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Query: UMLS:C0018133 (graft-versus-host disease)
 18,032 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using limiting dilution analysis, we have detected both the generation and suppression of autocytotoxic cells following autologous or allogeneic stimulation in vitro. Assay conditions were established in which the cytotoxic response toward an allogeneic sensitizing cell was consistent with a traditional single-hit kinetic model. Under identical conditions, cytolytic activity toward autologous phytohemaglutinin-activated lymphoblasts exhibited a distinct biphasic response. At low responder cell doses, a clear autocytotoxic response was observed. However, at higher responder cell numbers, this autocytotoxic reaction disappeared. This biphasic pattern of autocytotoxicity developed after stimulation with allogeneic or autologous peripheral blood mononuclear leukocytes (PBL) or Epstein-Barr virus-transformed B cells. This pattern of response is consistent with the counterpoised actions of two distinct cell populations, an autoaggressive population and a lower frequency autosuppressor population. Autocytotoxicity was not the result of mitogenic or xenogeneic antigenic stimulation, as it was observed after stimulation with autologous PBL in autologous serum and an autologous interleukin 2 preparation. Thus, cells capable of autocytotoxicity are present in peripheral blood but at a lower frequency than allocytotoxic T lymphocytes. Furthermore, autoaggressive cells are down-regulated by an autologous suppressor population. These findings suggest that immunologic self-tolerance is, at least in part, an actively maintained condition. Disturbances in this autoregulatory network may have relevance to the pathogenesis of some autoimmune diseases and graft-versus-host disease.
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PMID:Generation and regulation of autocytotoxicity in mixed lymphocyte cultures: evidence for active suppression of autocytotoxic cells. 298 27

The cases of 13 allogeneic marrow transplant recipients who had undergone laparotomy for manifestations of severe enteritis were reviewed to determine the causes of the severe intestinal disease and to assess the relation between clinical, histologic, and microbiologic findings. Laparotomies were performed a median of 63 days (range, 11 to 273 days) after transplantation for suspected peritonitis, intestinal obstruction, or bleeding. Intestinal tissue was available from small bowel resections in nine patients, intraoperative biopsies in one, and from autopsies in three patients who died shortly after laparotomy. Widespread small bowel ulceration was present in all 13 cases. Four causes of ulceration were identified: chemoradiation toxicity (n = 2), acute graft-versus-host disease (GVHD) (n = 5), opportunistic infections superimposed on either GVHD or toxicity from chemotherapy (n = 4), and Epstein-Barr virus-associated lymphoproliferative disorder (n = 2). Intestinal infections, unrecognized before laparotomy, were due to cytomegalovirus (CMV), herpes simplex virus (HSV), adenovirus, and Torulopsis glabrata. CMV- and HSV-infected cells, often lacking diagnostic inclusions, were identified in the intestine by in situ hybridization with biotinylated DNA probes. Eleven patients died in the perioperative period, and two died 452 and 558 days after surgery of complications of chronic GVHD. Poor outcomes were related to extensive intestinal involvement, which was commonly underestimated before surgery, failure to diagnose intestinal infections early, poor marrow function, impaired immunity, and refractoriness of severe GVHD.
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PMID:Diffuse intestinal ulceration after marrow transplantation: a clinicopathologic study of 13 patients. 301 41

The incidence of malignant lymphoma after bone marrow transplant seems very low. A 31 years old patient was treated with allogeneic bone marrow transplantation for chronic myeloid leukemia; she develops 12 days after grafting a severe graft-versus-host disease (GVH) refractory to treatment with steroids and Cyclosporin A. The GVH was then treated with an anti-T lymphocyte monoclonal antibody (OKT3). The disease responded dramatically to this treatment but the GVH reappeared immediately at the end of OKT3 therapy and the patient died the 103th day after grafting. The autopsy revealed extensive lymphoid infiltrate by a monoclonal IgM K immunoblastic proliferation. After organ or bone marrow transplant, a wide spectrum of lymphoid lesions can be observed, ranging from follicular or diffuse polyclonal hyperplasia to monoclonal immunoblastic lymphoma. The criteria for monoclonality are discussed. Epstein-Barr Virus infection associated with immunosuppressive treatments play probably a major role in the occurrence of a malignant lymphoma.
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PMID:[Immunoblastic lymphoma after bone marrow graft. Apropos of a case treated by OKT3 monoclonal antibodies for an acute graft versus host reaction]. 301 60

