Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.69 (BMT)
 2,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients undergoing bone marrow transplantation are susceptible to many different bacterial, fungal and viral infections. Among the viral pathogens, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus cause the greatest morbidity and mortality and have been the most common infectious causes of death following the grafting of allogeneic marrow. This great susceptibility to viral infections is due to the immunodeficiency in cellular and humoral immune responses lasting for months to years. Contributing factors are high-dose chemo/radiotherapy, graft-versus-host disease (GVHD) prophylaxis/treatment, GVHD itself, the degree of HLA disparity between donor and recipient and the underlying disease. Defects of T cell helper and cytotoxic functions contribute to the great incidence of viral infections. We described here the kinetic of immunological reconstitution and the role of T cell immunodeficiency. At day 30 to 40 after BMT, a minority of patients had recovery of virus-specific CD8+ T-cell response. Between day 40 and day 90 recovery of deficient CD8+ and CD4+ T cell responses occurred in the majority of the recipients of HLA identical BMT but only in the minority of the recipients of HLA partially incompatible BMT. New approaches should therefore be envisaged either to preserve donor T-cell-mediate immunity or tho accelerate immune reconstitution. Add-back of unmanipulated T-cells, or virus-specific T cells could improve antimicrobial defenses after BMT.
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PMID:[Antiviral immunodeficiency: EBV, CMV, adenovirus]. 943 82

Patients treated with BMT are extremely susceptible to infection with blood-borne viruses that can cause liver disease of variable clinical severity, from minimal biochemical changes to fulminant hepatic failure. Facing a patient with liver disfunction after BMT, one must bear in mind that more than one cause of liver disease, of viral and/or non-viral origin, may coexist. Moreover, besides the most important hepatotropic viruses, other agents, like herpesviruses (including CMV, adenoviruses, Epstein-Barr virus) may also be implicated, sometimes causing a life-threatening fulminant hepatitis, due to their cytopatic effect. Liver disease history and viral markers before transplant, together with the accurate assessment of the timing and type of clinical and biochemical deterioration are useful tools for a differential diagnosis. Liver biopsy, if taken in the early posttransplant period, is often difficult to interpret, while in case of liver disease occurring during immunosuppression tapering, histologic examination may discriminate between an exacerbation of viral hepatitis and an acute onset of chronic liver GVHD. While it seems that hepatitis G virus does not cause liver disease, the presence of hepatitis B virus (HBV) or hepatitis C virus (HCV) infection is a matter of concern for its consequences both early after BMT and for long-term survivors. Despite screening for blood and marrow donors for HBV and, more recently, for HCV markers, the rate of post-transplant infection (4% and 4-15% respectively, confirmed in prospective studies) with those viruses indicates that viral hepatitis still remains an important clinical problem in this setting, although the prognosis of chronic HCV and HBV infection appears more benign than expected, especially in children.
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PMID:Infections with hepatotropic viruses in children treated with allogeneic bone marrow transplantation. 963 Mar 33

Herpesviruses frequently cause serious complications after allogeneic bone marrow transplantation (allo-BMT). Recent studies have shown more rapid immune reconstitution after allogeneic peripheral blood stem cell transplantation (allo-PBSCT) compared with allo-BMT. However, it has not been clarified whether the improved immune reconstitution after allo-PBSCT is associated with a lower incidence of herpesvirus infections. We monitored the emergence of Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and HHV-7 DNA by a nested-double polymerase chain reaction in peripheral blood leucocytes from 22 allo-BMT and 16 allo-PBSCT patients. Each virus had an unique temporal profile of detection. HHV-6 DNA was detected most frequently at 3 weeks after transplantation, whereas CMV and EBV DNA were detected later (2-3 months). Detection rates of HHV-6 DNA at 3 and 4 weeks after allo-BMT were significantly higher than those after allo-PBSCT (9/16 v 2/13 at 3 weeks, P < 0.01; 10/21 v 1/15 at 4 weeks, P < 0.01). Detection rates of the other three herpesviruses after the two types of allogeneic transplantation were not significantly different throughout observation period. Furthermore, detection of HHV-6 DNA within the first 4 weeks was associated with delayed platelet engraftment after both allo-BMT and allo-PBSCT (P < 0.01). These results suggest an advantage for allo-PBSCT over allo-BMT in terms of suppression of HHV-6 reactivation and prevention of subsequent complications.
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PMID:Monitoring of human herpesviruses after allogeneic peripheral blood stem cell transplantation and bone marrow transplantation. 1023 97

