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We here report a 21-year-old male who presented with acute myelomonocytic leukemia (AMML) associated with acquired von Willebrand syndrome (AVWS). To our knowledge, this is the first case of AVWS caused by AMML. In our case, following remission-induction chemotherapy combined with idarubicin and cytarabine, the patient showed remarkable improvement of bleeding symptoms due to AVWS. Moreover, after an allogeneic stem cell transplantation from a sibling donor, both AMML and AVWS maintain complete remission.

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.

Background Chronic graft-versus-host disease (GVHD) appears several months following allogenic hematopoietic stem cell transplantation (HSCT) and is clinically analogous to autoimmune disorder. Polymyositis is a common neuromuscular disorder in chronic GVHD, but myasthenia gravis (MG) is extremely rare. Hence, its pathophysiology and treatment have not been elucidated. Case presentation A 63-year-old man with a history of chronic GVHD presented with ptosis, dropped head, and dyspnea on exertion, which had worsened over the previous several months. He showed progressive decrement of compound muscle action potential in the deltoid muscle evoked by 3-Hz repetitive nerve stimulation, a positive edrophonium test, and elevated levels of serum anti-acetylcholine receptor antibodies, which suggested a diagnosis of generalized MG. No thymoma was found. Flow cytometric analysis revealed a remarkable depletion of peripheral Tregs (CD4+CD25highFOXP3+ cells, 0.24% of the total lymphocytes). Administration of prednisolone and tacrolimus was insufficient to alleviate his symptoms; however, the use of rituximab successfully improved his condition. Conclusions Myasthenic symptoms appeared in the process of tapering prednisolone for the treatment of chronic GVHD, supporting the diagnosis of MG associated with chronic GVHD. The present case proposes a possibility that reduction of Tregs might contribute to the pathogenesis of MG underlying chronic GVHD. Immunotherapy with rituximab is beneficial for treatment of refractory MG and GVHD.

Rationale: Intestinal Behçet disease (BD) with myelodysplastic syndrome (MDS) is a rare condition that is resistant to various immunosuppressive therapies. Several cases in which hematopoietic stem cell transplantation (HSCT) was effective for intestinal BD with MDS accompanying trisomy 8 have been reported. Patient concerns: We report an 18-year-old female with a 7-year history of BD. Colonoscopy demonstrated a huge ulcer in the cecum. Chromosomal examination revealed a karyotype of trisomy 8 in 87% of cells. Bone marrow examination revealed dysplastic cells in multilineages. Diagnoses: A diagnosis of intestinal BD associated with MDS accompanying trisomy 8 was made. Interventions: The patient underwent ileocecal resection due to microperforations of ileocecal ulcers; she then underwent allogeneic peripheral blood stem cell transplantation (PBSCT) with her mother as a donor. Outcomes: After the PBSCT, the patient's symptoms due to BD (fever, oral aphthae, abdominal pain, and genital ulcers) completely disappeared, with no severe adverse events. Lessons: The present case demonstrates that HSCT including PBSCT might be an effective new therapeutic option for refractory intestinal BD with MDS when immunosuppressive therapy has achieved insufficient efficacy.

Intranuclear proteins, including high mobility group box 1 (HMGB1) and histone H3, released from inflammatory cells activate platelets and the coagulation systems, leading to development of disseminated intravascular coagulation (DIC) in individuals with sepsis. These observations prompted us to hypothesize that HMGB1 and histone H3 liberated from leukemia cells undergoing apoptosis after chemotherapy might play a role in development of DIC. To test this hypothesis, we prospectively measured plasma levels of coagulation markers and intranuclear proteins in patients with newly diagnosed acute leukemia (n = 17) before and after chemotherapy. Ten of 17 patients were diagnosed with DIC at the time of diagnosis of leukemia. Serum levels of HMGB1 and histone H3 were significantly higher in patients with DIC than in non-DIC patients. Of note, seven patients developed DIC or experienced exacerbation of coagulopathy after administration of anti-leukemic agents. Intriguingly, an increase in levels of HMGB1 and histone H3 were detected in five of seven patients. These findings suggest that intranuclear proteins spontaneously released from leukemia cells may play a role in development of leukemia-related DIC. Additionally, remission induction chemotherapy causes apoptosis of leukemia cells, leading to forced release of intranuclear proteins, which may exacerbate coagulopathy.

