Rhnull phenotype caused by a novel RHAG mutation, c.945+1G>A, in the Japanese population.

BACKGROUND: The Rh complex contributes to cell membrane structural integrity of erythrocytes. Rhnull syndrome is characterized by the absence of the Rh antigen on the erythrocyte membrane, resulting in chronic hemolytic anemia. We recently came across 3 Rhnull phenotype probands within two families with the same novel RHAG mutation in the Japanese population. MATERIALS AND METHODS: Detailed Rh phenotyping by hemagglutination was performed using monoclonal and polyclonal anti-D, -C, -c, -E, and -e; monoclonal and polyclonal anti-Rh17 antibodies; and polyclonal anti-Rh29 antibodies. RHAG mRNA transcripts were analyzed by reverse transcription-polymerase chain reaction, and the mutation was verified by genomic sequencing. RESULTS: The genomic region spanning exon 6 contained a G > A transition in the invariant GT motif of the 5' donor splice-site of Intron 6 (c.945+1G>A). The Rhnull phenotype was caused by an autosomal recessive mutation in Probands 1 and 2, determined by family history. Regarding clinical features, the degree of hemolysis varied slightly between these individuals, with Proband 3 displaying acute hemolytic anemia with an infection. While no standard therapy has been established, the condition of the patient in this study improved with conservative treatment, including hydration and antibiotics. CONCLUSION: The mechanisms of hemolysis due to the Rhnull phenotype can vary, but our findings indicate that acute hemolytic crisis caused by the Rhnull syndrome could be associated with infection.

Advanced glycation end products induce brain-derived neurotrophic factor release from human platelets through the Src-family kinase activation.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) exerts beneficial effects not only on diabetic neuropathies but also on cardiovascular injury. There is argument regarding the levels of serum BDNF in patients with diabetes mellitus (DM). Because BDNF in peripheral blood is rich in platelets, this may represent dysregulation of BDNF release from platelets. Here we focused on advanced glycation end products (AGEs), which are elevated in patients with DM and have adverse effects on cardiovascular functions. The aim of this study is to elucidate the role of AGEs in the regulation of BDNF release from human platelets. METHODS: Platelets collected from peripheral blood of healthy volunteers were incubated with various concentrations of AGE (glycated-BSA) at 37 °C for 5 min with or without BAPTA-AM, a cell permeable Ca2+ chelator, or PP2, a potent inhibitor of Src family kinases (SFKs). Released and cellular BDNF were measured by ELISA and calculated. Phosphorylation of Src and Syk, a downstream kinase of SFKs, in stimulated platelets was examined by Western blotting and immunoprecipitation. RESULTS: AGE induced BDNF release from human platelets in a dose-dependent manner, which was dependent on intracellular Ca2+ and SFKs. We found that AGE induced phosphorylation of Src and Syk. CONCLUSIONS: AGE induces BDNF release from human platelets through the activation of the Src-Syk-(possibly phospholipase C)-Ca2+ pathway. Considering the toxic action of AGEs and the protective roles of BDNF, it can be hypothesized that AGE-induced BDNF release is a biological defense system in the early phase of diabetes. Chronic elevation of AGEs may induce depletion or downregulation of BDNF in platelets during the progression of DM.

[Myelodysplastic syndrome with refractory hemorrhage due to reduced platelet aggregation activity].

A 75-year-old woman suffered a cat bite 10 months after myelodysplastic syndrome (MDS) diagnosis. She visited our hospital because the internal bleeding of the wound did not improve. Although the wound was treated, the bleeding did not stop. She was hospitalized for emergency medical treatment because the bleeding volume exceeded 200 ml. Although her platelet count was normal, the platelet function test showed a decrease in collagen and arachidonic acid aggregation. After platelet transfusion, her bleeding stopped. Patients with MDS may potentially have platelet dysfunction. In the case of bleeding without thrombocytopenia, a platelet function test should be performed and treatment intervention, such as platelet transfusion, should be considered.

Late onset post-transfusion hepatitis E developing during chemotherapy for acute promyelocytic leukemia.

