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Objectives: Patients with myeloproliferative neoplasms (MPNs) are at higher risk of developing secondary malignancies. In this study, we focused on patients with MPNs that complicated lymphoid neoplasms. To analyze the real-world status of lymphoid neoplasm treatment in patients with pre-existing MPNs in Japan, we conducted a multicenter retrospective study.Methods: Questionnaires were sent to collect the data on patients who were first diagnosed with either polycythemia vera, essential thrombocythemia or myelofibrosis and who later were complicated with lymphoid neoplasms defined as malignant lymphoma, multiple myeloma, or chronic lymphocytic leukemia/small cell lymphoma.Results: Twenty-four patients with MPNs complicated by lymphoid neoplasms were enrolled (polycythemia vera, n = 8; essential thrombocythemia, n = 14; and primary myelofibrosis, n = 2). Among these, diffuse large B-cell lymphoma (DLBCL) was the most frequently observed (n = 13, 54.1%). Twelve (92.3%) of the patients with DLBCL received conventional chemotherapy. Among these 12 patients, regarding cytoreductive therapy for MPNs, 8 patients stopped treatment, one continued treatment, and two received a reduced dose. Consequently, most patients were able to receive conventional chemotherapy for DLBCL with a slightly higher dose of granulocyte colony-stimulating factor support than usual without worse outcomes. All 3 patients with multiple myeloma received a standard dose of chemotherapy.Conclusion: Our data indicate that if aggressive lymphoid neoplasms develop during the course of treatment in patients with MPNs, it is acceptable to prioritize chemotherapy for lymphoma.

Objectives: Hemorrhagic events are a rare but potentially fatal complication in patients with polycythemia vera (PV).Methods: We analyzed the characteristics of hemorrhagic events in 267 patients with PV.Results: A median follow-up of 4.8 years revealed that 23 (8.6%) hemorrhagic events occurred. Significantly more hemorrhagic events occurred in younger patients aged below 60 years (n = 72) than in older patients aged 60 years or above (n = 191) (n = 12 [16.7%] vs. n = 11 [5.8%], respectively, P = 0.012). In univariate analysis among the younger patients, white blood cell (WBC) count ≥ 15 × 109/L (hazard ratio [HR] = 7.746, 95% confidence interval [CI] 2.082-28.830, P = 0.002), palpable splenomegaly (HR = 5.629, 95% CI 1.193–26.550, P = 0.029), and JAK2V617F allele burden ≥ 80% (HR = 22.850, 95% CI 2.885–181.00, P = 0.003) were associated with an increased risk of hemorrhagic events. In multivariate analysis, JAK2V617F allele burden ≥ 80% (HR = 9.394, 95% CI 1.046–84.380, P = 0.046) was a significant risk factor.Conclusions: There is an increased risk of hemorrhagic events after diagnosis in younger PV patients with a high JAK2V617F allele burden, high WBC count or palpable splenomegaly. It is important to consider treatment options that aim to avoid hemorrhagic events by reducing the JAK2V617F allele burden in younger PV patients.

Anaemia could develop in polycythemia vera (PV) due to phlebotomy-caused iron-deficiency and cytotoxic effect of cytoreductive therapy. Ropeginterferon alfa-2b treatment was not associated with ≥grade 3 anaemia in two recent clinical studies of 78 patients with PV. Only four cases of grade 2 anaemias occurred, the anaemia resolved. The mean haemoglobin levels were above 120.0 g/L. Therefore, ropeginterferon alfa-2b treatment does not lead to clinically significant anaemia and appears to manage PV without affecting normal erythropoiesis. “Both trials were registered at clinicaltrials.gov (A19-201: NCT04182100; A20-202: NCT05485948)”.

ABSTRACTObjectives Since MPL mutation is a rare driver gene mutation found in a small number of essential thrombocythemia (ET) patients, the clinical characteristics of patients with MPL mutations and their association with thrombotic events have not yet been elucidated in Japan.Methods We enrolled 579 Japanese ET patients based on the diagnostic criteria of the WHO classification 2017 and compared clinical characteristics of MPL-mutated patients (n = 22; 3.8%) to JAK2V617F-mutated (n = 299; 51.6%), CALR-mutated (n = 144; 24.9%), and triple-negative (TN) (n = 114; 19.7%) patients.Results Thrombosis during follow up was observed in 4 out of 22 (18.2%) in the MPL-mutated group, which was the highest among all driver gene mutation groups (JAK2V617F-mutated, 8.7%; CALR-mutated, 3.5%; TN,1.8%). The MPL- and JAK2V617F-mutated groups had worse thrombosis-free survival (TFS) than the CALR-mutated (p = 0.043) and TN groups (p = 0.006). Univariable analysis revealed that a history of thrombosis was a possible risk factor for thrombosis among MPL-mutated patients (hazard ratio: 9.572, p = 0.032).Conclusions MPL-mutated ET patients should require more intensive management to prevent recurrence of thrombosis.

