Lung transplantation for cystic fibrosis: 6-year follow-up.
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Lung transplantation is currently the most effective means of improving survival and quality of life in patients with end-stage cystic fibrosis. In reviewing our 6-year experience we sought to evaluate complications and survival after sequential bilateral lung transplantation. Between October 1996 and October 2002, 114 patients with cystic fibrosis were referred to us from 15 Italian regional centers and 2 support centers for cystic fibrosis as possible candidates for lung transplantation. Of these 114 patients, 99 were included in the waiting list and 15 were refused. The mean time spent on the waiting list was 6.8+/-5.2 months (range 1 day-21 months) for those patients receiving lung transplantation, and 5.4+/-4.5 months (range 10 days-18 months) for those 35 patients who died while on the waiting list. A total 55 patients (6 children and 49 adults), mean age 25.6+/-6.6 years (range 9-52 years), 29 males, underwent bilateral sequential lung transplantation. One patient had a second transplantation 14 months after the first. The most frequent medical non-infective complications after transplantation were chronic renal failure (n=27 patients), diabetes (n=31), osteoporosis (n=17), arterial hypertension (n=14), seizures (n=4), transient cerebral ischaemia (n=1), and transient bilateral blindness (n=1). Bacterial lower airways respiratory infections with the organisms that colonized patients' airways before lung transplantation developed in 42 patients; cytomegalovirus (CMV) infection in 41; and opportunistic infections of the lung with Pneumocystis carinii in 3 patients. Cultures of sputum or bronchoalveolar lavage fluid grew Aspergillus fumigatus in nine patients; aspergillosis of right bronchial anastomosis developed in one patient and a lung infection in another. Another patient had a pulmonary infection secondary to Aspergillus niger. An average of 1.3 episodes of acute rejection developed per patient in the first 6 months after lung transplantation. Freedom from bronchiolitis obliterans syndrome was 95% at 1 year, 82.5% at 2 years, 70% at 3 years, and 65% at 4, 5 and 6 years. Actuarial survival rates were 80% at 1 month, 79% at 1 year, 74% at 2 years, 70% at 3 years and 58% at 4, 5 and 6 years. Ten patients (17.8%) died in the early postoperative period (1-30 days) for the following reasons: primary graft failure (n=4), multiorgan failure (n=3), Burkholderia cepacia sepsis (n=1), myocardial infarction (n=1), and pulmonary embolism (n=1). Mortality was accounted for by 9 patients (16%) who died from 9 to 43 months after lung transplantation, for the following reasons: P. carinii infection (n=2), bronchiolitis obliterans syndrome (n=4), A. fumigatus pulmonary infection (n=1), unknown cause (n=1) and suicide (n=1). In conclusion, the leading causes of morbidity after lung transplantation for cystic fibrosis are pulmonary bacterial infection and opportunistic infections. Bronchiolitis obliterans develops in more than half of lung transplant recipients who survive for more than 3 years and is an important cause of death in the late post transplantation period. (+info)
Phenotype of airway epithelial cells suggests epithelial to mesenchymal cell transition in clinically stable lung transplant recipients.
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BACKGROUND: Obliterative bronchiolitis in chronic rejection of lung allografts is characterised by airway epithelial damage and fibrosis. The process whereby normal epithelium is lost and replaced by fibroblastic scar tissue is poorly understood, but recent findings suggest that epithelial cells can become fibroblasts through epithelial-mesenchymal transition (EMT). It is hypothesised that EMT occurs in lung allografts and plays a potential role in airway remodelling. METHODS: Sixteen stable lung transplant recipients underwent bronchoscopy with bronchoalveolar lavage (BAL), endobronchial biopsies, and bronchial brushings. Biopsy sections were stained for the fibroblast marker S100A4. Brushings were cultured on collagen, stained with anti-S100A4, and examined for further EMT markers including matrix metalloproteinase (MMP) zymographic activity and epithelial invasion through collagen coated filters. RESULTS: A median 15% (0-48%) of the biopsy epithelium stained for S100A4 in stable lung transplant recipients and MMP-7 co-localisation was observed. In non-stimulated epithelial cultures from lung allografts, S100A4 staining was identified with MMP-2 and MMP-9 production and zymographic activity. MMP total protein and activity was increased following stimulation with transforming growth factor (TGF)-beta1. Non-stimulated transplant epithelial cells were invasive and penetration of collagen coated filters increased following TGF-beta1 stimulation. CONCLUSIONS: This study provides evidence of EMT markers in lung allografts of patients without loss of lung function. The EMT process may represent a final common pathway following injury in more common diseases characterised by airway remodelling. (+info)
Minimal acute rejection after lung transplantation: a risk for bronchiolitis obliterans syndrome.
