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Biomedical subjects

Yoichi Takaue

Publications and source records attributed to Yoichi Takaue.

At least 73 records · Page 4Linked to original sources
PubMed2002

Identification of HLA-A24-restricted CTL epitope encoded by the matrix protein pp65 of human cytomegalovirus.

The activation of a specific cellular immune response against human cytomegalovirus (CMV) is an important key factor to solving CMV infection after bone marrow transplantation (BMT). In the present study, our purpose was to identify the HLA-A24-restricted cytotoxic T cell (CTL) epitope from the CMV immunogenic matrix protein pp65. We selected five CMV pp65 peptides with HLA-A24 binding motif from the HLA peptide binding predictions web site. Peptide binding assay was performed using biotinylated HLA-A24-restricted MAGE-1 peptide as a reference peptide and transporter associated with antigen processing (TAP)-deficient T2-A24 cells expressing high level of HLA-A24 protein as target cells. After co-incubation of biotinylated MAGE-1 and titrated amounts of competitor peptides with T2-A24 cells, the binding of each peptide was analyzed on a flow cytometer. Peptide binding assay showed that three out of five peptides derived from CMV pp65 bound to T2-A24 cells with various affinity levels. CTL induction assay using peptide-pulsed DC derived from eight HLA-A24(+) donors revealed that the peptide (QYDPVAALF) with the highest affinity was able to elicit potent CTLs which killed peptide-pulsed TISI cells. These CTLs were found to show the killing activity against human fibroblast cells transduced with both HLA-A*2402 and CMV pp65 cDNAs, and CMV-infected HLA-A24(+) fibroblast cells. These results suggested that the peptide (QYDPVAALF) is one of HLA-A24-restricted CTL epitope derived from CMV pp65 protein and may be of therapeutic value in peptide-based vaccines against CMV infection in BMT patients.

Antibodies, Monoclonal↗
PubMed2002

Limited efficacy of lamivudine against hepatitis B virus infection in allogeneic hematopoietic stem cell transplant recipients.

BACKGROUND: Reactivation of chronic hepatitis B virus (HBV) infection is a major complication when HBV carriers receive immunosuppressive therapy. Recipients of allogeneic hematopoietic stem cell transplantation (HSCT) carry the highest risk of fatal HBV disease (up to 12%). METHODS: In an attempt to identify a suitable procedure for the prevention and management of HBV reactivation, the administration of lamivudine over the course was tested in two patients. RESULTS: Generally, the patients transplant courses were successfully managed despite their difficult clinical situations: a high HBV load before transplant in one patient and intense steroid therapy for complicated acute graft-versus-host disease (GVHD) in the other patient. However, one patient showed a reactivation of HBV after discontinuing lamivudine and the other showed persistently high DNA polymerase activity despite prolonged administration of lamivudine. CONCLUSIONS: We concluded that lamivudine could have a place in the management of patients who suffer from chronic HBV infection and who are undergoing allogeneic HSCT. However, the efficacy of lamivudine seemed to be limited compared with other settings, including solid organ transplantation and autologous HSCT.

Adult↗
PubMed2002

Response-oriented preemptive therapy against cytomegalovirus disease with low-dose ganciclovir: a prospective evaluation.

BACKGROUND: Preemptive therapy against cytomegalovirus (CMV) disease has succeeded in reducing the incidence of CMV disease, but the toxicity of ganciclovir remains problematic. METHODS: We prospectively evaluated the efficacy and toxicity of a preemptive protocol with ganciclovir at a reduced initial dose in 40 patients who achieved engraftment after allogeneic hematopoietic stem cell transplantation. RESULTS: Twenty-three (58%) patients had high-risk features, including transplant from an HLA-mismatched or unrelated donor, or associated acute graft-versus-host disease. CMV antigenemia assay was performed weekly, and ganciclovir was started in a risk-adapted manner, in which the initial dose of ganciclovir was fixed at 5 mg/kg/d and then adjusted based on the results of a weekly CMV antigenemia assay. In this protocol, 23 (58%) patients demonstrated positive antigenemia, and 19 (48%) received a preemptive administration of ganciclovir. Only one patient had CMV disease in the gastrointestinal system, which was successfully treated with a regular therapeutic dose of ganciclovir. Consequently, the total dose of ganciclovir was significantly less than that in a previous protocol using the conventional double dose (5 mg/kg twice daily) of ganciclovir (134 mg/kg vs. 190 mg/kg on average, P=0.046). There were no significant toxicities attributed to ganciclovir, except for neutropenia <0.5 x 109/L, which developed in three patients for 3, 4, and 14 days, respectively, with granulocyte colony-stimulating factor support. CONCLUSION: Preemptive therapy with a low initial dose of ganciclovir appeared to be effective even in high-risk patients. Further randomized controlled trial is warranted.