Two patients with acute leukemia were treated with chemoradiotherapy and allogeneic bone marrow transplantation. Despite the prophylactic use of methotrexate after grafting, both patients developed severe graft-versus-host disease that was refractory to treatment with methylprednisolone. The graft-versus-host disease was then treated with a monoclonal antibody, 64.1, that reacts with a p19 antigen on human T cells. The disease responded dramatically to this treatment, but both patients subsequently developed a fatal polyclonal lymphoproliferative disorder arising in donor-derived B cells. Hybridization studies showed Epstein-Barr virus in both tumors. The combined effect of severe end-stage graft-versus-host disease and potent immunosuppressive therapy probably resulted in a progressive immunodeficiency syndrome that abrogated the T-cell-mediated surveillance mechanism that normally modulates the proliferation of Epstein-Barr-virus-infected B lymphocytes.
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PMID:Fatal Epstein-Barr-virus-associated proliferation of donor B cells after treatment of acute graft-versus-host disease with a murine anti-T-cell antibody. 608 3

T and B cells from one short-term and nine long-term patients who had received HLA-identical bone marrow transplants for aplastic anemia or hematologic malignancy were studied for their ability to synthesize immunoglobulin after in vitro stimulation with pokeweed mitogen, Herpes simplex type 1 antigen, tetanus toxoid, or Epstein-Barr virus. Purified T, OKT4, OKT8, or B cells from patients were cocultured with normal T and/or B cells in the presence of the various stimulants. Multiple regulatory defects were observed in long-term patients with and without chronic graft-versus-host disease. The lymphocytes from the long-term healthy chimeras exhibited fewer defects in their ability to regulate in vitro immunoglobulin synthesis than those of patients with chronic graft-versus-host disease. These findings suggest that the presence of chronic graft-versus-host disease delays or impairs the "rematuration" of the immune system after bone marrow grafting and that the rematurational process occurs at the clonal level.
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PMID:Functional diversity in OKT4 and OKT8 subsets from long-term survivors after HLA-identical marrow grafting. 609 85

Immunologic evaluation of two unrelated male infants with clinical and laboratory evidence of severe combined immunodeficiency (SCID) revealed T cells with a mature phenotype in the peripheral circulation of both patients although both had biopsy evidence of thymic alymphoplasia. Both had a normal number of T cells with a cytotoxic/suppressor surface marker (OKT8) but very few T helper cells (OKT4). Lymphocyte stimulation with the mitogens PHA, Con A, and pokeweed or with allogeneic cells resulted in no proliferation. However, addition of T cell growth factor, plus the phorbol ester TPA, to lymphocytes cultured with the T cell mitogen PHA did result in some proliferation of T cells. In both cases these T cells demonstrated an XX female karyotype and were probably of maternal origin. In contrast, proliferating B cells stimulated with Epstein-Barr virus demonstrated a normal XY male karyotype. The possibility that severe combined immune deficiency in these patients was the result of graft-versus-host disease induced by maternal lymphocytes is discussed.
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PMID:XX T cells and XY B cells in two patients with severe combined immune deficiency. 660 7

Costimulatory signals are absolutely required for T-cell activation after T-cell receptor/major histocompatibility complex-peptide interaction. So far, the best-known candidate essential costimulatory signal is mediated by interaction of CD28 on T cells with B7 on antigen-presenting cells. Using an allogeneic B7+ Epstein-Barr virus-transformed B-cell line as stimulator, we found that addition of a monoclonal antibody (MoAb) to B7 that efficiently blocks B7-CD28 interaction only partially inhibited proliferation and interleukin-2 (IL-2) production in primary and secondary mixed lymphocyte reactions (MLR), whereas the generation of cytotoxic T lymphocytes (CTL) was not affected. Inhibition of primary or secondary MLR-induced T-cell activation with cyclosporin A (CsA) at nontoxic concentrations also was never complete. However, the combination of CsA and anti-B7 MoAb B7-24 synergistically blocked allogeneic B cell-induced T-cell proliferation, IL-2 production, and CTL generation. These data suggest that the mere blockage of B7-CD28 interaction during allotransplantation will be insufficient to prevent rejection or graft-versus-host disease. However, low CsA concentrations, when combined with an agent blocking B7-CD28 interaction, can potentially achieve complete immunosuppression.
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PMID:Synergy between cyclosporin A and a monoclonal antibody to B7 in blocking alloantigen-induced T-cell activation. 750 79

