Akiko Yamane

Interferon-α2b-induced thrombocytopenia is caused by inhibition of platelet production but not proliferation and endomitosis in human megakaryocytes

Human interferon (IFN)-alpha is the standard therapy for chronic hepatitis C to prevent its progression to liver cirrhosis and hepatocellular carcinoma. Thrombocytopenia is one of the major adverse effects of IFN-alpha and often leads to dose reduction or treatment discontinuation. However, there is little information on how IFN-alpha inhibits human megakaryopoiesis. In this study, we demonstrated that IFN-alpha did not inhibit colony formation of megakaryocytes from human CD34(+) hematopoietic stem cells. IFN-alpha did not inhibit endomitosis but did inhibit cytoplasmic maturation of megakaryocytes and platelet production in vitro. IFN-alpha suppressed the expression of transcription factors regulating late-stage megakaryopoiesis, such as GATA-1, p45(NF-E2), MafG. IFN-alpha also significantly reduced the number of human platelets but not megakaryocytes, and did not inhibit endomitosis of human megakaryocytes in immunodeficient NOD/Shi-scid/IL-2R gamma(null) (NOG) mice transplanted with human CD34(+) cells (hu-NOG). We also demonstrated that a novel thrombopoietin mimetic, NIP-004, was effective for treating IFN-alpha-induced thrombocytopenia in hu-NOG mice. From ultrastructural study, IFN-alpha inhibited the maturation of demarcation membranes in megakaryocytes, although NIP-004 prevented the inhibitory effects of IFN-alpha. These results defined the pathogenesis of IFN-alpha-induced thrombocytopenia and suggested possible future clinical applications for thrombopoietin mimetics.

Extraction of previously deployed stent by an entrapped cutting balloon due to the blade fracture

During treatment for in‐stent restenosis, entrapment of cutting balloon occurred because of the blade fracture. Removal of the balloon caused stent extraction, inducing acute occlusion of the coronary artery. Application of cutting balloon for in‐stent restenosis requires every caution against such type of complications. Cathet Cardiovasc Intervent 2002;57:239–243.

The effect of a novel, small non-peptidyl molecule butyzamide on human thrombopoietin receptor and megakaryopoiesis

Thrombocytopenia is found in several conditions, and in many of them no treatment is available apart from platelet transfusion. Findings of this study suggest that butyzamide, an orally bioavailable human Mpl activator, may increase platelet production. See related perspective article on page 1445. Background Thrombocytopenia is a common problem in the management of patients with cancer and other conditions that affect hematopoietic cells. In previous clinical trials, the polyethylene-glycol-conjugated recombinant human megakaryocyte growth and development factor increased platelet counts in patients with idiopathic thrombocytopenic purpura and solid tumors undergoing chemotherapy. However, antibodies to polyethylene-glycol-conjugated recombinant human megakaryocyte growth and development factor develop in healthy volunteers and patients undergoing chemotherapy and cross-react with endogenous thrombopoietin. As a result, clinical development of polyethylene-glycol-conjugated recombinant human megakaryocyte growth and development factor was discontinued in 1998. The aim of this study was to identify an orally bioavailable human Mpl activator that does not develop autoantibodies against endogenous thrombopoietin. Design and Methods We screened our chemical library and created a novel non-peptidyl thrombopoietin receptor, Mpl activator named butyzamide. We evaluated the effect of butyzamide on megakaryopoiesis in vitro using Ba/F3 cells expressing Mpl and human hematopoietic stem cells. For the evaluation of its in vivo effect, we administered butyzamide orally to immunodeficient NOD/Shi-scid,IL-2Rγnull (NOG) mice transplanted with human fetal liver-derived CD34+ cells and investigated the production of human platelets. Results Butyzamide specifically reacted with human Mpl and activated the same signal transduction pathway as thrombopoietin. However, unlike thrombopoietin, butyzamide did not react with murine Mpl and was shown to require the histidine residue in the transmembrane domain of Mpl for its agonistic activity. Butyzamide induced colony-forming unit-megakaryocytes and polyploid megakaryocytes from human CD34+ hematopoietic progenitor cells, and its effects were comparable to those of thrombopoietin. When butyzamide was administered orally at the doses of 10 and 50 mg/kg for 20 days to NOG mice transplanted with human fetal liver-derived CD34+ cells, the human platelet count increased by 6.2- and 22.9-fold, respectively. Conclusions Butyzamide is an orally bioavailable human Mpl activator, and appears to have potential for clinical development as a therapeutic agent for patients with thrombocytopenia.

