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)

The number of patients undergoing BMT is rising steadily. The increase is due to a broadening of the indications for transplantation and an increase in the donor pool. There has been a progressive improvement in outcome particularly due to a fall in transplant-related mortality. Methotrexate and cyclosporin are the mainstay of graft versus host disease (GVHD) prophylaxis, but acute GVHD remains a major problem in the unrelated donor recipient. Infections remain an important cause of death and emphasise the crucial role of antimicrobial prophylaxis; death from Gram-negative sepsis has been significantly reduced by the use of prophylactic antibiotics. Fungal infections carry a high mortality, especially in allogenic transplant recipients. Fluconazole is used to protect patients in the neutropenic period and beyond in higher risk individuals. Viral infections, which may occur late, are emerging as a significant cause of morbidity and mortality in the allogeneic, particularly unrelated transplantation setting. A long term susceptibility to encapsulated bacteria suggests delayed immune reconstitution; revaccination policies are standard in most units. The longer term effects of transplantation are increasingly important with improving survival and include chronic GVHD, endocrine, cardiorespiratory and other systemic abnormalities. The increased risk of secondary malignancies is also of concern.
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PMID:Bone marrow transplantation: current situation, complications and prevention. 860 39

A novel mechanism for virus-induced autoimmunity in humans is described. Infection of immunocompromised bone marrow-transplanted patients with human CMV results in the formation of autoantibodies specific for the cell-surface protein CD13 (aminopeptidase N). CD13 is present on all CMV-susceptible cells and infection can be specifically blocked by antibodies against CD13. CMV particles carry CD13, which is incorporated in the viral envelope during budding of viral nucleo-capsids into Golgi-derived vacuoles. Antibodies against CD13 are virus-neutralizing, in efficiency comparable to antibodies against viral envelope glycoproteins. Autoantibodies against CD13 are present in patients who develop chronic GVHD following allogeneic bone marrow transplantation. This lesion shows striking similarities to certain autoimmune diseases in humans, of which scleroderma is one example. In vivo binding of antibodies to tissue structures known to be targets for chronic GVHD has been demonstrated in patients with chronic GVHD. Finally, patient serum containing CD13-specific antibodies binds to skin and mucosa tissue sections in vitro, a binding which is inhibited by CD13-specific monoclonal antibodies. Thus a virus infection can activate an immune response against a specific autoantigen, providing possibilities for destruction of non-infected host cells, as originally proposed by Fujinami & Oldstone (1985), and also for the molecular mimicry model for induction of autoimmunity. Our findings lend support to the idea that inhibiting the transfer of CMV infection in bone marrow transplants will reduce morbidity and mortality from CMV infection but will also reduce the incidence of chronic GVHD. Elimination of CD13+ cells in bone marrow is not believed to interfere with the chance of recipient repopulation, and may be a way to decrease morbidity and mortality substantially following BMT. For all patients, every effort should be taken to prevent a post-BMT CMV infection in order to reduce the risk of the later development of chronic GVHD.
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PMID:A novel mechanism for virus-induced autoimmunity in humans. 893 Jun 73

To evaluate the diagnostic utility of C-reactive protein (CRP) for the detection of sepsis in bone marrow transplantation, CRP levels were analyzed after pretransplant conditioning and variably combined in septic, focal or viral infections with graft-versus-host disease (GvHD) in 64 bone marrow recipients. The CRP levels after pretransplant conditioning were low. The peak levels of CRP were influenced independently by the type of infection (p = 0.016; septic and viral infections were significantly different) and GvHD (p = 0.003). The area under the receiver-operator characteristic (ROC) curve for peak CRP in sepsis was 0.653 and 0.618 with and without GvHD, respectively. It was concluded that GvHD and the type of infection were independent determinants of the CRP responses. GvHD did not affect the extent of the CRP response. Therefore, although not highly specific for sepsis, CRP remains a useful detector of sepsis in bone marrow transplantation.
Infection
PMID:The effects of pretransplant conditioning, graft-versus-host disease and sepsis on the CRP levels in bone marrow transplantation. 942 50