Endothelial dysfunction in the early phases of hematopoietic stem cell transplantation (HSCT) contributes to a common pathology between transplant-associated thrombotic microangiopathy (TA-TMA) and graft-versus-host disease (GVHD), which are serious complications of HSCT. Growth arrest-specific (Gas) 6 structurally belongs to the family of plasma vitamin K-dependent proteins working as a cofactor for activated protein C, and has growth factor-like properties through its interaction with receptor tyrosine kinases of the TAM family: Tyro3, Axl, and Mer. Serum Gas6 levels were significantly increased in HSCT patients with grade II to IV acute GVHD (aGVHD), and Gas6 and Mer expression levels were upregulated in aGVHD lesions of the large intestine and skin. The increased serum Gas6 levels were also correlated with elevated lactate dehydrogenase, d-dimer, and plasmin inhibitor complex values in HSCT patients with aGVHD. In human umbilical vein endothelial cells (ECs), exogenous Gas6 or the exposure of sera isolated from patients with grade III aGVHD to ECs induced the downregulation of thrombomodulin and the upregulation of PAI-1, as well as the upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, which were inhibited by UNC2250, a selective Mer tyrosine kinase inhibitor. In mouse HSCT models, we observed hepatic GVHD with hepatocellular apoptosis, necrosis, and fibrosis, as well as TA-TMA, which is characterized pathologically by thrombosis formation in the microvasculature of the liver and kidney. Of note, intravenous administration of UNC2250 markedly suppressed GVHD and TA-TMA in these mouse HSCT models. Our findings suggest that the Gas6-Mer axis is a promising target for TA-TMA after GVHD.

A 76-year-old man presented with a tracheal tumor associated with severe respiratory obstruction. A tracheotomy was performed due to respiratory failure. F-fluorodeoxyglucose (FDG) -positron emission tomography/computed tomography revealed an abnormal accumulation of FDG (maximum standardized uptake value: 16) in the trachea. A histopathological examination of the tracheal biopsy revealed extranodal NK/T-cell lymphoma, nasal type (ENKL). He was treated with concurrent radiotherapy (50 Gy) for the tracheal tumor and three courses of two-thirds dose ofdexamethasone, etoposide, ifosfamide, and carboplatin. Although the tumor responded remarkably well to this therapy, the patient died of an ENKL recurrence in the lungs and liver 11 months post therapy.

Light chain deposition disease (LCDD) is a rare systemic disorder caused by the deposition of light chain immunoglobulins, which often results in renal impairment associated with either nephrotic syndrome or asymptomatic proteinuria. B-cell neoplasms, such as multiple myeloma and lymphoproliferative disorders, are well-known underlying diseases in LCDD. Some chemotherapy regimens have been reported, but both evidence-based treatment and management for LCDD have yet to be established. We herein report three cases of LCDD treated with lenalidomide-based therapy, resulting in hematologic responses accompanied by a significant reduction in proteinuria and improvement in the renal function. We recommend lenalidomide-based therapy for renal impairment caused by LCDD.

