We retrospectively analyzed clinical and pathological features, treatments, and prognoses in 28 patients with newly diagnosed peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) in Niigata University Medical and Dental Hospital. Of them, 16 were males and 12 were females, and their median age was 62.5 (range, 26-88) years. The International Prognostic Index was high-intermediate/high in 68% of patients. Twelve patients were treated with CHOP/THP-COP and nine with third-generation chemotherapy regimens. At a median follow-up period of 30 (range: 1-164) months, the 2-year overall survival and progression-free survival rates were 61% and 44%, respectively. Further investigation of novel agents for treating PTCL-NOS is warranted.

A 37-year-old-woman was referred to our center after her uterine cervix health screening presented abnormal findings. We performed a biopsy of the uterine cervix to examine for cervical dysplasia, and diagnosed a diffuse large B-cell lymphoma transformed from mucosa-associated lymphoid tissue (MALT) lymphoma of the cervix. The patient presented with concurrent chlamydial cervicitis and received eradication therapy for Chlamydia trachomatis. Four months later, the CD20 positive abnormal lymphocyte disappeared and complete remission was achieved. MALT lymphoma is considered to correlate with infection and inflammation. Particularly, the relationship between gastric MALT lymphoma and Helicobacter pylori is well known. MALT lymphoma of the uterine cervix is rare, and its relationship with C.trachomatis infection is unknown. Further studies are warranted to investigate this association.

Diamond-Blackfan anemia (DBA) is a rare congenital disease caused by mutations in ribosomal protein genes and is characterized by pure red cell aplasia. While the prognosis is relatively favorable, quality of life (QOL) among DBA patients is negatively impacted by the adverse effects of long-term prednisolone (PSL) therapy and blood transfusions. We describe a 43-year-old man who was diagnosed with DBA (Hb of 2.18 g/dl) at the age of two months. He was initially treated with PSL and blood transfusions, followed by cyclosporine and low-dose (6 mg/day) PSL, which resulted in a sustained hemoglobin level of 9 g/dl without severe adverse events or loss of QOL. High levels of eADA and GSH as well as a RPS19 gene mutation were confirmed. The only curative therapy is hematopoietic stem cell transplantation, which is associated with significant mortality. However, using low-dose PSL to maintain a stable hemoglobin level may improve QOL for patients who receive curative treatment.

A 36-year-old woman with essential thrombocythemia (ET) was admitted to our hospital for acute lower abdominal pain. Given no family history of bleeding disorder, she was diagnosed with acquired von Willebrand syndrome. Despite having a medical history of venous thrombosis, she had never been treated for ET because of her preferences. On admission, CT scan revealed massive hemorrhage in the ascending colon with the leakage of a contrast agent. Furthermore, a delayed enhancement of fluid collection in the Douglas fossa followingcontrast CT indicated bloody ascites. Laboratory data revealed elevated platelets (1,569×10³/µl) and reduced von Willebrand factor (VWF) :RCo (32%) and VWF:Ag (48%). Platelet apheresis was initiated, combined with the infusion of VWF-containing concentrates and cytoreductive therapy with hydroxyurea. Three days after admission, her platelet count decreased to 992×10³/µl after the second round of platelet apheresis. CT scan revealed no hemorrhage, which implied hemostasis. Because of the absence of symptoms, she was discharged 23 days after admission. These results suggest that platelet apheresis, combined with infusion of VWF-containing concentrates and cytoreductive therapy with hydroxyurea, is an effective approach for the treatment of acquired von Willebrand syndrome characterized by emergent bleeding concomitant with ET.

