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Biomedical subjects

B Glass

Publications and source records attributed to B Glass.

At least 55 records · Page 3Linked to original sources
PubMed1997

Allogeneic peripheral blood progenitor cells for treatment of relapse after bone marrow transplantation.

Donor leukocyte infusions (DLI) are an effective therapy for patients who relapse with leukemia after bone marrow transplantation (BMT). Severe graft-versus-host disease and prolonged periods of pancytopenia compromise the success of this treatment in a substantial number of patients. We used filgrastim-mobilized peripheral blood progenitor cells (PBPCs), in some cases preceded by cytoreductive therapy, to circumvent some of the problems associated with DLI. Eleven patients (median age 41 years) received a total of 20 donor cell infusions. Their diagnosis was CML in hematological (two patients) or cytogenetic relapse (two patients), six patients suffered from acute myeloid leukemia (AM; n = 5) or Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL Ph+). One patient had multiple myeloma (MM). All six patients with acute leukemias received cytoreductive therapy prior to PBPC infusions; three patients with CML were pretreated with IFN alpha. Four of four patients with CML responded to PBPC infusions and currently are in complete clinical and molecular remission for time periods between 1 and 12 months. Six of six patients with acute leukemias achieved a complete remission. All of them relapsed after a median remission duration of 24 weeks (range 11-49 weeks). Three patients relapsed at extramedullary sites (CNS, testes, skin). Four of six acute leukemia patients received further cytoreductive therapy. All patients responded again and are in complete remission for time periods between 14 and 615 days. Two patients with acute leukemias have died due to dissemination of the disease. The patient with MM did not respond and is alive with disease. Severe (grade III) acute GVHD developed in two of 11 patients, three patients developed grade II disease, six patients did not show any signs of GVHD. Extensive chronic GVHD has developed in two cases to date. Patients with chemotherapy prior to PBPC infusion developed neutropenia and thrombocytopenia with a maximum duration of 20 and 14 days, respectively; prolonged periods of neutropenia did not occur. Two patients developed long-lasting thrombocytopenia in spite of PBPC infusion, in one case followed by leukemic relapse. Repeated courses of chemotherapy and PBPC infusion were generally tolerated well; no early deaths due to treatment-related toxicity or GVHD were observed. We conclude that the use of allogeneic PBPC instead of DLI in patients with relapse after BMT is technically feasible and safe. The efficacy of PBPC infusions seems comparable to DLI in patients with CML. Patients with acute leukemias also achieved complete albeit transient remissions. Aggressive chemotherapy followed by PBPC infusions resulted in only limited duration of cytopenia. The usage of PBPC infusion instead of non G-CSF-mobilized donor cells for treatment of relapse after BMT may reduce pancytopenia-related complications and merits further investigation.

Adult↗
PubMed1997

Allogeneic MHC-mismatched activated natural killer cells administered after bone marrow transplantation provide a strong graft-versus-leukaemia effect in mice.

Allogeneic lymphocytes administered with an unmanipulated bone marrow transplant provide a strong antileukaemic effect, the so-called graft-versus-leukaemia (GVL) effect. On the other hand, T-cell-mediated graft-versus-host-disease (GVHD) observed after transplantation of unmanipulated BM graft causes substantial morbidity and mortality. The aim of the present study was to determine the antileukaemic potential of enriched IL-2 activated NK cells administered 2 h after BMT. Balb/c (H-2d) mice were given a dose of A20 (H-2d, B-cell leukaemia) cells 2 d prior to lethal total body irradiation (TBI) and transplantation of either syngeneic or allogeneic anti-Thy1.2 (CD90) depleted bone marrow cells. Either syngeneic (Balb/c, H-2d) or allogeneic (C57BL/6, H-2b) enriched and IL-2 (200 U/ml for 24 h) activated NK cells were given 2 h after BMT. Injection of A20 leukaemia into normal Balb/c recipients led to death after a median of 14 d. A lethal dose of TBI followed by either syngeneic or allogeneic Thy1.2-depleted BMT resulted in a modest antileukaemic effect. The adoptive transfer of syngeneic enriched and IL-2 preincubated NK cells given at time of BMT exerted a significantly better GVL effect. However, the infusion of allogeneic enriched NK cells resulted in a stronger GVL effect. These results clearly demonstrate that allogeneic NK cells are superior to syngeneic NK cells in their potential to eradicate residual leukaemia cells after BMT without mediating clinical overt GVHD. This experimental setting may offer a strategy for treatment of haematological malignancies in a phase of minimal residual disease.