Background and Objectives Red blood cell (RBC) transfusion prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT) is linked to poor outcomes, but outcomes related to post-transplant, especially postengraftment transfusions, have not been fully investigated. We investigated allo-HSCT outcome in association with early postengraftment transfusion. Materials and Methods We reviewed RBC and platelet transfusions in 50 recipients of bone marrow transplantation, specifically analysing postengraftment transfusions from 31 to 60 days post-transplant with no relapse in our institution. Results Postengraftment RBC and/or platelet transfusions were needed in 22 (44·0%) patients. Pretransplant haemoglobin concentrations were negatively correlated with RBC transfusions performed from days 0 to 30, but not postengraftment. Regardless of product type, transfused patients were more anaemic and thrombocytopenic even at day 100, when most of them no longer required transfusion. Patients with postengraftment transfusions, especially those who were transfused both RBC and platelet, showed inferior overall survival (P = 0·016) with increases of both chronic graft-versus-host disease and relapse (P = 0·002 and 0·019, respectively). Postengraftment RBC and platelet transfusion were significant predictors for poor survival in multivariable analysis. Conclusions Postengraftment transfusion may be associated with adverse outcomes of allo-HSCT.

BACKGROUND: CD4+CD25highFOXP3+ regulatory T (Treg) cells, which include thymus-derived and peripherally induced cells, play a central role in immune regulation, and are therefore crucial to prevent graft-versus-host disease (GVHD). The increasing use of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for elderly patients with thymus regression, and our case of allo-HSCT shortly after total thymectomy, raised questions about the activity of thymus-derived Treg cells and peripherally induced Treg cells, which are otherwise indistinguishable. RESULTS: We found that despite pre-transplant thymectomy or older age, both naïve and effector Treg cells, as well as naïve and effector conventional T cells, proliferated in allo-HSCT recipients. Higher proportions of total Treg cells 1 month post allo-HSCT, and naïve Treg cells 1 year post allo-HSCT, appeared in patients achieving complete chimera without developing significant chronic GVHD, including our thymectomized patient, compared with patients who developed chronic GVHD. CONCLUSIONS: Treg cells that modulate human allogeneic immunity may arise peripherally as well as in the thymus of allo-HSCT recipients.

We here report a 47-year-old female with autoimmune myelofibrosis (AIMF) associated with liver damage caused by autoimmune hepatitis and Evans syndrome. Bone marrow biopsy revealed hypocellular marrow with grade 2 reticulin fibrosis and increased levels of B lymphocytes (CD20+), T lymphocytes (CD3+, CD8+), and plasma cells (CD138+). Immunohistochemical analysis revealed increased expression of transforming growth factor-β (TGF-β) in infiltrating lymphocytes and macrophages in the bone marrow. She was initially treated with oral prednisolone (PSL) for 2 months, which had a limited effect. However, after treatment with rituximab, the patient's pancytopenia showed improvement, allowing us to rapidly reduce the PSL dosage. The present case suggests the possibility that increased expression of TGF-β in infiltrating lymphocytes and macrophages of bone marrow may contribute to the pathogenesis of AIMF. Prednisolone combined with rituximab may thus be an effective option for steroid-refractory cases.

The pathogenesis of multiple myeloma (MM) has not yet been fully elucidated. Our microarray analysis and immunohistochemistry revealed significant up-regulation of growth arrest-specific gene 6 (Gas6), a vitamin K-dependent protein with a structural homology with protein S, in bone marrow (BM) cells of MM patients. ELISA showed that the serum levels of soluble Gas6 were significantly increased in the MM patients when compared with healthy controls. Gas6 was overexpressed in the human CD138-positive MM cell line RPMI-8226. Exogenous Gas6 suppressed apoptosis induced by serum deprivation and enhanced cell proliferation of the MM cells. The conditional medium from the human BM stromal cell line HS-5 induced cell proliferation and anti-apoptosis of the MM cells with extracellular signal-regulated kinase, Akt, and nuclear factor-κB phosphorylation, which were reversed by the neutralizing antibody to Gas6 or IL-6. The TAM family receptor Mer, which has been identified as a Gas6 receptor, was overexpressed in BM cells of MM patients. The knockdown of Mer by siRNA inhibited cell proliferation, anti-apoptosis, and up-regulation of intercellular cell adhesion molecule-1 (ICAM-1) in MM cells stimulated by an HS-5 cell-conditioned medium. Furthermore, the Gas6-neutralizing antibody reduced the up-regulation of IL-6 and ICAM-1 induced by a HS-5 cell-conditioned medium in MM cells. The present study provides new evidence that autocrine and paracrine stimulation of Gas6 in concert with IL-6 contributes to the pathogenesis of MM, suggesting that Gas6-Mer-related signaling pathways may be a promising novel target for treating MM.

