Biomedical subjects
Publications and source records attributed to R Storb.
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A phase I dose escalation trial of recombinant human macrophage colony-stimulating factor (rhM-CSF) in combination with conventional antifungal therapy was conducted in 24 marrow transplant recipients with invasive fungal infection. Daily doses ranged from 100 to 2,000 micrograms/m2/d. Toxicity, such as constitutional symptoms, directly ascribed to rhM-CSF was not observed; however, transient, dose-related thrombocytopenia was observed. Patients who received 2,000 micrograms/m2/d of rhM-CSF had a mean reduction in platelet count of 61,000/mm3 during the rhM-CSF infusion period, which was significant when compared with patients who received lower doses of rhM-CSF (P = .008). Fourteen of the 16 patients who received rhM-CSF after undergoing allogeneic bone marrow transplantation had no change in the severity of graft-versus-host disease (GVHD) while receiving rhM-CSF. One had an increase in the severity of GVHD and one had a decrease. There were no effects on neutrophil, monocyte, or lymphocyte counts. Six patients had resolution of their infections, 12 were not evaluable for response, and six did not respond. Ten patients survived 100 days after initiation of rhM-CSF and 14 died. Further trials with rhM-CSF to assess antifungal activity are indicated.
Canine granulocyte-macrophage colony-stimulating factor (caGM-CSF) was cloned and expressed to allow further investigation of GM-CSF in a large animal model. The cDNA is 850 base pairs (bp) long and encodes a peptide of 144 amino acids. The nucleotide and amino acid sequence homology between caGM-CSF and human GM-CSF (hGM-CSF) is 80% and 70%, respectively. A mammalian expression vector pCMV/CAGM was constructed and used to transfect COS cells for expression of caGM-CSF. Supernatant from transfected COS cells enriched with caGM-CSF was shown to have significant stimulating activity in granulocyte-macrophage colony forming unit (CFU-GM) assays of canine marrow. caGM-CSF, expressed from bacteria, was used to treat seven dogs at varying doses twice daily subcutaneously (sc) for 14 to 16 days. Circulating blood neutrophils and monocytes increased significantly. The increase in circulating eosinophils was variable. Thrombocytopenia developed during administration of caGM-CSF but corrected rapidly after cessation of treatment. Evaluation of survival times of 51Cr-labeled autologous platelets suggested increased consumption as the primary reason for thrombocytopenia. A species-specific GM-CSF will be a useful tool for hematologic or immunologic studies in dogs.
We report the case of a 6.5-year-old male who received an unrelated orthotopic liver transplant for hepatic failure and encephalopathy following non-A-non-B hepatitis and subsequently developed severe aplastic anemia. For treatment of his aplastic anemia, he received a successful marrow transplant from his 9-year-old genotypically HLA-identical sister following conditioning with cyclophosphamide 200 mg/kg and anti-thymocyte globulin 90 mg/kg. Significant veno-occlusive disease of the liver and graft-versus-host disease did not occur. The patient remains alive without clinical chronic active hepatitis or need for blood product therapy. His hematocrit is 36%, white blood cell count 9.7 x 10(3)/mm3, and platelet count 1.7 x 10(5)/mm3 almost 2 years after marrow transplantation.
Forty-seven patients with hematologic neoplasia received recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) by daily 2-hour infusion following allogeneic bone marrow transplantation from HLA-identical sibling donors in a phase I-II dose-escalation trial. Dose levels ranged from 30 to 500 micrograms/m2/d. At doses at or below 250 micrograms/m2/d, toxicity felt to be caused by rhGM-CSF was negligible. However, three of five patients treated with 500 micrograms/m2/d had unacceptable side effects caused by rhGM-CSF. Two different graft-versus-host disease (GVHD) prophylactic regimens were administered. Twenty-seven evaluable patients were administered regimens that did not contain methotrexate (MTX) (Group I) and reached an absolute neutrophil count of 1,000/microL by a median of day 14. In contrast, 18 patients who received GVHD prophylactic regimens containing MTX (Group II) reached an absolute neutrophil count of 1,000/microL on a median of day 20. Patients in Group I had fewer febrile days and, of those discharged, had shorter initial hospitalizations than patients in Group II. The overall incidence of severe acute GVHD (grade 2 or greater) in the rhGM-CSF-treated patients was 28% and was similar to that in historical "good risk" patients who did not receive rhGM-CSF. These preliminary data suggest rhGM-CSF is unlikely to exacerbate GVHD in HLA-identical sibling donor transplants and indicate the need for randomized trials of rhGM-CSF in allogeneic marrow transplant patients.
