Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although many cytokines have been previously implicated in graft-versus-host disease (GVHD), no study to date has comprehensively evaluated their expression over time or in different tissues affected by GVHD. Using a semi-quantitative reverse transcriptase-PCR technique and a murine model of acute GVHD, we have evaluated the expression levels of mRNA for a wide range of cytokines in spleen, gut and liver tissues at weekly intervals after bone marrow transfer. The earliest cytokine responses seen were increases in IL-2, IL-10, IFN-gamma, MIP-1 alpha and TNF-alpha in the spleen, suggesting a primarily Th1 pathway. Other cytokines (IL-1 alpha, IL-10 and MIP-1 alpha) were persistently elevated in GVHD mice, but were variable depending on the tissue. These data demonstrate that a wide range of cytokines are involved in the GVHD response and that their kinetic pattern of expression is different in various affected tissues.
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PMID:Kinetic and organ-specific patterns of cytokine expression in acute graft-versus-host disease. 765 87

Chronic myelogenous leukemia is a clonal proliferative disorder of pluripotent hematopoietic stem cells. Cure may be achieved by myeloablative conditioning treatment and marrow transplantation. In addition, allogeneic marrow can exert a graft-versus-leukemia effect. The graft-versus-leukemia effect may be directed against leukemia-specific antigens or against antigens on all hematopoietic cells, or it can be part of a graft-versus-host reaction. We report an informative post-transplant course of a patient with yet another leukemia-specific effect. This patient was transplanted with marrow from his HLA-identical sister in an advanced phase of CML and developed acute and chronic GVHD. After a severe pneumonia a high proportion of his metaphases in the bone marrow were male and Philadelphia chromosome negative. Later all metaphases were again female and leukemic cells could not be detected by reverse transcriptase polymerase chain reaction analysis (RT-PCR) for BCR/ABL. This course indicates that normal hematopoietic stem cells may survive intensive chemotherapy, bone marrow transplantation and GVHD. They may be recruited from a dormant state into proliferation during severe infections. In contrast, CML may be eliminated by the graft-versus-host reaction that recognizes recruited cells and spares dormant cells.
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PMID:Graft-versus-host reaction spares normal stem cells in chronic myelogenous leukemia. 870 5

The advent of methods for exploring T cell clonal diversity in detail by using the reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify the CDR3 segment of the T cell receptor (TCR) Vbeta gene represents a powerful tool for analyzing and monitoring T cell clones that may be responsible for graft-versus-host disease (GVHD) or specific immunity. In this report we describe studies of the posttransplant peripheral blood T cell repertoire in two patients receiving marrow grafts from unrelated donors. One patient received an unmodified T cell replete graft and the second patient received a T cell-depleted marrow graft. Both patients were matched with their donors for HLA-A and -B, but differed for a DRB1 minor mismatch. The patient receiving a TCD graft showed a progressive loss of expression of several Vbeta genes during the first 6 months, although expression of some Vbeta genes appeared transiently following reduction of immune suppression therapy and evidence of acute GVHD. Spectratyping of CDR3 segments revealed evolution of new clones and clonal deletion during the posttransplant period. This method in conjunction with a functional analysis and monitoring of host-reactive clones would provide a new approach for evaluating the activity of immunosuppressive therapy.
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PMID:T cell receptor clonal diversity following allogeneic marrow grafting. 882 81

Cord blood stem cell transplantation (CBSCT) was performed on a patient with acute promyelocytic leukemia. The patient was a boy 3 years and 8 months old, who had shown complete remission following treatment with intensive chemotherapy. However, after the final course of consolidation chemotherapy, chromosome analysis of his bone marrow aspirates revealed 46XY, t(15,17)(q22;q21), and a PML-RAR alpha fusion gene was detected by the reverse transcriptase-polymerase chain reaction test. All-trans retinoic acid diminished the chromosomal abnormality, but the PML-RAR alpha fusion gene remained. The patient was then treated with CBSCT from an HLA-matched sibling donor. The number of nucleated cells in the cord blood was 2.2 x 10(7)/kg of body weight, and that of granulocyte-macrophage colony-forming units 0.6 x 10(4)/kg. Methotrexate was given, on days 3 and 6, as prophylaxis against graft-versus-host disease (GVHD). The neutrophil count rose to above 500/microliters on day 22. The platelet count exceeded 50,000/microliters on day 48. Platelet transfusions were given 12 times after CBSCT, the last one on day 36. Grade I acute GVHD was treated with steroids. The patient was well and discharged on day 103, without symptoms or laboratory data suggestive of relapse. Following this experience we instituted a project of the Kanagawa Cord Blood Bank, which is scheduled for expansion nationwide.
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PMID:Successful engraftment of sibling cord-blood stem cell transplantation in a child with acute promyelocytic leukemia. 892 91

