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C Anasetti

Publications and source records attributed to C Anasetti.

At least 73 records · Page 4Linked to original sources
PubMed1999

Role of mitogen-activated protein kinases in activation-induced apoptosis of T cells.

A member of the mitogen-activated protein (MAP) kinase family, Jun N-terminal kinase (JNK), has been implicated in regulating apoptosis in various cell types. We have investigated the requirement for another type of MAP kinase, extracellular signal-regulated protein kinase (ERK) in activation-induced cell death (AICD) of T cells. AICD is the process by which recently activated T cells undergo apoptosis when restimulated through the T-cell antigen receptor. Here we show that both JNK and ERK are activated rapidly upon T-cell receptor (TCR) ligation prior to the onset of AICD. A chemical inhibitor of ERK activation, PD 098059, inhibits ERK activation and apoptosis, while JNK activation is not inhibited. This suggests that JNK activation is not sufficient for apoptosis. TCR cross-linking induces expression of the apoptosis-inducing factor, Fas ligand (FasL), and its expression correlates with ERK activation. In addition, apoptosis induced by direct ligation of the Fas receptor by anti-Fas antibody is not associated with ERK activation and is not inhibited by PD 098059. These data suggest that ERK activation is an early event during T-cell apoptosis induced by antigen-receptor ligation, and is not involved in apoptosis per se but in the expression of FasL. MAP kinase family members may be similarly involved in inducing apoptosis signals in other cell types.

Animals↗
PubMed1999

Marrow transplantation from unrelated donors for patients with severe aplastic anemia who have failed immunosuppressive therapy.

Allogeneic marrow transplantation offers curative therapy for patients with aplastic anemia. We analyzed retrospective results in 141 patients with severe aplastic anemia who received transplants between 1988 and 1995 from an unrelated volunteer donor identified through the National Marrow Donor Program (NMDP). All patients had failed one or more courses of immunosuppressive therapy. Of the patients, 121 (86%) received a radiation-containing conditioning regimen, and 20 (14%) were given chemotherapy only. Based on serologic human leukocyte antigen (HLA) typing (class I and II), 105 patients (74%) received HLA-matched marrow, and 36 (26%) received marrow mismatched for at least one HLA-A, -B, or -DR antigen. Allele-level (molecular) typing for HLA-DRB1 was available in 108 donor-recipient pairs; 77 patients received DRB -matched and 31 DRB1-mismatched transplants. All but 13% of patients were given a cyclosporine-containing regimen for graft-vs.-host disease (GVHD) prophylaxis, and 45 patients (32%) received marrow that was T cell-depleted. Among 131 evaluable patients, 116 (89%) achieved sustained engraftment and 15 (11%) did not. Among patients with engraftment, acute GVHD of grades II-IV developed in 60 patients (52%) and extensive chronic GVHD in 24 patients at risk (31%). Currently, 51 patients (36%) are surviving at 11-94 months (median 36) after transplantation. All but five have Karnofsky scores > or =80. Patients who received a serologically matched transplant fared somewhat better than did patients given a serologically mismatched transplant p = 0.03). Patients with donors matched by both serology and allele-level DRB1 typing had significantly better survival than DRB1-mismatched patients with 56 vs. 15% surviving at 3 years p = 0.001). Outcome in patients transplanted within 3 years of diagnosis was superior to that among patients transplanted with greater delay. Major causes of death were graft failure, GVHD, and infections. These data suggest that unrelated marrow transplantation offers successful therapy for a proportion of patients who have failed immunosuppressive therapy.

Adolescent↗
PubMed1999

The role of T cell costimulation by CD80 in the initiation and maintenance of the immune response to human leukemia.

