Standardized nomenclature for inbred strains of mice: sixth listing.
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Rules for designating inbred strains of mice are presented, along with a list of strains with their origins and characteristics, a table of biochemical polymorphisms, and standard subline designations. (+info)
Inhibition of allorecognition by a human class II MHC-derived peptide through the induction of apoptosis.
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The interaction of the T-cell receptor with the major histocomatibility complex (MHC)-peptide complex is central to T-cell activation. Variation in the nature of the peptide bound within the groove of the MHC molecule may result in an altered T-cell response. Because some naturally processed peptides bound within the groove of the class II MHC molecule are derived from the MHC molecules themselves, we studied the inhibitory effects of synthetic class II MHC peptides on alloimmune responses in vitro. Three peptides derived from a highly conserved region of the class II MHC alpha chains inhibited the rat mixed lymphocyte response (MLR) in a dose-dependent manner, with the human HLA-DQA1 peptide also inhibiting the human and mouse MLR. No effect was seen on mitogen-induced T-cell proliferation. HLA-DQA1 inhibited cytolytic T lymphocyte (CTL) generation in a dose-response fashion, with no reduction in preformed CTL killing, suggesting that the inhibitory effect is targeted at CD4(+) T-cell function. Cell-cycle analysis by flow cytometry showed that restimulation of primed T cells in the presence of HLA-DQA1 resulted in increased apoptosis, whereas unstimulated cells were not affected. These data demonstrate that synthetic peptides derived from highly conserved regions of the class II MHC alpha chain can alter CD4(+) T-lymphocyte alloimmune responses in vitro, and this effect is mediated by the induction of apoptosis in activated T cells. (+info)
B cell lymphoproliferative disorders following hematopoietic stem cell transplantation: risk factors, treatment and outcome.
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Twenty-six cases of B cell lymphoproliferative disorder (BLPD) were identified among 2395 patients following hematopoietic stem cell transplants (HSCT) for which an overall incidence of BLPD was 1.2%. The true incidence was probably higher, since 9/26 of the diagnoses were made at autopsy. No BLPD was observed following autologous HSCT, so risk factor analyses were confined to the 1542 allogeneic HSCT. Factors assessed were HLA-mismatching (> or = 1 antigen), T cell depletion (TCD), presence of acute GvHD (grades II-IV), donor type (related vs unrelated), age of recipient and donor, and underlying disease. Factors found to be statistically significant included patients transplanted for immune deficiency and CML, donor age > or = 18 years, TCD, and HLA-mismatching, with recipients of combined TCD and HLA-mismatched grafts having the highest incidence. Factors found to be statistically significant in a multiple regression analysis were TCD, donor age and immune deficiency, although 7/8 of the patients with immunodeficiencies and BLPD received a TCD graft from a haploidentical parent. The overall mortality was 92% (24/26). One patient had a spontaneous remission, but subsequently died >1 year later of chronic GVHD. Thirteen patients received therapy for BLPD. Three patients received lymphocyte infusions without response. The only patients with responses and longterm survival received alpha interferon (alphaIFN). Of seven patients treated with alphaIFN there were four responses (one partial and three complete). These data demonstrate that alphaIFN can be an effective agent against BLPD following HSCT, if a timely diagnosis is made. (+info)
Feasibility of finding an unrelated bone marrow donor on international registries for New Zealand patients.
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Allogeneic bone marrow transplantation is the treatment of choice for several hematological conditions. Unfortunately, for the majority (70%) of patients an HLA-matched sibling donor is not available and a matched unrelated donor must be found if they are to proceed to allogeneic transplantation. Most of the donors on international registries are of Caucasian ethnic origin. It has been recognized that patients from certain racial groups have a reduced chance of finding an unrelated donor. This study reports the feasibility of finding an unrelated donor for our local New Zealand patients of Caucasian, New Zealand Maori and Pacific Islander ethnic origin presenting with transplantable hematological conditions at a single center. The search was performed on international registries using HLA-A,B and DR typings for our patients. Six of six and five of six matches were evaluated. We have shown that Maori and Pacific Islanders have significantly lower hit rates than Caucasians when searched for 6/6 antigen matches, but there was no significant difference between the three ethnic groups in finding a 5/6 antigen matched donor. This study supports the policy of the New Zealand Bone Marrow Donor Registry in recruiting New Zealand Maori and Pacific Islanders. (+info)
Increased risk of chronic graft-versus-host disease, obstructive bronchiolitis, and alopecia with busulfan versus total body irradiation: long-term results of a randomized trial in allogeneic marrow recipients with leukemia. Nordic Bone Marrow Transplantation Group.