CD30 is a member of the tumor necrosis factor (TNF) receptor family, originally described as a marker for Hodgkin and Reed-Sternberg cells in Hodgkin's disease, which has been found to be preferentially expressed by T cells producing Th2-type cytokines. The presence of CD30 expression was assessed by both immunohistochemistry and reverse transcriptase-polymerase chain reaction in the target organs of patients with Th1- or Th2-dominated disorders. CD30 expression was found in neither the gut of patients with Crohn's disease nor in the gastric antrum of Helicobacter pylori-infected patients, where there was high interferon-gamma (IFN-gamma) expression. In contrast, high CD30 expression in the apparent absence of IFN-gamma expression was observed in the skin of patients with systemic sclerosis or chronic graft versus host disease (GVHD), which can be considered Th2-dominated disorders. Moreover, high levels of soluble CD30 were found in the serum of both systemic sclerosis and GVHD patients but not in the serum of patients suffering from multiple sclerosis, a Th1-dominated disorder. Thus, CD30 expression appears to be preferentially associated with Th2-type responses not only in vitro but also in vivo.
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PMID:In vivo CD30 expression in human diseases with predominant activation of Th2-like T cells. 912 1

We observed a patient in whom graft-versus-host disease (GVHD) appeared to induce a positive effect. This 32-year-old male with Philadelphia chromosome-positive acute lymphoblastic leukemia received a bone marrow transplant (BMT) from an HLA-identical sibling donor. We analyzed the bone marrow with the reverse transcriptase-polymerase chain reaction to screen for the minor bcr/abl transcript, which indicates the presence of minimal residual disease (MRD). MRD was present in the pre- and post-transplant phases. There was no evidence of acute GVHD by post-transplant day 45. We abruptly discontinued the immunosuppressive therapy in an attempt to eliminate MRD by inducing an antileukemic reaction during GVHD. GVHD associated with diarrhea and liver dysfunction developed on day 64. On day 105, MRD disappeared and GVHD was treated with prednisolone and cyclosporin. The disappearance of MRD may have been due to the graft-versus-leukemia (GVL) effect mediated by the alloimmune response of donor T lymphocytes. These findings suggest that induction of the GVL effect may be useful for eliminating MRD after BMT in leukemia patients at high risk of recurrence of the disease.
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PMID:Eradication of minimal residual disease during graft-versus-host reaction induced by abrupt discontinuation of immunosuppression following bone marrow transplantation in a patient with Ph1-ALL. 924 45

Chronic myeloid leukaemia (CML) can be treated successfully with allogeneic bone marrow transplantation (BMT) leading to long-term disease-free survival. Leukemia relapse, however, remains a significant clinical problem. Relapse following BMT presumably results from the expansion of small numbers of recipient leukaemic cells which have survived the conditioning therapy. In order to define patients who are at a high risk of leukaemia relapse, a variety of techniques have been employed to detect persistence of host haemopoiesis (mixed chimaerism, MC) or residual leukaemia (minimal residual disease, MRD). However, the precise relationship between the detection of MC and MRD post-BMT is unknown. We have investigated chimaerism and MRD status in 22 patients who were in clinical and haematological remission post-allogeneic BMT for chronic phase CML. Chimaerism was assessed using short tandem repeat PCR (STR-PCR) while BCR-ABL mRNA detection using reverse transcriptase polymerase chain reaction (RT-PCR) was performed to detect the presence of MRD. Seventeen patients received unmanipulated marrow (non-TCD) while in five patients a T cell-depleted transplant (TCD) was performed as additional GVHD prophylaxis. Chimaerism was evaluated in 18 patients (14 non-TCD, four TCD). Mixed chimaerism was an uncommon finding in recipients of unmanipulated BMT (21%) when compared to TCD BMT (100%). No evidence of MRD, as identified using the BCR-ABL mRNA RT-PCR assay, was detected in those patients who were donor chimaeras. Early and transient MC and MRD was detected in four patients (two non-TCD, two TCD) who have subsequently converted to a donor profile. One patient has stable low-level MC but remains MRD negative 4 years post-BMT. Late MC and MRD was observed in two patients who relapsed >6 years after TCD BMT for CML. We conclude that mixed chimaerism is a rare event in recipients of unmanipulated BMT and that donor chimaerism as detected by STR-PCR assay is consistent with disease-free survival and identifies patients with a low risk of leukaemic relapse post-BMT for CML.
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PMID:Persistent donor chimaerism is consistent with disease-free survival following BMT for chronic myeloid leukaemia. 925 92