Most human myeloid leukemias express both class I and class II HLA and it has been postulated that leukemia-associated peptides are presented by those molecules. It is possible, however, that leukemia cells escape the immune surveillance by lacking expression of "costimulatory" molecules required for activating the immune response. Human erythroleukemia line (HEL) has been the subject of previous detailed studies demonstrating surface expression of bona fide HLA molecules but inability to stimulate allogeneic response of proliferative or cytolytic T cells. We found that an HLA-DR+ subclone (HEL-DR+) expresses LFA-1, LFA-3, ICAM-1, ICAM-3, but neither CD80 nor CD86 on the surface. Transfection of CD80 cDNA into HEL-DR+ cells induced the allogeneic response of purified T cells from both cord blood and peripheral blood of adult donors, demonstrating that CD80 expression could lead to accessory cell-independent activation of naive T cells. Priming allogeneic peripheral blood T cells by HEL-DR+/CD80+ also lead to generation of cytotoxic T lymphocytes that lysed both HEL-DR+/CD80+ and wild type HEL-DR+ equally well, confirming CD80 expression is required only in the CTL induction phase but not in the CTL effector phase. We established and maintained alloproliferative T cell clones from adult blood by stimulation with the HEL-DR+/CD80+ line. The clones could respond not only to HEL-DR+/CD80+ line but also to the HEL-DR+ line; however, the proliferative response to HEL-DR+/CD80+ was amplified and sustained compared to the short-lived response to wild type HEL-DR+ cells. Therefore, expression of CD80 by HEL-DR+ cells was determinant both to initiate and sustain the T cell response. These experiments support the hypothesis that lack of expression of "costimulatory" molecules for T cells contributes to leukemia escape from immune surveillance, and provide preliminary data for the use of CD80 transfection in the immunotherapy of human leukemia.

Adult↗
PubMed1998

The costs and cost-effectiveness of unrelated donor bone marrow transplantation for chronic phase chronic myelogenous leukemia.

Unrelated donor transplantation prolongs survival in some patients with chronic myelogenous leukemia (CML) in chronic phase. However, there are growing concerns about the intensive resources required for this procedure given health care budget constraints. To address this issue, we conducted a study of the costs and cost-effectiveness of unrelated donor transplantation for chronic phase CML. The costs of transplantation were derived from 157 patients from the Brigham and Women's Hospital (BWH) and the Fred Hutchinson Cancer Research Center (FHCRC). Estimates of the effectiveness of transplantation were taken from our previous work using data from the International Bone Marrow Transplant Registry and the National Marrow Donor Program. The median cost of the first 6 months of care including donor identification, marrow collection, patient hospitalization for transplantation and all outpatient medications and readmissions through 6 months postmarrow infusion was $178,500 (range, $85,000 to $462,400) and the mean was $196,200. Mean costs for patients surviving beyond 6 months posttransplant were significantly lower than for patients dying within that period ($189,700 v $211,000, respectively, P =.03). Posttransplant follow-up costs were high for months 6 to 18, then decreased. The incremental cost-effectiveness of transplantation within 1 year of diagnosis versus -interferon therapy without transplant in the base case of a 35-year-old patient was $51,800/quality-adjusted life year (QALY) gained. Sensitivity analysis showed that most ratios were between $50,000 to $100, 000/QALY or within the intermediate zone of acceptable cost-effectiveness ratios.

Adolescent↗
PubMed1998

Optimizing outcome after unrelated marrow transplantation by comprehensive matching of HLA class I and II alleles in the donor and recipient.

In unrelated marrow transplantation, the benefit of matching class II HLA-DRB1 and DQB1 alleles of the donor and recipient is well documented. Little is known about the clinical relevance of matching for class I HLA-A, B, and C alleles. We used DNA-amplification methods to identify the HLA-A, B, and C alleles of 300 patients and their donors. The incidence of graft failure was correlated with multiple class I mismatching in the donor. The risk of grades III-IV acute graft-versus-host disease was highest with class II mismatching in the recipient. Mismatching for a single class I or class II allele had no effect on survival, but mortality was increased by mismatching for more than one class I allele and by simultaneous mismatching for class I and class II alleles. We conclude that matching HLA class I and class II alleles of the donor and recipient can improve outcome after unrelated marrow transplantation.

Alleles↗
PubMed1998

Bone marrow transplantation for children less than 2 years of age with acute myelogenous leukemia or myelodysplastic syndrome.

