Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006271 (bronchiolitis)
 5,174 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor necrosis factor (TNF)-alpha inhibitors have proven efficacy in various autoimmune diseases such as Crohn disease, rheumatoid arthritis, psoriasis, and ankylosing spondylitis. Indeed, some TNFalpha inhibitors have already been approved for the management of the inflammatory manifestations associated with Crohn disease and rheumatoid arthritis. These agents are increasingly used for treatment of corticosteroid-resistant graft-versus-host disease after bone marrow transplantation, and case reports have documented their efficacy in treating corticosteroid- and muromonab-resistant rejection after intestinal transplantation. Thus, the potential role of TNFalpha inhibitors in transplantation of other vascularized solid organs is worthy of investigation. Experimental evidence indicates that TNFalpha plays a key role in mediating ischemia/reperfusion (IR) injury after liver, kidney, intestine, heart, lung, and pancreas transplantation. TNFalpha was also identified as a marker cytokine during organ rejection. Single-center studies evaluating the role of TNFalpha inhibitors in kidney transplantation have been initiated but the results are not yet available. TNFalpha is known to be a contributing factor in kidney allograft rejection, and may have value in predicting the onset of steroid-resistant acute rejection after liver transplantation. Experimental and preliminary clinical data have shown that circulating levels of TNFalpha are increased during cardiac graft rejection, and indicate that TNFalpha plays a role in the pathogenesis of acute cardiac allograft rejection. Anti-TNFalpha therapy was shown to prolong cardiac allograft survival when used alone or in combination with other drugs. TNFalpha genotype has been strongly associated with mortality in humans due to acute cell-mediated heart transplant rejection. In addition, there is evidence for a genetic predisposition toward acute rejection after kidney and simultaneous kidney-pancreas transplantation. TNFalpha inhibition has been used successfully as part of an induction therapy for pancreatic islet cell transplantation. Apart from IR injury and acute rejection after lung transplantation, TNFalpha was also found to be involved in the pathoimmunology of obliterative bronchiolitis. In conclusion, a substantial body of experimental evidence and preliminary clinical data suggest that TNFalpha inhibitors may play an important role in solid-organ transplantation, both in the amelioration of IR injury and in the treatment and prevention of acute rejection. Pharmacodynamic monitoring and pharmacogenetic screening may help to identify patients most likely to benefit from TNFalpha blockade. Randomized controlled trials in patients undergoing solid-organ transplantation are needed to further elucidate the clinical value of TNFalpha inhibition.
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PMID:Biologics in the treatment of transplant rejection and ischemia/reperfusion injury: new applications for TNFalpha inhibitors? 1612 5

Lung transplantation is a therapeutic option for a number of end-stage pulmonary disorders. Early lung allograft dysfunction (ischemia-reperfusion injury) continues to be the most common cause of early mortality after lung transplantation and a significant risk factor for the development of bronchiolitis obliterans syndrome. Ischemia-reperfusion injury is characterized histopathologically by lung edema and a neutrophil predominate leukocyte extravasation. The specific mechanism(s) that recruit leukocytes to the lung during post-lung transplantation ischemia-reperfusion injury have not been fully elucidated. Because the ELR+ CXC chemokines are potent neutrophil chemoattractants, we investigated their role during post-lung transplantation ischemic-reperfusion injury. We found elevated levels of multiple ELR+ CXC chemokines in human bronchoalveolar lavage fluid from patients with ischemia-reperfusion injury. Proof of concept studies using a rat orthotopic lung transplantation model of "cold" ischemic-reperfusion injury demonstrated an increase in lung graft neutrophil sequestration and injury. In addition, lung expression of CXCL1, CXCL2/3, and their shared receptor CXCR2 paralleled lung neutrophil infiltration and injury. Importantly, inhibition of CXCR2/CXCR2 ligand interactions in vivo led to a marked reduction in lung neutrophil sequestration and graft injury. Taken together these experiments support the notion that increased expression of ELR+ CXC chemokines and their interaction with CXCR2 plays an important role in the pathogenesis of post-lung transplantation cold ischemia-reperfusion injury.
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PMID:CXCR2/CXCR2 ligand biology during lung transplant ischemia-reperfusion injury. 1627 53