We herein report the case of a leukemia patient who developed hepatitis E seven months after undergoing a transfusion with contaminated blood products. The latency period in this case was significantly longer than that of typical hepatitis E. Recently, chronic infection with hepatitis E virus (HEV) genotype 3 has been reported in immunocompromised patients. There is a possibility that our patient was unable to eliminate the virus due to immunosuppression following chemotherapy and the administration of steroids. The prevalence of HEV in healthy Japanese individuals is relatively high and constitutes a critical source of infection via transfusion. Hepatitis E is an important post-transfusion infection, and immunocompromised patients may exhibit a long latency period before developing the disease.

Successful treatment of severe newly diagnosed immune thrombocytopenia involving an alveolar hemorrhage with combination therapy consisting of romiplostim, rituximab and vincristine.

A 51-year-old man was admitted due to a severe bleeding tendency. After he was diagnosed with immune thrombocytopenia (ITP), several therapies, including steroids, steroid pulse, vincristine and rituximab, were administered; however, the patient's bleeding symptoms were not sufficiently controllable with these treatments. Subsequently, a diffuse alveolar hemorrhage was observed. Treatment with a thrombopoietin receptor agonist, romiplostim, was initiated to prevent lethal hemorrhaging, although the efficacy of thrombopoietic receptor agonists in such emergency situations has not been elucidated. The initiation of romiplostim achieved prompt remission in platelets. This case suggests that combination therapy with romiplostim, rituximab and vincristine is effective in cases of newly diagnosed severe therapy-resistant ITP.

A clinical study of alveolar bone tissue engineering with cultured autogenous periosteal cells: coordinated activation of bone formation and resorption.

In ongoing clinical research into the use of cultured autogenous periosteal cells (CAPCs) in alveolar bone regeneration, CAPCs were grafted into 33 sites (15 for alveolar ridge augmentation and 18 for maxillary sinus lift) in 25 cases. CAPCs were cultured for 6weeks, mixed with particulate autogenous bone and platelet-rich plasma, and then grafted into the sites. Clinical outcomes were determined from high-resolution three-dimensional computed tomography (3D-CT) images and histological findings. No serious adverse events were attributable to the use of grafted CAPCs. Bone regeneration was satisfactory even in cases of advanced atrophy of the alveolar process. Bone biopsy after bone grafting with CAPCs revealed prominent recruitment of osteoblasts and osteoclasts accompanied by angiogenesis around the regenerated bone. 3D-CT imaging suggested that remodeling of the grafted autogenous cortical bone particles was faster in bone grafting with CAPCs than in conventional bone grafting. The use of CAPCs offers cell-based bone regeneration therapy, affording complex bone regeneration across a wide area, and thus expanding the indications for dental implants. Also, it enables the content of particulate autogenous bone in the graft material to be reduced to as low as 40%, making the procedure less invasive, or enabling larger amounts of graft materials to be prepared. It may also be possible to dispense with the use of autogenous bone altogether in the future. The results suggest that CAPC grafting induces bone remodeling, thereby enhancing osseointegration and consequently reducing postoperative waiting time after dental implant placement.

A short-term preservation of human cultured periosteal sheets, osteogenic grafting materials, using a commercial preservation solution containing epigallocatechin-3-gallate (Theliokeep(®)) under hypothermic conditions.

In the past decade, it has increasingly been reported that epigallocatechin-3-gallate (EGCG), a major catechin derivative extracted from Green tea, has various bioactivities, including a cell-protective action on mammalian cells and tissues. In this study, we have tested a commercial preservation solution containing EGCG (Theliokeep(®)) in both two- and three-dimensional cultures of human periosteal sheets, which have been used as an osteogenic grafting material for periodontal regenerative therapy. When periosteal sheets were 3D-cultured on collagen mesh, cell viability was maintained for 2 days using the hypothermic EGCG preservation solution. Replenishment of EGCG solution with 2-day intervals prevented the time-dependent decline in cell viability at 3 days and later. As observed in nonpreserved control cultures, most cells were positive for proliferating cell-nuclear antigen (PCNA) in the cultures preserved at 4°C in the EGCG solution, whereas PCNA-negative cells were increased in the cultures preserved at 4°C in the MesenPRO medium. In periosteal sheets 2D-cultured in plastic dishes, the EGCG solution occasionally was associated with vacuole formation in the cytoplasm, but cells could again expand in the culture medium at 37°C. As observed in the nonpreserved periosteal sheets control, the osteogenic induction upregulated alkaline phosphatase in those cells and tissues preserved in the EGCG solution. The EGCG solution protected cells from the cold shock-induced membrane phospholipid peroxidation. Our data suggest that the EGCG solution acts as an antioxidant to protect periosteal cells from cold shock and preserves cells under chilled conditions. The limited period of preservation time could be expanded by repeating replenishment of the EGCG solution or by optimizing the formula to be more favorable for human periosteal sheets without sacrificing cell viability. This methodology of preserving human cultured periosteal sheets with EGCG would be expected to support and spread the clinical use of regenerative therapy with autologous periosteal sheets.