In Epstein-Barr virus (EBV) infection, the virus immortalizes B lymphocytes and cytotoxic T lymphocytes (CTLs) are directed toward both latent and lytic viral antigens expressed on EBV-infected B-cells. Various EBV-associated diseases occur as a result of this disruption of immune surveillance. In the majority of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) cases, the major cell types containing EBV DNA are not B-cells, but clonally proliferating T-cells or NK-cells. Proliferation of these cells produces severe immune reactions in the host, and the clinical features related to massive cytokine production at the onset of disease are unique and distinct from other EBV-associated diseases. In the treatment of EBV-HLH, therapeutic infusion of EBV-specific CTLs appears to be ineffective, and eradication of EBV-containing cells is useful but not sufficient to save lives, because of high incidence of acute mortality due to cytokine-induced multiple organ failure and neutropenia-associated opportunistic infections. The optimal treatment strategy for this disease consists of three steps: (1) control of cytokine storm including coagulopathy and multiple organ failure, (2) control of opportunistic infections, and (3) eradication of clonally proliferating EBV-containing T- or NK- cells by immunochemotherapy and, if necessary, hemopoietic stem cell/bone marrow transplantation (SCT/BMT).
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PMID:Treatment strategies for Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). 1097 82

Reactivation of latent herpesviruses results in outcomes ranging from asymptomatic shedding of viruses to severe diseases, depending on the immunological competence of the host. Severe and prolonged suppression of cellular and humoral immunity after hematopoietic stem cell transplantation is accompanied by a high incidence of symptomatic recurrent herpesvirus infections. Subclinical reactivation also occurs more frequently than previously expected in transplant recipients. An increasing viral load in the blood detected by an antigenemia assay or PCR and viral shedding in regional fluids have a predictive value for subsequent diseases. Monitoring of viral DNA in the peripheral blood after allogeneic bone marrow transplantation (allo-BMT) reveals unique temporal profiles of detection for each herpesvirus. Recent studies demonstrate that recovery of CD4+ T cells is enhanced within one month after allogeneic peripheral blood stem cell transplantation (allo-PBSCT) compared to allo-BMT. To clarify whether this immunological advantage could affect the reactivation of human herpesvirus (HHV), we monitored the emergence of viral DNA by a nested-double polymerase chain reaction in peripheral blood leukocytes. Detection rates of HHV-6 DNAs which peak at 3-4 weeks post-transplant, were significantly reduced after allo-PBSCT compared to allo-BMT, while those of other herpesviruses which tend to be reactivated later than this period (Epstein-Barr virus and cytomegalovirus) were similar between the two types of transplants. Detection of HHV-6 DNA within the first month after the transplant was associated with delayed platelet engraftment. These results underscore the important role of CD4+ T reconstitution in inhibiting virus reactivation post-transplant.
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PMID:Reactivation of human herpesviruses after allogeneic peripheral blood stem cell transplantation and bone marrow transplantation. 1134 4

To establish a practical monitoring system of human herpesviruses reactivation in patients undergoing stem cell transplantation, we developed a new, very rapid, highly sensitive, and quantitative PCR assay for accurate measurement of human cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) DNA using LightCycler. The LightCycler system revealed that there was a linear correlation in the wide range of viral template DNA at the indicated number of PCR cycles. Peripheral blood cells were collected from 16 patients undergoing stem cell transplantation. The cut-off level of CMV and HHV-6 was assessed as 10(2) copies/microg and that of EBV as 10(3). High numbers of CMV genomes were detected in 3/13 patients after transplant, and reactivation of HHV-6 was frequently seen, whereas none of the patient showed an elevation of EBV genome copies until the end of the observation period. In the present study, the reactivation of beta herpesviruses is associated with the occurrence of thrombotic microangiopathy (TMA) in two patients undergoing allogeneic BMT. Therefore, it may contribute in clarifying the pathological potential of human herpesviruses using a large number of clinical samples. Our results suggest that this system may be useful for monitoring viral reactivation.
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PMID:A rapid monitoring system of human herpesviruses reactivation by LightCycler in stem cell transplantation. 1175 54

We report a case of Epstein-Barr virus-associated lymphoproliferative disorder (EBV-LPD) after allogeneic bone marrow transplantation (allo-BMT) from a partially mismatched related donor for acute lymphocytic leukemia, which was treated successfully by donor lymphocyte infusion (DLI). A 54-year-old woman in first complete remission from acute lymphocytic leukemia received an unmanipulated bone marrow transplant from an HLA-A 1-locus-mismatched sibling donor after preconditioning with cyclophosphamide and total body irradiation. Prophylaxis against graft-versus-host disease (GVHD) was done with tacrolimus and short-term methotrexate. Skin GVHD (grade I) occurred on day 36, but this subsided spontaneously without treatment. On day 61, rapidly progressive cervical lymphadenopathy with fever developed. Lymph node biopsy revealed lymphoid cell proliferation, which was positive for LCA, L26 and LMP-1. A diagnosis of EBV-LPD was made. After withdrawal of the tacrolimus, DLI (1 x 10(6) CD3 cells/kg) resulted in remission. This case suggests that even in the absence of risk factors such as severe GVHD, intensive immunosuppressive therapy and ATG administration, allo-BMT from an HLA 1-locus-mismatched related donor can be complicated by EBV-LPD, and that reduction of immunosuppressive therapy and DLI can be an effective treatment for it.
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PMID:[Successful donor lymphocyte infusion for Epstein-Barr virus-associated lymphoproliferative disorder after allogeneic bone marrow transplantation from an HLA 1-locus-mismatched sibling donor in a patient with acute lymphocytic leukemia]. 1180 79