The subject was an 83-year-old female; she had a history of Propionibacterium acnes-related sarcoidosis at the age of 79 years. At diagnosis, she was treated with clarithromycin and achieved remission. Four years later, during a routine physical check-up, she presented with pulmonary opacities and swelling of multiple lymph nodes. A definitive diagnosis of lymphoma could not be made by inguinal lymph node biopsy. The patient’s general condition was good, and we observed her clinical course. Oh the 56th day of her illness, she died suddenly. Autopsy revealed diffuse large B-cell lymphoma (DLBCL). Sarcoidosis-lymphoma syndrome (SLS) was diagnosed after sampling hyalinized nodules from both lungs. The cause of death was organizing pneumonia around an epithelioid granuloma and cor pulmonale. Organization markedly increased around the DLBCL. These findings might be associated with cor pulmonale. Although SLS often appears during chronic active sarcoidosis, sudden death is rare and there are few reports on SLS in Japan. We report this case along with a review of the literature.

Congenital thrombotic thrombocytopenic purpura (TTP) is a rare hereditary deficiency of ADAMTS13 (von Willebrand factor-cleaving protease) characterized by thrombocytopenia and microangiopathic hemolytic anemia. The spectrum of the clinical phenotype is wide, ranging from asymptomatic episodes of thrombocytopenia to life-threatening multiorgan failure. Reportedly, some patients develop isolated thrombocytopenia during childhood. We herein report sibling cases of congenital TTP. An 11-year-old boy with thrombocytopenia accompanied by influenza virus infection was referred to our hospital. He had a history of severe neonatal jaundice. His 15-year-old brother also had recurrent thrombocytopenia with approximately 10 episodes of recurrence since 3 years of age. Their ADAMTS13 activities were low and ADAMTS13 inhibitors were negative, and a gene analysis confirmed the diagnosis of congenital TTP. Notably, congenital TTP should be included in the differential diagnosis, and it is essential to determine the ADAMTS13 activity for pediatric patients with thrombocytopenia of unknown etiology.

A 49-year-old female was initially diagnosed with acute myeloid leukemia (AML) M4 with a CD45＋CD13＋CD33＋CD34−HLA-DR＋ immunophenotype. She underwent allogeneic bone marrow transplantation, but the disease recurred. The bone marrow was infiltrated with 87.0% blasts negative for myeloperoxidase (MPO) staining. Immunophenotyping by flow cytometry identified the presence of a CD45-negative blast population. These blasts exhibited a CD13＋CD33＋CD19−CD10−CD34−HLA-DR− immunophenotype. The lack of CD45 expression is often observed in B-cell acute lymphoblastic leukemia, whereas CD45-negative AML is extremely rare; only one older male with AML-M0 has been reported. In the present case, the CD45-negative blasts had an MPO−CD13＋CD33＋ phenotype, which is similar to AML-M0.

Repeated cell divisions induce DNA damage accumulation, which impairs stem cell function during aging. However, the general molecular mechanisms by which this occurs remain unclear. Herein, we show that the expression of protection of telomeres 1a (Pot1a), a component of shelterin, is crucial for prevention of telomeric DNA damage response (DDR) and maintenance of hematopoietic stem cell (HSC) activity during aging. We observed that HSCs express high levels of Pot1a during development, and this expression declines with aging. Knockdown of Pot1a induced an age-related phenotype, characterized by increased telomeric DDR and reduced long-term reconstitution activity. In contrast, treatment with exogenous Pot1a protein prevented telomeric DDR, which decreased stem cell activity and partially rejuvenated HSC activity. These results highlight a general, reversible mechanism by which aging compromises mammalian stem cell activity, with widespread implications for regenerative medicine.

6-Mercaptopurine (6-MP) is one of the main components for the treatment of childhood acute lymphoblastic leukemia (ALL). However, many patients require a dose reduction of 6-MP due to its severe toxicities. NUDT15 variants are one of the factors that cause 6-MP intolerability in Asians. In each patient with heterozygous variants of NUDT15, 6-MP intolerability differs. Therefore, we hypothesized that the combination of NUDT15 genotype with ABCC4 genotype, which is associated with 6-MP efflux, might enable to accurately predict 6-MP intolerability. We analyzed the association between 6-MP-related events and the genotypes of NUDT15 and ABCC4. All patients with both NUDT15 rs116855232 heterozygous variants and ABCC4 rs3765534 variants suffered from severe leukopenia and required 6-MP dose reduction to less than 35 mg/m²/day. In conclusion, genotyping NUDT15 and ABCC4 facilitates the prediction of 6-MP intolerability. The results of this study will improve personalized medicines in Japanese patients with childhood ALL.