Lung transplantation remains the only effective therapy for patients with end-stage lung disease, but survival is limited by the development of obliterative bronchiolitis (OB). The chemokine receptor CXCR3 and two of its ligands, CXCL9 and CXCL10, have been identified as important mediators of OB. However, the relative contribution of CXCL9 and CXCL10 to the development of OB and the mechanism of regulation of these chemokines has not been well defined. In this study, we demonstrate that CXCL9 and CXCL10 are up-regulated in unique patterns following tracheal transplantation in mice. In these experiments, CXCL9 expression peaked 7 days posttransplant, while CXCL10 expression peaked at 1 day and then again 7 days posttransplant. Expression of CXCL10 was also up-regulated in a novel murine model of lung ischemia, and in bronchoalveolar lavage fluid taken from human lungs 24 h after lung transplantation. In further analysis, we found that 3 h after transplantation CXCL10 is donor tissue derived and not dependent on IFN-gamma or STAT1, while 24 h after transplantation CXCL10 is from recipient tissue and regulated by IFN-gamma and STAT1. Expression of both CXCL9 and CXCL10 7 days posttransplant is regulated by IFN-gamma and STAT1. Finally, we demonstrate that deletion of CXCR3 in recipients reduces airway obliteration. However, deletion of either CXCL9 or CXCL10 did not affect airway obliteration. These data show that in this murine model of obliterative bronchiolitis, these chemokines are differentially regulated following transplantation, and that deletion of either chemokine alone does not affect the development of airway obliteration.
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PMID:CXCR3 and its ligands in a murine model of obliterative bronchiolitis: regulation and function. 1670 71

Over the last decade, improvements in surgical techniques, lung preservation, immunosuppression, and management of ischemia-reperfusion injury and infections have contributed to increase the 1 year patient survival after lung transplantation to 70 to 80%. However, the incidence of acute rejection remains higher than after other types of solid organ transplantation, and long-term survival is threatened by bronchiolitis obliterans, which is thought to be a form of chronic allograft rejection. This article reviews major aspects of clinical presentation, risk factors, diagnosis, and management of acute and chronic rejection after lung transplantation.
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PMID:Acute and chronic rejection after lung transplantation. 1707

Small airway fibrosis (bronchiolitis obliterans syndrome) is the primary obstacle to long-term survival following lung transplantation. Here, we show the importance of functional microvasculature in the prevention of epithelial loss and fibrosis due to rejection and for the first time, relate allograft microvascular injury and loss of tissue perfusion to immunotherapy-resistant rejection. To explore the role of alloimmune rejection and airway ischemia in the development of fibroproliferation, we used a murine orthotopic tracheal transplant model. We determined that transplants were reperfused by connection of recipient vessels to donor vessels at the surgical anastomosis site. Microcirculation through the newly formed vascular anastomoses appeared partially dependent on VEGFR2 and CXCR2 pathways. In the absence of immunosuppression, the microvasculature in rejecting allografts exhibited vascular complement deposition, diminished endothelial CD31 expression, and absent perfusion prior to the onset of fibroproliferation. Rejecting grafts with extensive endothelial cell injury were refractory to immunotherapy. After early microvascular loss, neovascularization was eventually observed in the membranous trachea, indicating a reestablishment of graft perfusion in established fibrosis. One implication of this study is that bronchial artery revascularization at the time of lung transplantation may decrease the risk of subsequent airway fibrosis.
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PMID:Microvascular destruction identifies murine allografts that cannot be rescued from airway fibrosis. 1806 23

Primary graft dysfunction continues to be a major contributing factor to morbidity and mortality after lung transplantation. This condition is presumed to be the result of ischemia-reperfusion injury, which is associated with the release of endogenous substances that can activate the innate immune system. Primary graft dysfunction has been shown to be an independent risk factor for the development of bronchiolitis obliterans syndrome indicating that it can shape alloimmune responses. In this review, we focus on the classification, pathogenesis, possible prevention strategies, management and consequences of primary graft dysfunction.
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PMID:Pathogenesis, management, and consequences of primary graft dysfunction. 1870 51