Viral infections are important in SCT patients. Different viruses are challenges for the physician at different times after transplantation due to changing defects in the immune status of the patients. Infections with respiratory viruses in particular respiratory syncytial virus are important early after transplant but the knowledge about epidemiology, risk factors, and treatment is still limited. Parainfluenza and influenza viruses can also cause severe and sometimes fatal infections after SCT. During the acute GVHD phase, CMV has been the most important viral infection during the entire history of allogeneic SCT. Recent developments with antiviral prophylaxis, new techniques for early diagnosis, and the strategy of preemptive antiviral therapy has reduced its importance in matched sibling transplants. Instead CMV disease occurring late after SCT has become an increasingly important problem in patients who have undergone unrelated or mis-matched SCT due to poor development of T-cell function. Other herpesviruses such as human herpesvirus type 6 and EBV are also becoming important causes of severe complications after unrelated and mismatched SCT. For this group of patients new innovative preventive and therapeutic strategies are needed.
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PMID:Immune reconstitution and viral infections after stem cell transplantation. 963 Mar 32

Patients with compromised immune function suffer a wide variety of lung insults. Infections are the most common causes of both acute and chronic lung diseases, but many noninfectious conditions affect the lungs. The clinical presentation of these noninfectious conditions often mimic infections, thus causing diagnostic dilemmas. The spectrum of noninfectious lung injury and response in the immunosuppressed host includes interstitial edema, interstitial fibrosis, diffuse idiopathic pneumonia, acute respiratory distress syndrome, and obliterative bronchiolitis. Alveolar hemorrhage may complicate any of these conditions. Lung injury in the immunosuppressed host is associated with a diversity of etiologies: sepsis, irradiation, graft rejection, reperfusion injury, graft-versus-host disease, and chemotherapeutic agents and other drug reactions. These injuries most often present as diffuse pulmonary infiltrates on chest radiograph. Establishing a specific diagnosis and etiology for the injury is often problematic. From a pragmatic standpoint, excluding the possibility of infection is the principal aim of diagnostic testing.
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PMID:Noninfectious lung disease in the immunocompromised host. 1051 34

Over the past 3 years we have performed 10 haploidentical peripheral blood stem cell transplants in patients with incurable haematological malignancies and no prospect of a matched unrelated donor within an adequate time period. Conditioning consisted of ATG, TBI, thiotepa, cyclophosphamide and additional radioimmunotherapy in five patients. All patients received G-CSF mobilized peripheral blood stem cell grafts. GVHD prophylaxis consisted of T cell depletion by CD34+ selection; no post-transplant immunosuppression was given in nine patients. Stable engraftment was achieved in nine patients; one case of acute graft rejection was observed. Seven patients developed grade I acute GVHD, and six patients have developed chronic GVHD. Infections were the most significant clinical problem post transplant. Two patients have suffered a relapse of their disease and two further patients have died of transplant-related complications. After a median follow-up of 13 months (range 5-37 months) six patients are surviving in remission. We conclude that haploidentical PBSCT is a reasonable alternative to a MUD transplant.
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PMID:CD34+ selected cells in mismatched stem cell transplantation: a single centre experience of haploidentical peripheral blood stem cell transplantation. 1093 78

Expression of suicide genes (e.g. herpes simplex virus thymidine kinase,HSV-TK) in T cells is an appealing approach to regulate graft-versus-host disease in adoptive immunotherapy. Here we report the optimization of retroviral infection of canine T cells. Canine T cells were stimulated either with phytohemagglutinin (PHA, 2 microg/ml) for 24-72 hours or with 100 U/ml interleukin-2 for seven days. Stimulated cells were co-cultivated with irradiated virus-producing cells. Transduction efficiencies ranged from 4% to 45% using PG13, a gibbon ape leukemia virus envelope (env) pseudotyped packaging cell line. Infection of cells with GPenvAM12, expressing the amphotropic Moloney murine leukemia virus env, did not yield a satisfactory percentage of transduced cells. Enrichment of transduced cells was performed using immunoselection, and gave a purity of up to 98%. Transfusion of 1 x 10(6) transduced cells per kilogram body weight showed that transduced cells could convert mixed chimerism to 100% and transfer immunity to a specific antigen. Transduced cells were repeatedly detected in peripheral blood and bone marrow by polymerase chain reaction with primers specific for the HSV-TK gene. We have demonstrated the feasibility of using the canine model to study gene therapy as a preclinical model.
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PMID:Expression of HSV-TK suicide gene in primary T lymphocytes: the dog as a preclinical model. 1097 36

