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E D Thomas

Publications and source records attributed to E D Thomas.

At least 37 records · Page 2Linked to original sources
PubMed1997

Pros and cons of stem cell transplantation for autoimmune disease.

The data and discussion at this symposium have provided a most useful analysis of the autoimmune diseases and their potential for therapy by stem cell transplantation. These diseases are characterized by threat to life and particularly by chronic, painful and debilitating courses that warrant aggressive therapy. Selection of patients will be difficult because of the variable disease course and the necessity to choose patients who still have reversible disease. The safety of both autologous and allogeneic stem cell grafting has progressed to the point where, in many cases, the risks of the disease far outweigh those of transplantation. In my opinion the data presented at this symposium show that we should proceed cautiously with both autologous and allogeneic stem cell grafts. Purified stem cells, which have the advantage of being free of lymphocytes, should be used for the first series of autologous studies. These studies are attractive because of the low risk of transplant related complications but are less likely to be curative. Allogeneic grafts from perfectly matched donors have the advantage of providing a completely new immunological environment. For this reason, I believe that curative results are most probable after allogeneic stem cell engraftment. Emphasis should be on the identification of patients with HLA matched siblings. Initially, these studies will be carried out in patients with advanced disease, as was the case in the early days of transplantation for leukemia. In considering more aggressive treatment for autoimmune diseases it appears there are 3 possible approaches. First, and most conservative, is to store peripheral blood stem cells for possible future marrow rescue and then to give higher doses of immunosuppressive agents, especially in combination, to see whether there is an improvement over conventional doses. Second, for those who prefer a conservative approach to stem cell transplantation, is to give myeloablative and lymphoablative chemotherapy followed by purified (lymphocyte-free) hematopoietic stem cells. Third, and most likely to be curative, is myeloablative and lymphoablative therapy followed by stem cells from an HLA matched family member with subsequent short methotrexate and cyclosporine treatment to control GVHD. As we have heard, there are differences of opinion about whether the preparative regimen should include irradiation. It should be pointed out that total body irradiation is the most effective way to destroy lymphoid cells throughout the body. Careful monitoring of accumulating clinical results will pilot future investigation.

Animals↗
PubMed1997

Methotrexate and cyclosporine for graft-vs.-host disease prevention: what length of therapy with cyclosporine?

One hundred three patients with leukemia, aplastic anemia, or myelodysplastic syndrome were treated by marrow transplantation from genotypically HLA-identical siblings (n = 92) or HLA haploidentical family members differing for one HLA antigen on the nonshared haplotype (n = 11). To prevent graft-vs.-host disease (GVHD), they were administered postgrafting immunosuppression with a short course of intermittent methotrexate with daily cyclosporine for no more than 11 days. Customarily, we have given cyclosporine for 180 days after transplant. In the current study, we asked whether cyclosporine could be stopped earlier without affecting the risk of chronic GVHD. By day 60, patients who never had acute GVHD, or whose acute GVHD had resolved, were randomized to have cyclosporine stopped (n = 52) or continued for the usual 180 days (n = 51). Results were analyzed with a median follow-up of 9.3 years after transplant, and showed that patients in whom cyclosporine was discontinued on day 60 had a significantly more rapid onset (p = 0.001), but not a significantly higher overall incidence of chronic GVHD than those in whom the drug was stopped on day 180 (43 vs. 54%; p = 0.26). Transplant-related mortality was comparable among patients without preceding acute GVHD, regardless of when cyclosporine was discontinued (11% for both study arms). However, transplant-related mortality appeared to increase among patients with preceding acute GVHD in whom cyclosporine was stopped by day 60 (38 vs. 17%). Results suggest that cyclosporine can safely be discontinued early in patients who never had evidence of acute GVHD, while those with preceding acute GVHD would benefit from a longer course of the drug. Because of the relatively small sample sizes, these results would best be treated as promising preliminary findings that should be confirmed in larger randomized studies.

Adult↗
PubMed1995

Bone marrow transplantation from bench to bedside.

Marrow grafting, now more appropriately called hematopoietic stem cell grafting, has come a long way from early bench studies and desperate bedside therapeutic attempts in terminal patients. Grafting of hematopoietic stem cells is now standard therapy for selected diseases and stages of disease, and increasing application on an outpatient basis is rapidly lowering the cost of the procedure. The combined efforts of the now many clinical marrow transplant teams and the interested basic science laboratories will undoubtedly make the coming decade an exciting and productive time for science and for the well-being of patients with otherwise incurable diseases.