Successful remission of Evans syndrome associated with Graves' disease by using propylthiouracil monotherapy.

A 46-year-old woman with Graves' disease was admitted for anemia and thrombocytopenia. She had previously been treated with methimazole but she self-discontinued the treatment 6 months prior to admission. She was diagnosed with Evans syndrome associated with Graves' disease and treated with propylthiouracil without corticosteroids, which normalized her thyroglobulin level. Surprisingly, while Evans syndrome is characterized by frequent relapses, this patient has been in remission of Evans syndrome for approximately 4 years. The remission of Evans syndrome associated with Graves' disease in the absence of immunosuppressive therapy suggests that these 2 diseases have a common pathogenetic mechanism.

WT1 peptide vaccination in a CML patient: induction of effective cytotoxic T lymphocytes and significance of peptide administration interval.

Although antigen-specific immune responses including cytotoxic T cells (CTLs) against antigen peptide could be enhanced after tumor antigen peptide vaccinations, the immune responses do not necessarily result in a decrease or eradication of tumor cells in the vaccination trials. We focused on whether antigen-specific CTLs could be damaged by the repeated stimulation of antigenic peptide and whether regulatory T (Treg) cells would be increased by the administration of WT1 peptide. We administered WT1 peptide 22 times over 18 months in a CML patient who was being treated with imatinib. Although WT1 peptide administration every 2 weeks did not show any beneficial effects on the minimal residual disease (copies of bcr-abl transcripts), the transcripts remarkably decreased to the level of major molecular response after changing the administration interval of WT1 peptide from 2 to 4 weeks. An ex vivo study demonstrated that re-stimulation with WT1 peptide made WT1-specific T cells less reactive to WT1 tetramers and the impaired reactivity of CTLs lasted at least for 1 week. In addition, the cytotoxicity of the T cells was hampered by re-stimulation. Treg cells increased up to more than fivefold at the end of the WT1 administration period. The present findings suggested that the administration of the peptide every 4 weeks is superior to every 2 weeks. In addition, the findings that Treg cells increased gradually in accordance with the duration of WT1 peptide administration revealed the significance of manipulating Treg cells for establishing an efficient tumor antigen peptide vaccination.

Pharmacokinetic and pharmacodynamic analysis of cyclosporine A (CsA) to find the best single time point for the monitoring and adjusting of CsA dose using twice-daily 3-h intravenous infusions in allogeneic hematopoietic stem cell transplantation.

Pharmacological study is predictably effective in establishing an optimal monitoring strategy for the usage of cyclosporine A (CsA) to prevent graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation recipients. Pharmacokinetic profiling of 33 recipients administered CsA twice daily by 3-h intravenous infusion revealed that levels peaked 2-3 h after the start of infusion, and an exponential decline of CsA concentrations after the termination of infusion was observed. The correlation between the area under the curve (AUC(0-12)) and CsA concentration at various time points after infusion revealed that C (2) and C (3) correlated best with AUC(0-12) (r (2) = 0.725), while the trough concentration correlated poorly. Ex vivo T cell stimulation followed by intracellular cytokine detection with flow cytometry revealed that the capacity of T cells to produce cytokines upon stimulation was inversely proportional to the CsA concentration, and reached a minimum at about 700 ng/mL with a marginal decrease above this concentration. Extrapolation using the regression equations of this study and the data from our retrospective study leads to the assumption that the dose adjustment of CsA based on maintaining the C (3) concentration above 800 ng/mL may effectively prevent acute GVHD. To confirm this assumption, a prospective clinical study is required.