Adult↗
PubMed2002

Sustained molecular remission in a patient with CML in blastic crisis receiving dose-reduced hematopoietic stem-cell transplantation followed by early withdrawal of cyclosporine and prophylactic use of interferon-alpha.

A 54-year-old man with chronic myelocytic leukemia in blastic phase received reduced-intensity transplantation (RIST) from an HLA-identical unrelated donor. The preparative regimen consisted of busulfan, fludarabine, and anti-thymocyte globulin. Graft-versus-host disease (GVHD) prophylaxis was cyclosporine alone. Because he had a high risk of relapse, we discontinued cyclosporine on day 37, but he did not develop any signs of acute GVHD. To induce GVHD and augment a graft-versus-leukemia effect, we initiated interferon-alpha therapy on day 80 to a maximum dosage of three million units five times a week. He achieved molecular remission on day 94 followed by the development of extensive chronic GVHD the severity of which paralleled to the dose of interferon-alpha GVHD gradually subsided after discontinuation of interferon-alpha and the patient remains in molecular remission 18 months after transplantation. This case suggests that early withdrawal of cyclosporine and the prophylactic use of interferon-alpha are promising in RIST for high-risk leukemia.

Blast Crisis↗
PubMed2002

Mini-transplantation strategy for solid tumors.

In our phase I reduced-intensity stem cell transplantation (RIST) study with fludarabine (180 mg/m2) or cladribine (0.66 mg/kg) plus busulfan (8 mg/kg), with or without anti-thymocyte globulin (ATG), a total of 85 patients who had a variety of hematological (n=68) or metastatic solid tumors (n=17) were treated. This presentation will further update the results of our RIST program, highlighting several burning issues in the treatment of patients with solid tumors. Pathological classification of solid tumor in this program included renal cell carcinoma (RCC, n=8), rhabdomyosarcoma (n=2), malignant melanoma (n=2), neuroblastoma (n=2), osteosarcoma (n=1), alveolar saft-part-tumor (n=1) and cholangiocarcinoma (n=1). All received PBSCT from an HLA-identical or one antigen-mismatched relative. Regimen-related toxicities were mild and >90% donor chimerism was achieved before day 30 in a majority of patients. The overall survival for hematological and solid malignancies was the same ca. 70% at 1 year.

Clinical Trials, Phase I as Topic↗
PubMed2002

Hematopoietic and immune recovery after allogeneic peripheral blood stem cell transplantation and bone marrow transplantation in a pediatric population.

To compare the hematopoietic and immune recoveries after allogeneic transplantation with different cell sources, we analyzed the recovery patterns of blood components after allogeneic peripheral blood stem cell transplantation (PBSCT) in comparison with that after allogeneic bone marrow transplantation (BMT) in a pediatric population. Sixteen patients received PBSCT, and 24 received BMT between January, 1995 and March, 2000. The patients had acute lymphoblastic leukemia (ALL; n = 22), acute myelogenous leukemia (AML; n = 8), myelodysplastic syndrome (MDS; n = 3), or other diseases (n = 7). The median ages of patients in the PBSCT and BMT groups were 9 yr and 6 yr, respectively. Cyclosporin A (CsA) plus methotrexate or methylprednisolone was used as a graft-vs.-host disease (GvHD) prophylaxis regimen in the PBSCT group, whereas CsA alone or methotrexate alone was used in the BMT group. Circulating lymphocyte numbers and subpopulations determined by flow cytometric analysis were used as markers of immune recovery. In the PBSCT group, the median number of harvested CD34+ cells was 7.25 (range: 1.3-27.6) x 106/kg of the recipient's body weight, while the median number of harvested nucleated cells was 4.7 (range: 3.7-10.5) x 108/kg. All of the patients were engrafted. Myeloid engraftment occurred sooner after PBSCT than after BMT (median number of days to achieve absolute neutrophil counts (ANC) > 0.5 x 109/L; 11 and 15, respectively; p < 0.0001) and similar results were found for platelet engraftment (median number of days to achieve a platelet count of > 20 x 109/L; 12 and 21, respectively; p = 0.004). On the other hand, after PBSCT the absolute numbers of total circulating lymphocytes and lymphocyte subpopulations were not significantly different from those after BMT. The incidence of acute GvHD after PBSCT was the same as that after BMT, while chronic GvHD developed more frequently after PBSCT than after BMT (p = 0.005). In a pediatric population, the indications for PBSCT and BMT should be based on these findings in addition to regard for the donor's safety.

