Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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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)

Chronic graft-versus-host disease (GVHD) continues to be the major problem in the long-term survivors of allogeneic hematopoietic stem cell transplants. Because of its similarities to autoimmune disease, the pathogenesis of chronic GVHD has been thought to differ from acute GVHD. Autoreactive T lymphocytes are an important effector mechanism with interferon gamma playing a central role in the increased collagen deposition that is the central histopathologic feature of chronic GVHD. Therapies that prevent the development of acute GVHD have been unsuccessful in the prevention of chronic GVHD. None of the present therapies for established chronic GVHD are successful in the majority of patients.
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PMID:Chronic graft-versus-host disease. 951 98

Bone marrow transplantation (BMT) is now becoming a powerful strategy for the treatment of patients with autoimmune diseases. Using various animal models for autoimmune diseases, we have previously found that allogeneic BMT (not autologous BMT) can be used to treat autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), immune thrombocytic purpura, insulin-dependent diabetes mellitus (IDDM), chronic glomerulonephritis, and certain types of non-insulin-dependent diabetes mellitus. In contrast, we have found that the transplantation of T-cell-depleted bone marrow cells or partially purified hemopoietic stem cells (HSCs) from autoimmune-prone mice to normal mice leads to the induction of autoimmune diseases in the recipients. These findings have recently been confirmed even in humans; autoimmune diseases such as RA, SLE, multiple sclerosis, and Crohn's disease were resolved after allogeneic BMT. However, there have recently been reports on the rapid recurrence or persistence of autoimmune diseases after autologous BMT. Conversely, the adoptive transfer of autoimmune diseases such as myasthenia gravis, IDDM and Graves' disease by allogeneic BMT from donors to recipients has been reported. Based on these findings, we have proposed that autoimmune disease is 'a stem cell disorder'. To clarify the differences between normal and abnormal HSCs, we have established a new method for purifying HSCs. Using this method, we purified HSCs from normal and autoimmune-prone mice and compared the former with the latter. We have found that a major histocompatibility complex (MHC) restriction exists between normal HSCs and stromal cells, whereas there is no MHC restriction between abnormal HSCs and stromal cells either in vivo or in vitro; abnormal HSCs proliferate even in allogeneic environments. Abnormal HSCs thus appear to be more resilient than normal HSCs. In humans, BMT across MHC barriers has had a low success rate as a consequence of (1) graft-versus-host disease (GVHD), (2) graft rejection and (3) incomplete recovery of T cell functions. However, we have found that such problems can be overcome in mice. GVHD can be prevented if T-cell-depleted bone marrow cells are used. Graft rejection can be prevented by bone grafts to recruit donor stromal cells, since, as we have found, an MHC restriction exists between HSCs and stromal cells. In addition, we have found that stromal cells migrate from the bone marrow to the thymus, where they become engaged in positive selection. Therefore, the bone grafting to recruit donor stromal cells leads to a complete recovery of T cell functions, since T cells, which are positively selected by donor stromal cells in the thymus, can cooperate with donor B cells and antigen-presenting cells. In humans, it is well known that the success rate of BMT in patients more than 45 years old is low. Recently, we have found that the low success rate is due to the aging of the thymus, and that BMT plus embryonal thymus grafts can be used to treat late-onset autoimmune diseases in MRL/+ mice. Based on these findings, we would like to suggest that the transplantation of the embryonal thymus in conjunction with BMT will become a valuable strategy for treating older patients with various intractable diseases, including autoimmune diseases. We believe that similar conditions (to permit successful allogeneic BMT) to those in mice will be realized in humans in the near future.
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PMID:Bone marrow transplantation for autoimmune diseases. 958 93