ABSTRACTObjectives This Japanese cross-sectional survey evaluated the symptoms, daily living activities, and treatment needs of patients with polycythemia vera (PV), as perceived by patients themselves and their physicians.Methods The study was conducted at 112 centers (March to July 2022) and included PV patients aged ≥20 years (n = 265) and their attending physicians (n = 151). The patient and physician questionnaires included 34 and 29 questions, respectively, to assess daily living, PV symptoms, treatment goals, and physician-patient communication.Results Concerning daily living (primary endpoint), work (13.2%), leisure activities (11.3%), and family life (9.6%) were most affected by PV symptoms. Patients aged

Abstract Background Arterial occlusive events are an emerging problem in patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitor (TKI) therapy. Endothelial cell damage is thought to play an important role in the development of vascular events. Measurement of the peripheral vasodilator response by peripheral arterial tonometry (PAT) has reportedly been useful in the non-invasive assessment of endothelial dysfunction. To date, no studies have assessed endothelial function using PAT in patients with CML receiving TKIs. Method We measured the reactive hyperemia index (RHI) using PAT in young patients with CML (men aged ≤ 55 years and women aged ≤ 65 years) receiving TKIs. Results Thirty patients with CML were examined (mean age, 43.5 ± 9.8 years; men, 57%). The median RHI was 1.81. Among these patients, 16.7% and 83.3% were taking imatinib and second- or third-generation TKIs, respectively. There were no differences in the baseline characteristics between the low RHI (

Abstract Background Acquired erythrocytosis can be classified into polycythemia vera (PV) and non‐neoplastic erythrocytosis (NNE). The vast majority of PV patients harbor JAK2 mutations, but differentiating JAK2 mutation‐negative PV from NNE is challenging due to a lack of definitive molecular markers. Methods We studied the clinical features of 121 patients with erythrocytosis of which 47 (38.8%) were JAK2 mutation‐positive and also fulfilled the diagnostic criteria for PV, and 67 (55.4%) JAK2 mutation‐negative erythrocytosis patients who were diagnosed as NNE. Diagnosis was strictly based on driver mutation analysis and central pathology review. Results No JAK2 mutation‐negative PV patients were found in our cohort. The NNE group showed significantly younger (p

Objective Current guidelines for essential thrombocythemia (ET) patients recommend different treatment approaches based on thrombosis risk stratification models. However, these recommendations may not be applicable to some patients under real clinical settings. Therefore, we carried out a retrospective real-world validation study. Methods Thrombosis-free survival (TFS) was compared between treatment naïve ET patients receiving different treatment approaches. ET patients were stratified by three representative risk models, the conventional, the International Prognostic Score for thrombosis in ET (IPSET-thrombosis), and revised IPSET-thrombosis. Treatment decisions were largely made by individual physicians, taking into account patient preferences and backgrounds. Results A total of 179 ET patients were included, and thrombotic events were observed in 26 patients. TFS was significantly longer in high-risk patients of all risk models receiving a combination of cytoreductive therapy (CRT) and antiplatelet therapy (APT) compared to CRT alone. Similar results were seen in intermediate-risk patients stratified by IPSET-thrombosis. In contrast, in very low- and low-risk patients of all risk models, TFS was not affected by addition of CRT, indicating that observation or APT alone is an appropriate treatment approach for these patients. Conclusion We demonstrate that current guidelines provide optimal treatment approaches for Japanese ET patients under real-world clinical settings.

Background The etiology of POEMS syndrome and its associated polyneuropathy have not been fully elucidated. The clinical picture of POEMS-associated polyneuropathy and nutritional polyneuropathy due to vitamin B6 (VB6) deficiency are strikingly similar, both being typically sensorimotor, symmetrical, stocking and glove distribution, and more severe in the lower extremities.Case presentation We report two consecutive POEMS patients with VB6 deficiency who showed unusual rapid and drastic recovery of polyneuropathies within 6–8 weeks after oral VB6 supplementation. Case 1 was supplemented with VB6 from time of autologous stem cell transplantation. Polyneuropathy began to improve within one week, and he became walker-free and could walk unaided with a cane within 6 weeks. Case 2 was supplemented with VB6 from time of stem cell harvest, and he became cane-free and his gait almost normalized within two months. Nerve conduction studies were also confirmatory of neurologic recovery in both cases.Conclusions Objective physical improvement of POEMS-associated polyneuropathy has been reported to typically require approximately a year after autologous stem cell transplantation, and together with our observations of VB6 deficiency and supplementations leading to accelerated recoveries of polyneuropathy, VB6 deficiency most probably contributes to POEMS-associated polyneuropathy. VB6 acts as a coenzyme in approximately 150 biochemical reactions. VB6 has been reported to inhibit the hypoxia-inducible factor/vascular endothelial growth factor (VEGF) pathway, and VEGF levels are known to corollate with disease activity of POEMS syndrome. Therefore, VB6 deficiency may contribute not only to POEMS-associated polyneuropathy, but also to the etiology of POEMS syndrome itself.