We analyzed results of 40 infants less than 2 years of age who received bone marrow transplants (BMT) between May 1974 and January 1995 for treatment of acute myelogenous leukemia (AML; N = 34) or myelodysplastic syndrome (MDS; N = 6) to determine outcome and survival performance. Among the AML patients, 13 were in first remission, 9 were in untreated first relapse or second remission, and 12 were in refractory relapse. Patients were conditioned with cyclophosphamide in combination with either total body irradiation (TBI; N = 29) or busulfan (N = 11). Source of stem cells included 6 autologous donors, 15 HLA genotypically identical siblings, 14 haploidentical family members, and 5 unrelated donors. Graft-versus-host disease (GVHD) prophylaxis was methotrexate (MTX) for 17, MTX plus cyclosporine (CSP) for 14, or CSP plus prednisone for 3. Incidence of severe (grade 3-4) regimen-related toxicity was 10% and transplant-related mortality was 10%. Acute GVHD (grades II-III) occurred in 39% of allogeneic patients, and chronic GVHD developed in 40%. Relapse, the most significant problem for patients in this study, occurred in 1 MDS patient and 23 AML patients and was the cause of death for 19 patients. The 2-year probabilities of relapse are 46%, 67%, and 92%, respectively, for patients transplanted in first remission, untreated first relapse or second remission, and relapse. One MDS and 8 AML patients received second marrow transplants for treatment of relapse, and 5 of these survive disease-free for more than 1.5 years. All 6 MDS patients and 11 of 34 AML patients survive more than 1.5 years later. The 5-year probabilities of survival and disease-free survival are 54% and 38% for patients transplanted in first remission and 33% and 22% for untreated first relapse or second remission. None of the patients transplanted with refractory relapse survive disease-free. Outcome was significantly associated with phase of disease at transplantation and pretransplant diagnosis of extramedullary disease. Long-term sequelae included growth failure and hormonal deficiencies. Survival performance was a median of 100% (80% to 100%) and neurologic development for all survivors was appropriate for age. This study indicates that infants with AML have similar outcome after BMT compared with older children and that BMT should be performed in first remission whenever possible. In addition, allogeneic BMT provides effective therapy for the majority of infants with MDS.

Acute Disease↗
PubMed1998

Decreased rejection and improved survival of first and second marrow transplants for severe aplastic anemia (a 26-year retrospective analysis).

Between 1970 and 1996, 333 patients with severe aplastic anemia underwent HLA-matched related marrow transplant after conditioning with cyclophosphamide (CY). Thirty-five percent of patients transplanted between 1970 and 1976 (group 1), 12% of those transplanted between 1977 and 1981 (group 2), and 9% of patients transplanted between 1982 and 1997 (group 3) had graft rejection. Graft rejection occurred later among group 3 patients (median, 180 days) than among those in groups 1 and 2 (medians, 28 and 47 days, respectively; P < .001 group 3 v 2). In group 3, 92% of rejecting patients underwent a second transplant, compared with 78% and 77% in groups 1 and 2, respectively. Group 1 patients received various conditioning regimens before second transplant, whereas most patients of groups 2 and 3 received CY combined with antithymocyte globulin (ATG). Graft-versus-host disease (GVHD) prophylaxis after second transplant consisted of methotrexate (MTX) for all group 1 and 2 patients, whereas group 3 patients received MTX combined with cyclosporine (CSP). Over the three time periods studied, first graft rejection decreased from 35% to 9%, and the proportion of rejecting patients undergoing second transplants increased from 77% to 92%. The 10-year probability of survival after second transplants increased from 5% to 83%. Multivariate analysis showed MTX/CSP GVHD prophylaxis to be a significant factor accounting for the increase in patient survival after second transplant.

Adolescent↗
PubMed1998

Role of CD28 in acute graft-versus-host disease.

Because CD28-mediated T-cell costimulation has a pivotal role in the initiation and maintenance of T-cell responses, we tested the hypothesis that CD28 is critical for the development of graft-versus-host disease (GVHD). We compared the in vivo effects of CD28(-/-) T cells transplanted from B6 donor with the CD28 gene deleted by homologous recombination with those of CD28(+/+) T cells transplanted from wild-type C57BL/6 (B6) donor. Fifty million CD28(-/-) or CD28(+/+) splenocytes from B6 mice were transplanted into unirradiated (B6 x DBA/2)F1 (BDF1) recipients. Unlike CD28(+/+), CD28(-/-) T cells from B6 mice had lower levels of proliferation and interleukin-2 production, had a limited ability to generate cytotoxic T lymphocytes against the recipient, and did not induce immune deficiency, despite survival in the recipient for at least 28 days. The ability to prevent rejection was reduced by the absence of CD28, because as many as 1.0 x 10(7) CD28(-/-) CD8(+) cells were needed to prevent rejection of major histocompatibility complex (MHC) class-I incompatible marrow in sublethally irradiated (550 cGy) bm1 recipients, whereas 8.0 x 10(5) CD28(+/+) CD8(+) T cells were sufficient to produce a similar effect, indicating that CD28 on donor CD8(+) cells helps to eliminate host immunity. Two million CD4(+) CD28(-/-) or CD28(+/+) T cells were transplanted into sublethally irradiated (750 cGy), MHC class-II incompatible (B6 x bm12)F1 recipients. With CD28(-/-) cells, 44% of the recipients died at a median of 20 days compared with 94% at a median of 15 days with CD28(+/+) cells (P < .001). Two million CD8(+) CD28(-/-) or CD28(+/+) T cells were transplanted into sublethally irradiated (750 cGy), MHC class-I incompatible (B6 x bm1) F1 recipients. With CD28(-/-) cells, 25% of the recipients died at a median of 41 days compared with 100% at a median of 15 days with CD28(+/+) cells (P < . 001). (B6 x bm12)F1 and (B6 x bm1)F1 mice surviving after transplantation of CD28(-/-) cells recovered thymocytes, T cells, and B cells in numbers and function comparable with that of irradiation-control F1 mice. We conclude that CD28 contributes to the pathogenesis and the severity of GVHD. Our results suggest that the severity of GVHD could be decreased by the administration of agents that block CD28 function in T lymphocytes.