Animals↗
PubMed1996

Graft-versus-leukaemia activity can be predicted by natural cytotoxicity against leukaemia cells.

We have investigated graft-versus-leukaemia (GVL) effects after allogeneic bone marrow transplantation (BMT), using three murine leukaemia models, A20 (B lymphocytic), WEHI-3 (myelomonocytic) and PU5-1R (myeloid). Injection of leukaemia cells in a high number (10(6) cells) into syngeneic Balb/c mice (H-2d) invariably led to death with a median survival time of 22 d (A20), 18 d (WEHI-3) and 45 d (PU5-1R). A lower tumour load of A20 (5 x 10(5) cells) was used in some experiments resulting in a leukaemic death rate of 94%. Lethal total-body irradiation followed by syngeneic BMT prolonged survival (P<0.05) for animals bearing the leukaemia A20 and WEHI-3 but was unsuccessful for animals injected with cells from the monocytic leukaemia PU5-1R. Graft-versus-host (GVH)-nonreactive marrow of (C57 x Balb/c)F1 mice (H2bxd) exerted a significant GVL-effect with reduced relapse rate and improved survival in mice receiving the leukaemia cell line A20. In animals with low tumour load a significant reduction of the relapse rate from 82% following syngeneic BMT to 47% following allogeneic, GVH-nonreactive BMT could be achieved. Depletion of natural killer (NK) cells from the GVL-reactive semi-allogenic bone marrow graft enhances the relapse rate of the leukaemia A20 to 65%. In mice bearing the leukaemias WEHI-3 or PU5-1R allogeneic GVH-nonreactive BMT did not improve survival compared to syngeneic BMT. Transplantation of GVH-reactive bone marrow from DBA mice (MHC identical to Balb/c, minor difference) caused only a limited and insignificant reduction of relapse rate for animals with the leukaemia A20. These in vivo data are in close correlation with in vitro natural killer cell (NK) activity of the donor strains against the respective leukaemia targets. Depletion of NK cells from the GVL-reactive (C57 x Balb/c)F1 bone marrow resulted in a significant loss of GVL activity. We conclude that NK cells are involved in graft-versus-leukaemia effects independent of graft-versus-host disease (GVHD).

Animals↗
PubMed1996

Allogeneic peripheral blood progenitor cells: current status and future directions.

Increasing use is being made of mobilized peripheral blood as a source of hematopoietic stem and progenitor cells for transplantation. Initially, these efforts were focused on autologous applications. However, many centers are now using cells derived from normal donors mobilized with recombinant hematopoietic growth factors for allogeneic transplantation. This article reviews the key issues associated with the use of these cells for hematologic reconstitution and summarizes important recent developments in the field.

Blood Cell Count↗
PubMed1996

High lytic activity against human leukemia cells after activation of allogeneic NK cells by IL-12 and IL-2.

IL-12 is a novel cytokine with interesting features regarding its potential usefulness in peripheral blood stem cell transplantation and leukemia immunotherapy. We used cryopreserved leukemia cells of 18 patients with acute myelogenous (n= 14) or lymphocytic (n= 4) leukemia to investigate the effect of IL-12, alone or in combination with IL-2, on the cytolytic activity of NK cells against human leukemia targets. Effector cells were peripheral blood mononuclear cells from healthy donors which were depleted from CD3+ T cells by immunomagnetic separation. CD3-negative effector cells (mainly CD56+ NK cells) were treated for 24 h with various concentrations of IL-2 (100 U/ml to 1000 U/ml) and IL-12 (1 U/ml to 100 U/ml). Cytotoxicity was measured in a 4 h 51Cr-release assay. Whereas a two-fold enhancement of cytotoxic activity was observed after incubation with optimal doses of IL-2 or IL-12, the combination of both cytokines (500 U/ml IL-2, 100 U/ml IL-12) increased the lytic activity more than six-fold. This effect was accompanied by increased expression of cellular adhesion molecules (CD2, CD18) and CD25 on CD56+ effector cells. Of 18 leukemias investigated, five were completely resistant to lysis by effector cells activated with IL-2 or IL-12 alone. In three of these five cases, however, high cytolytic activity was observed after coincubation with IL-2 and IL-12. In comparison to allogeneic NK cells, autologous cells of three patients in remission demonstrated significantly lower cytotoxic activity. No killing of nonmalignant cells (PHA blasts) by allogeneic NK cells was observed. Our data demonstrate that IL-12 can enhance or even induce MHC-unrestricted cytotoxicity of IL-2-activated allogeneic natural killer cells. Since IL-12 has also been shown to have stem-cell mobilizing capacities, it could be used for the recruitment of both stem cells and antileukemic effector cells in the context of peripheral blood stem cell transplantation.