Immunotoxins (ITs) are potent cytotoxic agents used in the treatment of cancer, autoimmune disease, and graft-versus-host disease. Results from clinical trials demonstrate that many IT-treated patients, especially those with an intact immune system, develop anti-IT antibodies that may prohibit repeated IT dosing. We, therefore, evaluated a panel of novel immunosuppressive (IS) agents for their ability to inhibit the antitoxin immune response in mice receiving multiple courses of a ricin A chain (RTA)-containing IT and also assessed whether this suppression would result in an increase in IT-mediated antitumor activity. The results indicate that a 3-day pretreatment, plus one additional boost 2 weeks later, of a combination of hCTLA4Ig + anti-CD40L, virtually eliminated the anti-RTA response in normal mice receiving six weekly injections of an IT. When tested in BCL1 tumor-bearing mice, the concomitant use of a combination of hCTLA4Ig + anti-CD40L and six doses of the IT resulted in a 1.5-fold increase in tumor cell killing, as compared with treatment with IT alone. We conclude that a combination of IS + IT therapy should facilitate the administration of multiple courses of IT, as well as enhance its antitumor activity.
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PMID:Effect of immunosuppressive agents on the immunogenicity and efficacy of an immunotoxin in mice. 960 90

Cyclosporin A (CsA), a potent inhibitor of T-cell activation, has been shown to have several effects on thymocyte maturation, thymic stromal cells, and the generation of autoreactive T cells. In Lewis rats, the combination of lethal irradiation, syngeneic bone marrow transplantation, and a 4-week course of CsA administration causes the development of an autoimmune disease (CsA-AI) resembling allogeneic graft-versus-host disease. This occurs upon withdrawal of CsA, provided the thymus receives irradiation and is present during CsA treatment. In this study, the separate effects of irradiation or CsA treatment on thymic stromal cells and thymocytes, compared to the combinatory effects, were examined using immunohistochemistry and tricolor flow cytometric analysis. CsA treatment causes an involution of the thymic medulla and a strong reduction of the cell number of thymocytes and stromal cells residing in the medulla. However, within the remaining medullary area, changes in cell distribution and antigen density on these cells were not observed. Irradiation on the other hand causes a strong depletion of thymocytes. The thymocyte population is recovered within 2 weeks and a cortical and medullary region can be distinguished. CsA treatment in combination with irradiation results in a strongly inhibited recovery of the medulla during CsA treatment, whereas the cortex recovers to normal size and morphology. The presence of the medullary IDC and epithelial cells is reduced proportionally to the small size of the medulla. However, the distribution of these stromal cells is normal. During the CsA administration, the thymuses from irradiated and CsA-treated rats are very similar to thymuses from CsA-treated rats. In conclusion, no changes specific for irradiation plus CsA treatment have been observed. Regarding the distribution and size of medullary stromal cells and residing thymocytes, thymuses from irradiated and CsA-treated rats hardly differ from the thymuses from rats treated only with CsA. Therefore, irradiation seems essential in the generation of CsA-AI by eliminating suppressor-cell circuits in the periphery.
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PMID:Differential effects of X-irradiation and cyclosporin-A administration on the thymus with respect to the generation of cyclosporin-A-induced autoimmunity. 970 Mar 62

Autoantibodies to CRP were reported previously in patients suffering from toxic oil syndrome. This syndrome resembles autoimmune diseases such as systemic lupus erythematosus (SLE) or systemic scleroderma. We therefore examined the prevalence of antibodies to CRP and other acute-phase proteins in autoimmune diseases, including SLE, subacute cutaneous lupus erythematosus (SCLE), systemic scleroderma (SSc), and primary biliary cirrhosis (PBC), as well as in bone marrow transplantation-induced chronic graft-versus-host disease and eosinophilia-myalgia syndrome. IgG antibodies to CRP were found in 78% of SLE and in 30% of SCLE patients, while 16% of patients with PBC were positive. In up to 45% of patients with SSc predominantly IgG antibodies to ceruloplasmin were detectable. Lack of systemic involvement as in discoid lupus erythematosus and localized scleroderma (morphea) correlated with low or absent antibody formation. However, no correlation was found between anti-acute-phase protein antibodies with liver disease or other organ involvement. Adsorption studies revealed that non-native epitopes on the CRP molecule, termed modified CRP, are the main target of antibodies. Chronic inflammatory tissue injury in systemic autoimmune disease might increase the presentation of cryptic epitopes of CRP to the threshold required for T cell activation.
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PMID:Autoantibodies to C-reactive protein (CRP) and other acute-phase proteins in systemic autoimmune diseases. 973 58