In patients with MPNs, repression of MIRlet-7 and mutations in the polycomb genes EZH2 and ASXL1 correlate with HMGA2 overexpression.Hmga2 overexpression collaborates with JAK2V617F to promote lethal MPN in mice, highlighting the crucial role of Hmga2.

We herein report a 74-year-old woman who presented with autoimmune hemolytic anemia (AIHA) associated with pleural solitary fibrous tumor (SFT). Her AIHA was initially treated with 1 mg/kg daily of oral prednisolone (PSL) for 2 months, which had a limited effect. However, after surgical tumor resection, the patient showed remarkable improvement of AIHA with normalizations of serum lactate dehydrogenase and bilirubin levels, and we were able to rapidly reduce the PSL dosage. This is the first description of a case of AIHA caused by SFT.

From 1996 to the end of 2009, a total of 114 cases of hematopoietic stem cell transplantation were performed in the Department of Hematology, Fukushima Medical University. We report here a general overview of our results. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) was performed in 37 cases of acute leukemia, 10 of myelodysplastic syndrome, 5 of aplastic anemia, and 5 others. The 5-year survival rate with allo-HSCT was 51.1%. Autologous hematopoietic stem cell transplantation (auto-HSCT) was performed in 34 cases of malignant lymphoma, 15 of multiple myeloma, and 8 others. The 5-year patient survival rate was 75.2% with malignant lymphoma and 46.7% with multiple myeloma. These results are comparable to those from a nationwide survey in Japan, confirming that our hospital has attained a creditable level as a transplantation center.

A 44-year-old man whose platelet count had been at the lower limit of the normal range for years visited the urgent care department of our hospital for treatment of a high fever and severe fatigue. The influenza A virus was detected, and the patient therefore received the intravenous antiviral agent, peramivir. One week later, he developed systemic petechial rashes. A peripheral blood examination showed a markedly decreased platelet count (3.0×10(9) cells/L), and the bone marrow findings were compatible with a diagnosis of immune thrombocytopenia (ITP). Furthermore, a drug-induced lymphocyte-stimulating test was positive for peramivir. The thrombocytopenia slowly responded to treatment with oral prednisolone. This case suggests that neuraminidase inhibitors, including peramivir, can elicit or worsen ITP.

We experienced the case of a 67-year-old man with refractory heart failure. He presented with dyspnea and progressive pitting edema of the lower limbs. Diuretics were insufficient to improve his symptoms. Cardiac catheterization demonstrated pulmonary hypertension. Additional examinations confirmed polyneuropathy, organomegaly, endocrinopathy and monoclonal gammopathy. The plasma vascular endothelial growth factor (VEGF) level was 1,340 pg/mL. The patient was diagnosed with Crow-Fukase (POEMS) syndrome. Echocardiography detected left ventricular hypertrophy and diastolic dysfunction. Polysomnography demonstrated severe sleep-disordered breathing. We herein describe a case of pulmonary hypertension with Crow-Fukase syndrome accompanied by left ventricular diastolic dysfunction and sleep-disordered breathing.