Animals↗
PubMed1995

Leukemia-specific allogeneic donor T cells: quantification by limiting dilution assay.

Allogeneic T cells are capable of discriminating between leukemia cells and non-malignant hematopoetic cells. This has been concluded from clinical BMT data and demonstrated by in vitro experiments. We analyzed the frequency and specificity of leukemia-reactive T cells from syngeneic and allogeneic blood donors by limiting dilution assays for interleukin-2-producing (TH1) and cytotoxic (CTLp) T cells. Target cells were leukemia blasts obtained from a patient with common ALL. Control targets were generated by EBV transformation. Effector cells were generated from the peripheral blood of the patient in remission, from his syngeneic brother and from eight healthy, HLA-mismatched volunteers. The effector cells were stimulated with leukemia cells and interleukin-2. Neither the patient nor his brother were able to generate anti-leukemic CTLp or TH1. The HLA-mismatched allogeneic donors displayed anti-leukemic CTLp frequencies with a range from 0 to 68 million. TH1 cells with anti-leukemic specificity were not detectable. We conclude that there are great inter-individual differences in the GVL potential of fully allogeneic peripheral T lymphocytes. It is possible to identify T cell lines with reactivity against leukemia blasts and non-reactivity against normal hematological cells from the same individual. These cell lines are potential effector cells for immunotherapy of human leukemia.

Blood Donors↗
PubMed1995

Allogeneic mouse T cell lines distinguish three Balb/c leukemias from each other and from non-leukemic lymphocytes.

In order to separate graft-versus-leukemia (GVL) effect from graft-versus-host (GVH) reactions in allogeneic cell therapy, we established cytotoxic T cell lines (CTL) against irradiated A20, WEHI-3 and PU cells, ie cells from 3 hematopoietic tumors of Balb/c origin. Immunization with these cell lines did not lead to prolonged survival in Balb/c mice. The cytotoxic activity of the CTL was tested against the 3 leukemias. In all 9 combinations the highest specific lysis was achieved against the stimulating tumor. Cold target inhibition experiments showed that the activity against 51Cr-labelled leukemia cells could be almost completely inhibited by adding a sufficient amount of unlabelled target cells. On the other hand, when unlabelled concanavalin A-induced Balb/c blast cells were added, the inhibition was incomplete. By means of flow cytometry it was excluded that the different susceptibilities and inhibitory potentials of tumor cells and nonmalignant blasts are caused solely by differences in the MHC expression of the target cells. These findings confirm that allogeneic CTL are capable of discriminating malignant from nonmalignant cells, even if the tumor is nonimmunogenic in syngeneic animals.

Animals↗
PubMed1994

Influence of donor lymphocytes on the incidence of primary graft failure after allogeneic bone marrow transplantation in a murine model.

We used a murine model to determine the impact of donor lymphocyte subsets on the incidence of primary marrow graft failure after transplantation of lymphocyte-depleted bone marrow. After lethal irradiation with 7.5 Gy, Balb/c mice received 1 x 10(5) to 4 x 10(7) GvH-nonreactive (C57 x Balb)F1 or GvH-reactive C57Bl/6 marrow cells. Pretreatment with anti-Thy-1.2, anti-CD4/CD8, anti-asialo-GM1 or L-leucyl-L-leucine methyl ester (Leu-Leu-OMe) was employed to eliminate T lymphocytes and/or natural killer cells. Primary graft failure was defined as death with neutrophils < 0.5 x 10(9)/l. To assess long-term chimaerism, the percentage of H-2b-positive spleen cells was determined. Pretreatment with anti-Thy-1.2, anti-CD4/CD8 or Leu-Leu-OMe successfully eliminated GvHR-induced mortality. Graft failure rates gradually declined from 88% after transplantation of 1 x 10(5) cells to 0% after transplantation of 4 x 10(7) C57Bl/6 cells. The incidence of graft failure, however, was not altered by T-cell depletion, provided that the unspecific loss of marrow cells was compensated for. After transplantation of GvH-nonreactive (C57 x Balb)F1 bone marrow, neither ex-vivo treatment with anti-Thy-1.2 and anti-asialo GM1 nor addition of 1 x 10(7) donor thymocytes to the allograft significantly influenced engraftment. The data obtained in our animal model suggest that the total number of marrow cells is of critical importance for successful marrow engraftment and not the presence or absence of T cells, NK cells or GvHR.