Acute Disease↗
PubMed1998

Association between pretransplant interferon-alpha and outcome after unrelated donor marrow transplantation for chronic myelogenous leukemia in chronic phase.

Treatment options for patients diagnosed with chronic myelogenous leukemia (CML) in chronic phase (CP) who lack a suitable related donor for marrow transplantation include hydroxyurea, interferon-alpha (IFN-alpha), or transplantation from an unrelated donor (URD). Most studies support the view that treatment with IFN-alpha results in prolonged survival compared with hydroxyurea therapy. Some patients are offered URD transplantation as a second-line treatment; however, the impact of pretransplant IFN-alpha on the outcome of URD transplantation is uncertain. To address this question, we evaluated the effect of pretransplant IFN-alpha therapy in 184 patients undergoing URD transplantation for CML in CP at a single center. Of the 184 patients, 114 did not receive IFN-alpha, whereas 22, 23, and 25 patients received IFN-alpha for, respectively, 1 to 5, 6 to 12, and more than 12 months before transplant. Pretransplant IFN-alpha therapy administered for > or = 6 months was associated with an increased risk of severe (grades III-IV) acute graft-versus-host disease (GVHD; relative risk [RR], 3.0; 95% confidence interval [CI], 1.4 to 6.2; P = .004) and mortality (RR, 2. 1; 95% CI, 1.3 to 3.5; P = .003) relative to less than 6 months or no IFN-alpha therapy. Increased mortality occurred between 100 and 365 days after transplant (P = .005), was limited to patients with severe acute GVHD, and was due to chronic GVHD refractory to immunosuppressive therapy. Other variables associated with mortality included HLA-DRB1 or DQB1 (but not HLA-A or B) mismatched donors, age greater than 50 years, weight > or = 110% of ideal body weight, and the absence of cytomegalovirus (CMV) or fungal prophylaxis. For patients treated with IFN-alpha for less than 6 months before transplant, who were < or = 50 years of age, received a HLA-A, B, DRB1, and DQB1 matched URD transplant, and received CMV and fungal prophylaxis after transplant (n = 48), survival was 87% +/- 5% at 5 years. These data provide a rationale for immediate transplantation in preference to extended treatment with IFN-alpha when the patient is < or = 50 years of age and has an HLA-compatible unrelated volunteer donor.

Adolescent↗
PubMed1998

Unrelated and HLA-nonidentical related donor marrow transplantation for thalassemia and leukemia. A combined report from the Seattle Marrow Transplant Team and the International Bone Marrow Transplant Registry.

Allogeneic marrow transplantation is curative therapy for thalassemia, but fewer than 30% of patients have an HLA-identical sibling marrow donor. Selection of alternative donors of hematopoietic stem cells (unrelated individuals or HLA-nonidentical family members) has been aided by establishment of world-wide donor registries now exceeding 3.6 million volunteers and by DNA-based HLA typing to more closely match potential donors. Coupled with improved methods to control graft-versus-host disease and prevent fungal and cytomegalovirus infection, remarkable progress has been made in alternative donor transplantation. For patients 50 years of age or younger, with recently diagnosed chronic myelogenous leukemia (CML) in chronic phase, 1- and 5-year survivals after HLA-A, B, DRB1 identical unrelated marrow transplantation in Seattle are 82% and 74%, respectively. These results are essentially identical to outcome in similar patients given HLA-matched sibling allografts. However, the world-wide number of alternative donor transplants for thalassemia remains limited to date: 4 unrelated and 60 HLA-nonidentical related transplants have been reported to the IBMTR since 1969 with actuarial overall survival of 75%. Using the paradigm of CML, it is likely that access to curative therapy of thalassemia will improve with optimal HLA typing and donor selection early in the course of disease.