We have reviewed results of secondary therapy in 427 patients with acute graft-versus-host disease (GVHD) who did not have a durable satisfactory response after primary treatment. At the beginning of secondary treatment, 320 patients (75%) had rash, 252 (59%) had liver dysfunction, and 228 (53%) had gut dysfunction. Secondary treatment was with glucocorticoids (n = 249), cyclosporine (n = 80), antithymocyte globulin (n = 114), or monoclonal antibody (n = 19) either singly (n = 390) or in combination (n = 37). Parameters of GVHD severity were recorded weekly, and responses were determined according to values at the initiation of tertiary treatment or, for patients without such treatment, using values on day 29 of secondary treatment or the last recorded values before death, whichever occurred first. Minimal criteria for improvement or deterioration were defined for each organ, but no attempt was made to define liver or gut outcome if another complication such as venocclusive disease or infectious enteritis was present. Improvement or resolution of GVHD in the respective organ was seen in 45% of patients with skin disease, 25% of patients with evaluable liver disease, and in 35% of patients with evaluable gut disease. Overall complete or partial responses were seen in 40% of patients. The highest complete response rate with secondary therapy (23%) was seen when GVHD recurred during the taper phase of primary glucocorticoid treatment and was managed by increasing the dose of glucocorticoids. Multivariate analyses were performed to identify patient, disease, or treatment factors associated with likelihood of complete response or overall improvement. A similar analysis was performed to identify covariates associated with time to treatment failure (defined as initiation of tertiary therapy or death not due to relapse of malignancy). Severe dysfunction in the skin, liver, and gut at the beginning of treatment was associated both with a decreased likelihood of complete response and an increased treatment failure rate. The times to treatment failure and the proportions of patients in various response categories were similar for primary and secondary treatment, suggesting that the potential efficacy of new immunosuppressive agents for treatment of acute GVHD can be assessed meaningfully in patients who have not responded adequately to initial therapy.
Dendritic cells (DC) confer concanavalin A responsiveness to accessory cell-depleted canine lymphocytes. DC-lymphocyte cluster formation is followed by blast transformation and proliferation of lymphocytes. We investigated whether fibronectin, which is known to be involved in cell:cell interactions, might also be involved in the interaction between canine DC and lymphocytes. The addition of rabbit anti-dog fibronectin antiserum to concanavalin A-stimulated peripheral blood mononuclear cells decreased cluster formation and reduced 3H-thymidine incorporation by 57-70%. Similarly, when cell fractions, enriched for DC, were pretreated with anti-fibronectin antiserum before being added back to accessory cell-depleted lymphocytes, cluster formation was reduced and lymphocyte proliferation after concanavalin A stimulation decreased by 18-46% as measured by 3H-thymidine uptake. Ferritin-conjugated anti-fibronectin antibody was bound to the surface of DC, primarily at the dendritic processes. We conclude that fibronectin, located on the surface of canine DC, participates in the accessory cell function of these cells.