The phenomenon of T cell allorecognition is difficult to accommodate within the framework of a T cell repertoire positively selected in the thymus, unless allorecognition results from the cross-reactions of self-major histocompatibility complex restricted T cells. Herein, we demonstrate the dual specificity of cytotoxic T lymphocyte (CTL) clones for the immunodominant Epstein-Barr virus (EBV) epitope FLRGRAYGL, presented on HLA-B8, and the alloantigen HLA-B*4402. CTL which recognized peptide FLRGRAYGL in association with HLA-B8 could be reactivated in vitro from healthy individuals who had been exposed previously to EBV, using stimulator cells expressing the cross-reacting alloantigen HLA-B*4402. Limiting dilution analysis of the alloresponse to HLA-B*4402 in eight healthy individuals revealed that HLA-B8+, EBV-sero+ donors had higher CTL precursor frequencies for alloantigen HLA-B*4402 than EBV-sero- control donors. It is surprising that the majority (65-100%) of anti-HLA-B*4402 CTL, generated in limiting dilution mixed lymphocyte reactions between responder cells from HLA-B8+, EBV-sero+ individuals and HLA-B*4402+ stimulators, also recognized the EBV CTL epitope FLRGRAYGL/HLA-B8. In contrast to previous studies showing extensive diversity in the T cell repertoire against individual alloantigens, these data demonstrate that the response to an alloantigen can be dominated by CTL cross-reactive with a single viral epitope, thus illustrating a possible mechanism for the frequent clinical association between herpesvirus exposure and graft-versus-host disease after bone marrow transplants.
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PMID:An alloresponse in humans is dominated by cytotoxic T lymphocytes (CTL) cross-reactive with a single Epstein-Barr virus CTL epitope: implications for graft-versus-host disease. 751 82

Human dendritic cells (DC) generated from CD34+ hematopoietic progenitors cultured in the presence of granulocyte macrophage colony stimulating factor (GM-CSF) and tumor necrosis factor (TNF)-alpha are related to Langerhans cells (DLC) and have been shown to induce a strong proliferation of allogeneic CD4+ T cells. The present study shows that recombinant human IL-10 (h-IL-10) inhibits the primary and secondary proliferative responses of both CD4+ and CD8+ T cells induced by allogeneic CD1a+ DLC. The alloreaction induced by DLC generated after 5-18 days of culture of CD34+ HPC was equally inhibited by h-IL-10, thus indicating that DLC were sensitive to h-IL-10 at all stages of differentiation. This is further indicated by the h-IL-10-induced inhibition of the T cell alloreaction mediated by interdigitating DC freshly isolated from tonsils. h-IL-10 specifically acted on DLC as it did not affect the proliferation induced by Epstein-Barr virus lymphoblastoid cell lines (EBV-LCL) nor that induced by immobilized anti-CD3. The inhibitory effect of h-IL-10 was not due to the production of suppressive factors by the DLC, as the addition of DLC and IL-10 did not inhibit EBV-LCL-induced T cell proliferation. Rather, the inhibition of cytokine production (IL-2, GM-CSF, TNF, IFN-gamma) observed after 24 h of co-culture may explain the inhibition of T cell DNA synthesis detected 3 days later. The h-IL-10-induced inhibition of human DC mediated alloreaction advocates considering the use of h-IL-10 in the prevention of transplant rejection and graft versus host disease, phenomena initiated by DC.
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PMID:Interleukin 10 inhibits T cell alloreaction induced by human dendritic cells. 752 90

We investigated the use of donor leukocytes for the treatment of Epstein-Barr virus (EBV) lymphoproliferative disease following T cell-depleted bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). We wanted to determine whether donor leukocyte treatment would result in altered biological responses with respect to anti-EBV lymphoma activity, donor-host chimerism and graft-versus-leukemia (GVL) responses. Three patients with CML in cytogenetic remission received < 10(6)/kg donor leukocytes for treatment of EBV lymphoproliferative disease. Lineage specific chimerism and residual leukemia detection were assessed using sensitive PCR methodologies. Following donor leukocyte treatment 1 patient had no recurrence and the other 2 had responsive EBV lymphoma. The 2 patients who were mixed T cell chimeras before treatment, remained so after treatment. Two were BCR-ABL positive by PCR before and after treatment and both developed hematologic relapse. None of the 3 patients developed acute graft-versus-host disease (GVHD) with 1 patient developing limited chronic GVHD. These data suggest that small numbers of donor T cells can eradicate EBV lymphoproliferative disease but may not alter donor-host chimerism or mediate GVL responses.
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PMID:Adoptive immunotherapy using donor leukocytes following bone marrow transplantation for chronic myeloid leukemia: is T cell dose important in determining biological response? 765 86


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