Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.1.1.69 (BMT)
2,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The BCR-ABL gene rearrangement, the initial event in the development of chronic myeloid leukemia, primarily produces clonal expansion in CML by blocking apoptosis, a genetically programmed process of autonomous cell death. The mechanism by which BCR-ABL blocks apoptosis remains unclear, although recent data are beginning to shed light on the signaling pathway. As with other antiapoptotic signals, BCR-ABL induces cellular resistance to a wide spectrum of cytotoxic antitumor agents. However, apoptosis induced by both cytotoxic T lymphocytes and natural killer or lymphokine-activated killer cells is not blocked by BCR-ABL. A substantial number of patients with chronic myeloid leukemia can now be cured, and the prognosis has improved even for those patients who are not cured. Interferon-alpha has emerged as the treatment of choice for patients who do not undergo an allogeneic bone marrow transplantation. The availability of allogeneic bone marrow transplantation has been increased by the ability to find unrelated donors, although graft-versus-host disease remains a major problem. Adoptive immunotherapy with donor lymphocyte transfusions will induce durable remissions and possibly cures in many patients who relapse after allogeneic BMT. Moreover, a number of investigational approaches, especially autologous BMT, appear promising.
...
PMID:Biology and treatment of chronic myeloid leukemia. 909 Apr 88

We present a patient who underwent sibling allogeneic BMT because of refractory Ph+ve ALL and remained BCR-ABL-positive after marrow grafting. Haemopoietic precursor cells were predominantly BCR-ABL-negative and of donor origin. In T cells an exclusively donor genotype was demonstrated. Despite donor leucocyte infusion (DLI), 20 weeks after BMT BCR-ABL fusion mRNA increased in semiquantitative polymerase chain reaction and leukaemic infiltration of the patient's bone marrow was seen. After a second course of DLI the patient achieved sustained molecular remission but he developed severe graft-versus-host disease (GvHD) and died from bacterial sepsis 9 months after DLI.
...
PMID:Relapse of Philadelphia chromosome positive acute lymphoblastic leukaemia after marrow transplantation: sustained molecular remission after early and dose-escalating infusion of donor leucocytes. 913 59

The purpose of this study was to determine the long-term results of allogeneic bone marrow transplantation for chronic myeloid leukemia. A retrospective analysis was carried out of the outcome of 373 consecutive transplants performed at 38 European institutions between 1980 and 1988 and reported to the registry of the European Group for Blood and Marrow Transplantation. All transplants were carried out for first chronic phase of chronic myelogenous leukemia using unmanipulated marow cells from HLA-identical sibling donors. The probability of survival and leukemia-free survival at 8 years were 54% (95% CI: 49-59) and 47% (95% CI: 41-52) respectively. The probabilities of developing acute GVHD (II-IV) at 100 days and chronic GVHD at 4 years after transplant were 47% (95% CI: 41-53) and 52% (95% CI: 46-58) respectively. The probabilities of transplant-related mortality and leukemic relapse 8 years after BMT were 41% (95% CI: 36-48) and 19% (95% CI: 14-25), respectively. Transplant within 12 months of diagnosis was associated with reduced transplant-related mortality (34 vs 45%, P = 0.013) and resulted in improved leukemia-free survival (52 vs 44%, P = 0.03). The probability of relapse was significantly reduced in patients who developed chronic GVHD (RR = 0.33, P = 0.004). The probability of relapse occurring more than 2 years after transplant was increased more than five-fold in patients transplanted from a male donor (RR = 5.5, P = 0.006). Sixty-seven patients in hematologic remission were studied for residual disease by two-step RT/PCR for BCR-ABL mRNA and 61 (91%) tested negative. We conclude that bone marrow transplantation can induce long-term survival in approximately one-half of CML patients; the majority of survivors have no evidence of residual leukemia cells when studied by molecular techniques. The probability of late relapse is increased with use of a male donor.
...
PMID:Long-term results after allogeneic bone marrow transplantation for chronic myelogenous leukemia in chronic phase: a report from the Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation. 933 56