Introduction Few studies have reported the outcomes of adolescents and young adults (AYAs) with chronic-phase chronic myeloid leukaemia (CML-CP) on tyrosine kinase inhibitors (TKIs).Materials and methods We retrospectively analysed the clinical features, treatment response, and long-term outcomes of 42 AYA patients, in comparison to older patients. The initial therapies of AYA patients between 2001 and 2016 included imatinib (n = 24), dasatinib (n = 13) and nilotinib (n = 5).Results In AYA patients, the peripheral blood (PB) white blood cell count and percentage of blasts at the diagnosis were significantly higher, haemoglobin levels were lower and the spleen size was larger. The major molecular response (MMR), event-free survival (EFS) and overall survival (OS) rates were comparable. A sub-analysis comparing imatinib to second-generation TKIs as the initial therapy also showed that their prognosis was comparable.Discussion In conclusion, the tumour burden at the diagnosis of CML-CP is higher in AYA patients; however, their prognosis was not worse in comparison to older patients treated with TKIs. KEY MESSAGESFew studies have reported the outcomes of adolescents and young adults (AYAs) with chronic-phase chronic myeloid leukaemia (CML-CP) on tyrosine kinase inhibitors (TKIs). This study showed the tumour burden at the diagnosis of CML-CP is higher in AYA pa tients; however, their prognosis was not worse in comparison to older patients treated with TKIs. Understanding the biological and non-biological features of AYA patients with CML-CP on TKI therapy is essential for better management and to improve the outcomes.

The mode of cytokine receptor activation is diverse. Here, the authors find that the marine-sponge derived lectin ThC, a bivalent sugar binding protein, activates human cytokine receptor MPL. This mode of action resembles the pathogenic activation of MPL by mutant molecular chaperon calreticulin in hematologic malignancies.

Polycythemia vera (PV) is one of the myeloproliferative neoplasms and has higher frequency of the JAK2 V617F mutation. Hemorrhagic stroke is rare in PV, and myelofibrosis is secondary to PV. A 76-year-old Japanese man was diagnosed as PV with the JAK2 V617F mutation at the age of 63 years. He developed anemia together with secondary myelofibrosis, and then 40 mg ruxolitinib was started at 70 years. At 76 years, he presented with apathy and was diagnosed with intracerebral hemorrhage (ICH) in the right thalamus. Six months later, he developed multiple ICHs in bilateral cerebellar hemispheres. Leukocyte count was 57,600/μL, platelet count was 66,000/μL, and the level of hemoglobin was 8.7 g/dL. Bleeding time was 6 min. The agglutination ability when adding collagen was 41%. A patient with the JAK2 V617F mutation developing hemorrhagic stroke due to late-stage PV and secondary myelofibrosis was reported, implying various mechanisms for recurrent and multiple ICH.

Chemotherapy for hemodialysis (HD) patients is a challenging situation because HD patients are generally frail, and the pharmacokinetics and pharmacodynamics of most chemotherapeutics in HD patients are unknown. We report a classical Hodgkin lymphoma (cHL) patient successfully treated with 34 courses of brentuximab vedotin (BV) monotherapy, of which 30 courses were carried out during HD. Although grade 2 peripheral sensory neuropathy and one occasion of febrile neutropenia were observed, treatment was well-tolerated overall and effective. This is the first report of successful BV administration in a cHL patient on HD, and also the first to report efficacy and safety of extended courses of BV in an HD patient. Treatment options for cHL in the HD patient are limited, and extended courses of BV monotherapy may be an optimal treatment approach for some patients.

TAFRO syndrome is a relatively new disease entity first reported in 2010. We report a case of TAFRO syndrome accommodated by abnormal exacerbation of moderately differentiated gastric adenocarcinoma. The pathophysiology of TAFRO syndrome is largely unknown, but because the disease often responds to immunosuppressive therapy and also because T follicular helper (Tfh) cells are reported to be drastically decreased in TAFRO syndrome, involvement of a dysregulated immune system can be speculated. Growing evidence points toward a pivotal role of Tfh cells in tumor immunity through supporting ectopic lymphoid structures, which are recruitment sites for cells directly engaging in antitumor activity such as CD8+ T cells, NK cells, and macrophages. In fact, Tfh cells are reported to positively correlate with longer survival in human colorectal and breast cancer. Combined with our observations of hyperprogressive gastric cancer in the presented patient, an impaired tumor immunity is strongly indicated in TAFRO syndrome.

Leukemic stem cells (LSCs) in chronic myeloid leukemia are resistant to imatinib and therefore are a cause of relapse. The authors show that IRAK1/4-NF-κB-PD-L1 signaling is critical to mediate imatinib resistance in LSCs and that combining imatinib with blocking this signalling pathway can eliminate LSCs.