Adolescent↗
PubMed2002

Effect of fluconazole prophylaxis on fungal blood cultures: an autopsy-based study involving 720 patients with haematological malignancy.

To investigate the utility of blood culture of invasive fungal infections in patients with haematological malignancies, an autopsy survey was conducted in 720 patients who were treated between 1980 and 1999. We identified 252 patients with invasive mycosis. These included Candida (n = 94), Aspergillus (n = 91), Zygomycetes (n = 34), Cryptococcus (n = 7), Trichosporon (n = 11), Fusarium (n = 1), and unknown fungi (n = 20). Of the 94 patients with invasive candidiasis, 20 had positive blood cultures. Of the 11 patients with invasive trichosporonosis, seven had positive blood cultures. The sensitivities of blood cultures were 1.1%, 0% and 14% for detecting invasive aspergillosis, zygomycosis and cryptococcosis respectively. Multiple regression analysis showed a significant correlation between results of Candida blood cultures and some variables, including prophylactic use of absorbable antifungals (P = 0.0181) and infection by Candida albicans (P = 0.0086). The sensitivity of blood cultures decreased when patients received antifungal chemoprophylaxis. Unless these agents are inactivated in culture bottles, conventional blood cultures might produce false-negative results.

Adolescent↗
PubMed2002

Impact of stem cell source and conditioning regimen on erythrocyte recovery kinetics after allogeneic haematopoietic stem cell transplantation from an ABO-incompatible donor.

We evaluated erythrocyte recovery in 121 allogeneic haematopoietic stem cell transplantation (HSCT) recipients. There were 35 major and minor ABO-incompatible transplants, respectively, including 10 bi-directionally ABO-incompatible transplants. The use of peripheral blood stem cells facilitated erythrocyte recovery, regardless of the presence or absence of major ABO-incompatibility, and was associated with a frequent detection of anti-host isohaemagglutin early after minor ABO-incompatible transplantation, which was not associated with clinically relevant haemolysis. The use of a reduced-intensity regimen combining a purine analogue and busulphan did not delay erythrocyte recovery after major ABO-incompatible transplantation, suggesting this regimen had a strong activity against host plasma cell.

ABO Blood-Group System↗
PubMed2002

HLA-identical sibling peripheral blood stem cell transplantation in children and adolescents.

Allogeneic peripheral blood stem cell transplantation (PBSCT) was performed in children and adolescents for the treatment of malignant (n = 49) and nonmalignant hematological disease (n = 8). Granulocyte colony-stimulating factor (G-CSF)-mobilized PBSCs were apheresed from 57 HLA-matched siblings aged 9 months to 24 years (median, 8 years) without any serious adverse, effects. No abnormalities were found in these donors for a median follow-up of 25 months (range, 6-56 months). Patients were conditioned with a TBI-containing regimen (n = 17) or a non-TBI regimen (n = 40). GVHD prophylaxis consisted of methotrexate (MTX) plus cyclosporine A (CSP) for 23 patients, CSP plus methylprednisolone (mPDN) for 22 patients, MTX only for 7 patients, CSP only for 4 patients, and MTX plus CSP plus mPDN for 1 patient. Engraftment was prompt, with a median number of days to reach an absolute neutrophil count (ANC) above 0.5 x 10(9)/L of 13 days (range, 8-23 days), with 1 graft failure. Acute GVHD (grades II-IV) occurred in 8 (16%) of 49 evaluable patients, and chronic GVHD developed in 23 (64%) of 36 evaluable patients. Notably, two thirds of chronic GVHD was extensive. The Kaplan-Meier estimate of 3-year disease-free survival was 0% for refractory disease (n = 6), 37.2% +/- 11.8% for high-risk malignancies (n = 25), 81.4% +/- 9.7% for standard-risk malignancies (n = 18), and 100% for nonmalignant disease (n = 8). The estimated 100-day nonrelapse mortality rate was 9.9% +/- 4.2%. In conclusion, allogeneic PBSCT is feasible in a pediatric population. Although the grade of acute GVHD was set low, as in Japanese BMT studies, the incidence and severity of chronic GVHD appears to be relatively high. For nonmalignant disease, the question arises of whether the higher incidence and severity of chronic GVHD is a drawback of this procedure. For high-risk malignancies, whether or not a graft-versus-leukemia effect prevents relapse needs to be clarified in future comparative studies with BMT.