In a retrospective single centre study we examined the outcome of five different therapy approaches in 48 patients in whom a relapse of CML (13 cytogenetic relapses, 35 hematological relapses: 10 chronic phase (CP), nine accelerated phase, 16 blast crisis) occurred after allogeneic BMT. Cyclosporin A (CsA) withdrawal, interferon alpha-2b (IFN-alpha) therapy, donor leukocyte transfusions (DLT), second transplantation (2nd BMT), and chemotherapy (CTX) alone were used and studied for their response rates. Patients who achieved a complete hematologic and cytogenetic remission (CR) were studied for BCR-ABL transcripts and for their chimerism status by PCR. A strong antileukemic effect was observed after abrupt CsA withdrawal, with 10 of 20 patients achieving a CR (50%). All 10 patients with early stage (nine cytogenetic and one CP), but none of the patients with advanced disease recurrence, responded to CsA withdrawal. IFN-alpha induced in five of 11 patients (45%) a stable cytogenetic remission, whereas treatment with DLT induced a CR in only two of 14 patients (14%). A second transplant was performed in six patients. Three of six patients (50%) survive disease-free at a median of 19 months after the 2nd BMT (range 10-25). The use of CTX alone did not induce a remission.
...
PMID:A retrospective single centre study of the outcome of five different therapy approaches in 48 patients with relapse of chronic myelogenous leukemia after allogeneic bone marrow transplantation. 946 77

BCR-ABL antisense oligodeoxynucleotides (ODN) have provided evidence of antileukemia effect when tested in vitro against Philadelphia-positive (Ph-pos) cells and in vivo when injected into leukemic mice. On the basis of the results obtained in vitro at diagnosis, eight patients with chronic myelogenous leukemia (CML) were selected and submitted to autologous bone marrow transplantation (ABMT) with bone marrow (BM) cells purged in vitro with junction-specific (J-sp) BCR-ABL antisense ODN at the time of transformation in accelerated phase or during second chronic phase. Mononuclear BM cells were treated in vitro for 24 or 72 hours with 150 micro/mL of antisense ODN yielding a median recovery of 47.6% mononuclear cells, 48.8% CD34(+) cells, and 20.3% clonogenic cells. After a conditioning regimen including busulphan and etoposide, the reinfused treated cells allowed engraftment and hematologic reconstitution in all patients. Evaluation of the antileukemic effect by standard cytogenetic analysis and fluorescence in situ hybridization showed a complete karyotypic response in two cases and a minimal or no response in the other six. The patient autografted in second chronic phase died in blast crisis 7 months after ABMT; of the seven patients autografted in transformation, three developed blast crisis 21 to 39 months after reinfusion, one died from unrelated BMT complications 30 months after ABMT, and three are in persistent second chronic phase 14 to 26 months after autograft. The low toxicity of the protocol and the hemopoietic reconstitution observed in all patients make this approach feasible; the marked karyotypic response observed in some patients and the duration of the second chronic phase show that ODN-mediated BM purging and autograft is a promising treatment for this high-risk group of CML.
...
PMID:BCR-ABL antisense oligodeoxynucleotide in vitro purging and autologous bone marrow transplantation for patients with chronic myelogenous leukemia in advanced phase. 955 70

We report a patient with Ph chromosome-positive CML who underwent an HLA-identical T cell-depleted BMT from a sibling donor. DNA polymorphism analysis showed complete donor chimaerism after BMT, followed by mixed chimaerism of granulocytes, natural killer cells and B lymphocytes, with T lymphocytes host-derived at day +120 post BMT. From month +20 haematopoiesis was exclusively of host origin in all cell lineages. RT-PCR was used in order to detect residual disease, but at the time, analysis did not show BCR-ABL transcripts. This case is unusual in that non-malignant stem cells of recipient origin survived the transplant and reconstituted haematopoiesis after BMT. Two years post transplant, no molecular or haematological relapse was documented. The observation that subsequent recipient recovery without molecular relapse implies that, at least in this case, the GVL effect can occur in the absence of donor T cells.
...
PMID:Autologous reconstitution with BCR-ABL-negative haematopoiesis after T cell-depleted allogeneic BMT for CML. 975 52