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Effective prophylaxis of acute GVHD should bring about improved patient survival by decreasing severe infections during the first 3 months after transplantation and reducing the incidence of chronic GVHD while not compromising the quality of hematopoietic engraftment or increasing the incidence of leukemic relapse by impairing the graft-versus-leukemia effect. None of the current approaches to prevention of GVHD succeed at meeting these expectations, although postgrafting immunosuppressive therapy comes closest to the ideal. The technique of T cell depletion has been very effective in reducing the incidence of GVHD, but conditioning programs must be developed that will be more successful at eliminating host immune and malignant cells. It is doubtful that this will be achieved with systemic chemotherapy and total body irradiation. Innovative approaches such as the use of monoclonal antibodies, either alone or linked to short-lived radioactive isotopes with short linear energy transfer, promise to result in less toxic but more efficient programs, not only providing better eradication of malignant disease but also ameliorating the problem of graft failure. It is conceivable, however, that it will never be possible to kill all leukemic cells with chemoradiotherapy of any form, and the graft-versus-leukemia effect may be essential. Perhaps in the future it will be possible to distinguish lymphocytes causing the graft-versus-leukemia effect from those causing GVHD, isolate them, and use them in attempts at therapy. In the meantime, postgrafting immunosuppressive drugs are used most frequently to prevent and treat GVHD, and steadily improving survival statistics can be expected.
Retroviral vectors carrying the neomycin phosphotransferase (neo) gene have been shown to confer G418 resistance to canine keratinocytes at relatively high frequency. To investigate the usefulness of keratinocytes as potential target cells for gene therapy, we used a retroviral vector (LASN) that contains both human adenosine deaminase (hADA) and neo genes. We show here that LASN-transduced canine keratinocytes expressed high levels of hADA, a human protein of therapeutic relevance. Selection of LASN-transduced keratinocytes in medium containing G418 resulted in a population of cells that expressed even higher levels of hADA, about 80-fold higher than the endogenous canine ADA level. However, the G418-selected cells had a reduced proliferative potential and altered morphology indicative of terminal differentiation. To test whether L-histidinol is more beneficial for selection of keratinocytes than G418, we constructed two retroviral vectors that contain both the neo and the histidinol dehydrogenase (hisD) genes. Cocultivation of primary keratinocytes with lethally irradiated PA317 retrovirus packaging cells that produce these vectors gave rise to 12-53% drug-resistant colonies in either G418 or L-histidinol. In contrast to G418, selection of transduced keratinocytes in L-histidinol had no apparent effect on the proliferative potential or morphology of drug-resistant cells containing the vectors. Given the utility of this selection system, two hisD-based generic constructs containing cloning sites for cDNA expression from either the retroviral promoter or from an internal human cytomegalovirus immediate early promoter were constructed. Our results suggest that hisD will be a useful selectable marker for use in studies of keratinocyte differentiation and for transfer of genes into keratinocytes for the purposes of gene therapy.
Dogs given total-body irradiation and marrow transplants from DLA-identical littermates exhibit prompt and sustained hematopoietic engraftment. However, animals given three preceding blood transfusions from the marrow donor before transplant become sensitized and reject the marrow graft. Rejection is due to exposure to polymorphic minor non-DLA histocompatibility antigens expressed on blood mononuclear cells. We sought to determine whether heat treatment would prevent blood from sensitizing recipients in this model since heating blood to 45 degrees C for 45 min abrogates the ability of blood mononuclear cells to stimulate in mixed lymphocyte culture. Three of 4 evaluable dogs given heat-treated blood before transplant rejected their marrow grafts. To prevent possible reexpression/reacquisition of mononuclear cell functional activity in vivo after transfusion, subsequent dogs were given heated blood that was additionally exposed to 2000 cGy gamma irradiation. Eight of 10 evaluable dogs given blood treated in this fashion engrafted. Unexpectedly, 9 out of 10 evaluable dogs transfused with blood treated only with gamma irradiation also engrafted. These results demonstrate that treatment of blood with gamma irradiation alone or in combination with heat prevents transfusion-induced sensitization to minor histocompatibility antigens. Results from this canine model suggest that blood products be gamma irradiated before transfusion in patients who are transplant candidates in order to prevent sensitization to minor histocompatibility antigens and reduce the risk of marrow graft rejection.
