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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three groups of patients with leukaemia and myelodysplasia were assessed with regard to the blood product support they required during their period of bone marrow hypoplasia following treatment. One group received myelo-ablative remission-induction chemotherapy followed by appropriate consolidation therapy (two courses in patients with acute myeloid leukaemia and one or two intensification courses in patients with acute lymphoblastic leukaemia); whilst the other two had 'conditioning' with chemotherapy and radiotherapy prior to autologous bone marrow transplantation (auto-BMT) or T cell depleted allogeneic bone marrow transplantation (allo-BMT). There was no statistically significant difference in blood product requirements between the three groups. However, platelet requirements during remission-induction chemotherapy alone were significantly less than for allo-BMT or auto-BMT. Platelet requirements for patients undergoing auto-BMT were also significantly higher than for patients receiving consolidation chemotherapy; and were required for a longer period than for patients receiving allogeneic-BMT. There was no difference in blood product support between ABO matched and mismatched transplants within the allogeneic group, but the presence of graft versus host disease and/or cytomegalovirus infection did significantly increase the requirements for blood product support.
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PMID:Blood product support in patients undergoing chemotherapy and autologous or allogeneic bone marrow transplantation for haematological malignancies. 193 21

Manifestation of graft-versus-leukemia (GVL) effect in MHC-compatible and -incompatible, allogeneic bone marrow transplantation and the roles of T cell subsets contaminated in the donor bone marrow were studied using radiation-induced leukemia-bearing C3H mice maintained under specific-pathogen-free (SPF) condition. The results indicated that BMT from MHC-incompatible allogeneic (B10) donor significantly improved the survival of the treated mice as compared with that from syngeneic (C3H) donor. When donor (B10) bone marrow cells were treated with either anti-Thy 1.2 or anti-Lyt 2.2 antibody plus complement prior to BMT, a beneficial GVL effect was completely abolished. On the other hand, BMT from MHC-compatible allogeneic donors (B10.BR, CBA, AKR) failed to show an improvement in survival. However, intentional enhancement of GVH reaction by preimmunization of B10.BR donor mice with a relatively small number (10(4) approximately 10(5] of C3H spleen cells or by an addition of B10.BR lymph node cells to the donor bone marrow resulted in a significant improvement in survival. The depletion of all T cells completely abrogated the GVL effect, while the depletion of either Lyt 2+ or L3T4+ T cells from donor (B10.BR) bone marrow resulted in only partial, if any, abrogation of GVL effect. The results indicate that GVL effect observed in leukemic mice treated with allogeneic BMT from MHC-compatible (B10.BR) and -incompatible (B10) donors was totally dependent on T cells contaminated in the donor bone marrow, and suggest that the roles of T cell subsets in the induction of GVL effect were different between MHC-compatible (B10.BR) and -incompatible (B10), allogeneic BMT.
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PMID:Graft-versus-leukemia effect in MHC-compatible and -incompatible allogeneic bone marrow transplantation of radiation-induced, leukemia-bearing mice. 194 75

The AML model in the BN rat has contributed considerably to improved understanding of the various aspects of leukaemia growth, responses to chemotherapy, application of BMT as treatment modality and the possibilities and limitations for the detection of residual disease during the remission phase. Obviously, there are restrictions with regard to the extrapolation of the rat data to the human situation. Leukaemia growth in inbred rats is highly reproducible, while in humans it presents a high degree of individual variation. However, several characteristics are shared and the aim should be to identify the similarities as well as the dissimilarities between human and rat leukaemia. In that way progress may be envisaged with respect to reaching the final goal of curing human leukaemia.
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PMID:Minimal residual disease in acute leukaemia: preclinical studies in a relevant rat model (BNML). 195 83