Abstract A subset of essential thrombocythemia (ET) cases are negative for disease-defining mutations on JAK2, MPL, and CALR and defined as triple negative (TN). The lack of recurrent mutations in TN-ET patients makes its pathogenesis ambiguous. Here, we screened 483 patients with suspected ET in a single institution, centrally reviewed bone marrow specimens, and identified 23 TN-ET patients. Analysis of clinical records revealed that TN-ET patients were mostly young female, without a history of thrombosis or progression to secondary myelofibrosis and leukemia. Sequencing analysis and human androgen receptor assays revealed that the majority of TN-ET patients exhibited polyclonal hematopoiesis, suggesting a possibility of reactive thrombocytosis in TN-ET. However, the serum levels of thrombopoietin (TPO) and interleukin-6 in TN-ET patients were not significantly different from those in ET patients with canonical mutations and healthy individuals. Rather, CD34-positive cells from TN-ET patients showed a capacity to form megakaryocytic colonies, even in the absence of TPO. No signs of thrombocytosis were observed before TN-ET development, denying the possibility of hereditary thrombocytosis in TN-ET. Overall, these findings indicate that TN-ET is a distinctive disease entity associated with polyclonal hematopoiesis and is paradoxically caused by hematopoietic stem cells harboring a capacity for cell-autonomous megakaryopoiesis.

Background: Anti-myelin-associated-glycoprotein (MAG) neuropathy is a distal, predominantly demyelinating, sensory or sensory-motor polyneuropathy most often developing in the context of an IgM-type monoclonal gammopathy due to monoclonal gammopathy of undetermined significance or lymphoplasmacytic lymphoma. Rituximab is considered standard therapy for treatment naïve patients, but optimal treatment methods for relapsed/refractory patients have not been established. Case presentation: We demonstrate that tirabrutinib, a second-generation Burton kinase inhibitor, led to drastic improvements of polyneuropathy that were affirmed by nerve conduction studies in a rituximab-refractory anti-MAG neuropathy patient. Tirabrutinib continues to give excellent disease control with no apparent adverse events at 11 months since initiation, and the patient remains free of plasmapheresis sessions which were originally mandatory. Conclusion: Tirabrutinib is an extremely promising treatment option for anti-MAG neuropathy.

Radiation-induced myopathy (RIM) is a rare complication occurring years after radiotherapy. RIM basically occurs within the irradiation field, but some cases have been reported to be accommodated by myopathy outside the irradiation field, and the actual extent of RIM is obscure. The presented case also showed decreased MMT scores and abnormal needle electromyography results in the muscles outside the irradiated field, and the patient was initially thought to have RIM both within and outside the irradiated field. However, while systemic postmortem muscle sampling revealed prominent myopathy in line with RIM in the irradiated muscles, only mild myogenic changes that could be explained by other causes such as age-related sarcopenia, radiculopathy, and disuse atrophy were observed in the non-irradiated muscles. The number of biopsy sites in live patients is limited due to the invasive nature of the procedure, but we were privileged to systemically evaluate the extent of myopathy through multiple muscle sampling including muscles both inside and outside of the irradiation field because this was an autopsy case. Through the presented case, we conclude that RIM is a phenomenon most probably limited to the muscles within the irradiated field, and myopathy outside the irradiation is due to other causes.

Abstract Purpose Although platelet-rich plasma (PRP) therapy has become an increasingly popular treatment for sports-related injuries, the molecular mechanisms of PRP on tissue healing process remain poorly understood. The aim of the present study was to develop an experimental method quantifying the efficacy of PRP with murine patellar tendon injury model, leading to future elucidation of the mechanisms of PRP on healing processes. Methods Full-thickness defects were created in the central third of the murine patellar tendon. The prepared allogenic PRP gel was applied on the defect of the patellar tendon (PRP group), while the remaining mice served as the untreated control group. Mice were sacrificed at 2, 4, 6, 8, and 10 weeks after the operation, with histological sections obtained in each time point (n = 4 / time point / group). Semi-quantitative histological evaluation was performed in accordance with the Bonar score. The variables included in this scoring system were cell morphology, ground substance, collagen arrangement, and vascularity, with higher grades indicating worse tendon structures. In addition, the ratio of the collagen fibers to the entire tendon tissue (FT ratio) was measured using KS400 software as a quantitative histological evaluation. Results The total Bonar score in the PRP group was significantly lower than in control group. With regard to the variables in the Bonar score, the vascularity score was significantly higher in the PRP group at 2 and 4 weeks, while the collagen arrangement score was significantly lower in the PRP group at 8 weeks. Based on a quantitative evaluation, the recovery speed of the patellar tendon determined by FT ratio was significantly faster in the PRP group than in the control group at 6 and 8 weeks. Conclusions We have developed an experimental method for histological and quantitative evaluation of the effects of PRP on tissue healing using murine patellar tendon injury model. The results of this study suggest that the local application of PRP could enhance the tissue-healing process both directly through action on localized cells and indirectly through the recruitment of reparative cells through the blood flow. Further investigations will be needed to confirm the mechanisms of PRP in tissue-healing processes with the development of this experimental model.