Daily oral verapamil before but not after rapid atrial excitation prevents electrical remodeling

BACKGROUND Intravenous verapamil has been reported to prevent electrical remodeling induced by rapid atrial excitation of several minutes to several hours. However, the clinical efficacy of verapamil when taken orally and daily remains controversial. PURPOSE We attempted to demonstrate our hypothesis that if verapamil prevents calcium (Ca) overload, its efficacy would be greater when taken before, rather than after, the onset of rapid atrial excitation. METHODS In 24 dogs, pacing and recording electrodes were sutured onto the right atrium. After a 5-day recovery period, rapid atrial pacing at 400 ppm was started, followed 2 days later by oral verapamil (8 mg/kg per day) in eight dogs (After group; A). In another eight dogs, oral verapamil administration was begun 1 week before the initiation of rapid pacing (Before group; B). In the remaining eight dogs, only rapid atrial pacing was started, without oral verapamil (Control group; C). We measured the effective refractory period (ERP) and conduction velocity (CV), and calculated wavelength (WL) at cycle lengths 200 and 300 ms on the day before (P0), and after 2 (P2), 7 (P7), 14(P14) days of rapid pacing. RESULTS In response to rapid atrial pacing, ERP, CV, WL decreased and progressively and comparably in A and C (P<0.05 vs. P0). In contrast, in B, these parameters did not change significantly and remained greater than those in A and C (P<0.05). Moreover, the adaptation of ERP to rate was preserved only in B. The duration of atrial fibrillation (AF) was shorter in B than in A and C (P<0.05). The inducibility of AF tended to be lower, and the fibrillation cycle length was longer in B than in A and C. CONCLUSIONS Oral verapamil started before but not after rapid atrial excitation prevents electrical remodeling. Verapamil may exert beneficial effects when it is taken during sinus rhythm, but not after more than 2 days of atrial tachyarrhythmia.

Safety and efficacy of total body irradiation, cyclophosphamide, and cytarabine as a conditioning regimen for allogeneic hematopoietic stem cell transplantation in patients with acute lymphoblastic leukemia

Disease relapse still greatly interferes with the success of allogeneic hematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukemia (ALL). This study retrospectively evaluated the long‐term safety and efficacy of a conditioning regimen consisting of total body irradiation (TBI; 12 Gy), cyclophosphamide (CY; 60 mg kg−1, two doses), and high‐dose cytarabine (Ara‐C; 2 g m−2; four doses) for patients with ALL. Fifty‐five patients (median age: 31‐years old) were evaluated. Stem cells were from human leukocyte antigen‐identical siblings in 22 patients and from alternative donors in 33. There were no cases of early death before engraftment, and 100‐day transplant‐related mortality was 7.3%. With a median follow‐up period of 9.6 years, 5‐year overall and disease‐free survival were 63.2% (95% CI: 46.5–79.9%) and 63.6% (95% CI: 47.1–80.1%) in patients with complete remission, respectively, both of which were significantly higher than the values of 27.3% (95% CI: 8.7–46.0%) and 22.7% (95% CI: 5.3–40.1%) for patients in advanced stages (P < 0.01). These results suggest that TBI and CY (TBI‐CY) plus Ara‐C could be a feasible and effective conditioning regimen for adult patients with ALL both in remission and in advanced stages, and a future study to compare this combination therapy with TBI‐CY is required. Am. J. Hematol. 2012.