Animals↗
PubMed1995

Reconstitution of cellular immunity against cytomegalovirus in recipients of allogeneic bone marrow by transfer of T-cell clones from the donor.

BACKGROUND: Cytomegalovirus (CMV) disease in immunocompromised patients correlates with a deficiency of CD8+ cytotoxic T lymphocytes specific for CMV. We evaluated the safety and immunologic effects of immunotherapy with clones of these lymphocytes in recipients of allogeneic bone marrow transplants. METHODS: Clones of CD8+ cytotoxic T cells specific for CMV proteins were isolated from the blood of bone marrow donors. Fourteen patients each received four intravenous infusions of these clones from their donors beginning 30 to 40 days after marrow transplantation. The reconstitution of cellular immunity against CMV was monitored before and during the period of infusions and for up to 12 weeks after the final infusion. The rearranged genes encoding the T-cell receptor served as markers in evaluating the persistence of the transferred T cells. RESULTS: No toxic effects related to the infusions were observed. Cytotoxic T cells specific for CMV were reconstituted in all patients. In vitro measurements showed that cytotoxic activity against CMV was significantly increased (P < 0.001) after the infusions in 11 patients who were deficient in such activity before therapy. The level of activity achieved after the infusions was similar to that measured in the donors. Analysis of rearranged T-cell-receptor genes in T cells obtained from two recipients indicated that the transferred clones persisted for at least 12 weeks. Cytotoxic-T-cell activity declined in patients deficient in CD4+ T-helper cells specific for CMV, suggesting that helper-T-cell function is needed for the persistence of transferred CD8+ T cells. Neither CMV viremia nor CMV disease developed in any of the 14 patients. CONCLUSIONS: The transfer of CMV-specific clones of CD8+ T cells derived from the bone marrow donor is a safe and effective way to reconstitute cellular immunity against CMV after allogeneic marrow transplantation.

Adolescent↗
PubMed1995

1994 Consensus Conference on Acute GVHD Grading.

Grading acute graft-versus-host disease (GVHD) is usually based on quantification of rash, serum bilirubin and diarrhea. Standard criteria have been developed and used for > 20 years by most transplant centers. However, neither the standard GVHD grading system nor any of several revisions has been validated in the context of GVHD prophylaxis with cyclosporine. The 1994 Consensus Conference on Acute GVHD Grading held in Keystone in January 1994 provided an opportunity to: (1) review data regarding these standard criteria; (2) determine if there are sufficient data to revise these criteria; and (3) develop recommendations for reporting results of GVHD prevention trials. Data were provided for 8249 patients from 12 large transplant centers and 2 transplant registries. Standard GVHD grading criteria were found to distinguish different mortality risks and treatment response rates. Analysis of new data suggested that persistent nausea with histologic evidence of GVHD but no diarrhea be included as stage 1 gastrointestinal GVHD. Additional studies were recommended to evaluate heterogeneity of outcome within GVHD grades prior to making further revisions. To improve comparability between publications, reports of GVHD prevention trials should include an accurate description of the grading system used and should report actuarial rates of grades II-IV and III-IV GVHD corrected for graft failure and potential interventions for early relapse. Additional information should include indications for therapy of GVHD and response.

Acute Disease↗
PubMed1994

Marrow transplantation for patients in accelerated phase of chronic myeloid leukemia.

The records were reviewed of 58 patients receiving transplants in Seattle with unmanipulated marrow from HLA-identical siblings during the accelerated phase (AP) of chronic myeloid leukemia. Variables examined for association with survival and relapse included the interval from diagnosis to transplant, the reasons for categorization as AP, age, regimen, and cytomegalovirus serology. Four patients relapsed. The 4-year probabilities of survival, relapse-free survival, nonrelapse mortality, and relapse were 0.49, 0.43, 0.51, and 0.12, respectively. After completion of the stepwise multivariate analysis, age less than 38 years and categorization as AP solely on the basis of chromosomal abnormalities emerged as being independently significantly associated with improved survival. The 4-year probability of survival for the 16 patients categorized as AP because of chromosomal abnormalities and receiving transplant less than 1 year from diagnosis was 0.74. The low probability of relapse in these patients suggests that more aggressive preparative regimens are not indicated for patients receiving transplants in AP because of the increased risk of transplant-related mortality.