Characterization and isolation of a large population of cells are indispensable procedures in biological sciences. Flow cytometry is one of the standards that offers a method to characterize and isolate cells at high throughput. When performing flow cytometry, cells are molecularly stained with fluorescent labels to adopt biomolecular specificity which is essential for characterizing cells. However, molecular staining is costly and its chemical toxicity can cause side effects to the cells which becomes a critical issue when the cells are used downstream as medical products or for further analysis. Here, we introduce a high-throughput stain-free flow cytometry called in silico-labeled ghost cytometry which characterizes and sorts cells using machine-predicted labels. Instead of detecting molecular stains, we use machine learning to derive the molecular labels from compressive data obtained with diffractive and scattering imaging methods. By directly using the compressive ‘imaging’ data, our system can accurately assign the designated label to each cell in real time and perform sorting based on this judgment. With this method, we were able to distinguish different cell states, cell types derived from human induced pluripotent stem (iPS) cells, and subtypes of peripheral white blood cells using only stain-free modalities. Our method will find applications in cell manufacturing for regenerative medicine as well as in cell-based medical diagnostic assays in which fluorescence labeling of the cells is undesirable.

Small cell lung cancer (SCLC) is a type of high-grade neuroendocrine carcinoma. It initially responds to chemotherapy but rapidly becomes chemoresistant and it is highly proliferative. The prognosis in SCLC is poor. We have established a novel SCLC cell line, SCLC-J1, from a malignant pleural effusion in a patient with advanced SCLC. SCLC-J1 cells express ganglioside GD2, CD276, and Delta-like protein 3. RB1 is lost.These features of the new SCLC cell line may be useful in understanding the cellular and molecular biology of SCLC and in designing better treatment.

Myelofibrosis (MF) can occur due to a wide variety of causes including malignant lymphoma. We report a case of splenic marginal zone lymphoma complicated by MF mimicking primary myelofibrosis (PMF). The JAK2, CALR and MPL mutations are detected in more than 90% of PMF cases, and when detected, the diagnosis of PMF is usually straight forward. Mutational analysis should be done in all cases of MF, and in triple-negative cases, an exhaustive investigation of other causes of MF should be carried out before a diagnosis of triple-negative PMF is rendered.

Trio-next generation sequencing is useful to identify undiagnosed inherited diseases. We have attended a patient with trigenic ADH5/ALDH2/ADGRV1 pathogenic variants, which caused two distinct diseases, myelodysplastic syndrome and Usher syndrome. Whole genome sequencing of peripheral blood from the patient and his parents were applied to identify disease-causing genes. Sanger sequencing was performed to validate the identified ADH5/ALDH2/ADGRV1 variants. Our results identified disease-associated variants in ADGRV1 (disease inheritance autosomal recessive) and in ADH5 (disease inheritance also autosomal recessive) and a variant in ALDH2 (disease inheritance autosomal dominant). Although the variants identified in ADH5 and ALDH2 have been reported, their co-existence in association with disease-causing variation in a third gene has not. They broaden the spectrum of ADGRV1 in Usher syndrome. Findings on next generation sequencing guided rapid and accurate diagnosis, resulting in patient-tailored therapeutic intervention.

JAK2V617F is the most frequent driver mutation in myeloproliferative neoplasms (MPNs) and is associated with vascular complications. However, the impact of hematopoietic JAK2V617F on the aortic aneurysms (AAs) remains unknown. Our cross-sectional study indicated that 9 (23%) out of 39 MPN patients with JAK2V617F exhibited the presence of AAs. Next, to clarify whether the hematopoietic JAK2V617F contributes to the AAs, we applied a bone marrow transplantation (BMT) with the donor cells from Jak2V617F transgenic (JAK2V617F) mice or control wild-type (WT) mice into lethally irradiated apolipoprotein E-deficient mice. Five weeks after BMT, the JAK2V617F-BMT mice and WT-BMT mice were subjected to continuous angiotensin II infusion to induce AA formation. Four weeks after angiotensin II infusion, the abdominal aorta diameter in JAK2V617F-BMT mice was significantly enlarged compared to that in the WT-BMT mice. Additionally, the abdominal AA-free survival rate was significantly lower in the JAK2V617F-BMT mice. Hematopoietic JAK2V617F accelerated aortic elastic lamina degradation as well as activation of matrix metalloproteinase (MMP)-2 and MMP-9 in the abdominal aorta. The numbers of infiltrated macrophages were significantly upregulated in the abdominal aorta of the JAK2V617F-BMT mice accompanied by STAT3 phosphorylation. The accumulation of BM-derived hematopoietic cells carrying JAK2V617F in the abdominal aorta was confirmed by use of reporter GFP-transgene. BM-derived macrophages carrying JAK2V617F showed increases in mRNA expression levels of Mmp2, Mmp9, and Mmp13. Ruxolitinib decreased the abdominal aorta diameter and the incidence of abdominal AA in the JAK2V617F-BMT mice. Our findings provide a novel feature of vascular complications of AAs in MPNs with JAK2V617F.