Animals↗
PubMed1994

Induction of graft-versus-leukemia (GVL) activity in murine leukemia models after IL-2 pretreatment of syngeneic and allogeneic bone marrow grafts.

To investigate GVL effects, Balb/c mice (H-2d) received 5 x 10(5) A20 (B cell leukemia) or 1 x 10(6) WEHI-3 (myelomonocytic leukemia) cells. These cell lines lead to death after a median of 19 (WEHI-3) or 30 days (A20). A lethal dose of total body irradiation followed by syngeneic BMT resulted in significantly prolonged survival of leukemia-bearing animals. Transplantation of (C57 x Balb/c)F1 (H-2bxd) allogeneic, but GVH-non-reactive marrow grafts differentially influenced the relapse rates in the two leukemia models. Whereas allogeneic BMT reduced the relapse rates in A20-bearing mice, the leukemia-free survival was not improved in mice bearing the leukemia WEHI-3 compared with syngeneic BMT. Pre-treatment of allogeneic (C57 x Balb/c)F1 or syngeneic Balb/c marrow cells with 200 U/ml IL-2 for 24 h did not reduce relapse rates in animals inoculated with A20 leukemia cells compared with unmanipulated bone marrow. In contrast, IL-2 treatment of syngeneic or allogeneic GVH non-reactive donor marrow significantly decreased the relapse rate in mice inoculated with WEHI-3 leukemia cells. The NK cell-mediated lysis of cultured leukemia cells was determined in vitro using a conventional 56Cr-release assay. Our data revealed a strong correlation between the level of natural killer activity determined in vitro and GVL activity in vivo.

Animals↗
PubMed1993

Repeated complete remission in a patient with acute promyelocytic leukemia after treatment with 13-cis-retinoic acid first and with all-trans-retinoic acid in relapse.

The use of retinoic acid is a new approach in the treatment of acute promyelocytic leukemia. We outline the therapy in a 61-year-old patient with acute promyelocytic leukemia who had not responded to standard chemotherapy but in whom the administration of 13-cis-retinoic acid resulted in complete remission for 24 months. In relapse the patient was treated with all-trans-retinoic acid in combination with two cycles of daunorubicin and cytosine arabinoside and achieved another complete remission.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

High-dose chemotherapy and hematopoietic stem cell rescue in patients with relapsed Hodgkin's disease.

Fifty-one consecutive patients with Hodgkin's disease (HD) have been treated with high-dose chemotherapy (HDT) and transplantation of autologous bone marrow (BM) (n = 44), autologous BM plus peripheral blood stem cells (PBSC) (n = 2), PBSC (n = 1), syngeneic (n = 1), or allogeneic BM (n = 3). All patients had received standard salvage chemotherapy prior to HDT and were classified as sensitive (n = 33) or resistant (n = 17) to this treatment; one patient was in untreated relapse prior to BMT. The preparative regimens for patients receiving autologous BM and/or PBSC consisted of cyclophosphamide, VP 16, and BCNU (CVB) (n = 44) or BCNU, etoposide, ara-C, and melphalan (BEAM) (n = 3). The patients receiving allogeneic transplants were treated with the CVB regimen (n = 2) or busulfan (16 mg/kg body wt.) and cyclophosphamide (200 mg/kg body wt.). With a median follow-up of 12 months, overall survival for 44 patients grafted with autologous BM is 61% +/- 9%, progression-free survival for patients with sensitive disease is 44% +/- 11%; no patient with resistant relapse survived beyond 1 year post transplant. Two of three patients grafted with allogeneic BM still survive 15 and 24 months after BMT with Karnofsky performance scores of 70% and 100%, respectively. The main toxicity encountered with the CVB regimen was interstitial pneumonia (IP), seen in four of 15 patients (27%) receiving > or = 600 mg/m2 of BCNU. Three of these patients have died. The results show that HDT followed by hematopoietic stem cell rescue may effectively salvage an important fraction of patients with relapsed HD who respond to standard chemotherapy. The same approach is largely unsuccessful in patients with proven refractoriness to standard chemotherapy. Whether HDT followed by BMT or PBSC support is superior to intensive chemotherapy without stem cell support can be answered only by a prospectively randomized trial.

Adolescent↗
PubMed1993

Epidural anesthesia for labor in an ambulatory patient.