Myeloproliferative neoplasms (MPN) are characterized by chronic proliferation of myeloid cells, extramedullary hematopoiesis and occasional leukemic transformation. Mutations in JAK2, CALR and MPL have been established as drivers of myeloproliferative phenotype, but their roles in disease progression with clonal expansion remain unclear. In addition, studies have shown mutations in epigenetic modifiers including TET2, DNMT3A, ASXL1 and EZH2, and aberrant expressions of microRNAs in MPN, but downstream of these changes is also largely unknown. Recently, we showed high expression of HMGA2 mRNA partly correlated with reduced microRNA let-7 in granulocytes of patients with MPN, including 100% patients with primary myelofibrosis (MF) and 20% polycythemia vera and essential thrombocythemia (Harada-Shirado et al, Brit J Haematol, 2015). In mice, loss of epigenetic modifiers such as BMI1 and EZH2, along with the Arf/Ink4a knockout (Oguro et al, J Exp Med, 2012) or the JAK2 V617F (Sashida et al, ASH, 2013), leads to overexpression of HMGA2 with accelerating MPN. We have generated transgenic (Tg) mice of Hmga2 cDNA with truncated 3'UTR (ΔHmga2) lacking binding sites of let-7 thatrepresses expression of HMGA2 (Ikeda et al, Blood, 2011). Δ Hmga2 mice overexpress HMGA2 and develop MPN-like disease, and represent a clonal advantage in competitive repopulations with serial bone marrow (BM) transplants (BMT). Here, to clarify if HMGA2 affect JAK2 V617F+ hematopoiesis, we crossed Δ Hmga2+/- mice with JAK2 V617F+/- Tg mice (Shide et al, Leukemia, 2008). Δ Hmga2-/-JAK2 V617F-/- wild type (WT), Δ Hmga2+/-JAK2 V617F-/- (Δ Hmga2 -Tg), Δ Hmga2-/-JAK2 V617F+/- (JAK2 V617F-Tg) and Δ Hmga2+/-JAK2 V617F+/- (double-Tg) mice were born at expected Mendelian ratios and we could analyze 5 - 6 of each. At 3 months old, leukocytosis, thrombocytosis, anemia and splenomegaly were most severe in double-Tg compared with JAK2 V617F-Tg or Δ Hmga2 -Tg mice. Relative to WT, peripheral leukocyte and platelet counts were nearly 16- and 4-fold higher in double-Tg, while 3- and 2-fold higher in JAK2 V617F-Tg mice, respectively. Mean spleen weights were 0.067, 0.10, 0.83 and 2.8 g in WT, Δ Hmga2 -Tg, JAK2 V617F-Tg and double-Tg mice, while BM cell counts were 2.4, 2.8, 0.4 and 1.2 x 107/femur, respectively. However, JAK2 V617F-Tg and double-Tg equally showed MF whereas no MF was detected in WT and DHmga2-Tg, suggesting that HMGA2 partly recovers cellularity in fibrotic BM. In the absence and presence of JAK2 V617F, HMGA2 augments lineage- Sca1+ Kit+ cells (WT: Δ Hmga2-Tg: JAK2 V617F-Tg: double-Tg= 0.17%: 0.19%: 0.17%: 0.27% in BM cells), endogenous erythroid colonies (1: 11: 13: 21 CFU-E/104 BM cells) and CD71+ Ter119+ erythroblasts (23%: 29%: 5.7%: 10% in BM and 2.0%: 4.4%: 7.9%: 16% in spleen cells), indicating HMGA2 contributes to expansion of hematopoietic stem/progenitor cells (HSPC) and erythroid commitment in JAK2 V617F+ hematopoiesis. Most Δ Hmga2-Tg and JAK2 V617F-Tg survived for over one year, but all double-Tg mice died within 4 months after birth due to severe splenomegaly and MF with no acute leukemia. To study the effect of HMGA2 on JAK2 V617F+ HSPC activity, we performed BMT with 0.25 x 106 Ly5.2+Δ Hmga2-Tg, JAK2 V617F-Tg or double-Tg cells with 0.75 x 106 Ly5.1+ competitor WT cells to lethally irradiated Ly5.1+ WT mice. Proportions of Ly5.2+ cells were higher in recipients of Δ Hmga2 -Tg than double-Tg cells, while JAK2 V617F-Tg cells were almost rejected at 8 weeks after BMT. To confirm role of HMGA2 without let-7 repression in JAK2 V617F+ hematopoiesis, we performed another BMT with 1 x 104 KIT+ cells of JAK2 V617F-Tg mice transduced with retroviral vector of Hmga2 with each let-7 -site-mutated full-length 3'UTR (Hmga2-m7) to sublethally irradiated WT mice. Recipients of JAK2 V617F-Tg cells with Hmga2-m7 developed MPN-like disease, whereas donor cells were rejected in recipients of JAK2 V617F cells with empty vector. In conclusion, HMGA2 may play a crucial role in hematopoiesis harboring JAK2 V617F by expanding HSPC, leading to disease progression. Disclosures No relevant conflicts of interest to declare.