We report about a 48-year-old woman diagnosed with primary central nervous system lymphoma (PCNSL). After chemotherapy and autologous stem cell transplantation, she presented with a continuous high-grade fever. Positron emission tomography-computed tomography revealed prominent hepatosplenomegaly and high diffuse uptake of 18F-fluorodeoxyglucose in the liver, spleen, and lungs. Intravascular large B-cell lymphoma (IVLBCL) was diagnosed using random skin biopsy. There were no symptoms of IVLBCL at the time of diagnosis of PCNSL. The histopathological features of PCNSL and IVLBCL were nearly similar. These findings suggest that IVLBCL was the recurrence of PCNSL rather than a separate entity.

Functionally rejuvenated induced pluripotent stem cell (iPSC)-derived antigen-specific cytotoxic T lymphocytes (CTL) are expected to be a potent immunotherapy for tumors. When L-asparaginase-containing standard chemotherapy fails in extranodal natural killer/T-cell lymphoma, nasal type (ENKL), no effective salvage therapy exists. The clinical course then is miserable. We demonstrate prolonged and robust eradication of ENKL in vivo by Epstein-Barr virus-specific iPSC-derived antigen-specific CTL, with iPSC-derived antigen-specific CTL persisting as central memory T cells in the mouse spleen for at least six months. The anti-tumor response is so strong that any concomitant effect of the programmed cell death 1 (PD-1) blockade is unclear. These results suggest that long-term persistent Epstein-Barr virus-specific iPSC-derived antigen-specific CTL contribute to a continuous anti-tumor effect and offer an effective salvage therapy for relapsed and refractory ENKL.

Abstract Background Acquired von Willebrand syndrome (aVWS) is a rare bleeding disorder with laboratory findings similar to those of congenital von Willebrand disease (VWD). Patients with aVWS may require prophylactic treatment to prevent excessive bleeding following surgery. To our knowledge, to date, there have been no reports on perioperative management for breast cancer patients with aVWS. Case presentation A 60-year-old woman with breast cancer was diagnosed with aVWS due to polycythemia vera. Pre-operative laboratory testing showed a high platelet count and low von Willebrand factor (VWF) activity. The VWF activity did not improve despite an attempt to suppress platelet count with hydroxyurea. Therefore, we decided to perioperatively supplement with plasma-derived factor VIII (FVIII) containing von Willebrand factor (FVIII/VWF concentrates) to perform curative surgery for breast cancer safely. Consequently, the patient did not develop hemorrhage during/after surgery and was discharged on postoperative day 7, as planned, without problems. Conclusions For a patient with aVWS, which carries a high risk of hemorrhage during the perioperative period, initiation of appropriate management like supplementation of FVIII/VWF concentrates might enable safe curative surgery for breast cancer, and collaboration with the hematology department is critical.

Abstract: High-mobility group AT-hook 2 (HMGA2) is crucial for the self-renewal of fetal hematopoietic stem cells (HSCs) but is downregulated in adult HSCs via repression by MIRlet-7 and the polycomb-recessive complex 2 (PRC2) including EZH2. The HMGA2 messenger RNA (mRNA) level is often elevated in patients with myelofibrosis that exhibits an advanced myeloproliferative neoplasm (MPN) subtype, and deletion of Ezh2 promotes the progression of severe myelofibrosis in JAK2V617F mice with upregulation of several oncogenes such as Hmga2. However, the direct role of HMGA2 in the pathogenesis of MPNs remains unknown. To clarify the impact of HMGA2 on MPNs carrying the driver mutation, we generated ΔHmga2/JAK2V617F mice overexpressing Hmga2 due to deletion of the 3′ untranslated region. Compared with JAK2V617F mice, ΔHmga2/JAK2V617F mice exhibited more severe leukocytosis, anemia and splenomegaly, and shortened survival, whereas severity of myelofibrosis was comparable. ΔHmga2/JAK2V617F cells showed a greater repopulating ability that reproduced the severe MPN compared with JAK2V617F cells in serial bone marrow transplants, indicating that Hmga2 promotes MPN progression at the HSC level. Hmga2 also enhanced apoptosis of JAK2V617F erythroblasts that may worsen anemia. Relative to JAK2V617F hematopoietic stem and progenitor cells (HSPCs), over 30% of genes upregulated in ΔHmga2/JAK2V617F HSPCs overlapped with those derepressed by Ezh2 loss in JAK2V617F/Ezh2Δ/Δ HSPCs, suggesting that Hmga2 may facilitate upregulation of Ezh2 targets. Correspondingly, deletion of Hmga2 ameliorated anemia and splenomegaly in JAK2V617F/Ezh2Δ/wild-type mice, and MIRlet-7 suppression and PRC2 mutations correlated with the elevated HMGA2 mRNA levels in patients with MPNs, especially myelofibrosis. These findings suggest the crucial role of HMGA2 in MPN progression.