Establishment of culturing system for ex-vivo expansion of angiogenic immature erythroid cells, and its application for treatment of patients with chronic severe lower limb ischemia.

Angiogenesis therapy by bone marrow-mononuclear cell implantation (BMI) has been utilized. We found that erythroid cells played an essential role in angiogenesis by BMI. We then tried to establish a novel cell therapy by implantation of ex vivo expanded immature erythroblasts cultured from hematopoietic stem/precursor cells. Immature to mature erythroblasts were purified from human bone marrow, and mRNA expression were analyzed. Strongly expressed VEGF and PLGF in immature erythroid cells decreased according to erythroid maturation. To expand very immature erythroid cells, we established a two-step culturing system, i.e., bone marrow cells were cultured in the presence of Flt-3L, SCF and TPO for 7 days, and the cells were further cultured in the presence of SCF, IGF-I and EPO for an additional 7 days. The in vivo angiogenic effects of implantation of the ex vivo expanded cells were stronger than that of BMI in mouse limb ischemia model. Three patients with severe chronic lower limb ischemia accompanied by Burger's disease or collagen arteritis were enrolled in a pilot clinical trial of the novel cell therapy by transplantation of ex-vivo expanded immature erythroid cells. In the clinical trial, most clinical symptoms such as rest pain and skin ulcers improved in 4 weeks, and did not recur in the one-year follow-up. No adverse events were observed in any of the patients. Moreover this novel cell therapy required only a small amount of bone marrow collection. Further enrollment of patients with chronic severe lower limb ischemia is necessary to confirm the efficacy and safety of this novel cell therapy, and to estimate the necessary amount of bone marrow aspirate.

WT1 peptide vaccination in combination with imatinib therapy for a patient with CML in the chronic phase.

Although tyrosine kinase inhibitors is effective for dramatically reducing CML cells, it might be difficult to eradicate completely the CML stem cells. We aimed to clarify the safety and effects of WT1 peptide vaccination in combination with imatinib therapy for a CML patient. A 51 year-old male with CML in CP, who showed a resistance against imatinib therapy for 2.5 years, began to be treated with 9 mer modified-type WT1 peptides in combination with standard dose of imatinib. Although every 2-week-administration of WT1 peptides for 22 weeks did not show definite effects on the quantification of bcr-abl transcripts, by changing the administration from every 2 weeks to 4 weeks bcr-abl transcripts decreased remarkably. After 11 months of every 4-week-administration of the peptides and 12 months post cessation of the peptides bcr-abl transcripts achieved to the level below detection by RQ/RT-PCR (complete molecular response). WT1/MHC tetramer(+)CD8(+) CTLs, which appeared after the second administration of WT1 peptides and remained more than 15 in number among 10(6) CD8(+) T cells throughout the administration of WT1 peptides, are still present in the blood on 14th month post cessation of the peptides. An in vitro study as to the cytotoxicity of lymphocytes induced by mixed lymphocyte peptide culture demonstrated that cultured lymphocytes possessed cytotoxicity against WT1 expressing leukemia cells and the cytotoxicity was WT1-specific and MHC class I restricted. The present study showed that WT1 peptide vaccination in combination with TKI is feasible and effective in the therapy for imatinib-resistant CML.

Transformation of dendritic cells from plasmacytoid to myeloid in a leukemic plasmacytoid dendritic cell line (PMDC05).

We investigated the transformation from pDCs to mDCs in a pDC line (PMDC05) which was established from a patient with pDC leukemia in our laboratory. PMDC05 cells were separated into two fractions according to the expression of BDCA1 and CD123. BDCA1(-)CD123(+) cells were found to be pDC-like cells by their morphology, surface phenotypes, mRNA expression and the function. In addition, BDCA1(-)CD123(+) cells were demonstrated to have a proliferating capacity and revealed the ability to transform to BDCA1(+)CD123(-) cells which showed mDC-like properties. Our data demonstrated the possibility of transformation from pDCs to mDCs in human DC lineage.