Renal amyloidosis is typically characterized by nephrotic syndrome, often with massive proteinuria and refractory peripheral edema. We report the case of a patient with renal amyloidosis associated with nephrotic syndrome who maintained remission for 6 years after undergoing high-dose chemotherapy followed by autologous peripheral blood stem-cell transplantation (auto-PBSCT). The patient was a man aged in his 50s who had developed nephrotic syndrome. Bone marrow aspiration and kidney biopsy determined that the cause of the nephrotic syndrome was renal amyloidosis due to multiple myeloma, and the patient was admitted to our department in July 2003. After one course of chemotherapy, auto-PBSCT was performed in March 2004. Following transplantation, serum M-protein was no longer detectable from March 2005, and the patient achieved complete hematological remission. Subsequently, proteinuria decreased, serum albumin levels normalized, and nephrotic syndrome improved. As of 6 years after transplantation, in March 2010, the patient remained in remission, meaning that auto-PBSCT proved extremely effective as a treatment for renal amyloidosis in this case.

To clarify whether measurement of serum haptoglobin (Hp) has impact on understanding pathophysiology in bone marrow failure (BMF) syndromes, we investigated concentrations of serum Hp by nephelometric procedure in 156 Japanese patients with BMF, including 54 aplastic anemia (AA), 50 paroxysmal nocturnal hemoglobinuria (PNH), and 52 myelodysplastic syndromes (MDS) patients. The frequencies with low concentrations of serum Hp (