The effectiveness of two epidural analgesic regimens on the ability to ambulate was compared in women in labor by a prospective, randomized, double-blind design. One group of patients received epidural fentanyl, a 75-micrograms bolus and an infusion of fentanyl 2.5 micrograms/mL at 15 mL/h (FENT, n = 53). A second group received ultra low-dose bupivacaine (0.04%), epinephrine (1.7 micrograms/mL), and fentanyl (1.7 micrograms/mL) (BEF, n = 77), a 15-mL bolus followed by an infusion at 15 mL/h. Adequate analgesia was rapidly obtained in 90.6% of patients in the FENT group and 92.2% of patients in the BEF group (P = 0.89). Seventy percent of patients in the FENT group ambulated versus 68% in the other group. The BEF mixture provided analgesia of longer duration (287 +/- 171 min versus 156 +/- 72 min, P = 0.0001). The number of patients delivering during administration of only their study drug (without needing higher doses of local anesthetics) was 52% for BEF and 21% for FENT (P = 0.0005). Hip flexion weakness precluding ambulation occurred in 17% (P = 0.002) of BEF patients and orthostatic hypotension in 9% (P = 0.08). Neither problem occurred in FENT patients. Neonatal outcome was similar in both groups. Approximately 70% of women receiving epidural analgesia with fentanyl or ultra low-dose bupivacaine, epinephrine, and fentanyl may ambulate safely during labor.

Adolescent↗
PubMed1993

The influence of graft-versus-host reactivity, lymphocyte depletion, and cell dose on allogeneic bone marrow engraftment.

Graft rejection has hampered the use of T cell depletion (TCD) in allogeneic bone marrow transplantation. A model of host-versus-graft (HVGR) and graft-versus-host reaction (GVHR) as two inversely related processes has been proposed. We investigated graft rejection rates in graft-versus-host-reactive and graft-versus-host-nonreactive situations in a rat and a mouse model. Model 1: LEW rats were pretreated with a fixed myeloablative dose of busulfan and increasing doses of the immunosuppressive cyclophosphamide. The animals received different doses of semiallogeneic GvH-nonreactive BM cells. Graft rejection rates were dependent on the bone marrow cell number transplanted and on the pretransplant immunosuppression. Graft rejection rates following transplantation of GvH-reactive CAP marrow and genetically GvH-nonreactive (CAP x LEW)F1 marrow were the same. In conclusion, there was no advantage with respect to engraftment for the GvH-reactive marrow. Model 2: In irradiated Balb/c mice, graft rejection rates following T cell-depleted and unmanipulated transplantation of GvH-reactive or GvH-nonreactive bone marrow grafts were identical. All experiments were done with graded numbers of BM cells and revealed a strong impact of the BM cell dose on engraftment. In our experiments the cell loss during the ex-vivo manipulation was approximately 50% and, in contrast to the clinical situation, we readjusted to the intended number after TCD. Our experiments demonstrate that neither GvHR nor T cells but the BM cell dose has a strong impact on engraftment of allogeneic bone marrow.

Animals↗
PubMed1993

Natural killer cells as effector cells of graft-versus-leukemia activity in a murine transplantation model.

The transfer of cytotoxic effector cells reduces the risk of relapse after allogeneic BMT. Two murine leukemia cell lines, A20 (B lymphocytic) and WEHI-3 (myelomonocytic), were used to investigate antileukemic effector mechanisms operating independently from graft-versus-host disease (GVHD). Different results were obtained with the two leukemia models. After injection of A20 cells, the majority of Balb/c recipients treated with syngeneic BMT died due to leukemia relapse (89%). The transplantation of MHC-matched DBA marrow resulted in chronic GvHD but did not reduce the risk of relapse (86%). Grafting of MHC-mismatched (but GvH-nonreactive) marrow cells from (C57xBalb)F1 hybrids, however, led to a significantly lower relapse rate (47%, p < 0.05). In vitro testing revealed that F1 cells but not Balb/c or DBA cells exert NK cell activity against A20. The elimination of NK 1.1-positive cells from the graft reduced the antileukemic activity of (C57xBalb)F1 marrow against A20 in vivo. After injection of WEHI-3 leukemia cells, syngeneic BMT cured most of the recipients (62%) and transplantation of (C57xBalb)F1 marrow provided no additional benefit. In contrast to unmanipulated Balb/c and (C57xBalb)F1 cells, which showed no NK activity against WEHI-3 in vitro, IL-2 treated effector cells were highly cytotoxic. Transfer of IL-2 preincubated grafts significantly decreased the relapse rate of WEHI-3 (19 vs. 38%) after syngeneic and allogeneic BMT. Our data indicate that GvL activity can be separated from GvHD. In our murine model, GvL activity appears to depend more on the donors NK/LAK cell activity than on the presence or absence of GvHD.

Animals↗