The principle aim of residual disease analysis in patients with chronic myeloid leukaemia (CML) is to gauge patient response to treatment and, in patients after allogeneic BMT, to enable early diagnosis of relapse. RT-PCR is by far the most sensitive assay to detect residual disease in CML and can enable a single leukaemia cell to be detected in a background of 10(5)-10(6) normal cells. This is approximately 1000 x greater than the routine detection limit of the other methods. After allogeneic BMT, many CML patients are BCR-ABL positive for prolonged periods of time without subsequently relapsing. Thus the simple presence or absence of residual BCR-ABL transcripts in patients' leukocytes is of little value in the management of individual cases. Quantitative PCR techniques can distinguish between those PCR positive patients who have low or falling BCR-ABL levels on sequential analysis from those who have levels that are increasing. Provided assays are performed frequently enough, rising or persistently high numbers of BCR-ABL transcripts can be detected prior to frank relapse and this information may be used for early therapeutic intervention. Most patients who respond to treatment for relapse by donor lymphocyte infusion (DLI) achieve durable molecular remission. Quantitative PCR is also useful to gauge the response of CML patients to IFN-alpha. We have found that the great majority of patients in complete cytogenetic remission after treatment with IFN-alpha remain PCR positive and harbour a minority population of BCR-ABL positive myeloid precursor cells. It is unlikely therefore this treatment modality completely eliminates the disease in any patient.
...
PMID:Minimal residual disease in chronic myeloid leukaemia. 984 16

In this study we analysed the incidence and clinical impact of the persistence of host haemopoiesis (mixed chimaerism, MC) after allogeneic BMT in 35 consecutive patients with haematologic malignancies using a total CD4+ cell-depleted graft with an adjusted dose of CD8+ cells (1x10(8)/kg). Chimaerism was assessed by PCR amplification of VNTRs in 30 evaluable patients: 19 non-CML and 11 CML cases which were also evaluated for the BCR-ABL transcript by RT-PCR. All but one had complete engraftment with a donor profile early post-BMT. At the end of the study period, 12 of 30 patients displayed MC (40%). The overall disease-free survival for MC patients was clearly unfavourable when compared to those who exhibited a donor profile (24.7% vs. 100%, P = 0.005). However, we found that only two of five patients with MC in the non-CML group relapsed, whereas a clear correlation could be made between MC and relapse in CML (seven showed MC, preceding cytogenetic or haematological relapse in six of them, which displayed a prior BCR-ABL mRNA positivity). In addition, a quantitative-PCR approach enabled us to demonstrate that increasing amounts of MC are invariably associated with subsequent relapse, whereas a low stable level of host or complete donor haemopoiesis is consistent with clinical complete remission. Although these results suggest that the clinical impact of MC may depend on the underlying disease, it is compatible with the concept that the graft-versus-leukaemia effect against CML is mainly exerted by donor CD4+ lymphocytes. Elimination of this cellular subset may be responsible for the inability of the graft to prevent a progressive increase in the tumor cell burden.
...
PMID:Increasing mixed haematopoietic chimaerism after BMT with total depletion of CD4+ and partial depletion of CD8+ lymphocytes is associated with a higher incidence of relapse. 1010 May 62