A77 1726 is a malononitrilarnide (MNA) and the active metabolite of leflunomide. Leflunomide has been extensively investigated and shown to be a potent immunosuppressive drug. However, the half-life of A77 1726 is about 15-18 days in humans and the leflunomide is, therefore, currently being evaluated for the treatment of autoimmune disease and not for transplantation. The search for analogues has led to the development of MNA 715 and 279, derivatives of A77 1726. Previous limited experimental experience has shown these MNAs to prevent skin allograft and xenograft rejection and graft-versus-host disease in rodents, and to reverse ongoing allograft rejection. The aim of the present study was to verify the efficacy of these MNAs in a cardiac retransplant model of sensitized rats, concerning prevention of accelerated rejection, inhibition of antibody production and interaction with cyclosporin A (CsA). Heterotopic cardiac transplantation and retransplantation in Dark Agouti (DA) to Piebald Virol Glaxo (PVG) rats was used. Subgroups of rats were given either CsA, MNA 715, MNA 279 or combined CsA/MNA for 10 days starting either day 0 or day -1, as of regrafting or no treatment. Titres of allospecific IgM and IgG were quantitated by flow cytometry. Ten days of MNA 715 or 279 from day -1 prevented accelerated rejection of the retransplant, as did CsA. Neither treatment given from day 0 prevented rejection within 24 h. However, a combination of MNA 715 or 279 and CsA from day 0 effectively prevented accelerated regraft rejection. Production of specific alloantibodies was reduced in all immunosuppressed subgroups, IgG titres at day 7 in MNA-treated subgroups being significantly lower compared with those in the CsA-treated subgroup. In conclusion, MNA 715 and 279 were shown to be potent immunosuppressants with the capacity to prevent accelerated regraft rejection in rat cardiac transplants, most efficiently in combination with CsA, and to suppress specific alloantibody production.
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PMID:Malononitrilamides 715 and 279 prevent accelerated cardiac allograft rejection synergistically with cyclosporin A in presensitized rats. 977 97

BMT can both transmit and eliminate autoimmune diseases, and hence it has been suggested as an optional treatment for severe autoimmune conditions. In this communication we deal with the question of whether chronic GVHD is an autoimmune disease in itself, review the literature reports of autoimmune diseases following BMT in humans, and describe the autoimmune nature of the post-BMT state. Chronic GVHD, which is a frequent complication post-BMT, has clinical and pathogenic characteristics similar to autoimmune diseases, such as scleroderma and Sjogren's syndrome. Although the pathogenesis of chronic GVHD is not yet clear, thymic damage induced by acute GVHD may contribute to both the immunodeficiency and autoimmunity characterising chronic GVHD. A similar phenomenon is syngeneic GVHD, which results from an imbalance between autoreactive and autoregulatory lymphocytes. Additionally, other autoimmune diseases have been reported in post-BMT patients, and among these the most common are hypothyroidism, hyperthyroidism, myasthenia gravis and immune cytopenias. Although these diseases also occur also outside the post-BMT setting, they are unique with respect to pathogenesis (no association between myasthenia gravis and thymic pathology), diagnosis (symptoms of hyperthyroidism may be inadvertently related to other conditions), and prognosis (post-BMT autoimmune cytopenias may be fatal and treatment non-responsive). Nevertheless, many other autoimmune diseases have been reported after BMT, and these are mainly presented as case reports. Regarding the mechanism of post-BMT autoimmunity, the minority of cases stem from donor-related transfer of pathogenic lymphocytes or their progenitors, while most of the cases (either chronic GVHD or specific diseases) can be attributed to the immunologic imbalances characterising the post-BMT setting. The factors that may expose an individual to autoimmunity development post-BMT include genetic predisposition, an environmental factor such as CMV, and the nature of the donor who may aid in creating microchimerism and subsequently chronic GVHD and its related autoimmune manifestations.
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PMID:Autoimmune diseases and autoimmunity post-bone marrow transplantation. 982 15