Cancer cells are thought to circumvent immune surveillance through PD-1/PD-L1 signaling. However, the genetic basis for PD-L1-PD-L1-mediated immune escape has not been completely understood, with the exception of elevated PD-L1 expression by gene amplification and the utilization of an ectopic promoter by translocation. Recently, we demonstrated a unique genetic mechanism of immune escape caused by structural variations (SVs) commonly disrupting the 3′ part of the PD-L1 gene. These SVs invariably cause a marked elevation of aberrant PD-L1 transcripts that are stabilized by truncation of the 3′-untranslated region (UTR), and thereby widely affect multiple common cancer types, including adult T-cell leukemia/lymphoma (27%), diffuse large B-cell lymphoma (8%), and adenocarcinoma of the stomach (2%). All SVs invariably result in a prominent increase of aberrant PD-L1 transcripts commonly lacking an intact 3′-UTR, which most typically generate gene fusions with ectopic sequences including integrated viral genomes. In this review, the critical role of 3′-UTR disruption is briefly summarized.

Immune checkpoint inhibitors are the most striking innovation in the clinical development of immunotherapy. Monoclonal antibodies (mAbs) restore and augment the antitumor immune activities of cytotoxic T cells by mainly blocking immune checkpoint molecules on T cells or their ligands on antigen-presenting and tumor cells. Based on preclinical data, many clinical trials have demonstrated the acceptable safety profiles and efficacies of mAb in various cancers. The A first-in-class approved immune checkpoint inhibitor is ipilimumab, which is a fully humanized mAb that blocks the immunosuppressive signal by cytotoxic T-lymphocyte antigen 4. In 2011, the US Food and Drug Administration approved the use of ipilimumab for the treatment of advanced metastatic melanoma. Then, nivolumab, which is a humanized mAb that blocks programmed death-1 (PD-1), was approved for use in the treatment of advanced melanoma in 2014 and of advanced non-small-cell lung carcinoma (NSCLC) in 2015 in Japan. Pembrolizumab, which is another anti-PD-1 antibody, was approved for use in the treatment of advanced melanoma and advanced NSCLC as the first-line therapy in 2016 in Japan. Thereafter, nivolumab was also approved for use in the treatment of advanced renal cell cancer in August 2016, of Hodgkin's lymphoma in December 2016, and of head and neck cancer in March 2017 in Japan. Moreover, phase III trials of anti-PD-1 mAb and anti-PD-ligand 1 mAb for use in the treatment of cancers, such as gastric, ovarian, bladder, and esophageal cancers, are ongoing. Several clinical trials have investigated new agents, alone and in combination, for use in the treatment of various cancers. Current advances in tumor immunology have unveiled the importance of immunosuppressive cells, such as regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages, especially in a tumor microenvironment (TME). Some data from basic research in mouse models and the immunomonitoring of cancer patients suggest that the inhibition of immunosuppressive cells and the cytokines related to them activate and infiltrate cytotoxic T cells and in TME, which could be one of the next combination strategies. The current clinical development of, translational research on, and future challenges in utilizing immune checkpoint inhibitors are described.