Humoral hypercalcemia due to parathyroid hormone-related peptide (PTHrP) elevation is a well-known complication of various malignancies, but the situation is rare concerning hematological malignancies except for adult T-cell leukemia/lymphoma. We report a case of Richter’s syndrome with humoral hypercalcemia, and demonstrate by reverse transcription polymerase chain reaction (RT-PCR) that peripheral blood PTHrP levels were 2,500-fold higher compared to healthy controls. PTHrP production by tumor cells in chronic lymphocytic leukemia (CLL) and Richter’s syndrome has been previously demonstrated by nonquantitative methods such as immunohistochemistry and northern blot analysis, but this is the first report using the RT-PCR method. The presented case did not have hypercalcemia when initially diagnosed as small lymphocytic lymphoma (SLL), and as reported earlier, the development of hypercalcemia may be an indication of the transformation to Richter’s syndrome in patients with CLL/SLL.

The patient, a 79-year-old Japanese man, was diagnosed with the chronic phase of chronic myeloid leukemia and begun on nilotinib therapy in April 2011. The therapeutic response was major molecular response in August. About 19 months after the start of nilotinib therapy at 400 mg/day (November 2012), an adenocarcinoma (24x20 mm) confined to the head of the pancreas developed. In February 2013, a pancreaticoduodenectomy was performed. The therapy regimen was switched to dasatinib at 100 mg/day, beginning in April. The response was still major molecular response with no recurrence of pancreatic carcinoma in July 2013. There have been 29 reported cases of secondary neoplasms associated with nilotinib therapy. These secondary neoplasms were characterized by relatively frequent occurrence of papilloma (6 cases), gastric cancer (3 cases), fibroma (3 cases), and thyroid neoplasms (2 cases). The present case, however, is the first to be reported as carcinoma of the pancreas. This report describes the case.

Neurological symptoms induced by the infiltration of malignant lymphoma into the nervous systems are subsumed under the term neurolymphomatosis (NL). Here, we report the case of a 30-year-old Japanese man with primary testicular lymphoma complicated, as seen in various neurological findings, by secondary NL prior to testicular swelling. Painless right scrotal enlargement was noticed more than 1 month after the appearance of neurological complications such as right upper extremity numbness, dysarthria, facial palsy, and diplopia. Proactive investigation and biopsies of extranodal sites at high risk of central nervous system infiltration of malignant lymphoma, such as the testes, should be considered when secondary NL is suspected based on imaging findings.

Vancomycin-intermediately resistant Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) are associated with treatment failure. hVISA contains only a subpopulation of cells with increased minimal inhibitory concentrations, and its detection is problematic because it is classified as vancomycin-susceptible by standard susceptibility testing and the gold-standard method for its detection is impractical in clinical microbiology laboratories. Recently, a research group developed a machine-learning classifier to distinguish VISA and hVISA from vancomycin-susceptible S. aureus (VSSA) according to matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) data. Nonetheless, the sensitivity of hVISA classification was found to be 76%, and the program was not completely automated with a graphical user interface. Here, we developed a more accurate machine-learning classifier for discrimination of hVISA from VSSA and VISA among MRSA isolates in Japanese hospitals by means of MALDI-TOF MS data. The classifier showed 99% sensitivity of hVISA classification. Furthermore, we clarified the procedures for preparing samples and obtaining MALDI-TOF MS data and developed all-in-one software, hVISA Classifier, with a graphical user interface that automates the classification and is easy for medical workers to use; it is publicly available at https://github.com/bioprojects/hVISAclassifier. This system is useful and practical for screening MRSA isolates for the hVISA phenotype in clinical microbiology laboratories and thus should improve treatment of MRSA infections.

Hypereosinophilic syndrome (HES) is a systemic disease characterized by an increased peripheral blood eosinophil count accompanied by systemic organ dysfunction. HES is classified into idiopathic HES, primary (neoplastic) HES (HESN), and secondary (reactive) HES (HESR). In this case report, a patient who developed peripheral blood eosinophilia and granulation tissue in the pharynx and paranasal sinus, which was initially diagnosed as chronic eosinophilic leukemia (CEL), categorized as HESN, but was eventually identified after the patient had died as natural killer/T-cell (NK/T) lymphoma, nasal type (ENKL), categorized as HESR, is presented. ENKL-induced HES is very rare but must be considered.

During mouse ontogeny, hematopoietic cells arise from specialized endothelial cells, i.e., the hemogenic endothelium, and form clusters in the lumen of arterial vessels. Hemogenic endothelial cells have been observed in several embryonic tissues, such as the dorsal aorta, the placenta and the yolk sac. Recent work suggests that the mouse embryonic head also produces hematopoietic stem cells (HSCs)/progenitors. However, a histological basis for HSC generation in the head has not yet been determined because the hematopoietic clusters and hemogenic endothelium in the head region have not been well characterized. In this study, we used whole-mount immunostaining and 3D confocal reconstruction techniques to analyze both c-Kit+ hematopoietic clusters and Runx1+ hemogenic endothelium in the whole-head vasculature. The number of c-Kit+ hematopoietic cells was 20-fold less in the head arteries than in the dorsal aorta. In addition, apparent nascent hematopoietic cells, which are characterized by a "budding" structure and a Runx1+ hemogenic endothelium, were not observed in the head. These results suggest that head HSCs may not be or are rarely generated from the endothelium in the same manner as aortic HSCs.

