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At least 19 recordsLinked to original sources
PubMed1989

In vitro synergism of 4-hydroperoxycyclophosphamide and cisplatin: relevance for bone marrow purging.

Autologous bone marrow transplantation with 4-hydroperoxycyclophosphamide (4-HC)-purged bone marrow gives long-term remission in almost half of relapsed acute nonlymphocytic leukemia and non-Hodgkin's lymphoma patients, but relapse of disease is the main cause of failure, suggesting ineffective purging in some cases. Cisplatin (CP) has activity against a variety of human tumors and is not commonly used for initial therapy of leukemia and lymphoma. Using established human leukemia cell lines, combinations of 4-HC and CP were investigated as a potential regimen for improving the ex vivo removal of leukemia cells from bone marrow. The cell lines (K-562 and Raji) were incubated for 1 (4-HC) or 4 h (CP), washed, and assayed for inhibition of colony formation in semisolid media. In both cell lines, CP (4h) was more potent than 4-HC (1 h). Combinations of the drugs in various molar ratios were studied after the cells were sequentially incubated with 4-HC and CP. The effects of the drugs were analyzed using the multiple drug-effect analysis of Chou and Talalay. Analysis of data on in vitro inhibition of colony formation suggested that all combinations studied were synergistic in both cell lines, with the greatest synergism being found in the Raji cell line. In addition, for K-562 cells we could detect at least a 4.6 log reduction in cloning with the CP:4-HC combination (1:10 molar ratio). We conclude that CP is a potential candidate in drug combinations for ex vivo bone marrow purging because of its high potency against human leukemia cell lines, its synergistic activity in combination with 4-HC, and its ability to reduce a high tumor burden when combined with 4-HC.

Bone Marrow↗
PubMed1990

Application of serum-free liquid bone marrow cultures to bone marrow purging for autologous bone marrow transplantation in acute lymphoblastic leukemia.

We have previously established a serum-free (SF) culture medium which allows normal haematopoietic progenitor cells to be maintained for at least 4 weeks as in the conventional serum dependent SD) medium. In the present study we investigated the efficiency of the SF liquid system to sustain normal residual haemopoiesis to the detriment of the leukemic population in patients with ALL. Probes for a potential selective effect were brought through leukemic progenitor cell assay (CFU-ALL) and the polymerase chain reaction (PCR) study of the bcr/abl translocation. In 13 experiments done in 12 patients, morphological blast cells and the ALL-CFU were dramatically reduced within 3 weeks of incubation in both SF and SD cultures. In 5/5 experiments in SD conditions and 2/5 experiments in SF conditions, leukemic cells expressing the bcr/abl fusion gene also disappeared within the same period. There was no difference in the CFU-GM production between SF and SD mediums. Erythropoiesis exhibited a slower decline in conditions SF, compared to the conditions SD. These results indicate that the liquid marrow culture may selectively deplete the leukemic lymphoblastic cells and enable repopulation by residual normal hemopoietic cells. It may be useful to purge leukemic cells for clinical autologous bone marrow transplantation in patients with ALL.

Bone Marrow Cells↗
PubMed1987

Low antigen density tumor cells: an obstacle to effective autologous bone marrow purging?

Autologous bone marrow transplantation is a potentially curative approach to the treatment of various tumors that are refractory to conventional therapies. A major problem associated with the procedure is the possibility of tumor cell contamination in the autologous graft used to reconstitute the patient's immune system after supralethal chemoradiotherapy. A variety of different approaches to eliminating tumor cells from bone marrow have been proposed and tested. These include destruction of tumor cells with antibody and complement, use of antibody conjugated to drugs or toxins, and the physical separation of antibody-coated tumor cells by attachment to magnetic microspheres. Each of these approaches has different limitations and technical problems. One problem common to all, however, is that the tumor cells most likely to avoid removal are those demonstrating a low level of surface antigen. In this paper we have offered a practical approach to amplifying the unique surface antigen expression in order to enable this elusive tumor cell population to be eliminated. The approach proposed is adaptable to all the techniques currently being studied, since it is designed to add additional antigens to tumor cells which can then be used as targets at which to direct the various purging strategies.