In conclusion, lessons from the animal model of lymphoid leukaemia suggest that in the setting of allogeneic BMT, under certain conditions GVL effects may be separable from GVHD; more specifically, GVL effects may be induced despite development of tolerance of donor cells against allogeneic host alloantigens. The latter phenomenon suggests that either curative GVL effects may be inducible despite subclinical GVHD or alternatively that effector cells of GVL may recognize different tumour-associated targets different from cell surface determinants of 'normal' alloantigens. Alternatively, effector cells of GVL may be distinguished from effector cells of GVHD. It is tempting to suggest that NK and IL2-aspirated NK cells may play a major role as effector cells of GVL in an MHC non-restricted fashion, different from classical CD8+ cytotoxic cells that certainly play a major role in GVHD and GVL. Once proven, the latter hypothesis may help develop new and safer therapeutic approaches since NK cells and products of the NK cell family are unlikely to play a major role, if any, in GVHD. The feasibility of induction of GVL-like effects by MHC non-restricted effector cells, such as that observed by CMI, most likely through cytokine-activated NK cells, seems promising because such effector mechanisms may be utilized clinically through either adoptive transfer of in vitro-activated lymphocytes or activation of lymphocytes in vivo by administration of cytokines such as IL2 and alpha IFN. Similarly, induction of CCI following ABMT may permit establishment of GVL-like effects with no major risk of GVHD. Our animal models suggest that both approaches may be beneficial and perhaps even combined. From a practical standpoint, activation of antitumour effector cells in vivo is much more feasible, in comparison with the cumbersome and expensive technologies for large-scale in vitro manipulation of IL2-activated 'LAK' cells or tumour-infiltrating lymphocytes ('TIL') at dose ranges required for obtaining clinically meaningful responses. No less important is the fact that more potent immunotherapy may be inducible by cytokine combinations (such as IL2 and alpha IFN). We are currently investigating additional cytokine combinations in order to attempt to optimize antitumour effects inducible by allogeneic and syngeneic lymphocytes since it appears logical that amplifying in vivo antitumour responses by multiple cytokine combinations may yield better antitumour effects.
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PMID:Control of relapse due to minimal residual disease (MRD) by cell-mediated cytokine-activated immunotherapy in conjunction with bone marrow transplantation. 195 88

A graft versus leukaemia (GvL) effect makes a significant contribution to the lower risk of relapse seen in patients after BMT compared with patients receiving chemotherapy alone. Both T cell-dependent and T cell-independent effectors of GvL exist, and both may play an important role in the elimination of minimal residual disease after BMT. There is evidence that GvL activity may be separable from GvHD either by identifying T cell clones recognizing specific leukaemia antigens or by using immunomodulatory drugs or cytokines to enhance T cell-independent GvL mechanisms which operate without alloreactivity and therefore without concomitant exacerbation of GvHD. These approaches should improve survival after both autologous and allogeneic BMT.
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PMID:Graft versus leukaemia effects after marrow transplantation in man. 195 89

In a study carried out for patients receiving intrafamilial HLA-A,B,DR identical, MLC negative bone marrow transplants, RFLP profiles of HLA-class II for 27 donor recipient pairs were analyzed. Twenty-four pairs were found HLA-class II identical while three pairs were HLA-DP incompatible. The patients of these three pairs did not reveal any acute GVHD greater than or equal to grade II. The seven cases of acute GVHD greater than or equal to grade II found in our panel were HLA-DR, DQ, and DP compatible. Thus, in practical terms pretransplantation HLA-DP typing does not seem necessary for intrafamilial HLA-identical, MLC negative BMT. On the other hand, this work confirmed that it is possible to type for HLA-DP using molecular biological techniques, and this in itself may have some important implications for unrelated BMT.
Leukemia 1990 Mar
PMID:HLA-DP genotyping in HLA-A,B, and DR identical intrafamilial bone marrow transplantation. 196 10

An anti-leukemic effect of allogeneic bone marrow has been repeatedly demonstrated in experimental animal models. Clinical data supporting this "graft versus leukemia" (GVL) effect are derived from several different observations which include: 1) the association of GVHD (acute and chronic) with decreased leukemic relapses; 2) identical twin transplants are associated with a higher relapse rate compared to allogeneic MHC-matched sibling transplants; 3) T cell depletion of donor bone marrow decreases GVHD and increases leukemic relapse rates; 4) Allogeneic BMT without GVHD have a lower leukemic relapse rate compared to identical twin transplants and T cell depleted transplants. The mechanisms of this GVL effect remain poorly understood, but clearly involve the immune system. It is hoped that current advances in basic understanding of the immune system and its activation will enable the "antileukemic" components of the GVL effect to be prospectively controlled and intentionally used as leukemia therapy.
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PMID:The graft versus leukemia effect: possible mechanisms and clinical significance to the biologic therapy of leukemia. 204 83