Chronic graft-versus-host disease (GVHD) is the principal cause of transplantation-related morbidity and nonrelapse mortality late after allogeneic hematopoietic stem cell transplantation. The safety and potential efficacy of tacrolimus for the salvage treatment of chronic GVHD was evaluated in a single-arm, open-label phase 2 study. A total of 39 evaluable patients with chronic GVHD who failed previous immunosuppressive therapy with cyclosporine and prednisone were treated with tacrolimus starting at a median of 20 months (range, 3-68 months) after transplantation. At 3 years after the start of treatment, 5 patients (13%) had discontinued tacrolimus and were in complete remission, and 3 were considered clinically stable but not able to discontinue tacrolimus. A total of 31 patients (79%) experienced treatment failure; 22 (56%) who failed therapy had a change in immunosuppressive regimen because of progression (n = 18) or toxicity (n = 4). Nine patients (23%) died during continued treatment with tacrolimus. Two patients were lost to follow-up, at 11 and 19 months. The median duration of treatment with tacrolimus was 9 months (range, 1-29 months). Infections (144 episodes) were the most frequent adverse event. Nephrotoxicity occurred in 16 patients (41%); tacrolimus was discontinued in only 2 patients because of progressive deterioration in renal function. The Kaplan-Meier estimate of survival was 64% (95% confidence interval, 49%-79%) at 3 years posttransplantation. Seven patients had discontinued all immunosuppression at last contact, leading to an estimated 29% probability of stopping all immunosuppression by 3 years posttransplantation. Four patients died after relapse of malignancy. The response rate is consistent with previous reports of salvage treatment for chronic GVHD, indicating that a small group of patients failing cyclosporine may respond or stabilize with tacrolimus.
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PMID:Changing from cyclosporine to tacrolimus as salvage therapy for chronic graft-versus-host disease. 1112 11

Infections with the beta-herpesviruses human herpesvirus-6 (HHV-6) and human herpesvirus-7 (HHV-7) are ubiquitous in childhood. The immunosuppression secondary to organ or bone marrow transplantation together with posttransplantation management may favour viral replication and reactivation. HHV-6 and -7 induce immunosuppression by targeting lymphocytes, natural killer cells and monocytes. HHV-6 is commonly detected posttransplantation but variability in definitions of clinical syndromes related to this virus and detection methods have complicated understanding of the clinical relevance of HHV-6 posttransplantation. Clinical symptoms associated with HHV-6 include febrile illness, pneumonitis, hepatitis, encephalitis and bone marrow suppression. However, the majority of HHV-6 infections are asymptomatic. The incidence of HHV-7 infection and its clinical manifestations posttransplantation are even less well characterised. In addition, HHV-6 and HHV-7 are related to CMV disease or acute graft-versus-host disease and, indirectly, to increases in resource utilisation. Based on the potential relevance of these two beta-herpesviruses in transplant recipients, further studies are required to establish their real impact in transplantation. For this, sensitive and specific molecular diagnostic techniques allowing for the rapid detection and quantitation of virus and for the analysis of susceptibility to current antiviral agents are required.
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PMID:Human herpesvirus-6 and -7 in transplantation. 1124

Patients undergoing hematopoietic stem cell transplantation (HSCT) experience a prolonged period of dysfunctional immunity associated with an increased risk of bacterial and viral infections. Effective approaches toward vaccinating patients against common pathogens are being explored but are limited by poor levels of responsiveness. Relevant studies examining the nature of reconstitution of cellular and humoral immunity and its impact on vaccination strategies against infectious pathogens are reviewed. Following transplantation, deficiencies in cellular immunity are characterized by the inversion of CD4/CD8 ratios, a decreased proliferative response to mitogens, and the development of anergy to recall antigens as measured by delayed-type hypersensitivity testing. The impact on humoral immunity consists of decreased levels of circulating immunoglobulin, impaired immunoglobulin class switching, and a loss of complexity in immunoglobulin gene rearrangement patterns. In this setting, a loss of protective immunity has been demonstrated against viral and bacterial pathogens previously targeted by childhood vaccination. Infections due to encapsulated bacterial organisms such as Streptococcus pneumoniae and Haemophilus influenzae type B remain prevalent even in the late posttransplantation period. The efficacy of vaccination following HSCT is influenced by the time elapsed since transplantation, the nature of the hematopoietic graft, the use of serial immunization, and the presence of graft-versus-host disease. Strategies to enhance vaccine efficacy include pretransplantation immunization of the stem cell donor and the use of cytokine adjuvants.
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PMID:Vaccination against infectious disease following hematopoietic stem cell transplantation. 1130 51


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