A 5-month-old male presented with fever, hepatosplenomegaly, leukocytosis with atypical lymphoblasts, anemia and thrombocytopenia. Severe combined imunodeficiency syndrome (T-, B+, NK+), B lymphoproliferative disease and hemophagocytic lymphohistiocytosis triggered by Epstein-Barr virus (EBV) were diagnosed. As his clinical situation deteriorated rapidly, BMT was performed with unmanipulated marrow stem cells from his EBV-positive HLA-identical sister after conditioning with dexamethasone (1.75 mg/kg/day), cyclophosphamide (114 mg/kg) and etoposide (10 mg/kg), with no immunosuppression given post transplant. Engraftment occurred on day 6 with explosive proliferation of donor CD8(+) T cells. The patient died 3 days later from acute respiratory distress syndrome. Autopsy revealed full donor engraftment and no signs of hemophagocytic lymphohistiocytosis or B lymphoproliferative disease. Thus, transplanted T cells can expand very rapidly within days after BMT and clear EBV lymphoproliferative disease and hemophagocytic lymphohistiocytosis.
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PMID:Allogeneic bone marrow transplantation for active Epstein-Barr virus-related lymphoproliferative disease and hemophagocytic lymphohistiocytosis in an infant with severe combined immunodeficiency syndrome. 1196 Feb 73

The optimal treatment for natural killer (NK) cell leukemia after chronic active Epstein-Barr virus (CAEBV) infection has not been determined. A 15-year-old boy presented with NK cell leukemia following CAEBV infection for 5 years. The peripheral blood and BM had an increased number of CD3(-)CD56(+) large granular lymphocytes and a monoclonal integration of the EBV genome was detected. Chemotherapy was not sufficiently effective to control the disease. Allogeneic BMT from an HLA-identical sister was performed using a conditioning regimen consisting of total body irradiation, cyclophosphamide and thiotepa. The patient is disease-free with a perfect performance status 24 months after BMT. This is the first report to show that allogeneic BMT is potentially able to cure NK cell leukemia after CAEBV infection.
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PMID:Successful treatment of natural killer (NK) cell leukemia following a long-standing chronic active Epstein-Barr virus (CAEBV) infection with allogeneic bone marrow transplantation. 1279 98

A major risk faced by bone-marrow and solid organ transplant patients is the development of post-transplant lymphoproliferative disease or post-transplant lymphoma (PTLD). In pediatric transplantation, PTLD onset is often associated with a rapid rise in Epstein-Barr virus (EBV) load in peripheral blood mononuclear cells (PBMC). We have analyzed EBV viral loads in PBMC over time using real-time quantitative PCR in 56 patients, 19 of which have been followed for more than 1 year. In nine patients; eight bone marrow (BMT) and one kidney transplant, PTLD was associated with a rapid rise in viral load, exceeding 1 x 10(5) EBV genomes/microg of PBMC-derived DNA. Four of these patients exceeded 1 x 10(6) EBV genomes/microg PBMC DNA. All patients with viral loads exceeding 1 x 10(5) EBV genomes/microg PBMC DNA were clearly at high risk for transplant-associated mortality, with only six of nine surviving. Importantly, only one of these deaths was directly attributable to EBV. A second elevated state of EBV load, defined as exceeding 2 x 10(4) EBV genomes/microg PBMC, was seen in a total of 12 BMT, kidney, heart, and liver transplant patients. These patients did not appear to be at immediate lethal risk for PTLD and one EBV-attributable death was found in this group as well. Thirty-four transplant patients whose EBV viral load oscillated from undetectable to 10 000 EBV genomes/microg PBMC DNA are reported as well. The threshold for normal EBV viral load based on our combined experience with viral load analysis is defined as 1 x 10(4) EBV genomes/microg PBMC DNA. The ability to rapidly analyze EBV load allows rapid changes in viral load, such as those that occur with PTLD onset, and the impact of anti-CD20 antibody therapy to be rapidly detected.
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PMID:Monitoring and modulation of Epstein-Barr virus loads in pediatric transplant patients. 1289 10


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