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by complement-mediated hemolysis, venous thrombosis, and bone marrow failure. In May 2003, a 33-year-old man was admitted to a hospital with right hypochondralgia and fever. He had a history of aplastic anemia. The patient's diagnosis of diffuse microvessel thrombosis in the hepatic vein due to an unknown cause was derived from the findings of a contrast-enhanced computed tomography examination of the abdominal region, angiographic evaluation of abdominal vessels, and pathohistologic examination of a liver biopsy sample. The patient was subsequently treated with warfarin. The abdominal pain and fever continued, however, and anemia gradually appeared. In April 2004, the patient was referred to our hospital to examine the cause of the thrombosis. On admission, slight anemia and a low serum haptoglobin level were observed. A flow cytometry evaluation of CD55 and/or CD59, CD59, and CD48 expression in erythrocytes, granulocytes, and monocytes, respectively, showed that the respective proportions of negative populations were 5.6%, 97.1%, and 96.2%. The patient then received a diagnosis of aplastic anemia/PNH syndrome, which had caused the hemolytic anemia and thrombosis, although no hemoglobinuria had been observed during his clinical course. This patient is, to our knowledge, the first reported case of a PNH patient with thrombosis present only in hepatic microvessels and not in hepatic large vessels, in spite of the presence of few hemolytic events.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is often associated with comorbidity or mortality, due to graft-versus-host disease (GVHD), opportunistic infections, and regimen-related toxicities. Recently, several studies have shown that pre-transplant red blood cell (RBC) transfusions may increase risks of such allo-HSCT-related complications, possibly due to iron overload caused by pre-transplant RBC transfusions. However, it is unknown how post-transplant RBC and platelet (PLT) transfusions influence the long-term outcome of allo-HSCT. In this study, to clarify impact of RBC and PLT transfusions at early after engraftment of allo-HSCT, we investigated the clinical and laboratory findings and long-term outcomes of 71 recipients of allo-HSCT including 48 bone marrow transplantation and 23 peripheral blood stem cell transplantation who received leukoreduced and irradiated RBC and/or PLT from days 31 to 50, after exclusion of patients who did not achieve complete chimera (>90% donor cells) before day 30 or engraftment (neutrophil count > 0.5 x 109 /L) up to day 35; whose disease relapsed until day 60; and who did not survive until day 100. In these 71 patients, 33 (46.5%) patients received RBC and/or PLT transfusion, while 38 (53.5%) received no transfusion from days 31 to 50. Among groups of those patients who received RBC (RBC-transfused patients), PLT (PLT-transfused patients), and both (RBC/PLT-transfused patients) transfusions, pre-transplant findings, including age, sex, sources, serum ferritin (Ft) levels, conditioning regimens, and blood group and HLA compatibilities were not significantly different. However, even at day 100, significant decreases of both Hb concentrations and platelet counts, but not leukocyte counts, were observed in RBC-transfused patients, PLT-transfused patients, and RBC/PLT-transfused patients (Table 1), although vast majority of them no longer required transfusion after day 50. Moreover, serum Ft and C-reactive protein (CRP) levels were higher at day 100 in RBC-, PLT-, and RBC/PLT-transfused patients versus other patients (Table 1). Risk of clinically significant chronic GVHD (cGVHD) by transfusions of both RBC and PLT from days 31 to 50 did not reach statistical significance [hazard risk (HR) = 2.75, p = 0.06], but cumulative incidence of cGVHD was significantly greater in RBC/PLT-transfused patients compared with other patients (p = 0.03). Risk of cGVHD was also correlated with elevated CRP levels (HR = 3.28, p = 0.02) rather than serum Ft levels (HR = 1.40, p = 0.6) at day 100 in univariable analysis, although multivariable analysis did not show significant differences in CRP levels (p=0.07). Moreover, non-relapse mortality was greater in patients who received RBC transfusion compared other patients (p = 0.02), although overall survival (p=0.1) and cumulative incidence of relapse (p=0.4) were not different. In conclusion, both RBC and PLT transfusions early after engraftment of allo-HSCT may be correlated with following elevations of CRP and serum Ft levels and contribute to adverse long-term outcomes of allo-HSCT with an increase of cGVHD. Disclosures No relevant conflicts of interest to declare.

It is known that the expression of WT1 increases in leukemic cells from patients with acute and chronic leukemia, and that in leukemic patients, the WT1 elicits WT1 peptide-specific cytotoxic T-lymphocytes (CTLs) in an HLA-restricted manner, suggesting the possibility that immune therapy targeting WT1 may be effective. Also, the WT1 is highly expressed in bone marrow (BM) cells from paroxysmal nocturnal hemoglobinuria (PNH) patients (Shichishima et al, Blood, 2002). However, the significance of high expression of the WT1 in PNH remains unknown. To clarify some roles of WT1 peptide-specific CTLs of PNH patients in the expansion of a PNH clone in this study, we studied the frequencies of WT1 peptide-specific CD8+ CTLs in peripheral blood (PB) mononuclear cells (MNCs) from 4 PNH patients with the HLA-A*2402 allele by flow cytometry (FCM) using a WT1 peptide-specific and HLA-A*2402-restricted tetramer. Subsequently, we examined cell cytotoxicity of a WT1 peptide-specific and HLA-A*2402-restricted CTL clone (TAK-1; Ohminami et al, Blood, 2000) to BM MNCs from the patients using 51Chromium-releasing assay, of which the results were presented at effector versus target ratios (E:T) of 1:1 and 3:1. We also investigated the changes in the proportions of CD59− cells of 7-amino-actinomycin D-negative, viable, CD34+ cells from the patients by FCM after coincubation of BM MNCs with the TAK-1 at an E:T of 1:1. Tetramer analysis showed that the frequencies of WT1 peptide-specific and HLA-restricted CD8+ T cells in PNH patients (mean ± standard deviation; 12.138 ± 2.090 / 104 cells) with the HLA-A*2402 allele were higher than those in HVs (n=10; 3.498 ± 2.591 / 104 cells) (p