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Bronchiolitis obliterans syndrome (BOS) is a major cause of lung allograft dysfunction. Although previous studies have identified mild to severe rejection (grade>or=A2) as a risk factor for BOS, the role of minimal rejection (grade A1) remains unclear. To determine if A1 rejection by itself is a risk factor for BOS, we performed a retrospective cohort study on 228 adult lung transplant recipients over a 7-year period. Cohorts were defined by their most severe rejection episode (none, A1 only, and >or=A2) and analyzed for the subsequent development and progression of BOS using univariate and multivariate time-dependent Cox regression analysis. In the univariate model, the occurrence of isolated minimal rejection was a risk factor for all stages of BOS. Similarly, multivariate models that included HLA mismatch, cytomegalovirus pneumonitis, community acquired viral infection, underlying disease and type of transplant demonstrated that A1 rejection was a distinct risk factor for BOS. Furthermore, the associated risk with A1 rejection was slightly greater than the risk from >or=A2 and treatment of A1 rejection decreased the risk for subsequent BOS stage 1. We conclude that minimal rejection is associated with an increased risk for BOS development and progression that is comparable to A2 rejection. (+info)
Clinical impact of community-acquired respiratory viruses on bronchiolitis obliterans after lung transplant.
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Community-acquired viral respiratory tract infections (RTI) in lung transplant recipients may have a high rate of progression to pneumonia and can be a trigger for immunologically mediated detrimental effects on lung function. A cohort of 100 patients was enrolled from 2001 to 2003 in which 50 patients had clinically diagnosed viral RTI and 50 were asymptomatic. All patients had nasopharyngeal and throat swabs taken for respiratory virus antigen detection, culture and RT-PCR. All patients had pulmonary function tests at regular intervals for 12 months. Rates of rejection, decline in forced expiratory volume (L) in 1 s (FEV-1) and bacterial and fungal superinfection were compared at the 3-month primary endpoint. In the 50 patients with RTI, a microbial etiology was identified in 33 of 50 (66%) and included rhinovirus (9), coronavirus (8), RSV (6), influenza A (5), parainfluenza (4) and human metapneumovirus (1). During the 3-month primary endpoint, 8 of 50 (16%) RTI patients had acute rejection versus 0 of 50 non-RTI patients (p=0.006). The number of patients experiencing a 20% or more decline in FEV-1 by 3 months was 9 of 50 (18%) RTI versus 0 of 50 non-RTI (0%) (p=0.003). In six of these nine patients, the decline in FEV-1 was sustained over a 1-year period consistent with bronchiolitis obliterans syndrome (BOS). Community-acquired respiratory viruses may be associated with the development of acute rejection and BOS. (+info)
BLT1-mediated T cell trafficking is critical for rejection and obliterative bronchiolitis after lung transplantation.
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Leukotriene B4 is a lipid mediator that recently has been shown to have potent chemotactic activity for effector T lymphocytes mediated through its receptor, BLT1. Here, we developed a novel murine model of acute lung rejection to demonstrate that BLT1 controls effector CD8+ T cell trafficking into the lung and that disruption of BLT1 signaling in CD8+ T cells reduces lung inflammation and mortality in the model. In addition, we used BLT1-deficient mice and a BLT1 antagonist in two tracheal transplant models of lung transplantation to demonstrate the importance of BLT1 for the recruitment of T cells into tracheal allografts. We also show that BLT1-mediated CD8+ T cell recruitment plays an important role in the development of airway fibroproliferation and obliteration. Finally, in human studies of lung transplant recipients, we found that BLT1 is up-regulated on T lymphocytes isolated from the airways of patients with obliterative bronchiolitis. These data demonstrate that BLT1 contributes to the development of lung rejection and obliterative bronchiolitis by mediating effector T lymphocyte trafficking into the lung. This is the first report that describes a pathologic role for BLT1-mediated T lymphocyte recruitment in disease and identifies BLT1 as a potential therapeutic target after lung transplantation. (+info)
Lung transplantation: opportunities for research and clinical advancement.