Adolescent↗
PubMed2002

The role of PGE(2) in the differentiation of dendritic cells: how do dendritic cells influence T-cell polarization and chemokine receptor expression?

The role of prostaglandin E(2) (PGE(2)) in the function of dendritic cells (DCs), T-cell polarization, and expression of chemokine receptors was evaluated in human cells. Immature DCs were generated from peripheral blood CD14(+) cells using a combination of GM-CSF and interleukin-4 (IL-4) with or without PGE(2). On day 6, maturation of DCs was induced by the addition of tumor necrosis factor alpha with or without PGE(2). DCs harvested on day 6 (immature DCs) or day 9 (mature DCs) were examined using functional assays. In the presence of PGE(2), immature and mature DCs showed, phenotypically, a lower expression of CD1a and, functionally, a higher allostimulatory capacity at a high DC/T-cell ratio than control cells cultured in the absence of PGE(2). DCs cultured in the presence of PGE(2) induced the differentiation of naïve T cells toward a helper T-cell type 1 (Th1) response, which was independent of IL-12 secretion in the basal state despite a slightly lower interferon gamma secretion compared with control cells. However, the function of cytotoxicity-stimulating autologous T cells was not augmented by the addition of PGE(2). Immature DCs expressed the inflammatory chemokine receptors, CCR1 and CXCR4, but not CCR6, regardless of the presence or absence of PGE(2). Mature DCs expressed CCR7 equally, measured using a migration test and the measurement of calcium flux with macrophage inflammatory protein-3beta and reverse transcription-polymerase chain reaction assay in all of the groups. All of these findings suggest that PGE(2) affects the DC-promoted differentiation of naïve T cells to a Th1 response in the basal state, without affecting chemokine receptor expression on DCs.

CD3 Complex↗
PubMed2002

Therapeutic potential of a reduced-intensity preparative regimen for allogeneic transplantation with cladribine, busulfan, and antithymocyte globulin against advanced/refractory acute leukemia/lymphoma.

PURPOSE: Cladribine (2-CdA) is a purine analogue that exhibits activity against a variety of hematological malignancies and has a potent immunosuppressive effect. We therefore performed a pilot study to evaluate the feasibility of a novel 2-CdA-based reduced-intensity stem cell transplantation (RIST) regimen. EXPERIMENTAL DESIGN: A total of 16 scheduled patients with hematological malignancies were enrolled for comparison of their data with conventional stem cell transplantation (n = 19). The regimen for RIST consisted of 2-CdA (0.11 mg/kg/day for 6 days), busulfan (4 mg/kg/day for 2 days), and rabbit antithymocyte globulin (2.5 mg/kg/day for 4, 2, or 0 days). The underlying diseases included acute myelogenous leukemia (n = 6), chronic myelogenous leukemia (n = 2), myelodysplastic syndrome (n = 6), and non-Hodgkin's lymphoma (n = 2). RESULTS: After RIST, four patients died before day 100 as a result of acute graft-versus-host disease (n = 1), bacteremia (n = 1), disseminated candidasis (n = 1) and congestive heart failure (n = 1). Another patient died of cerebral infarction on day 140. Thus, acute-phase regimen-related toxicities >grade III were observed in only one patient. Engraftment and complete donor chimerism were achieved by day 28 in 14 evaluable patients, and 6 of them (43%) experienced grade II-IV acute graft-versus-host disease. With a median follow-up of 328 days (range, 231-633 days), the actuarial 1-year overall and disease-free survival rates were 69% and 50%, respectively. Notably, among seven high-risk patients (five patients had been in complete remission two or more times and two not in complete remission with refractory disease at transplant), only two patients developed leukemia relapse after RIST. Although the recovery of CD4+ cells was significantly slower (P = 0.02) in RIST than in conventional stem cell transplantation, the incidence of clinically documented infections was not significantly different between the two groups. CONCLUSION: The results suggest that this novel regimen containing 2-CdA is well tolerated and induces early complete donor chimerism. The unexpected durable remission achieved in patients with advanced disease at transplant suggests the presence of an acceptable antileukemia/lymphoma effect, which would warrant a further clinical trial.