Antibodies, Monoclonal↗
PubMed1990

CD9 is an unreliable antibody for bone marrow purging.

Various procedures are useful in purging bone marrow of pre-B lineage contamination prior to autologous bone marrow transplantation. Specific monoclonal antibodies are used in combination with complement, magnetic microspheres, chemotoxins, phototherapy or lectins. In this setting, the usual monoclonal antibody cocktail consists of CD9 (DU-ALL-1), CD10 (WCMH 15.14) and CD19 (HD37). Antigens reacting with all three monoclonal antibodies are present on early and mature pre-B lymphocytes. However, CD9 positive antigens have also been shown to be present on megakaryocytes, platelets and mature granulocytes. In our studies, we have found that CD10 and CD19 expression predictably vary according to disease status, with low positivity in remission and higher positivity in relapse. CD9 expression, however, varies independently of disease status and is frequently inconsistent within individual patients. As such, use of CD9 for marrow purging may result in the removal of a broad range of cell populations not related to the underlying disorder.

Antibodies, Monoclonal↗
PubMed1990

Bone marrow purging by a xanthine oxidase-antibody conjugate.

The selective cytotoxicity of the xanthine oxidase conjugated to an 8A monoclonal antibody recognizing a human plasma cell-associated antigen has been described. The selectivity and the toxicity of the hypoxanthine/conjugated xanthine oxidase system was increased by removing the excess of conjugate and by adding chelated iron. Under these experimental conditions the cytotoxicity of the conjugate exceeded that of free xanthine oxidase by one order of magnitude. The conjugate effectively purged bone marrow from infiltrating neoplastic plasma cells and added target Raji cells, provided blood was removed and bone marrow peroxidases were exhausted. In conditions of purging effectiveness the conjugate had no toxicity to CFU-GM. No toxicity to mice was observed after i.v. injection of xanthine oxidase-antibody conjugate up to 2.9 U/kg body weight. Thus the hypoxanthine/conjugated xanthine oxidase system could be an effective and nontoxic tool for the ex vivo bone marrow purging in multiple myeloma patients for autologous transplantation.

Antibodies, Monoclonal↗
PubMed1987

CFU-GM content of bone marrow graft correlates with time to hematologic reconstitution following autologous bone marrow transplantation with 4-hydroperoxycyclophosphamide-purged bone marrow.

Autologous bone marrow transplants (BMTs) can repopulate the hematologic system of patients treated with marrow-ablative chemotherapy and/or radiotherapy. However, treatment of the bone marrow graft to eliminate residual tumor cells prior to reinfusion can delay the return of peripheral blood elements, presumably from damage to or loss of hematopoietic stem cells responsible for hematologic recovery. To develop a model predictive of hematologic recovery, we studied the progenitor cell contents of 4-hydroperoxycyclophosphamide (100 micrograms/mL)-purged bone marrow grafts of 40 consecutive patients undergoing autologous BMT at this center. Granulocyte-macrophage colonies (CFU-GM) were grown from all grafts after treatment with this chemotherapeutic agent, but erythroid (BFU-E) and mixed (CFU-GEMM) colonies were grown from only 44% and 33% of the grafts respectively. The recovery of CFU-GM after purging ranged from 0.07% to 23%. The logarithm of CFU-GM content of the treated grafts was linearly correlated with the time to recovery of peripheral blood leukocytes (r = -0.80), neutrophils (r = -0.79), reticulocytes (r = -0.60), and platelets (r = -0.66). The CFU-GM content of purged autologous bone marrow grafts may reflect the hematopoietic stem cell content of the grafts and thus predict the rate of hematologic recovery in patients undergoing autologous BMT.

Adolescent↗
PubMed1986

Reconstitution of hematopoiesis after bone marrow purging with ricin A chain immunotoxin.