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Between February 1972 and December 1987, 192 adults (greater than or equal to 18 years old) with acute lymphoblastic leukemia were transplanted using genotypically HLA-identical marrow donors. Median patient age was 23 years. Eighty-nine patients were in marrow remission and 103 were in relapse. Conditioning regimens included chemotherapy alone (three patients) or in combination with 9.2-17.5 Gy total body irradiation (189 patients). Graft-versus-host disease (GVHD) prophylaxis consisted of methotrexate and/or cyclosporine. Seventy-nine patients developed grades II-IV acute GVHD and 28 of 122 patients who survived at least 100 days developed chronic GVHD. Relapse-free survival at 5 years was 21% for patients transplanted in first remission, 15% for those in greater than or equal to 2nd remission, and 12% for those transplanted in relapse. Patient and donor characteristics were evaluated in multivariate analyses for their effect on development of acute GVHD, survival, relapse, and relapse-free survival. An increased risk of developing acute GVHD was associated with increasing donor age. Variables significantly associated with both increased survival and relapse-free survival included transplantation in first remission, younger patient age, and not developing interstitial pneumonia. A decreased probability of relapse was associated with transplantation in first remission, male patient sex, and grades II-IV acute GVHD.
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Allogeneic marrow transplantation from an HLA-identical sibling has proven to be an effective treatment for severe aplastic anemia with restoration of normal hematopoiesis and long-term survival in 70-80% of recipients. Results are related to patient age, with improved survival in younger patients. Marrow transplantation from HLA nonidentical family and unrelated donors has been less successful and is the focus of ongoing clinical research. Graft rejection and graft-versus-host disease (GVHD) remain major problems. A number of pre- and post-transplant immunosuppressive regimens to prevent these complications continue to be studied. The risk of graft rejection is increased in patients who have been transfused before transplant, whereas the risk is decreased with the infusion of larger numbers of transplanted marrow cells. The incidence of graft rejection is 10-32% when cyclophosphamide is used alone as the pretransplant conditioning regimen. The addition of donor buffy coat cells and whole body or limited field radiation have reduced the rate of graft rejection, but increased the incidence of complications such as chronic GVHD and secondary malignancies. GVHD is an immune disorder caused by incompatibility between donor and recipient for histocompatibility antigens. Approximately 18-40% of patients experience moderate to severe acute GVHD. Previous pregnancy in female donors and increasing age of the patient are factors predictive of its development. Methotrexate and cyclosporin have been used most frequently as prophylactic immunosuppressive agents; various combinations of these drugs and prednisone are being evaluated. Symptomatic chronic GVHD occurs in approximately 25% of recipients.(ABSTRACT TRUNCATED AT 250 WORDS)
In a previous study, we reported that patients with hematologic malignancies who had received prior chest radiotherapy had a 32% risk of developing fatal interstitial pneumonia (IP) when prepared for bone marrow transplantation (BMT) with a regimen containing total body irradiation (TBI). To determine if avoidance of TBI would lessen the incidence of fatal IP, 37 patients who had received prior chest radiotherapy in excess of 2000 cGy were prepared with busulfan (BU, 4 mg/kg x 4 days) and cyclophosphamide (CY, 60 mg/kg x 2 days) followed by autologous (n = 15) or allogeneic (n = 22) BMT. Thirty-five of these patients had recurrent or refractory hematologic malignancies and most were heavily pretreated. Results were compared with the group of similar patients (n = 25) previously treated at our institution with a CY/TBI conditioning regimen. Among those treated with BU/CY, two patients (5%) developed fatal interstitial pneumonia, 12 (32%) died of other transplant related toxicities and 13 (35%) died of relapse. Seven (19%) patients remain alive and well. Among those treated with CY/TBI, eight (32%) died of pneumonia, six (24%) died of relapse, nine (36%) died of other causes and two (8%) remain alive and well. The 5% incidence of fatal interstitial pneumonitis in the chemotherapy conditioned group was significantly less than the 32% incidence in the previously treated CY/TBI group (p = 0.005). However, long-term survival and relapse probabilities were not significantly better than seen previously with CY/TBI, although a trend towards improved survival was observed in the BU/CY group. Avoidance of TBI appeared to lower the incidence of fatal pneumonitis in patients with prior chest radiotherapy.