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

---

Query: EC:2.1.1.69 (BMT)
2,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After BMT, donor T cells are activated which can display GvHD as well as GvL activities. In order to study this GvL-specific T-cell response in vitro, proliferative T-cell clones from post-BMT PBMCs were generated by stimulation with a patient's leukemic cells. One CD4+ T-cell clone (designated M-33) displayed strong proliferative activity against the patient's leukemic cells but not against the patient's EBV-LCLs. The induction of proliferation, however, appeared not to be leukemia specific. Detailed analysis of the reactivity patterns revealed that T-cell clone M-33 recognizes an as yet unknown nonpolymorphic determinant in the context of self HLA-DRw52, presented by all but one type of APC. T-cell clone M-33 proliferated upon stimulation by PB-MCs, freshly isolated B cells, monocytes, dendritic cells, leukemic B cells, and nonleukemic B-cell blasts; solely in vitro EBV-transformed B cells and in vivo EBV-infected B cells failed to induce proliferation of T-cell clone M-33. Neither surface expression of MHC or accessory molecules on the EBV cells nor suppression caused by the EBV-infected cells could explain their failure to stimulate T-cell clone M-33. We therefore hypothesize that the absence of the stimulatory capacity once the B cells are virally infected could be the result of competition for MHC class II binding of the Epstein-Barr viral peptides, thus affecting the postulated DRw52-restricted peptide for recognition by T-cell clone M-33.
...
PMID:Epstein-Barr virus infection abrogates the stimulatory capacity of B cells to a major histocompatibility complex class-II-restricted proliferative T-cell clone. 774 17

Hepatic venocclusive disease causes considerable morbidity and mortality following bone marrow transplantation. There are two hypotheses regarding the aetiology of this syndrome; firstly that changes in plasma coagulation factors and natural anticoagulants lead to a prothrombotic state and secondly that endothelial cell activation stimulates intravascular deposition of fibrin. We have investigated these mechanisms by measuring the changes in proteins C and S and factors VII and X in the post transplant period and by using the plasma concentration of factor VIIa as an in vivo marker of potential endothelial cell tissue factor expression. Protein C fell in both allograft and autograft patients but more so in the allografts. Similar results were found for factors VII and X. These changes were predominantly due to hepatic dysfunction induced by the chemo-radiotherapy. Factor VIIa levels were unchanged in both the allograft and autograft patients. We conclude that there is no convincing evidence for a procoagulant state following BMT as there are both anticoagulant and procoagulant changes. The absence of any changes in factor VIIa levels suggests that tissue factor was not exposed to the general circulation following BMT but does not exclude focal expression at the sites of thrombosis.
...
PMID:Factor VIIa and other haemostatic variables following bone marrow transplantation. 797 71

Severe thrombotic alterations, such as veno-occlusive disease of the liver, may occur in the early phase following high-dose chemoradiotherapy and BMT. In this study, performed in patients with hematological malignancies subjected to allogeneic (10 cases) and autologous (20 cases) BMT, we have monitored laboratory hemostatic parameters to better understand the pathogenetic mechanism of thrombosis and particularly of veno-occlusive disease. Prothrombin time, activated partial thromboplastin time, plasma fibrinogen, markers of hypercoagulability (thrombin-antithrombin complex and prothrombin fragment F1+2); natural anticoagulants (protein C, protein S and antithrombin) together with fibrinolytic parameters (plasminogen, alpha 2-antiplasmin, tissue-plasminogen activator, plasminogen activator inhibitor and D-dimer) were assessed before transplant, on day 0 and weekly for 1 month thereafter. A hypercoagulability state, not related to an impairment of the anticoagulant and fibrinolytic systems, was documented before and after autologous and allogeneic transplant. Two patients developed veno-occlusive disease: they did not show any difference from the other patients before transplant while they presented a decrease of the natural anticoagulants along with altered fibrinolytic parameters only at the clinical onset of veno-occlusive disease. In conclusion, in this study a state of marked hypercoagulability was documented in BMT patients and the hemostatic laboratory parameters evaluated were not able to predict the occurrence of the thrombotic complications.
...
PMID:Hypercoagulability in patients undergoing autologous or allogeneic BMT for hematological malignancies. 824 85