Variable magnitude of drug interaction between oral voriconazole and cyclosporine A in recipients of allogeneic hematopoietic stem cell transplantation

Drug interaction between voriconazole and calcineurin inhibitors is often problematic after allogeneic hematopoietic stem cell transplantation (HSCT) or solid organ transplantation. We previously demonstrated an unpredictable inter‐individual variability in the magnitude of this drug interaction; however, the route of drug administration was not taken into account. In this study, the drug interaction between voriconazole and calcineurin inhibitors was further analyzed under the condition that both agents were administered orally. Twenty adult recipients of HSCT who had already been on a steady dose of oral cyclosporine A (CsA) and were started on oral voriconazole (400 mg/d) were eligible. The changes in the concentration/dose (C/D) ratio of CsA were evaluated by comparing the trough concentrations of CsA measured before and 7–10 d after initiating voriconazole. The median C/D ratio of CsA increased significantly from 64.1 to 114.3 (ng/mL)/(mg/kg) after initiating voriconazole (p < 0.01), and the median increase was 83.0% (range, 0.3–224.7%). The plasma concentration of voriconazole did not correlate significantly with the increase of the C/D ratio (ρ = −0.18, p = 0.45). These results indicate that the magnitude of drug interaction between oral voriconazole and CsA is widely variable, and it could not be explained by the difference in the blood levels of voriconazole. Further studies are required to elucidate the mechanism for this variability.

Oral ribavirin therapy for lower respiratory tract infection of respiratory syncytial virus complicating bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation

Respiratory syncytial virus (RSV) is the leading cause of community-acquired viral respiratory infection, particularly in pediatric patients [1]. RSV usually causes self-limited upper respiratory tract infection in healthy individuals. However, in contrast, RSV often causes serious lower respiratory tract infection (LRTI) in recipients of hematopoietic stem cell transplantation (HSCT), and outbreaks of RSV infection in hematology or HSCT wards have also been reported [2–5]. RSV infection has been increasingly diagnosed and is currently detected in about half of the HSCT recipients with community-acquired respiratory virus infection [6]. Because of its propensity to cause life-threatening infections [1], anti-viral therapy is indicated in HSCT recipients who develop RSV infection, particularly LRTI. Aerosolized ribavirin is the only approved therapeutic agent against RSV infection at present. However, its clinical benefit is limited, and it is associated with adverse events in patients and potential toxic effects in health care workers [7]. Therefore, the safety and efficacy of systemic administration of high-dose ribavirin have been evaluated by several investigators, but the results remain inconclusive. We here present a patient with bronchiolitis obliterans (BO) who developed respiratory failure caused by LRTI due to RSV more than 2 years after allogeneic HSCT. The patient was successfully treated with oral ribavirin at a dose of 600 mg/body/day, and a prompt eradication of RSV as well as resolution of LRTI was obtained. A 51-year-old woman with acute lymphoblastic leukemia underwent allogeneic bone marrow transplantation (BMT) from a human leukocyte antigen-identical sibling. Cyclosporine A (CsA) and short-term methotrexate were given as a prophylaxis of graft-versus-host disease (GVHD). One year after BMT, she developed BO requiring oxygen supplementation. Combination therapy with tacrolimus and prednisolone improved her pulmonary function. Oxygen saturation by pulse-oximetry improved to 95–97% in room air, and oxygen supplementation was no longer necessary. Two and a half years after BMT, when still on tacrolimus and prednisolone (15 mg/day), she started complaining of non-productive cough, dyspnea, and rhinorrhea without a concomitant high-grade fever. The laboratory data showed a white blood cell count of 4.4 9 10/L with 89% neutrophils and 8% lymphocytes, serum immunoglobulin G 498 mg/dL, and C-reactive protein 2.89 mg/dL. RSV was detected in the nasopharyngeal swab by immunofluorescence assay using a commercially available kit. In addition to bronchial dilatation, computed tomography of the lungs revealed patchy ground-glass opacities and tiny centrilobular nodules distributed in both the central and peripheral zones, predominantly in the lower fields (Fig. 1). The patient rapidly developed respiratory failure (oxygen saturation ranged from 80% to 82% in room air) and was placed on oxygen supplementation. Based on these findings including T. Mori (&) Y. Nakamura J. Kato A. Yamane Y. Aisa S. Okamoto Division of Hematology, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan e-mail: tmori@sc.itc.keio.ac.jp