A leukemic plasmacytoid dendritic cell line, PMDC05, with the ability to secrete IFN-alpha by stimulation via Toll-like receptors and present antigens to naïve T cells.

We established a plasmacytoid dendritic cell (pDC) line (PMDC05) from leukemia cells of pDC leukemia. PMDC05 cells were positive for CD4, CD56, CD33, HLA-DR, CD123 (IL-3Ralpha) and CD86 in the absence of lineage markers. mRNA of TLR1, TLR2, TLR4, TLR7 and TLR9 was clearly expressed and among these TLRs, TLR7 was prominent. Production of IFN-alpha and IL-12 in PMDC05 was enhanced by the stimulation with CpG-A and LPS, respectively. PMDC05 possessed a considerable antigen presenting ability, which was enhanced by culturing with IL3, influenza virus or LPS. PMDC05 could be a useful tool for investigating the pathophysiology of pDCL.

Inhibitory effects of the antiepileptic drug ethosuximide on G protein-activated inwardly rectifying K+ channels.

Antiepileptic drugs protect against seizures by modulating neuronal excitability. Ethosuximide is selectively used for the treatment of absence epilepsy, and has also been shown to have the potential for treating several other neuropsychiatric disorders in addition to several antiepileptic drugs. Although ethosuximide inhibits T-type Ca(2+), noninactivating Na(+), and Ca(2+)-activated K(+) channels, the molecular mechanisms underlying the effects of ethosuximide have not yet been sufficiently clarified. G protein-activated inwardly rectifying K(+) channels (GIRK, or Kir3) play an important role in regulating neuronal excitability, heart rate and platelet aggregation. In the present study, the effects of various antiepileptic drugs on GIRK channels were examined first by using the Xenopus oocyte expression assay. Ethosuximide at clinically relevant concentrations inhibited GIRK channels expressed in Xenopus oocytes. The inhibition was concentration-dependent, but voltage-independent, and time-independent during each voltage pulse. However, the other antiepileptic drugs tested: phenytoin, valproic acid, carbamazepine, phenobarbital, gabapentin, topiramate and zonisamide, had no significant effects on GIRK channels even at toxic concentrations. In contrast, Kir1.1 and Kir2.1 channels were insensitive to all of the drugs tested. Ethosuximide also attenuated ethanol-induced GIRK currents. These inhibitory effects of ethosuximide were not observed when ethosuximide was applied intracellularly. In granule cells of cerebellar slices, ethosuximide inhibited GTPgammaS-activated GIRK currents. Moreover, ADP- and epinephrine-induced platelet aggregation was inhibited by ethosuximide, but not by charybdotoxin, a platelet Ca(2+)-activated K(+) channel blocker. These results suggest that the inhibitory effects of ethosuximide on GIRK channels may affect some of brain, heart and platelet functions.

Induction of antigen-specific cytotoxic T lymphocytes by using monocyte-derived DCs transfected with in vitro-transcribed WT1 or SART1 mRNA.

To evaluate the usefulness of monocyte-derived dendritic cells transfected with tumor antigen mRNA for dendritic cell-based antitumor immunotherapy, we attempted to generate antigen-specific cytotoxic T cells by priming lymphocytes with monocyte-derived dendritic cells transfected with in vitro-transcribed tumor antigen mRNA. Mature monocyte-derived dendritic cells were generated from microbeads-separated CD14(+) cells by culturing with GM-CSF/IL-4 for 7 days and with TNF-alpha, IL-1alpha, IL-6, and PGE(2) for the last one day. Monocyte-derived dendritic cells, lymphocytes, and target cells, which were positive for HLA-A24, were used in the present study. Although lymphocytes prestimulated with untransfected monocyte-derived dendritic cells did not possess the cytotoxic ability against the target cells in a (51)Cr-release cytotoxicity assay, lymphocytes primed with tumor antigen RNA-transfected monocyte-derived dendritic cells were cytotoxic against the tumor antigen-expressing cells but not against the target cells without the expression of the antigen. The cytotoxic ability of the lymphocytes was blocked by the addition of antibodies against MHC class I but not by antibodies against MHC class II. These findings revealed that monocyte-derived dendritic cells transfected with WT1 or SART1 mRNA are able to induce tumor antigen-specific cytotoxic T cells and applicable for antitumor dendritic cell-based cellular immunotherapy.