A decrease in levels of circulating anticoagulant protein C has been shown to occur following autologous BMT, and this deficiency may contribute to a hypercoagulable state placing patients at risk for thromboembolic events. We report four patients who suffered a variety of thrombotic complications following BMT (non-bacterial thrombotic endocarditis, superior vena cava thrombosis, thrombotic stroke, purpura fulminans, small bowel infarction secondary to diffuse microvascular thrombosis), which were preceded by or temporally related to decreased levels of protein C. Treatment with fresh frozen plasma (FFP) led to slight, temporary increases in protein C levels but infusions of FFP did not prevent either death or extension of the thrombus in these four cases, suggesting the need for higher protein C doses and/or concomitant anticoagulation. Though no direct causal relationship between these thrombotic complications and the protein C deficiency can be proved, a generalized hypercoagulable state caused by protein C deficiency may have contributed to the development, severity or progression of these complications.
...
PMID:Thrombotic complications of BMT: association with protein C deficiency. 843 11

The natural anticoagulants (antithrombin III, protein C, protein S), plasminogen and tissue plasminogen activator antigen (t-PA ag), were measured in 27 consecutive patients following allogeneic BMT. Thrombosis and veno-occlusive disease were not seen in this study. Changes in the levels of these proteins occurred mainly during acute GVHD. There were 14 patients who had no acute GVHD (group I) and 13 patients who had acute GVHD (group II). No changes in antithrombin III (ATIII), protein C, protein S and t-PA levels were found in group II before the appearance of acute GVHD when compared with group I. However, we noted a significant rise in protein S (p = 0.01), antithrombin III (p = 0.001) and t-PA ag (p = 0.0004) levels during acute GVHD. In contrast, protein C levels decreased early in GVHD (p = 0.005), and then increased progressively over the course of a month post-GVHD. No changes in plasminogen levels were observed. These results might reflect activation of and/or damage to endothelial cells during GVHD.
...
PMID:Alterations in natural anticoagulant levels during allogeneic bone marrow transplantation: a prospective study in 27 patients. 848 78

Deficiencies in circulating anticoagulant protein C (PC) occur in patients undergoing hematopoietic stem cell transplantation. These deficiencies may predispose to thrombotic and other complications, and may contribute to the morbidity of transplantation. In most patients, PC reaches a nadir 14 days after the preparative regimen and then begins to increase toward normal. However, low PC has been seen months after transplantation. Neither the frequency of, nor risk factors for, this prolonged deficiency are known. We examined 71 adults undergoing stem cell transplantation and found low PC antigen and activity in 21% and 20% of patients, respectively. Low PC at day 100 correlated strongly with low PC pre-chemotherapy (PC antigen, r = 0.69, P < 0.001; PC activity, r = 0.59, P < 0.001). The incidence of deficiency of PC at day 100 was lower in patients undergoing peripheral stem cell transplantation compared with patients undergoing autologous BMT (12.5% vs 35%; P = 0.05), although several significant confounding variables exist. We conclude that deficiencies in protein C persist at least 100 days after stem cell transplantation in nearly one quarter of patients undergoing this procedure. Therefore, patients undergoing stem cell transplantation may be at prolonged risk of thrombotic and other complications. Further studies to determine the risk of prolonged deficiency based on stem cell source need to be performed.
...
PMID:Prolonged deficiency of protein C following hematopoietic stem cell transplantation. 870 97

An 18-year-old white male developed severe hepatic veno-occlusive disease (VOD) during an autologous bone marrow transplant for primary refractory nodular sclerosing Hodgkin's disease. As a result of VOD-induced hepatic dysfunction, coagulation studies revealed depression of vitamin K dependent procoagulant factor VII. Intravenous recombinant tissue plasminogen activator 20 mg over h on 4 consecutive days and continuous heparin infusion (1000 unit bolus followed by 150 units/kg/day) resulted in rapid reversal of the VOD syndrome. During treatment, procoagulant factors II, VII, IX and X levels increased indicating the return of hepatic synthesizing capacity. Factor V levels, which were elevated pre-therapy, also rose dramatically. Plasma antigen levels of protein C, a natural anticoagulant, remained severely depressed. No clinical evidence of bleeding and only minimal systemic fibrinolysis was noted. Despite concerns regarding the use of lytic therapy in a thrombocytopenic post-BMT patient, serial measurements of coagulation parameters during severe VOD suggested that low dose rt-PA improved portions of the systemic hemostatic profile.
...
PMID:Treatment of hepatic veno-occlusive disease with low-dose tissue plasminogen activator: impact on coagulation profile. 887 29