Hemorrhagic colonic ulcers caused by dasatinib for chronic myelogenous leukemia

Dasatinib, a multi-kinase inhibitor that is active against BCR-ABL1 and SRC family kinases, has been reported to exert notable efficacy in the treatment of imatinib-resistant or -intolerant chronic myeloid leukemia (CML) in all phases [1–5]. Dasatinib therapy is generally well tolerated, although severe hematological and non-hematological adverse events are observed. The most common non-hematological adverse events are gastrointestinal symptoms, fluid retention, and skin rash [1–5]. It is notable that gastrointestinal bleeding accounts for 14–26% of gastrointestinal adverse events due to dasatinib [1–6]. A recent report evaluating the bleeding diathesis due to dasatinib revealed that more than 80% of the bleeding was observed in the gastrointestinal tract [7]. However, the characteristics and clinical courses of gastrointestinal bleeding due to dasatinib are yet to be fully elucidated. Herein, we present a case of melena due to multiple colonic ulcers under dasatinib treatment for CML, in which colonic ulcers completely resolved within 12 days after discontinuation of dasatinib. A 43-year-old woman with chronic-phase CML had been initially treated with imatinib at a daily dose of 400 mg. A complete molecular response was achieved at 1 year after treatment with imatinib. However, 4 years after initiating imatinib therapy, leukocytosis (42.6 9 10/L) together with blasts in the peripheral blood (17%) was observed. Bone marrow examination showed increased blasts (11.8%) and additional chromosomal abnormality of t(21;21)(q22;q22), indicating a progression to the accelerated phase. Dasatinib (70 mg) was initiated twice daily, which successfully led to normalization of white blood cell count and disappearance of blasts from the peripheral blood. However, anemia and thrombocytopenia persisted, and red blood cell and platelet transfusions were required. She had had mild diarrhea shortly after initiating dasatinib, and suddenly developed melena 3 months after initiating dasatinib, when the platelet count was 21 9 10/L. Her white blood cell count was 3.8 9 10/L with 77% of neutrophils and 11% of lymphocytes. Endoscopic examination of the lower gastrointestinal tract showed multiple aphthous ulcers of the colon (Fig. 1a). Dasatinib was discontinued, and melena ceased in 2 days. As much as 12 days after the discontinuation of dasatinib, another endoscopic examination was performed, and showed almost complete resolution of ulcerative lesions of the colon (Fig. 1b). She then received total body irradiation (12 Gy), high-dose cytarabine, and cyclophosphamide as a conditioning for allogeneic cord blood transplantation, and has shown mild gastrointestinal toxicities, but has not developed melena since. In this case, we confirmed by endoscopy that hemorrhagic colonic ulcers probably caused by dasatinib almost completely healed within 12 days after discontinuation of dasatinib. The mechanism of dasatinib-induced gastrointestinal bleeding is yet to be understood. Its inhibitory activity against platelet-derived growth factor receptor (PDGFR) kinase might be a possible explanation, since PDGFR-b plays an important role in angiogenesis and Y. Ono T. Mori (&) J. Kato A. Yamane S. Okamoto Division of Hematology, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan e-mail: tmori@sc.itc.keio.ac.jp