Bone marrow cells from healthy individuals were treated with an antihuman T cell immunotoxin (IT101). The treated marrow cells were cultured for multilineage hematopoietic colonies (CFU-GEMMT) containing various myeloid cell lineages and T lymphocytes, erythroid colonies (BFU-E), and granulocytic colonies (CFU-C). Optimal conditions were defined for the elimination of clonogenic human T leukemic cells artificially admixed with bone marrow cells. Marrow purging with IT101 led to the restoration of hematopoietic colony formation which was abolished in the presence of T leukemic cells. Mixed colonies grown from bone marrow treated with IT101 contained cells that reacted with monoclonal anti-T-cell antibodies. This suggests that pluripotent stem cells are not affected by marrow IT101 purging and may be able to regenerate lymphoid as well as myeloid lineages.

Antibodies, Monoclonal↗
PubMed1989

Establishment of a reliable experimental procedure for bone marrow purging with mafosfamide (ASTA Z 7557).

Bone marrow purging with cyclophosphamide derivatives (Mafosfamide) requires the establishment of a defined experimental procedure for reliable leukemic cell destruction while sparing normal hematopoietic stem cells to ensure engraftment. We previously defined the granulocyte-macrophage colony-forming unit (CFU-GM) LD95 as being the maximum tolerable dose of drug to use. We now report, in 20 patients with acute non-lymphoblastic leukemia (n = 5), acute lymphoblastic leukemia (n = 5), chronic myelogenous leukemia (n = 5), and non-Hodgkin's lymphoma (n = 5), that the nature of the cells treated (i.e., buffy coat cells or mononuclear cells) significantly influences the accuracy of the LD95 determination, whereas other parameters such as hematocrit or nucleated cell concentration do not. We subsequently define the most reliable experimental procedure for in vitro purging with Mafosfamide: incubation of 2 x 10(7) buffy coat cells/ml with a hematocrit of 5%. We show that the wide individual susceptibility to the drug is not related to any incubation procedure. In a series of 163 patients with hematological malignancies, we confirm the large variation of sensitivity to the drug according to patient susceptibility and diagnosis. These data favor the adjustment of the dose of Mafosfamide on an individual basis, prior to bone marrow purging for autologous bone marrow transplantation.

Bone Marrow↗
PubMed1992

Autologous bone marrow transplantation for acute myelogenous leukemia using 4-hydroperoxycyclophosphamide and VP-16 purged bone marrow.

Thirty adult patients with acute myelogenous leukemia (AML) in remission were treated with hyperfractionated total body irradiation, VP-16, and cyclophosphamide followed by infusion of autologous bone marrow purged with 4-hydroperoxycyclophosphamide and VP-16. Fifteen patients were transplanted in first remission (R1), 13 in second remission (R2), and two in third remission (R3). All patients had hematopoietic engraftment. The median time to achieve a white blood cell count of 1.0 x 10(9)/l and a neutrophil count of 500 x 10(6)/l was 32 days. The median time to achieve an unsupported platelet count of 50 x 10(9)/l was 70 days. There were four transplant-related deaths, all in patients in R2. Ten patients have relapsed, including both patients transplanted in R3. The disease-free survival (DFS) of all patients is 52%, median follow-up not yet reached. Although the number of patients in each group is small and follow-up is limited, there is a trend toward improved actuarial DFS in patients transplanted in R1 compared with patients transplanted in R2 (72 vs 39%; p = 0.081). Use of VP-16 in the conditioning regimen as well as in the purging procedure is feasible in the treatment of patients with AML.

Adult↗
PubMed1992

Engraftment of leukocyte subsets following autologous bone marrow transplantation in acute myeloid leukemia using anti-myeloid (CD14 and CD15) monoclonal antibody-purged bone marrow.