Three patients developed abdominal pain and abnormal liver enzymes without hyperbilirubinemia, early after autografting for lymphoma. Two had received conditioning therapy with busulfan, cyclophosphamide and continuous infusion etoposide; the other had received busulfan and melphalan. Doppler ultrasound in all cases demonstrated thrombosis of the main portal vein and its branches. In the two patients tested, transient deficiencies in protein C (both cases) and protein S (one case) were observed. One case was chronologically related to anti-fibrinolytic therapy and resolved spontaneously. The other two cases resolved after treatment with low molecular weight heparin. Portal vein thrombosis should be considered in the differential diagnosis of abdominal pain and liver dysfunction after BMT.
...
PMID:Acute portal vein thrombosis after autologous stem cell transplantation. 893 50

Circulating anticoagulants protein C (PC) and antithrombin III (AT) are markers of, and possibly involved in the pathogenesis of, significant organ dysfunction, in patients undergoing autologous peripheral blood stem cell (PSBC) or autologous bone marrow (BM) transplantation. The effect of the stem cell source, the use of hematopoietic growth factors (GFs), and the specific preparative regimen on the incidence of organ system dysfunction or on post-transplant levels of circulating anticoagulants has not been well studied. We analyzed 205 patients in an attempt to correlate organ dysfunction and AT and PC deficiencies with these transplant-specific factors (78 BMT with GM-CSF after transplant, 95 PBSCT without GM-CSF after transplant, and 32 PBSCT with GM-CSF after transplant). Patients transplanted with PBSC had a lower incidence of pulmonary dysfunction (20 vs 40%, P = 0.006) and liver dysfunction (4 vs 13%, P = 0.05) than patients receiving BM. The use of GF after transplant did not influence the development of subsequent organ dysfunction. In multivariate analysis, the stem cell source was again predictive of pulmonary dysfunction. In contrast, although patients transplanted with PBSC also had a lower incidence of PC deficiency (50 vs 81%, P < 0.01) and AT deficiency (20 vs 54%, P < 0.01) as compared with patients receiving BM, use of GM-CSF after transplant was a more significant risk factor for the development of anticoagulant deficiency (PBSC with GF vs PBSC without GF: PC deficiency 50 vs 78%, P = 0.007; AT deficiency 20 vs 47%, P = 0.005). In the multivariate analysis GM-CSF use was the only significant risk factor for development of anticoagulant deficiency. Since the clinical significance of anticoagulant deficiency has been well shown, further studies examining these effects of hematopoietic GFs appear warranted.
...
PMID:Factors predicting morbidity following hematopoietic stem cell transplantation. 905 18

Factors that enhance hypercoagulability following BMT may have a pathogenetic role in VOD. To investigate the relevance of hemostatic parameters for the development of VOD, we prospectively measured protein C, protein S, antithrombin III (AT III), von Willebrand factor, and factor VIII in 50 consecutive patients undergoing allogeneic BMT. Each parameter was determined before conditioning, on day 0 of BMT and weekly for 3 weeks, and patients were monitored prospectively for the occurrence of VOD. VOD occurred in 26 patients at median post-BMT day 8.5 (range, day -2 to 17). Thirteen patients had mild, 10 had moderate and three had severe VOD. No coagulation parameters were significantly different at the baseline or on day 0 of BMT between patients with no/mild VOD and moderate to severe VOD. On day 7 and thereafter, levels of protein C and AT III were significantly lower in patients with moderate to severe VOD when compared to patients with no/mild VOD. Levels of protein C and AT III decreased before the clinical onset of VOD in patients with moderate to severe VOD. Early post-BMT reduction of these parameters may indicate the development of moderate to severe VOD.
...
PMID:Relevance of proteins C and S, antithrombin III, von Willebrand factor, and factor VIII for the development of hepatic veno-occlusive disease in patients undergoing allogeneic bone marrow transplantation: a prospective study. 982 16


1 2 Next >>

---