Recently, the active development of oncolytic virotherapy has gathered attention. Enterovirus research seeks to better understand its pathogenicity. In particular, coxsackievirus A21 (CVA21) is a promising candidate for oncolytic virotherapy, and thus is the focus of many clinical trials. We have reported that coxsackievirus B3 (CVB3) had potent oncolytic activity for cancer, and induced immunogenic cell death of CVB3-infected cells. We then genetically engineered wild type CVB3 and successfully produced a novel recombinant CVB3-miRT, improving its safety by the introducing an organ-specific miRNA target sequence. We also developed the production method of CVB3 agent, and are conducting a clinical trial of CVB3 therapy for cancer patients. In this report, we review recent clinical progress in oncolytic virotherapy of CVA21 and clinical development of our CVB3.

Annually, it is estimated that approximately 150-200 children aged 0-16 years are diagnosed with acute myeloid leukemia (AML). In Japan, clinical studies with ANLL91, AML99, CCLSG-AML9805, and JPLSG-AML05 protocols were performed historically, and the risk stratification with a combination of chemotherapy and hematopoietic stem cell transplantation resulted in the improvement of clinical outcomes. Regarding the onset of pediatric AML at the molecular level, mutations in FLT3-ITD or KIT (Class I mutation) showed a poor prognosis, but the ratio of mutations in Class III-V genes was smaller than that in adult AML. In contrast, several pediatric AML cases are complicated due to chromosome fragility syndrome or congenital bone marrow failure syndrome. To improve the clinical outcomes, clinical application of next generation sequencing may allow for personalized therapy in each patient in the future.

Acute myeloid leukemia (AML) is a genetically heterogeneous disease, and its prognosis is stratified on the basis of chromosomal and genetic alterations. Core binding factor (CBF) leukemia consists of AML with t (8;21) (p22;q22) and inv16 (q16q16) /t (16;16) (q16;q16) and is included in AML with recurrent genetic abnormality according to WHO classification. Although CBF-AML is categorized as favorable-risk AML, approximately 40% of patients show relapse. The t (8;21) and inv16 (q16q16) /t (16;16) (q16;q16) result in RUNX1-RUNX1T1 and CBFB-MYH11 fusion genes, respectively; however, the fusion proteins encoded by these genes alone are insufficient for the development of leukemia. Activating kinase mutations in KIT, FLT3, and N-RAS have been frequently found, and their cooperation with RUNX1-RUNX1T1 or CBFB-MYH11 is thought to be crucial for leukemogenesis in CBF-AML. Recently, mutations in ASXL2, ZBTB7A, CCND2, and DHX15 have been frequently identified in t (8;21) AML, but their biological and clinical significance have not been elucidated. Thus, a combination of several genetic alterations is associated with the development of CBF-AML, and comprehensive genetic analysis is necessary for the stratification of this leukemia. CBF-AML is a still heterogeneous disease entity, and it is necessary to elucidate the combinations of genomic abnormalities and clonal evolutions for better understanding of the disease and to develop a new treatment strategy.

Since the turn of the century, many agents against multiple myeloma (MM) have been introduced into daily clinical practice. The development of further agents is ongoing and some of these will reach the point of use in clinical practice in the near future. As various treatment options become available, the selection of an appropriate treatment strategy for an individual patient becomes more important. Treatment selection and decision making are based on the following two apparently opposite factors: 1) generalized findings and evidence from clinical trials, and 2) disease risks and background of individuals, which are diverse among patients. Proteasome inhibitors (PIs) are central players in MM treatment. In this review, we summarize evidence for the efficacy and safety of a first generation PI, bortezomib, and discuss its advantages in controlling disease risks and myeloma-defining events in patients with transplant-ineligible, untreated, newly diagnosed MM (NDMM). We also highlight on recent knowledge regarding the use of second generation PIs such as carfilzomib and ixazomib in the treatment of transplant-ineligible, untreated NDMM.