Plasmacytoid dendritic cell leukemia with potent antigen-presenting ability.

We report 2 patients with plasmacytoid dendritic cell leukemia (pDCL) expressing CD4, CD56, CD33, CD36, HLA-DR, CD123, CD86 and CD83 in the absence of lineage markers (myeloid, B, T or natural killer cells) except for CD33. Culturing leukemic blasts of both cases with IL-3 for 4 days increased the expression of surface molecules associated with antigen presentation, e.g. CD1a and CD40. Leukemic blasts of both cases possessed a considerable level of antigen-presenting ability to allogeneic lymphocytes in mixed leukocyte cultures. Culturing the blasts with IL-3 for 4 days markedly increased allogeneic antigen presenting ability. Combined with data showing evident graft-versus-leukemia effects without graft-versus-host disease in a cord blood stem cell transplanted pDCL case, leukemic cells in pDCL may act as potent antigen presenting cells in vivo, too.

Enhancement of anti-tumor cytotoxicity of expanded gammadelta T Cells by stimulation with monocyte-derived dendritic cells.

In order to establish the method of generating powerful gammadelta T cells for anti-tumor immunotherapy, we investigated the effects of monocyte-derived dendritic cells (mo-DCs) on anti-tumor cytotoxicity of expanded gammadelta T cells. Activation of gammadelta T cells co-cultured for 2-3 days with immature or mature mo-DCs was evaluated by CD69 expression and anti-tumor cytotoxicity using two assays : the 5- (and 6-) carboxyfluorescein diacetate, succinimidyl ester-based cytotoxicity assay and the calcein-AM-based Terascan assay. gammadelta T cells were used as effector cells and myeloma cell line (RPMI8226) or chronic myelogenous leukemia blastic crisis cell line (C2F8) were used as target cells. CD69 expression on gammadelta T cells was enhanced by co-culture with both immature and mature mo-DCs in a cell-number-dependent fashion. CD69 expression was enhanced after addition of mo-DCs of either autologous or allogeneic origin. Activation of gammadelta T cells with mo-DCs enhanced anti-tumor cytotoxicity of gammadelta T cells against RPMI8226 and C2F8 in an effector-to-target ratio-dependent manner. Activation of gammadelta T cells by mo-DCs was associated with the enhancement of anti-tumor cytotoxicity of gammadelta T cells. Potent gammadelta T cells activated by mo-DCs were considered to be applicable to an efficient gammadelta T cell-mediated immunotherapy for tumors.

Plasma brain natriuretic peptide during myeloablative stem cell transplantation.

OBJECTIVE: Cardiovascular complication is one of the serious complications in stem cell transplantation (SCT). We measured plasma brain natriuretic peptide (BNP) concentrations in patients who received SCT to evaluate possible cardiac toxicity of the regimens employed in SCT. PATIENTS: Ten patients with allogeneic SCT and 5 patients with autologous SCT using myeloablative conditioning regimens were enrolled. The preparative chemotherapy for 8 patients with allogeneic SCT included cyclophosphamide (60 mg/kg i.v. for 2 days) and other drugs and that for autologous SCT included cyclophosphamide (50 mg/kg for 2 days) and other drugs. Total body irradiation (TBI) was employed only in the patients who received allogeneic SCT. METHOD: Plasma BNP was measured using a radioimmunoassay for human BNP before and after SCT. RESULTS: In 13 of 15 patients, BNP levels were elevated after SCT. In patients who received a total body irradiation (TBI) of 13.2 Gy, BNP levels were higher than those without irradiation (p=0.01). The BNP level reached a peak within 6 months after SCT in most patients and fell thereafter. But 7 of the 15 patients (46.7%) had an abnormally high level of plasma BNP even after 6 months of SCT which suggests subclinical myocardial damage. CONCLUSION: A rise in plasma BNP was frequently observed after SCT, and may be considered to represent cardiac damage caused by the preparative chemotherapy and/or total body irradiation. Since a rise was noted 6 months after SCT, long-term evaluation of cardiac function is important.