The cell surface phenotype of leukocyte subsets during reconstitution following autologous bone marrow transplantation (ABMT) using bone marrow purged with anti-myeloid monoclonal antibodies (MoAbs) and complement (C') was evaluated in 20 patients with acute myeloid leukemia (AML). Repopulation of B and T lymphocytes, natural killer (NK) cells, and myeloid cells was assessed by phenotypic analysis using two-color cytofluorography of peripheral blood mononuclear cells (PBMNC) at several time points up to 2 years post-transplantation. In spite of removal of the majority of monomyeloid cells of the autograft by purging with anti-CD14 and anti-CD 15, engraftment occurred rapidly. The myeloid cells appeared normal by surface phenotype. An early rise in NK cells, characterized by expression of CD57 and CD 16, was seen. The CD4:CD8 ratio remained low throughout the study period, primarily due to a persistently low CD4 level. ABMT using bone marrow purged with the anti-myeloid MoAbs PM-81 and AML-2-23 and C' resulted in prompt engraftment of neutrophils. Although there was a prolonged time for recovery of lymphocyte subsets, this did not result in an increased risk of early infectious complications. Late infectious complications post-transplantation were limited to herpes zoster infection in one patient 18 months post-transplantation, and bacterial meningitis in that same patient 2 months later. This study demonstrates that ABMT in patients with AML using bone marrow purged with the anti-myeloid MoAbs PM81 (anti-CD15) and AML-2-23 (anti-CD14) and C' results in rapid hematologic engraftment and delayed phenotypic immunologic reconstitution without significant acute or chronic clinical toxicities.

Adolescent↗
PubMed1991

High-dose therapy and autologous peripheral stem cell transplantation for patients with bone marrow metastases and relapsed lymphoma: an alternative to bone marrow purging.

Throughout a 4-year period, we reinfused autologous peripheral stem cells rather than purged autologous bone marrow following high-dose therapy to 57 patients with relapsed lymphoma and bone marrow metastases. Approximately 7 x 10(8) circulating mononuclear cells/kg patient weight were collected for each patient with 6-19 4-h apheresis procedures while hemopoiesis was unperturbed. Following collection, the cells were cryopreserved. Administration of high-dose therapy, which included either combination chemotherapy or combination chemotherapy plus total body irradiation, was followed by i.v. administration of the thawed autologous stem cells. The rate of hemopoietic recovery varied with the specific high-dose therapy administered. Sixty-two percent of 50 evaluable patients had a clinical complete response. The actuarial event-free survival for these patients 4 years after transplantation was 30%, and the projected survival at 4 years was 51%. Patients with relapsed lymphoma and bone marrow metastases who receive high dose therapy followed by peripheral stem cell transplantation can experience long-term event-free survival. Whether similar patients would fare as well with the same high-dose therapy followed by a purged autologous bone marrow transplantation would require a randomized prospective study.

Adult↗
PubMed1986

Normal blast colony formation: an in vitro tool for monitoring human bone marrow 'purging'.

A major problem in autologous bone marrow transplantation is that it is impossible to evaluate in vitro the effect of drug treatment on haematopoiesis. However, Gordon and colleagues have recently established a colony forming assay which detects very immature blast progenitor cells. This method can be used to measure the myelotoxicity of drugs used for removing malignant cells from bone marrow ('purging') before autografting and we have analysed the action of mafosfamide on normal blast colony formation. Treatment in vitro with mafosfamide did not impair the formation of blast colonies containing very primitive cells (type I) but suppressed the formation of the colonies of more mature cells (types II and III) which grow under the same culture conditions. The surviving type I blast colony-forming cells were capable of self-renewal and differentiation. In contrast granulocyte-macrophage colony-forming units (GM-CFU) were totally destroyed by treatment with mafosfamide.

Bone Marrow↗
PubMed1992

Bone marrow purging prior to autologous transplantation.

Our data suggest that ex vivo bone marrow purging using monoclonal antibodies (MoAbs) and sheep-anti-mouse immunobeads (SAM beads) prior to autologous bone marrow transplantation (ABMT) allows satisfactory tumor cell reduction without critical stem cell losses. Nevertheless, there is only a reduction but no elimination of tumor cells. The consequences will have to be clinically discussed.

Antibodies, Monoclonal↗