Monoclonal antibodies (mAbs) with new mechanisms of action are emerging as promising agents for patients with multiple myeloma (MM). Of these, anti-CD38 antibodies and anti-signaling lymphocytic activation molecule F7 (SLAMF7) antibody have demonstrated efficacy for relapsed and refractory myeloma (RRMM). Two CD38-targeting antibodies, daratumumab and isatuximab had significant activity as single agents, whereas the SLAMF7-targeting antibody, elotuzumab, did not. Patients with RRMM treated with 16 mg/kg daratumumab achieved at least PR of 36% and 29% in two distinct phase 2 studies. More favorable results of phase 3 study of 16 mg/kg daratumumab with lenalidomide and dexamethasone revealed that 92.9% of patients with RRMM achieved at least partial response (PR), with a 43.1% complete response (CR) rate. The median PFS was better in daratumumab arm (Not Reached) than control arm (18.4 months). When combined with lenalidomide plus dexamethasone, elotuzumab, at a dose of 10 mg/kg, improved the median PFS from 14.9 months to 19.4 months in a phase 3 study named ELOQUENT-2. In addition to IMiDs, bortezomib was a hopeful partner. Regarding toxicity, these mAbs are tolerable even in elderly patients. The most common adverse event is an infusion-related reaction. Based on several published reports, we suggest that mAbs combined with standard agents could be successfully adapted for the treatment of newly diagnosed patients with MM.

Recent progress in the development of novel therapeutic agents has remarkably improved the treatment outcome for multiple myeloma (MM). Proteasome inhibitors such as bortezomib, carfilzomib, and ixazomib; immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide, and pomalidomide; the histone deacetylase (HDAC) inhibitor panobinostat; and the monoclonal antibody, elotuzumab, have all been approved in Japan, although only bortezomib and lenalidomide have been approved for initial therapy. Accordingly, the Japanese Society of Hematology has released updated treatment guidelines for MM. Initial treatments with bortezomib-based 2-3 drug regimens and lenalidomide＋dexamethasone are recommended for patients eligible for autologous stem cell transplantation (ASCT), while bortezomib＋melphalan＋prednisolone and lenalidomide＋dexamethasone are recommended for patients who are not eligible for ASCT. These novel agents provide us with wider therapeutic options for relapsed or refractory patients. Consequently, treatment paradigms for MM continue to rapidly evolve, and it is important to select the optimal treatment strategy for each patient.

Patients with acute lymphoblastic leukemia (ALL) in adolescents and young adults (AYA) generation are treated by both pediatricians and adult hematologists. Because their participation rate in clinical trials has been low, the treatment results have been unsatisfactory. However, with a recent widespread adaptation of pediatric-based regimen in adult ALL trials, their prognosis has dramatically improved. Moreover, their characteristic biology is being rapidly elucidated. For further improvement of AYA-ALL prognosis and quality of life, the collaboration between pediatricians and adult hematologists is essential and multidisciplinary approach is necessary.

Fusion genes found in cases of acute lymphoblastic leukemia (ALL) are reported to be associated with age, such as MLL rearrangements in neonates and BCR-ABL1 in adults. However, the pathogenesis of ALL in adolescents and young adults (AYA) remains largely unknown. To investigate the potential role of fusion genes, we performed RNA-sequencing on 73 BCR-ABL1-negative ALL patients who were all AYA. Interestingly, DUX4-IGH was the most frequent fusion gene detected in B-ALL (18.5%) and was preferentially detected in the AYA generation. ZNF384 and MEF2D genes were also recurrently identified as functionally relevant fusion genes in 16.7% and 9.3% of AYA with B-ALL, respectively. Patients with DUX4 and ZNF384 fusion genes displayed better prognosis, while those with the MEF2D fusion gene displayed a worse outcome. To improve treatment outcome, the fusion genes detected in this study will be useful for risk stratification and target therapy.