Long-term success in lung transplantation continues to be challenged by chronic graft dysfunction, which is manifest as bronchiolitis obliterans syndrome (BOS). The mechanisms of BOS involve both immune-mediated pathways (rejection, autoimmune-like mechanisms), and alloimmune-independent pathways (infection, aspiration, ischemia, primary graft failure), which lead to a fibroproliferative responses. BOS correlates histologically with obliterative bronchiolitis in terminal bronchioles and evidence of aberrant remodeling in the airway epithelium, vasculature, stroma, and lymphoid system. A potentially important mechanism that supports the progressive and therapy-resistant nature of BOS is a continuous cycle of ongoing injury and aberrant remodeling. Namely, anatomical and functional abnormalities induce and exacerbate immune-mediated and alloimmune-independent pathways through various mechanisms (e.g., epithelial remodeling decreases mucociliary clearance that exacerbates aspiration-related injury). From this viewpoint, we review current therapeutic strategies and revisit the role of transplant surgeons in attenuating the initial transplant-related injuries to prevent the lung grafts from entering the remodeling-injury cycle.
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PMID:Bronchiolitis obliterans syndrome: alloimmune-dependent and -independent injury with aberrant tissue remodeling. 1870 52

Lung transplantation (LT) under urgency-code mechanical ventilation (UCMV) has been identified in the International Society for Heart and Lung Transplantation (ISHLT) Registry as a negative prognostic factor increasing the likelihood of mortality. The objective of this study was to review our experience of UCLT for with cystic fibrosis (CF) patients compared with elective LT (ELT). From October 1993 to October 2007, we performed 259 consecutive LTs in 250 patients, of whom 78 (31.20%) had CF. Our study group comprised CF patients who received UCLT (n = 23). The type of LT in the UCLT group was as follows: bipulmonary (18), left unipulmonary (2), and bilobar transplantation from cadavers (3). The UCLT group more often required cardiopulmonary bypass (CB) (P = .025), pulmonary tailoring (P = .030), and longer periods of pulmonary ischemia (P = .066) than the ELT group. We noticed a greater number of cases of pneumonia during the first postoperative month in the UCLT group. However, incidence of surgical complications, early and perioperative mortality, and episodes of acute and chronic rejection (bronchiolitis obliterans syndrome) did not differ between the groups. Survival rates at 1, 3, 5, and 10 years were 73.66%, 63.74%, 42.49%, and 42.49%, respectively, in the UCLT group (mean, 1927 [SE = 366] days) and 75.95%, 71.32%, 63.37%, and 63.37% in the ELT group (mean, 2946 [SE = 281] days; P = .3417). In our experience, UCLT in patients with CF is fully justified. Careful selection of such cases permits acceptable long-term survival rates to be achieved with no increase in early or perioperative mortality.
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PMID:Urgency-code lung transplantation for cystic fibrosis: experience and results. 1901 Jan 96

Primary graft dysfunction (PGD) is a severe form of ischemia/reperfusion acute lung injury that is a major cause of early morbidity and mortality after lung transplantation. Survivors of PGD have worse long-term lung function and an increased chance of developing bronchiolitis obliterans syndrome (BOS), the manifestation of chronic rejection. This review examines the current state of PGD research in the context of a recent consensus statement by the International Society for Heart and Lung Transplantation (ISHLT) designed to standardize the definition of PGD in clinical research efforts. This article will review this definition and issues surrounding it, outcome studies examining the long-term effects of PGD, and the established clinical risk factors for PGD. Translational studies exploring the pathogenesis of PGD will be highlighted, and the current state of PGD prevention and management will also be described. Finally, we will summarize efforts at finding genetic and molecular markers for PGD and discuss future directions for PGD research.
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PMID:Primary graft dysfunction. 1913 29

Lung transplantation is the ultimate treatment of end-stage lung disease. After transplantation, the 1-year survival rate is 80%. However, 5-year survival rates drop to 50% due to bronchiolitis obliterans syndrome (BOS). Ischemia/reperfusion injury, infections, and acute rejection are major risk factors contributing to the development of BOS. These risk factors are also associated with increased oxidative stress. Oxidative stress is a condition whereby prooxidants overwhelm the antioxidant defense system and may contribute to the pathogenesis of BOS by inducing more tissue injury and inflammation. This article reviews the current state of knowledge on oxidative stress in lung transplantation and BOS.
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PMID:Lung transplantation: does oxidative stress contribute to the development of bronchiolitis obliterans syndrome? 1929 41


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