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Leukemic patients receiving marrow from HLA-identical sibling donors were randomized to treatment with either busulfan 16 mg/kg (n = 88) or total body irradiation ([TBI] n = 79) in addition to cyclophosphamide 120 mg/kg. The patients were observed for a period of 5 to 9 years. Busulfan-treated patients had an increased risk of veno-occlusive disease (VOD) of the liver (12% v 1%, P =.01) and hemorrhagic cystitis (32% v 10%, P =.003). Acute graft-versus-host disease (GVHD) was similar in the two groups, but the 7-year cumulative incidence of chronic GVHD was 59% in the busulfan-treated group versus 47% in the TBI group (P =.05). Death from GVHD was more common in the busulfan group (22% v 3%, P <.001). Obstructive bronchiolitis occurred in 26% of the busulfan patients but in only 5% of the TBI patients (P <.01). Complete alopecia developed in 8 busulfan patients and partial alopecia in 17, versus five with partial alopecia in the TBI group (P <.001). Cataracts occurred in 5 busulfan-treated patients and 16 TBI patients (P =.02). The incidence of relapse after 7 years was 29% in both groups. Seven-year transplant-related mortality (TRM) in patients with early disease was 21% in the busulfan group and 12% in the TBI group. In patients with more advanced disease, the corresponding figures were 64% and 22%, respectively (P =.004). Leukemia-free survival (LFS) in patients with early disease was 68% in busulfan-treated patients and 66% in TBI patients. However, 7-year LFS in patients with more advanced disease was 17% in the busulfan group versus 49% in the TBI group (P <.01). In patients with chronic myeloid leukemia (CML) in first chronic phase, 7-year LFS was 72% and 83% in the two groups, respectively. (+info)
Transplantation of anergic histoincompatible bone marrow allografts.
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BACKGROUND: Successful allogeneic bone marrow transplantation relies on global immunosuppression or elimination of T cells. In contrast, the induction of anergy can inactivate specific sets of alloreactive T cells in the donor marrow. Previous work has shown that anergy can be induced by blocking the interaction of the B7 molecule on the surface of antigen-presenting cells with the CD28 molecule on the surface of T cells, thus preventing key signaling events essential for the activation of T cells. To investigate the feasibility of this approach with respect to transplantation of histoincompatible bone marrow, we undertook a clinical trial of ex vivo induction of anergy in T cells present in donor marrow to recipient alloantigens. METHODS: Outcomes in 12 transplant recipients were evaluated. The recipients' peripheral-blood lymphocytes were collected before myeloablation and served as alloantigen-presenting cells. To induce alloantigen-specific anergy, bone marrow from a donor mismatched with the recipient for one HLA haplotype was cocultured with irradiated cells from the recipient for 36 hours in the presence of CTLA-4-Ig, an agent that inhibits B7:CD28-mediated costimulation. After conventional myeloablation and immunoprophylaxis, the treated donor cells were transfused into the recipient. RESULTS: After the induction of anergy, the frequency of T cells capable of recognizing alloantigens of the recipient in donor marrow was sharply reduced (P<0.001), whereas the responsiveness to alloantigens from persons unrelated to the recipient or the donor was unaffected (P=0.51). In the 11 patients who could be evaluated, the haploidentical bone marrow cells engrafted. Of these 11 patients, 3 had acute graft-versus-host disease (GVHD) confined to the gastrointestinal tract. No deaths were attributable to GVHD. Five of the 12 patients were alive and in remission 4.5 to 29 months after transplantation. CONCLUSIONS: Donor bone marrow treated ex vivo to induce anergy to alloantigens from the recipient can reconstitute hematopoiesis in vivo with a relatively low risk of GVHD. (+info)
HLA-C and HLA-DQB1 compatibility in unrelated cord blood transplants.