Angioimmunoblastic T-Cell Lymphoma with Polyclonal Proliferation of Plasma Cells in Peripheral Blood and Marrow

phoadenopathy rapidly progressed after his first visit to our hospital in September, and a month later, WBC count was elevated to 27.3 ! 10 9 /l. The peripheral blood smear showed 31% of plasma cells, and the bone marrow smear disclosed diffuse infiltration of plasma cells (41.2% of all nucleated cells) ( fig. 1 ). No dysmorphic feature of plasma cells was observed. The patient was admitted to our hospital on October 8, 2004. On admission, he had fever, dyspnea and generalized lymphadenopathy. Chest X-ray showed consolidation in the right lower and left upper lung fields and mild bilateral pleural effusion. A computed tomographic scan revealed hepatosplenomegaly as well as mediastinal, pulmonary hilar, axillary, paraaortic and ilioinguinal lymphadenopathy. Laboratory findings showed leukocytosis (WBC 28.2 ! 10 9 /l with 30.5% plasma cells), mild anemia (hemoglobin 11.5 g/dl) and thrombocytopenia (platelets 65 ! 10 9 /l). Flow cytometric analysis showed that plasma cells in the peripheral blood and marrow were positive for CD19 and CD38, but lacking CD10, CD20 and CD56. No laterality of and -immunoglobulin light chain expression on the plasma cells was observed ( fig. 2 a, b). Gene rearrangement of immunoglobulin heavy chains (JH) and light chains (J ), using DNA extracted from the peripheral blood, was negative. The values of serum IgG, IgA and IgM were 6,690, 2,100 and 333 mg/dl, respectively. Immunoelectrophoresis of serum protein revealed a polyclonal increase in -globuAngioimmunoblastic T-cell lymphoma (AILT) is characterized by generalized lymphadenopathy, anemia, hepatosplenomegaly, skin eruption and polyclonal hypergammaglobulinemia. Polyclonal plasmacytosis in peripheral blood and bone marrow is not a recognized feature of AILT. Polyclonal plasmacytosis is a rare event, which has been observed in infectious diseases, drug reactions, malignant diseases and autoimmune diseases [1–5] . Most cases have an indolent or self-limited clinical course. However, for cases with lymphadenopathy and rapid polyclonal plasma cell proliferation, the underlying disease has not been well characterized to date, probably because immediate initiation of treatment is required without histological confirmation of lymph nodes. Lymph node biopsy has not been performed, even in the reported cases [6, 7] . Here, we report a case of AILT that presented with progressive polyclonal plasmacytosis in the peripheral blood and bone marrow. A 63-year-old man presented with cervical and axillary lymphadenopathy on September 6, 2004. The white blood cell (WBC) count and its differential were normal. His past medical history was unremarkable except that he received clarithromycin for his common cold for 4 days and olopatadine hydrochloride for subsequent skin rash from his general practitioner in July 2004. The patient reported immediate disappearance of the skin rash, which was deemed to be caused by clarithromycin. LymReceived: May 17, 2006 Accepted after revision: July 7, 2006 Published online: November 10, 2006

Long‐term follow‐up of reduced‐intensity allogeneic hematopoietic stem cell transplantation for refractory or relapsed follicular lymphoma

Although allogeneic hematopoietic stem cell transplantation (HSCT) is considered the only curative treatment for refractory or relapsed follicular lymphoma (FL), transplant-related mortality (TRM) greatly interferes with the success. A variety of reduced-intensity conditionings (RICs) have been used to reduce TRM, but an optimal conditioning for FL has not been fully established. We retrospectively evaluated the outcome of allogeneic HSCT for FL with RIC consisting of fludarabine and melphalan. Nineteen adult patients with relapsed or refractory FL were conditioned with fludarabine (125 mg/m2) and melphalan (140 mg/m2), and received grafts from an HLA-identical sibling (n = 6) or an unrelated donor (n = 13). For the prophylaxis of graft-versus-host disease (GVHD), cyclosporine A or tacrolimus with short-term methotrexate was given. There were no early deaths before engraftment, and all patients achieved engraftment. Three patients died of extensive-type chronic GVHD (n = 2) or bacterial infection (n = 1) without disease progression. With a median follow-up period of 75.2 months (range: 33.3–111.9 months), 16 patients were alive without disease progression. Both the 5-year overall and progression-free survival rates were 84.2% (95% CI: 67.7–100%). These results strongly suggest that allogeneic HSCT with RIC using fludarabine and melphalan could be a promising treatment choice for refractory or relapsed FL.