Bone Marrow Transplantation↗
PubMed1998

Expression of CD86 on human marrow CD34(+) cells identifies immunocompetent committed precursors of macrophages and dendritic cells.

Macrophages and dendritic cells derive from a hematopoietic stem cell and the existence of a common committed progenitor has been hypothesized. We have recently found in normal human marrow a subset of CD34(+) cells that constitutively expresses HLA-DR and low levels of CD86, a natural ligand for the T cell costimulation receptor CD28. This CD34(+) subset can elicit responses from allogeneic T cells. In this study, we show that CD34(+)/CD86(+) cells can also present tetanus toxoid antigen to memory CD4(+) T cells. CD86 is expressed at low levels in macrophages and high levels in dendritic cells. Therefore, we have tested the hypothesis that CD34(+)/CD86(+) cells are the common precursors of both macrophages and dendritic cells. CD34(+)/CD86(+) marrow cells cultured in granulocyte-macrophage colony-stimulating factor (GM-CSF)-generated macrophages. In contrast, CD34(+)/CD86(-) cells cultured in GM-CSF generated a predominant population of granulocytes. CD34(+)/CD86(+) cells cultured in GM-CSF plus tumor necrosis factor-alpha (TNF-alpha) generated almost exclusively CD1a+/CD83(+) dendritic cells. In contrast, CD34(+)/CD86(-) cells cultured in GM-CSF plus TNF-alpha generated a variety of cell types, including a small population of dendritic cells. In addition, CD34(+)/CD86(+) cells cultured in granulocyte colony-stimulating factor failed to generate CD15(+) granulocytes. Therefore, CD34(+)/CD86(+) cells are committed precursors of both macrophages and dendritic cells. The ontogeny of dendritic cells was recapitulated by stimulation of CD34(+)/CD86(-) cells with TNF-alpha that induced expression of CD86. Subsequent costimulation of CD86(+) cells with GM-CSF plus TNF-alpha lead to expression of CD83 and produced terminal dendritic cell differentiation. Thus, expression of CD86 on hematopoietic progenitor cells is regulated by TNF-alpha and denotes differentiation towards the macrophage or dendritic cell lineages.

Antigen Presentation↗
PubMed1998

Bone marrow transplants from unrelated donors for patients with chronic myeloid leukemia.

BACKGROUND: Chronic myeloid leukemia can be cured by marrow transplantation from an HLA-identical sibling donor. The use of transplants from unrelated donors is an option for the 70 percent of patients without an HLA-identical sibling, but the morbidity and mortality associated with such transplants have been cause for concern. We analyzed the safety and efficacy of transplants from unrelated donors for the treatment of chronic myeloid leukemia and identified variables that predict a favorable outcome. METHODS: Between May 1985 and December 1994, 196 patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase received marrow transplants from unrelated donors. RESULTS: The median follow-up was 5 years (range, 1.2 to 10.1). Graft failure occurred in 5 percent of patients who could be evaluated. Acute graft-versus-host disease of grade III or IV severity was observed in 35 percent of patients who received HLA-matched transplants, and the estimated cumulative incidence of relapse at five years was 10 percent. The Kaplan-Meier estimate of survival at five years was 57 percent. Survival was adversely affected by an interval from diagnosis to transplantation of one year or more, an HLA-DRB1 mismatch, a high body-weight index, and an age of more than 50 years. Survival was improved by the prophylactic use of fluconazole and ganciclovir. The Kaplan-Meier estimate of survival at five years was 74 percent (95 percent confidence interval, 62 to 86 percent) for patients who were 50 years of age or younger who received a transplant from an HLA-matched donor within one year after diagnosis. CONCLUSIONS: Transplantation of marrow from an HLA-matched, unrelated donor is safe and effective therapy for selected patients with chronic myeloid leukemia.

Adolescent↗
PubMed1998

Pharmacokinetics of cyclophosphamide and its metabolites in bone marrow transplantation patients.