Little is known about the mechanisms and the kinetics of the so-called graft-versus-leukemia (GVL) response induced by donor lymphocyte infusions (DLI) in patients with leukemic relapse after allogeneic bone marrow transplantation (BMT). We sought to elucidate this problem by sequentially studying three patients with relapsed chronic myeloid leukemia after sex-mismatched BMT from time before donor leukocyte infusion until achievement of complete molecular remission. Lineage-specific chimerism was assessed longitudinally by a combined fluorescent immunophenotyping and sex chromosome-specific in situ hybridization approach. Results were related to quantitative detection of bcr-abl transcripts by competitive differential reverse transcriptase-polymerase chain reaction (RT-PCR), qualitative bcr-abl RT-PCR, and multiplex PCR-based DNA donor/recipient chimerism. All patients had predominant donor lymphopoiesis at the time of DLI, suggesting a state of tolerance to recipient leukemic and/or normal cells. In contrast, granulopoiesis and erythropoiesis were mainly recipient derived in both patients with hematologic relapse and partly recipient derived in the patient with molecular relapse. Eighty percent, 90%, and 8% of CD34(+) cells, respectively, were found to be of recipient origin at relapse, and few donor stem cells predicted for cytopenia post-DLI. Responses were seen after a time lag of 5 to 13 weeks after DLI and resulted in reversal to full donor chimerism within a critical switch period of 4 to 5 weeks. A sudden decrease in recipient cells was paralleled by a sharp decrease in bcr-abl transcript numbers detectable several weeks before achievement of molecular remission and onset of clinical graft-versus-host disease (GVHD). This response pattern was confirmed by retrospective RT-PCR analysis in an additional five patients. Prospective monitoring of stem cell chimerism and response may enable us to individually tailor adoptive immunotherapy in the future.
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PMID:Kinetics of the graft-versus-leukemia response after donor leukocyte infusions for relapsed chronic myeloid leukemia after allogeneic bone marrow transplantation. 1023 94

We have previously shown that pretreatment of mice with keratinocyte growth factor (KGF), an epithelial tissue repair factor, can ameliorate graft-versus-host disease (GVHD) after intensive chemoradiotherapeutic conditioning and allogeneic bone marrow transplantation (BMT). To determine whether this effect was dependent on a KGF-mediated mechanism affecting repair of conditioning-induced epithelial cell injury, we studied GVHD in the absence of conditioning using BALB/c severe combined immune-deficient (SCID) recipients given C57BL/6 T cells. KGF (5 mg/kg per day, subcutaneously) given either before or after T-cell transfer enhanced body weights and extended survival. KGF-treated recipients had elevated serum levels of the Th2 cytokine interleukin 13 (IL-13) on day 6 after T-cell transfer concomitant with reduced levels of the inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interferon gamma (IFN-gamma). A 3-day KGF pretreatment also depressed the secondary in vitro mixed lymphocyte response (MLR) of C57BL/6 splenocytes taken 7 days after in vivo alloimmunization with irradiated BALB/c spleen cells. To determine whether KGF would inhibit host-antidonor-mediated BM rejection, pan-T-cell-depleted BALB/c BM cells were infused into sublethally irradiated C57BL/6 mice and administered KGF either before or before and after BMT. Surprisingly, all KGF schedules tested actually resulted in enhanced alloengraftment. The presence of KGF receptor on donor antihost alloreactive T cells could not be detected by binding studies with radiolabeled KGF, reverse transcriptase-polymerase chain reaction, and Western blotting. Therefore, the mechanism of action of KGF on inhibiting T-cell-mediated immune effects may not be due to a direct effect of KGF on T cells. These studies demonstrate that KGF, by mechanisms independent of repair of conditioning-induced injury, has great potential as an anti-GVHD therapeutic agent with the added benefit of inhibiting the rejection of pan-T-cell-depleted donor BM allografts. (Blood. 2000;96:4350-4356)
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PMID:Keratinocyte growth factor facilitates alloengraftment and ameliorates graft-versus-host disease in mice by a mechanism independent of repair of conditioning-induced tissue injury. 1111 Jul 12

A 15-year-old girl with Ph-positive chronic myelogenous leukemia in first chronic phase received bone marrow from her human leukocyte antigen matched brother. Twenty three months after bone marrow transplantation hematological relapse occured which was treated with two infusions of donor lymphocytes (DLI) (0.5x10(8) CD3/kg b.w./infusion). To enforce the graft-versus-leukemia effect (GvL), the first DLI was followed by administration of interferon-alpha (INF-alpha) 6x10(6) U/day for 30 days, whereas, after the second infusion INF-alpha was given at the same dose until hematological remission was achieved (80 doses). Minimal residual disease (MRD) was detected by conventional cytogenetics (Ph chromosome), fluorescence in situ hybridization (FISH) cytogenetics (BCR/ABL translocation) and reverse transcriptase-polymerase chain reaction (RT-PCR) Ecotropic virus integration site-1 (EVI-1 gene expression), whereas cellular chimerism was monitored by assessment of microsatellite markers PCR and Y-chromosomal DNA content FISH. When hematological remission was achieved the pancytopenia was observed and the cytogenetic and molecular investigations revealed only partial remission and mixed chimerism, however, with predominance of donor origin hematopoiesis. To diminish the myelosupressive effect of donor CD3 cells without switching-off the GvL effect, a low dose of cyclosporine A was given. Further observation revealed significant improvement of hematopoiesis with parallel gradual decline of MRD and increase of donor hematopoiesis up to complete chimerism. Graft-versus-host disease was not observed at any stage of the treatment.
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PMID:Donor lymphocyte infusion followed by interferon-alpha plus low dose cyclosporine A for modulation of donor CD3 cells activity with monitoring of minimal residual disease and cellular chimerism in a patient with first hematologic relapse of chronic myelogenous leukemia after allogeneic bone marrow transplantation. 1124 34


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