Quantitative competitive RT-PCR techniques have been developed to detect BCR-ABL fusion transcripts in CML but they are hardly reproducible. In this work, we have developed BCR-ABL quantification by real time RT-PCR using the ABI PRISM 7700 (Perkin Elmer), a new technique which allows simple and rapid quantification of a target sequence during the extension phase of PCR amplifications. A fluorogenic probe labeled with both a reporter dye at the 5' end and a quencher-dye at the 3' end hybridizes to the target sequence on the third exon of the ABL gene. The exonuclease activity of the Taq DNA polymerase cleaves the probe and releases the reporter dye, resulting in an increase in the fluorescence signal. The absolute copy number of the target sequence (BCR-ABL) or a control gene (ABL) in an unknown sample can then be calculated using a calibration curve prepared from a set of BCR-ABL RNA standards, and results are expressed as a BCR-ABL/ABL ratio. In our hands, the sensitivity of a serial dilution of total RNA from a positive cell line (K562) in a negative cell line (HL60) was 10(-4). Fifteen CML patients in cytogenetic CR, including 11 allografted patients, two autografted patients and two patients treated by IFN were studied sequentially by this new real time quantitative RT-PCR technique in parallel with conventional qualitative two round nested RT-PCR. The two autografted patients showed high BCR-ABL/ABL ratio in all samples. The two patients treated by IFN showed a progressive decrease in the ratio. In the 11 allografted patients, four were sequentially studied 2 years or more after allo-BMT, and all ratios were below 10(-4). The four patients remained in clinical and cytogenetic CR. The seven other allografted patients were studied immediately after the procedure. Three of them showed a progressive decrease in the BCR-ABL/ABL ratio which reached 10(-4) 7 months after allo-BMT. The three patients remained in hematologic and cytogenetic CR. The remaining four allografted patients had progressive increase of BCR-ABL ratio; three developed cytogenetic relapse 9, 11, 28 months after allo-BMT, and the last patient remained in cytogenetic CR in the bone marrow but developed granulocytic sarcoma. Results of real-time quantitative RT-PCR were in agreement with those of qualitative two round nested PCR. However, evolution changes in the results of real-time quantitative RT-PCR often preceded those of the conventional technique: a decrease of the BCR-ABL/ABL ratio preceded progression from first round to second round positivity and then negativity with the classical technique; conversely, an increase in the ratio preceded evolution with the classical technique. Thus, real-time quantitative RT-PCR may show better correlation with clinical and cytogenetic evolution than conventional qualitative techniques and may help in making early therapeutic decisions in CML, especially after molecular relapse.
...
PMID:Detection of BCR-ABL transcripts in chronic myeloid leukemia (CML) using a 'real time' quantitative RT-PCR assay. 1036 Mar 86

Patients with CML post allogeneic BMT or during treatment with Interferon were monitored in bone marrow and peripheral blood for BCR-ABL transcripts by RT-PCR and in the majority of cases also by Southern blotting. Bone marrow and peripheral blood samples were obtained simultaneously and tested by RT-PCR with the objective to determine the usefulness to follow CML patients by testing peripheral blood rather than bone marrow samples. For the purpose of this study we have considered the test results obtained from bone marrow samples as the standard. A total of 111 CML patients were examined who underwent either an allogeneic BMT (n=91) or were treated with Interferon (n=20) amounting to a total of 163 assessments for BCR-ABL. Concordance of results was observed in 153 samples (93.9%). 10 samples showed discordance. Seven of these were subjected to repeat testing by RT-PCR. The previously obtained discordant results were confirmed. The sensitivity of peripheral blood assays was calculated to be 96.2% with a specificity of 89.5%. RT-PCR results restricted to Southern blot negative patients showed concordance of bone marrow and peripheral blood in 91.1% of tested samples with a sensitivity of 92.7% and a specificity of 88.6%. The subset of patients in which Southern blot testing was not available showed concordance at a similar level. Complete concordance was seen in all patients that were found to be positive by Southern blotting. We conclude from this study that peripheral blood testing for BCR-ABL transcripts by RT-PCR is a test with high sensitivity and specificity and may potentially replace bone marrow testing. This approach will probably result in a high level of acceptance by patients and may permit more frequent monitoring.
...
PMID:Comparative testing of peripheral blood and bone marrow for BCR-ABL transcripts in patients post allogeneic bone marrow transplantation and during interferon treatment for chronic myeloid leukemia. 1049 72


<< Previous 1 2 3 Next >>

---