OBJECTIVES: To characterize the pharmacokinetics of cyclophosphamide and 5 of its metabolites in bone marrow transplant patients and to identify the mechanism of the increase in 4-hydroxycyclophosphamide area under the plasma concentration-time curve (AUC) from day 1 to day 2 of cyclophosphamide administration. METHODS: Cyclophosphamide was administered by intravenous infusion (60 mg/kg over 1 hour, once a day) for 2 consecutive days to 18 patients. Cyclophosphamide and 4-hydroxycyclophosphamide concentration time data on day 1 and day 2 were fitted to a model to estimate 4-hydroxycyclophosphamide formation (CLf) and elimination (CLm) clearances. Erythrocyte aldehyde dehydrogenase-1 activity was measured ex vivo just before the first cyclophosphamide infusion was started (0 hours) and 24 hours after the second cyclophosphamide infusion (48 hours). RESULTS: From day 1 to day 2, the AUC of cyclophosphamide, deschloroethyl cyclophosphamide and phosphoramide mustard decreased 24.8%, 51%, and 29.4% (P < .02), the AUC of 4-hydroxycyclophosphamide and carboxyethylphosphoramide mustard increased 54.7% and 25% (P < .01), whereas the AUC of phosphoramide mustard was not significantly changed (P > .3). The CLf of 4-hydroxycyclophosphamide increased 60% (P < .001), its CLm decreased 27.7% (P < .001), and the fraction of cyclophosphamide dose converted to 4-hydroxycyclophosphamide increased 16% (P < .001) from day 1 to day 2. The activity of patient erythrocyte aldehyde dehydrogenase-1 decreased 23.3% (P < .02) from 0 hours to 48 hours. CONCLUSIONS: The AUC of 4-hydroxycyclophosphamide increased from day 1 to day 2 as a result of increased formation and decreased elimination clearances of 4-hydroxycyclophosphamide. Aldehyde dehydrogenase-1 activity appears to decline as a consequence of cyclophosphamide administration.

Aldehyde Dehydrogenase↗
PubMed1998

Effect of HLA matching on outcome of related and unrelated donor transplantation therapy for chronic myelogenous leukemia.

This article examines the diversity and biologic role of human lymphocyte antigen (HLA) genes as related to marrow transplantation for chronic myelogenous leukemia (CML). A better understanding of the nature and function of HLA variation is necessary as unrelated marrow transplantation evolves into a safe and effective treatment for CML. HLA matching is an important aspect of donor selection criteria and has a role in engraftment as well as the development of graft-versus-host disease and tolerance after transplant.

Bone Marrow Transplantation↗
PubMed1998

Reproducibility in retrospective grading of acute graft-versus-host disease after allogeneic marrow transplantation.

We have undertaken a formal study to evaluate the reproducibility of retrospective assessments for grading the severity of acute GVHD. Using criteria previously established by the Seattle group, three reviewers independently assigned GVHD severity grades for a set of 100 marrow transplant patients. Significant differences were found in the distribution of GVHD grades assigned by one of the reviewers as compared to the other two reviewers. In only 40% of cases did all three reviewers assign the same GVHD grade, and in only 68-71% of cases did all three reviewers assign the same grade within 0-I vs II-IV or 0-II vs III-IV categories. Despite the high rate of disagreement between any two reviewers, at least two reviewers assigned the same overall GVHD grade in 93% of cases. These results suggest that current criteria for assessing the severity of GVHD by a single reviewer are not sufficiently reliable for rigorous clinical studies. As an alternative to the original criteria, we have developed and tested simplified criteria that summarize the clinical course of GVHD as reflected by the progression of disease and the amount of immunosuppressive treatment used to control the disease. Our results suggest that the revised criteria might yield more reproducible retrospective grading than the original criteria. Although the original criteria and the revised criteria might produce different results for individual patients, the overall distributions of grades with the two systems were similar. The proposed revised criteria could be implemented without disrupting the continuity and consistency with previous grading assigned by the original criteria.

Bone Marrow Transplantation↗
PubMed1998

T cell alloreactivity induced by normal G-CSF-mobilized CD34+ blood cells.

