No increase in gastric, colon or lung cancer, despite being the most prevalent neoplasm in the Japanese, was observed. In multivariate analysis, occurrence of chronic GVHD and malignant lymphoma as a primary disease was associated with a higher risk for developing solid tumors. Eighteen patients are still alive, and their 5-year probability of survival since diagnosis of solid tumors is 59.7%. Our data suggest that the incidence and risk factors of secondary solid tumors in Japanese allo-HSCT recipients are comparable to those reported in Western countries and emphasize that the early detection of solid tumors has a crucial role in improving OS.

Air-leak syndrome following allo-SCT in adult patients: report from the Kanto Study Group for Cell Therapy in Japan.

We retrospectively investigated air-leak syndrome (ALS), including pneumothorax and mediastinal/s.c. emphysema, following allogeneic hematopoietic SCT. Eighteen patients (1.2%) developed ALS among 1515 undergoing SCT between 1994 and 2005 at the nine hospitals participating in the Kanto Study Group on Cell Therapy. The median onset of ALS was at 575 days (range: 105-1766) after SCT and 14 patients (77.8%) had experienced late onset noninfectious pulmonary complications (LONIPC) before ALS. Chronic GVHD (cGVHD) was the strongest risk factor for ALS (odds ratio 13.5, P=0.013 by multivariate analysis). Repeat SCT, male sex and age <38 years at the time of transplantation were also significant risk factors for ALS. Patients with ALS had a significantly worse survival rate than those without ALS (61.5 vs 14.9% at 3 years; P=0.000). The main cause of death was respiratory complications in 8 of the 18 patients. In conclusion, ALS is a rare complication of SCT that is more likely to occur in relatively young male patients with cGVHD and/or LONIPC. It is possible that better understanding and treatment of LONIPC may lead to prevention of ALS.