To develop a new therapeutic monoclonal Antibody (mAb) for Hodgkin lymphoma (HL), we immunized a BALB/c mouse with live HL cell lines, alternating between two HL cell lines. After hybridization, we screened the hybridoma clones by assessing direct cytotoxicity against a HL cell line not used for immunization. We developed this strategy for establishing mAb to reduce the risk of obtaining clonotypic mAb specific for single HL cell line. A newly established mouse anti-human mAb (4713) triggered cytoskeleton-dependent, but complement- and caspase-independent, cell death in HL cell lines, Burkitt lymphoma cell lines, and advanced adult T-cell leukemia cell lines. Intravenous injection of mAb 4713 in tumor-bearing SCID mice improved survival significantly. mAb 4713 was revealed to be a mouse anti-human pan-HLA class II mAb. Treatment with this mAb induced the formation of large pores on the surface of target lymphoma cells within 30 min. This finding suggests that the cell death process induced by this anti-pan HLA-class II mAb may involve the same death signals stimulated by a cytolytic anti-pan MHC class I mAb that also induces large pore formation. This multifaceted study supports the therapeutic potential of mAb 4713 for various forms of lymphoma.

Detection of the JAK2V617F mutation is essential for diagnosing patients with classical myeloproliferative neoplasms (MPNs). However, detection of the low-frequency JAK2V617F mutation is a challenging task due to the necessity of discriminating between true-positive and false-positive results. Here, we have developed a highly sensitive and accurate assay for the detection of JAK2V617F and named it melting curve analysis after T allele enrichment (MelcaTle). MelcaTle comprises three steps: 1) two cycles of JAK2V617F allele enrichment by PCR amplification followed by BsaXI digestion, 2) selective amplification of the JAK2V617F allele in the presence of a bridged nucleic acid (BNA) probe, and 3) a melting curve assay using a BODIPY-FL-labeled oligonucleotide. Using this assay, we successfully detected nearly a single copy of the JAK2V617F allele, without false-positive signals, using 10 ng of genomic DNA standard. Furthermore, MelcaTle showed no positive signals in 90 assays screening healthy individuals for JAK2V617F. When applying MelcaTle to 27 patients who were initially classified as JAK2V617F-positive on the basis of allele-specific PCR analysis and were thus suspected as having MPNs, we found that two of the patients were actually JAK2V617F-negative. A more careful clinical data analysis revealed that these two patients had developed transient erythrocytosis of unknown etiology but not polycythemia vera, a subtype of MPNs. These findings indicate that the newly developed MelcaTle assay should markedly improve the diagnosis of JAK2V617F-positive MPNs.

A gain-of-function mutation in the myeloproliferative leukemia virus (MPL) gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs). The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system)-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5%) of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner.

Sirtuins, NAD-dependent protein deacetylases, play important roles in cellular functions such as metabolism and differentiation. Whether sirtuins function in tumorigenesis is still controversial, but sirtuins are aberrantly expressed in tumors, which may keep cancerous cells undifferentiated. Therefore, we investigated whether the inhibition of sirtuin family proteins induces cellular differentiation in leukemic cells. The sirtuin inhibitors tenovin-6 and BML-266 induce granulocytic differentiation in the acute promyelocytic leukemia (APL) cell line NB4. This differentiation is likely caused by an inhibition of SIRT2 deacetylase activity, judging from the accumulation of acetylated α-tubulin, a major SIRT2 substrate. Unlike the clinically used differentiation inducer all-trans retinoic acid, tenovin-6 shows limited effects on promyelocytic leukemia-retinoic acid receptor α (PML-RAR-α) stability and promyelocytic leukemia nuclear body formation in NB4 cells, suggesting that tenovin-6 does not directly target PML-RAR-α activity. In agreement with this, tenovin-6 induces cellular differentiation in the non-APL cell line HL-60, where PML-RAR-α does not exist. Knocking down SIRT2 by shRNA induces granulocytic differentiation in NB4 cells, which demonstrates that the inhibition of SIRT2 activity is sufficient to induce cell differentiation in NB4 cells. The overexpression of SIRT2 in NB4 cells decreases the level of granulocytic differentiation induced by tenovin-6, which indicates that tenovin-6 induces granulocytic differentiation by inhibiting SIRT2 activity. Taken together, our data suggest that targeting SIRT2 is a viable strategy to induce leukemic cell differentiation.

We describe a Japanese family with familial platelet disorder with propensity to develop myeloid malignancies (FPD/MM). Among the three affected individuals, two members developed myeloid malignancies. Sequence studies demonstrate that all affected individuals of the pedigree display a heterozygous single nucleotide deletion in exon 8 of the RUNX1 gene.