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Lung transplantation is the only definitive therapy for many forms of end-stage lung diseases. However, the success of lung transplantation is limited by many factors: (1) Too few lungs available for transplantation due to limited donors or injury to the donor lung; (2) current methods of preservation of excised lungs do not allow extended periods of time between procurement and implantation; (3) acute graft failure is more common with lungs than other solid organs, thus contributing to poorer short-term survival after lung transplant compared with that for recipients of other organs; (4) lung transplant recipients are particularly vulnerable to pulmonary infections; and (5) chronic allograft dysfunction, manifest by bronchiolitis obliterans syndrome, is frequent and limits long-term survival. Scientific advances may provide significant improvements in the outcome of lung transplantation. The National Heart, Lung, and Blood Institute convened a working group of investigators on June 14-15, 2004, in Bethesda, Maryland, to identify opportunities for scientific advancement in lung transplantation, including basic and clinical research. This workshop provides a framework to identify critical issues related to clinical lung transplantation, and to delineate important areas for productive scientific investigation. (+info)
Reciprocal regulation of airway rejection by the inducible gas-forming enzymes heme oxygenase and nitric oxide synthase.
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Obliterative bronchiolitis (OB) develops insidiously in nearly half of all lung transplant recipients. Although typically preceded by a CD8(+) T cell-rich lymphocytic bronchitis, it remains unresponsive to conventional immunosuppression. Using an airflow permissive model to study the role of gases flowing over the transplanted airway, it is shown that prolonged inhalation of sublethal doses of carbon monoxide (CO), but not nitric oxide (NO), obliterate the appearance of the obstructive airway lesion. Induction of the enzyme responsible for the synthesis of CO, heme oxygenase (Hmox) 1, increased carboxyhemoglobin levels and suppressed lymphocytic bronchitis and airway luminal occlusion after transplantation. In contrast, zinc protoporphyrin IX, a competitive inhibitor of Hmox, increased airway luminal occlusion. Compared with wild-type allografts, expression of inducible NO synthase (iNOS), which promotes the influx of cytoeffector leukocytes and airway graft rejection, was strikingly reduced by either enhanced expression of Hmox-1 or exogenous CO. Hmox-1/CO decreased nuclear factor (NF)-kappaB binding activity to the iNOS promoter region and iNOS expression. Inhibition of soluble guanylate cyclase did not interfere with the ability of CO to suppress OB, implicating a cyclic guanosine 3',5'-monophosphate-independent mechanism through which CO suppresses NF-kappaB, iNOS transcription, and OB. Prolonged CO inhalation represents a new immunosuppresive strategy to prevent OB. (+info)
The evolution of isolated bilateral lung contusion from blunt chest trauma in rats: cellular and cytokine responses.
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Lung contusion is the leading cause of death from blunt thoracic trauma in adults, but its mechanistic pathophysiology remains unclear. This study uses a recently developed rat model to investigate the evolution of inflammation and injury in isolated lung contusion. Bilateral lung contusion with minimal cardiac trauma was induced in 54 anesthetized rats by dropping a 0.3-kg hollow cylindrical weight onto a precordial shield (impact energy, 2.45 Joules). Arterial oxygenation, pressure-volume (P-V) mechanics, histology, and levels of erythrocytes, leukocytes, albumin, and inflammatory mediators in bronchoalveolar lavage (BAL) were assessed at 8 min, at 4, 12, 24, and 48 h, and at 7 days after injury. The role of neutrophils in the evolution of inflammatory injury was also specifically studied by depleting these cells with intravenous vinblastine before lung contusion. Arterial oxygenation was severely reduced at 8 min to 24 h postcontusion, but became almost normal by 48 h. Levels of erythrocytes, leukocytes, and albumin in BAL were increased at +info)