Type I diabetes is a systemic autoimmune disease. Although transplantation of pancreatic tissues restores glucose homeostasis, grafts are affected by acute and chronic rejection as well as re-occurrence of autoimmune destruction. One newly recognized promising strategy to interrupt these detrimental processes is hematopoietic chimerism induced by bone marrow transplantation (BMT). The application of hematopoietic chimerism has three domains in the treatment of Type I diabetes mellitus: (1) tolerance induction to pancreas or pancreatic islet grafts; (2) prevention of the re-occurrence of autoimmune processes in the graft; (3) prevention of the onset of overt diabetes once the pre-diabetic state is clearly identified. Unfortunately, conventional BMT is associated with significant morbidity and mortality due to graft-versus-host disease (GVHD), failure of engraftment and lethal conditioning. The risk of these complications cannot be justified in the treatment of non-malignant diseases including Type I diabetes. This chapter will outline potential strategies to achieve hematopoietic chimerism without the risk of deadly complications. With these strategies, it may be possible to apply hematopoietic chimerism in the treatment of Type I diabetes, both to induce tolerance to islet allografts as well as to intervene and interrupt the autoimmune process in its early stages.
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PMID:Tolerance induction for islet transplantation. 986 69

A 41-year-old woman received a syngeneic BMT for CLL and subsequently developed acute skin GVHD. Transfusion-related allogeneic GVHD was excluded on the basis of an unchanged HLA type in circulating lymphocytes. Short tandem repeat PCR was used to confirm syngeneicity between donor and recipient. The patient had a personal and family history of autoimmune disease which may have made her particularly susceptible to development of syngeneic GVHD. The distinction between allogeneic and syngeneic or autologous GVHD is important because of therapeutic implications.
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PMID:Acute skin GVHD following syngeneic BMT for CLL. 989 25

Fetal CD34(+) CD38(+) cells have recently been found to persist in maternal peripheral blood for many years after pregnancy. CD34(+) CD38(+) cells are progenitor cells that can differentiate into mature immune-competent cells. We asked whether long-term fetal microchimerism occurs in T lymphocyte, B lymphocyte, monocyte, and natural-killer cell populations of previously pregnant women. We targeted women with sons and used polymerase chain reaction for a Y-chromosome-specific sequence to test DNA extracted from peripheral blood mononuclear cells (PBMC) and from CD3, CD19, CD14, and CD56/16 sorted subsets. We also asked whether persistent microchimerism might contribute to subsequent autoimmune disease in the mother and included women with the autoimmune disease scleroderma. Scleroderma has a peak incidence in women after childbearing years and has clinical similarities to chronic graft-versus-host disease that occurs after allogeneic hematopoietic stem-cell transplantation, known to involve chimerism. Sixty-eight parous women were studied for male DNA in PBMC and 20 for PBMC subsets. Microchimerism was found in PBMC from 33% (16 of 48) of healthy women and 60% (12 of 20) women with scleroderma, P =.046. Microchimerism was found in some women in CD3, CD19, CD14, and CD56/16 subsets including up to 38 years after pregnancy. Microchimerism in PBMC subsets was not appreciably more frequent in scleroderma patients than in healthy controls. Overall, microchimerism was found in CD3, CD19, and CD14 subsets in approximately one third of women and in CD56/16 in one half of women. HLA typing of mothers and sons indicated that HLA compatibility was not a requirement for persistent microchimerism in PBMC subsets. Fetal microchimerism in the face of HLA disparity implies that specific maternal immunoregulatory pathways exist that permit persistence but prevent effector function of these cells in normal women. Although microchimerism in PBMC was more frequent in women with scleroderma than healthy controls additional studies will be necessary to determine whether microchimerism plays a role in the pathogenesis of this or other autoimmune diseases.
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PMID:Long-term fetal microchimerism in peripheral blood mononuclear cell subsets in healthy women and women with scleroderma. 1006 76


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