In this study, the hypothesis that a subset of granulocyte colony-stimulating factor (G-CSF)-mobilized CD34+ blood cells may actively induce an allogeneic T cell response in vitro was tested. Circulating CD34+ cells were purified to > or =98% by high gradient magnetic separation and then analyzed for the coexpression of HLA-DR, the common beta-chain of the leukointegrin family CD18 and costimulatory molecules CD80 (B7-1) and CD86 (B7-2). These antigens were expressed on average on: 94.9 +/- 2.5%, 64.4 +/- 15.4%, 0% and 1.9 +/- 1.2% CD34+ blood cells, respectively. Irradiated CD34+ cells induced a high proliferative response of allogeneic, but not autologous, purified CD4+ and CD8+ T cells in primary mixed leukocyte culture (MLC). An average three-fold lower CD4+ and CD8+ T cell response was induced by mononuclear cells from G-CSF-treated donors. A lower frequency of allostimulating cells among mononuclear cells rather than among CD34+ cells in the apheresis was documented by limiting dilution assay (LDA). As previously observed with marrow, sorted CD34+/CD18+ cells induced the proliferation of allogeneic T cells in MLC, while CD34+/CD18- cells, which were >94% HLA-DR+ and contained both committed (CFU-C) and early (LTC-IC) hematopoietic progenitors, stimulated allogeneic T cells poorly. Three-color staining cytofluorimetry indicated that expression of CD80 and CD86 were upregulated in 6.9 +/- 4.9 and 10.7 +/- 2.6% CD34+ blood cells respectively, after 24-30 h of culture with autologous or allogeneic mononuclear cells, or with CD4+, or CD8+ T cells, but not with medium alone. Moreover, the upregulation of CD86 was observed on CD34+/CD18+ rather than on CD34+/CD18- cells after 30 h in MLC. Blocking experiments demonstrated that preincubation of stimulator and responder cells with anti-CD80 plus anti-CD86 monoclonal antibodies induced a 84 +/- 8% inhibition of CD34+ cell allostimulating activity after 6 days in primary MLC. These results suggest that G-CSF-mobilized CD34+ hematopoietic progenitors with alloantigen presenting function express CD18 and may upregulate CD80 and CD86 upon interaction with T cells. Since activation of B7 costimulatory molecules represents an active costimulatory pathway on G-CSF-mobilized CD34+ cells, the blockade of these molecules or, alternatively, the use of selected non-immunogenic CD34+/CD18- blood stem cells may represent a new strategy for reducing graft rejection and overcoming HLA barriers in allogeneic stem cell transplantation.

Antibodies, Monoclonal↗
PubMed1998

Alloantigen presenting capacity, T cell alloreactivity and NK function of G-CSF-mobilized peripheral blood cells.

In this study we addressed whether the proportion and the function of antigen presenting cells (APC), T and NK lymphocytes are modified in the apheresis product of six healthy donors who received a stem cell mobilizing treatment with glycosylated G-CSF at 10 microg/kg/day x 5 days s.c. Flow cytometry analysis showed comparable percentages of HLA-DR+, CD19+, CD86+, CD80+ and CD1a+ cells in preG-CSF-peripheral blood mononuclear cells (preG-PBMC) and after mobilization in G-PBMC, whereas the proportion of CD14+ monocytes significantly increased in G-PBMC (3+/-1% vs 17+/-8%, P = 0.003). Analysis of lymphocyte subsets in preG-PBMC and G-PBMC showed similar proportions of CD3+, CD4+, CD8+ and CD28+ T cells, but a significantly lower percentage of CD16+ (11+/-7% vs 4+/-1%, P=0.01), CD56+ (15+/-6% vs 5+/-2%, P= 0.008), CD57+ (16+/-9% vs 5+/-2%, P=0.04), CD25+ (19+/-2% vs 9+/-6%, p=0.009) and CD122+ (5+/-2% vs 2+/-1%, P = 0.05) cells in G-PBMC. Unfractionated preG-PBMC and G-PBMC were irradiated and tested in primary mixed leukocyte culture (MLC) with two HLA-incompatible responders and induced efficient alloresponses in four of six cases, whereas G-PBMC stimulated poorly in the remaining two cases. Also, in allo-MLC with irradiated G-PBMC we detected lower amounts of IFN-gamma (P = 0.04) and of IL-2 (P = 0.06) than in allo-MLC with preG-PBMC. Furthermore, freshly isolated preG-PBMC and G-PBMC from each donor exerted comparable allogeneic responses to HLA-incompatible irradiated mononuclear cells in all cases. However, G-PBMC showed no NK activity against K562 target cells at any effector:target ratio tested. These data suggest that normal G-PBMC may prevent Thl alloresponses, maintain efficient alloreactivity to HLA mismatched antigens and have impaired NK activity.

Antigen Presentation↗