Acute Disease↗
PubMed1994

Marrow transplantation for chronic myeloid leukemia: a randomized study comparing cyclophosphamide and total body irradiation with busulfan and cyclophosphamide.

A prospective randomized study was conducted comparing two conditioning regimens for the treatment of patients with chronic myeloid leukemia in chronic phase by marrow transplantation from HLA identical siblings. Sixty-nine patients received 60 mg/kg of cyclophosphamide on each of 2 successive days followed by 6 fractions of total body irradiation each of 2.0 Gy (CY-TBI), and 73 patients received 16 mg/kg of busulfan delivered over 4 days followed by 60 mg/kg CY on each of 2 successive days (BU-CY). There was no significant difference between the CY-TBI and the BU-CY groups in the 3-year probabilities of survival (0.80 for both), relapse (0.13 for both), or event-free survival (CY-TBI, 0.68; BU-CY, 0.71) or in speed of engraftment or incidence of venocclusive disease of the liver. The 4-year probabilities of survival and event-free survival for patients transplanted within 1 year of diagnosis were 0.86 and 0.72, respectively, for each group. Significantly more patients in the CY-TBI group experienced major creatinine elevations. There was significantly more acute graft-versus-host disease in the CY-TBI group. Fever days, positive blood cultures, hospitalizations, and inpatient hospital days were significantly more common in the CY-TBI group than in the BU-CY group. In conclusion, the BU-CY regimen was better tolerated than, and associated with survival and relapse probabilities that compare favorably with, the CY-TBI regimen.

Adolescent↗
PubMed1994

Stem cell transplantation: past, present and future.

Attempted human allogeneic marrow transplants in the 1950s and 60s were largely unsuccessful. In the past two decades the probability of success has improved steadily depending on the type and stage of disease. Cure rates range from about 90% for nonmalignant diseases transplanted early to 15% for patients with advanced leukemia. Most marrow transplants have involved an HLA matched sibling donor but, more recently, through the National Marrow Donor Program, a matched unrelated volunteer marrow donor can be found for many patients without a family donor. Current research involves new preparative regimens for elimination of malignant cells, better prevention of graft-versus-host disease, and the use of hematopoietic growth factors and cytokines. Autologous transplants, which use the patient's own marrow, are increasing. The hematopoietic stem cell, which is responsible for marrow regeneration after a transplant, has been isolated and characterized. Stem cells for transplantation can now be obtained from the peripheral blood after mobilization of these cells by chemotherapy or hematopoietic growth factors. A variety of technological advances makes it possible to perform transplants with less time in the hospital and a corresponding saving in cost.

Cytokines↗
PubMed1993

The effects of daily recombinant human granulocyte colony-stimulating factor administration on normal granulocyte donors undergoing leukapheresis.

The effects of daily administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) to eight normal volunteers donating granulocytes for neutropenic relatives undergoing marrow transplantation were studied. Granulocyte donors consisted of seven marrow donors (5 syngeneic, 2 HLA identical) and one haploidentical son who had not donated marrow. All donors were administered daily rhG-CSF at a mean dose of 5 micrograms/kg/d (range 3.5 to 6.0) for a mean of 11.75 days (range 9 to 14 days), and granulocytes were collected a mean of 7.6 times (range 4 to 12). RhG-CSF was well tolerated and only minor side effects were observed. All donors became anemic from marrow donation and the removal of red blood cells during the collection procedures. Red blood cell transfusions were not given. All donors had a decrease in platelet counts and the magnitude of the decrement appeared to be greater than in historical donors. This was due in part to increased removal of platelets with the collection product, but a direct effect of rhG-CSF on platelet production cannot be excluded. The mean precollection granulocyte level was 29.6 x 10(9)/L (range 11.8 to 79.8), which was a 10-fold increase over baseline. The mean number of granulocytes collected was 41.6 x 10(9) (range 1.3 to 144.1), which was a six-fold increase over historical donors not receiving rhG-CSF. The mean granulocyte level 24 hours after transfusion into neutropenic recipients was 0.95 x 10(9)/L (median 0.57 and range .06 to 9.47). This study indicates that rhG-CSF is safe to administer to normal individuals, significantly improves the quantity of granulocytes collected, and results in significant circulating levels of granulocytes in neutropenic recipients. Further studies to evaluate rhG-CSF in normal granulocyte donors are warranted.

Adult↗