Adolescent↗
PubMed2002

[Reduced-intensity allogeneic hematopoietic stem cell transplantation (mini-transplantation) for solid tumors].

There are accumulating evidence of immunological therapeutic effect induced by reduced-intensity allogeneic hematopoietic stem cell transplantation (mini-transplantation) for solid malignancies. The reduced toxicity of a mild preconditioning regimen in mini-transplantation has facilitated its application to patients with various solid tumors. The so-called graft-versus-tumor (GVT) effect usually appears when graft-versus-host disease develops. Therefore, it is suggested that the fundamental mechanism of the GVT effect is a reaction by T-lymphocytes against various tumor-associated alloantigens of the tumor cells. Although mini-transplantation appears effective in some patients with renal cell carcinoma or breast cancer, it is still unclear whether the therapeutic mechanism could work on other solid tumors. Well-designed prospective clinical trials are warranted in order to determine the role of mini-transplant in the therapeutic strategy for solid tumors.

Breast Neoplasms↗
PubMedDate not supplied

Freeze-thawing procedures have no influence on the phenotypic and functional development of dendritic cells generated from peripheral blood CD14+ monocytes.

Little is known about the potential influence of cryopreservation on the biologic activities of dendritic cells (DCs). In this study, we examined the effects of freeze-thawing on the phenotypic and functional development of human DCs obtained from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood CD14+ cells. CD14+ cells were cultured, immediately or after freeze-thawing, with granulocyte-macrophage CSF and interleukin-4 for 9 days, and then with added tumor necrosis factor-alpha for another 3 days. For both fresh and freeze-thawed monocytes, immature DCs harvested on day 6 and mature DCs harvested on day 9 of culture were examined under the same conditions. Cells were compared with regard to their 1) capacities for antigen endocytosis and chemotactic migration (immature DCs), and 2) allogeneic mixed lymphocyte reaction and antigen-specific cytotoxic T lymphocyte responses (mature DCs). Freeze-thawing did not affect the viability or subsequent maturation of DCs at any stage of development. Furthermore, essentially no difference was observed in phenotype or function between cells generated from fresh or cryopreserved/thawed cells. Although this study design was limited with the use of fetal bovine serum, the observation still suggests that freeze-thawing does not affect viability, phenotype, subsequent maturation, or functions of DCs at any stage of maturation.

Cells, Cultured↗
PubMedDate not supplied

Expansion of alpha-galactosylceramide-stimulated Valpha24+ NKT cells cultured in the absence of animal materials.

Valpha24+ NKT is an innate lymphocyte with potential antitumor activity. Clinical applications of Valpha24+ natural killer (NK) T cells, which are innate lymphocytes with potential antitumor activity, require their in vitro expansion. To avoid the potential dangers posed to patients by fetal bovine serum (FBS), the authors evaluated non-FBS culture conditions for the selective and efficient expansion of human Valpha24+ NKT cells. Mononuclear cells (MNCs) and plasma from the peripheral blood of normal healthy donors were used before and after G-CSF mobilization. MNCs and plasma separated from apheresis products were also used. MNCs were cultured for 12 days in AIM-V medium containing alpha-galactosylceramide (alpha-GalCer) (100 ng/mL) and IL-2 (100 U/mL) supplemented with FBS, autologous plasma, or autologous serum. The cultured cells were collected and their surface markers, intracellular cytokines, and cytotoxicity were evaluated. The highest expansion ratio for Valpha24+ NKT cells was obtained from G-CSF-mobilized MNCs cultured in medium containing 5% autologous plasma. Cultures containing MNCs and autologous plasma obtained before and after G-CSF mobilization had approximately 350-fold and 2,000-fold expansion ratios, respectively. These results suggest that G-CSF mobilization conferred a proliferative advantage to Valpha24+ NKT cells by modifying the biology of cells and plasma factors. Expanded Valpha24+ NKT cells retained their surface antigen expression and production of IFN-gamma and exhibited CD1d-independent cytotoxicity against tumor cells. Valpha24+ NKT cells can be efficiently expanded from G-CSF-mobilized peripheral blood MNCs in non-FBS culture conditions with alpha-GalCer and IL-2.

Blood Component Removal↗