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BACKGROUND AND OBJECTIVE: Umbilical cord blood (UCB) cells have been definitively proved to be a source of hematopoietic stem cells with repopulating capacity when transplanted into pediatric hosts with neoplastic or non-neoplastic disease. Moreover, due to the immaturity of the UCB lymphoid compartment, these transplants are usually associated with a low incidence and severity of GvHD. This clinical observation and the immaturity of the UCB lymphoid compartment justify the acceptance of UCB units which differ from their recipient by 1 or 2 HLA antigens of the six HLA A, B and DRB1 antigens conventionally typed. Whether the number and type of HLA disparities affect clinical outcome of UCB transplants has not, however, been clearly demonstrated yet. DESIGN AND METHODS: In the present study on 14 pediatric patients with high risk leukemia transplanted with UCB from unrelated donors, evaluation of HLA compatibility was extended to HLA-C and DQB1 genes and correlated to the engraftment rate and occurrence of GvHD. Conditioning regimen and GvHD prophylaxis were identical in all cases. HLA-A and B antigens were typed by serology, whereas DNA based methods were used to define HLA-C gene groups, and HLA-DRB1 and DQB1 alleles. RESULTS: Conventional HLA-A, B and DRB1 typing demonstrated that 12 recipient/donor pairs differed at one HLA locus, while 2 pairs had 2 HLA disparities. The extended HLA-typing showed that only one out of the six pairs with a different HLA-A locus had additional mismatches at HLA-C and DQB1 loci, whereas all the remaining 8 pairs, which already differed at HLA-B and/or DRB1 loci after conventional typing, had additional HLA-C and/or DQB1 mismatches (p = 0.002). By contrast, engraftment rate and occurrence of GvHD did not significantly correlate with level of HLA-mismatches even after extended HLA-typing. INTERPRETATION AND CONCLUSIONS: The present data show that additional mismatched HLA-C and/or DQB1 antigens are significantly more frequent in pairs which after conventional HLA-typing differed at HLA-B and/or DRB1 loci, than in those showing one HLA-A mismatch. This observation provides an additional criterion for selection of UCB donors with the closest HLA-match when more than one unit are available. We did not, however, observe any correlation between engraftment rate, occurrence of GvHD and degree of HLA disparities detected either by standard or extended typing. These data support the notion that certain HLA differences do not affect the clinical outcome of UCB transplants and indicate that the expensive and time consuming molecular typing of HLA-C and DQB1 loci might be avoided for UCB donor selection. (+info)
Rapamycin reverses chronic graft vascular disease in a novel cardiac allograft model.
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BACKGROUND: Chronic graft vascular disease (CGVD) in cardiac allografts has been defined as a slowly evolving vasculopathy unresponsive to conventional immunosuppression. We compared 4 rodent models of CGVD to evaluate the reproducibility of CGVD in heart allografts. Rapamycin (Rapa) and cyclosporine (CSA) were then used to treat CGVD. METHODS AND RESULTS: Hearts were harvested and placed heterotopically into allogenic recipients. CGVD scores of PVG allografts from ACI recipients treated with CSA on days 1 through 10 were significantly elevated on day 90 (n=16) compared with other models (immunosuppression used): (1) Lewis to F344 recipients (CSA), (2) Brown Norway to Lewis (FK506), and (3) DA to Wistar-Firth (methylprednisolone, azathioprine, CSA). Although delayed (day 60 to 90) CSA treatment had no effect (n=6), delayed Rapa (3 mg. kg-1. d-1 IP) reversed CGVD in PVG grafts (0.22+/-0.19 on day 90, n=6). ACI isografts showed no evidence of CGVD (n=6) at day 90. Immunohistochemistry of PVG grafts revealed perivascular infiltrates consisting of CD4(+) T cells and limited numbers of macrophages persisting up to day 90. Flow cytometry demonstrated increased levels of anti-donor antibody at day 90, which was significantly inhibited by Rapa treatment. CONCLUSIONS: PVG grafts developed a significant increase in CGVD without evidence of ongoing myocardial rejection. This CGVD appeared to be mediated by both cellular and humoral mechanisms, given CD4(+) perivascular infiltrates and increased levels of anti-donor antibody. The anti-CGVD effectiveness of Rapa during a period in which there was little myocardial cellular infiltrate supports a novel mechanism of effect such as smooth muscle or B-cell inhibition. (+info)