One hundred and seven consecutive patients with acute non-lymphocytic leukemia (ANL) aged less than 56 years were allocated to receive either allogeneic (allo-BMT) or autologous bone marrow transplantation (auto-BMT) when first complete remission (CR1) was achieved. CR was obtained in 96 patients. Twenty-four patients had an HLA-identical sibling donor and 20 of these (83%) had an allograft in CR1. Thirty-three patients (44% of the CR1 patients without donor) had an autograft in CR1. The reasons for not transplanting patients in CR1 were early relapse (nine patients), refusal (11 patients) or medical problems (23 patients). The 4-year leukemia-free survival (LFS) probability for all the CR1 patients was 25%. For the allo-BMT patients, the 4-year LFS was 71%, and for the auto-BMT patients 31% (log-rank p = 0.028). The relapse probabilities were 33% and 48% respectively (p = 0.40). If the results are analysed according to the intent of the protocol, patients with a donor had an LFS of 53%, and patients without a donor an LFS of 16% (p = 0.003). This study confirms the value of allo-BMT for consolidation of ANL in CR1. The attempt to autograft all CR1 patients without a compatible donor has not resulted in any marked improvement of LFS.
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PMID:Allogeneic or autologous bone marrow transplantation for acute non-lymphocytic leukemia in first remission. 207 Jan 37

Use of allogeneic BMTs continues to increase. During the 33-year period between 1955 and 1987, more than 20,000 patients received allogeneic BMTs; more than 50% of these were performed in the 3 years, 1985 through 1987. Transplants are effective therapy for leukemia and other hematologic diseases. They are the treatment of choice for aplastic anemia and chronic myelogenous leukemia, those who fail conventional therapy for acute leukemia, and a variety of immune deficiency disorders. Successful application of BMT is limited by complications such as graft failure, GvHD and interstitial pneumonia, and, until recently, the requirement for an HLA-identical sibling donor. In the past few years, an increasing number of transplants was performed using HLA partially matched related or unrelated donors, with some success. The development of posttransplant complications can often be predicted by risk factor assessment. In this report, current data from the IBMTR are summarized and several risk factors affecting outcome identified.
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PMID:Current status of allogeneic bone marrow transplantation. 210 63

We have used elutriation to deplete lymphocytes from the marrow allografts of 64 patients to date. The first phase I trial (1 x 10(6) lymphocytes/kg IBW) was designed to test the procedure for potential toxicities, most notably, graft failure. Study 2 (1 x 10(6) lymphocytes/kg, no CsA) was expected to reduce potential toxicity incurred from long term immunoprophylaxis while study 3 was aimed at reducing the incidence of GVHD by further reducing lymphocyte dose (5 x 10(5)/kg). Graft lymphocyte dose was based on morphologic determination and was subsequently confirmed by limiting dilution analysis and flow cytometry. Although grafts were standardized solely by lymphocyte dose, the product was more uniform than the original harvested BM with respect to other cell populations. Nearly all study I (n = 40) and study III (n = 20) patients engrafted with a median time to ANC greater than 500/ul of 19 days. Three of the 4 patients consecutively enrolled in study II failed to engraft, thus terminating the trial. While a moderate proportion of study I patients had AGVHD (44%) with attendant morbidity, only 20% of study III patients were found to have mild AGVHD (less than or equal to stage I). To date, this cohort has no organ or chronic GVHD and no GVHD-associated morbidity. Median follow-up times for patients in studies I and III are 27 and 11 months, respectively. Overall actuarial survival (n = 60) is 42% at 38 months (38% study I, 80% study III). Good prognosis study I patients experienced 45% actuarial survival versus 9% in the poor prognostic group. While lymphocyte depletion has been effective in reducing the incidence and severity of AGVHD, new strategies are needed to address the issue of disease relapse. As with other methods, lymphocyte depletion by elutriation caused an increased rate of leukemia relapse. The actuarial probability of remaining in remission for recipients of elutriated marrow containing 1 x 10(6) and 5 x 10(5) lymphocytes/kg, respectively, were 60% and 46% at 16 months. Elutriation provides a rapid, reproducible and flexible methodology for graft manipulation which has been effective in reducing the incidence and severity of AGVHD. However, if lymphocyte depletion is to fulfill its promise as a means of reducing the overall morbidity of allogeneic BMT, new strategies may be needed to address the issue of relapse. These may include changes in marrow ablative therapy and post-graft immunosuppression. Equally as important may be the ability to further manipulate accessory cells and lymphoid populations presently excluded from the graft.
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PMID:Using elutriation to engineer bone marrow allografts. 213 32


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