It is well known that adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) should be treated based on pediatric ALL protocol, which could yield better survival rates. However, an optimal treatment strategy for AYAs with acute myeloid leukemia (AML) is not yet established and corresponding data are limited. Compared with ALL, clinical and biological characteristics of pediatric and adult AML are relatively similar. Moreover, treatment strategy is quite similar, although pediatric protocols are more intensive and transplant indications are narrower. Previous reports show that AYAs with AML have similar to relatively lower survival rates and higher treatment-related mortality than children with AML. These results indicated that intensive pediatric chemotherapy is effective for preventing AML relapse in AYAs but higher toxicity rates compensates overall survival. To improve the outcomes of AYAs with AML, it is essential to develop optimal intensive chemotherapy, introduce novel targeted therapies, and adopt better risk stratification, particularly to determine appropriate transplant indications. These strategies should be accomplished by close cooperation between pediatric hematologists/oncologists and adult hematologists.

Based on various studies, the survival of adolescent and young adults (AYAs) with acute myeloid leukemia (AML) was reportedly similar to or worse than younger children. AYAs with AML treated in adult institutions are usually offered the same treatment as that of the older adults. Although pediatric protocols generally include intensified regimens compared with adult protocols, it is still controversial whether an intensified pediatric AML regimen results in an improved survival for the AYA population. Somatic mutations have proven to be significantly prognostic in AML. Although such molecular markers are becoming increasingly important as a means of risk stratification for both children and adults with AML, the prevalence and significance of somatic mutations remain largely unknown in AYAs with AML. In addition to the biological characteristics of cancer, non-biological factors, such as compliance with treatment, may influence the treatment outcomes of AYAs. AYAs have specific and unique needs that are different from children and older adults such as psychosocial care, transition from the pediatric to adult care environment, and fertility considerations among long-term survivors. A further multidisciplinary approach for AYAs with AML is still an issue among adult institutes.

Since adolescents and young adults (AYAs) with lymphoma began to be treated by pediatric hematologists and hematology physicians, few data have been collected regarding lymphoma in this generation of patients in Japan. We analyzed the number of pediatric hospitals that have treated hematological AYA patients. In half of the pediatric facilities, patients >15 years of age had been treated, and 40% of those facilities treated >1 AYA every year. A past lymphoma study by the Japanese Pediatric Leukemia/Lymphoma Study Group included some AYA patients. However, only the B-NHL03 study analyzed the difference between children and AYAs. In that study, 25 AYAs (7.8%) were treated among all 321 study patients. The 5-year overall survival rates of patients aged <10, 10-14, >14 years, were 88.7%, 87.0%, and 79.3%, respectively. However, this difference was not statistically significant because of the less number of patients. We analyzed data of stem cell transplantation in patients with non-Hodgkin lymphoma (NHL). Of the allogeneic transplant patients, children and AYAs did not significantly differ in treatment results. However, the 5-year transplant-related mortality after autologous transplantation was significantly higher in children than in AYAs. In NHL patients, the survival rate of AYAs after transplantation was not inferior to that of children.

Malignant lymphoma (ML) is one of the most common malignancies among adolescents and young adults (AYA), accounting for approximately 20% of newly diagnosed cancers in this group. Although Hodgkin lymphoma represents only approximately 4%-5% of all cancers in children younger than 15 years of age, its incidence increases to approximately 16% in AYA. In non-Hodgkin lymphoma, the common malignancies affecting AYA include diffuse large B-cell lymphoma, Burkitt lymphoma, and anaplastic large cell lymphoma. Although it is generally accepted that AYA with ML experience outcomes that are worse than those experienced by children with ML, there are several critical issues. Hemato-oncologists and pediatric oncologists often follow diverse treatment strategies for ML, and it is unclear as to which treatment strategy is more suitable for AYA. Considering other aspects, tumor biology may explain the different outcomes. In Japan, there are no detailed data regarding the incidence, biology, treatment, prognosis, and long-term outcomes of ML in AYA. In future clinical trials, it will be important to determine whether the different outcomes result from the differences between the therapeutic approaches in pediatric and adult regimens or they are attributable to other factors such as variation in tumor biology and aging.