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Purpose of Review: Chronic lung allograft dysfunction (CLAD) remains a major barrier preventing long-term survival following lung transplantation. As our clinical knowledge regarding its definition and presentation has significantly improved over the last years, adequate biomarkers to predict development of CLAD, phenotype of CLAD or prognosis post-CLAD diagnosis are definitely needed., Recent Findings: Radiological and physiological markers are gradually entering routine clinical practice. In-depth investigation of biological samples including broncho-alveolar lavage, biopsy and serum has generated potential biomarkers involved in fibrogenesis, airway injury and inflammation but none of these are universally accepted or implemented although progress has been made, specifically regarding donor-derived cell-free DNA and donor-specific antibodies., Summary: Although a lot of promising biomarkers have been put forward, a very limited number has made it to routine clinical practice. Nevertheless, a biomarker that leads to earlier detection or more adequate disease phenotyping would advance the field enormously., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: To investigate the diagnostic yield of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in lung transplant recipients., Methods: A single-center, retrospective cohort study including 234 18F-FDG PET examinations in 199 lung transplant recipients. Indication for PET referral, 18F-FDG PET diagnosis/findings and final clinical diagnosis were classified into 3 groups: malignancy, infection/inflammation not otherwise specified, and chronic lung allograft dysfunction with restrictive allograft syndrome phenotype. Sensitivity/specificity analysis was performed to determine accuracy of 18F-FDG PET in each group., Results: Sensitivity of 18F-FDG PET for malignancy was 91.4% (95% confidence interval, 82.5%-96.0%) and specificity was 82.3% (95% confidence interval, 74.5%-88.1%). Infection/inflammation not otherwise specified and restrictive allograft syndrome as indication for 18F-FDG PET comprised relatively small groups (14 and 31 cases, respectively). In addition, 18F-FDG PET revealed clinically relevant incidental findings in 15% of cases., Conclusions: Referral for 18F-FDG PET after lung transplantation mainly occurred to confirm or rule out malignancy. In this specific setting, 18F-FDG PET has a high diagnostic yield. Accuracy of 18F-FDG PET for other indications is less clear, given small sample sizes. Clinically relevant diagnoses, unrelated to the primary indication for 18F-FDG PET, are found relatively often in this immunocompromised cohort., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

The application of stereology to lung casts and two-dimensional microscopy images is the gold standard for quantification of the human lung anatomy. However, these techniques are labor intensive, involving fixation, embedding, and histological sectioning of samples and thus have prevented comprehensive studies. Our objective was to demonstrate the application of stereology to volumetric multiresolution computed tomography (CT) to efficiently and extensively quantify the human lung anatomy. Nontransplantable donor lungs from individuals with no evidence of respiratory disease ( n = 13) were air inflated, frozen at 10 cmH 2 O, and scanned using CT. Systematic uniform random samples were taken, scanned using micro-CT, and assessed using stereology. The application of stereology to volumetric CT imaging enabled comprehensive quantification of total lung volume, volume fractions of alveolar, alveolar duct, and tissue, mean linear intercept, alveolar surface area, alveolar surface area density, septal wall thickness, alveolar number, number-weighted mean alveolar volume, and the number and morphometry of terminal and transitional bronchioles. With the use of this data set, we found that women and men have the same number of terminal bronchioles (last generation of conducting airways), but men have longer terminal bronchioles, a smaller wall area percentage, and larger lungs due to a greater number of alveoli per acinus. The application of stereology to multiresolution CT imaging enables comprehensive analysis of the human lung parenchyma that identifies differences between men and women. The reported data set of normal donor lungs aged 25-77 yr provides reference data for future studies of chronic lung disease to determine exact changes in tissue pathology. NEW & NOTEWORTHY Stereology has been the gold standard to quantify the three-dimensional lung anatomy using two-dimensional microscopy images. However, such techniques are labor intensive. This study provides a method that applies stereology to volumetric computed tomography images of frozen whole human lungs and systematic uniform random samples. The method yielded a comprehensive data set on the small airways and parenchymal lung structures, highlighting morphometric sex differences and providing a reference data set for future pathological studies.

Background: Alterations in the lung microbiota may drive disease development and progression in patients with chronic respiratory diseases. Following lung transplantation (LTx), azithromycin is used to both treat and prevent chronic lung allograft dysfunction (CLAD). The objective of this study was to determine the association between azithromycin use, CLAD, acute rejection, airway inflammation, and bacterial microbiota composition and structure after LTx., Methods: Bronchoalveolar lavage samples (n = 219) from 69 LTx recipients (azithromycin, n = 32; placebo, n = 37) from a previously conducted randomized placebo-controlled trial with azithromycin were analyzed. Samples were collected at discharge, 1, and 2 years following randomization and at CLAD diagnosis. Bacterial microbial community composition and structure was determined using 16S ribosomal RNA gene sequencing and associated with clinically important variables., Results: At discharge and following 1 and 2 years of azithromycin therapy, no clear differences in microbial community composition or overall diversity were observed. Moreover, no changes in microbiota composition were observed in CLAD phenotypes. However, acute rejection was associated with a reduction in community diversity (p = 0.0009). Significant correlations were observed between microbiota composition, overall diversity, and levels of inflammatory cytokines in bronchoalveolar lavage, particularly CXCL8., Conclusions: Chronic azithromycin usage did not disturb the bacterial microbiota. However, acute rejection episodes were associated with bacterial dysbiosis., (Copyright © 2019 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Pulmonary graft vs. host disease is a diverse and underestimated complication following allogenic hematopoietic stem cell transplantation. We aimed to compare the airway architecture with chronic lung allograft dysfunction post lung transplantation. Inflated explant lungs from graft vs. host disease patients were compared with lungs with chronic lung allograft dysfunction following lung transplantation, and control lungs using a combination of CT, microCT, and histology (n = 6 per group) and pathology in the (small) airways was further quantified and analyzed. Following allogenic hematopoietic stem cell transplantation, three patients presented as bronchiolitis obliterans syndrome and three patients showed interstitial changes and restriction. The CT analysis demonstrated a strong similarity between bronchiolitis obliterans syndrome after lung transplantation and post allogenic hematopoietic stem cell transplantation, evidenced by severe ( > 50%) airway obstruction from generation 9, with 70.8% of the airways ending in obstruction. Further analysis indicated that the airways either collapsed or accumulated matrix along a segment of the airway. In patients with restriction and interstitial changes following allogenic hematopoietic stem cell transplantation, the degree of airway obstruction was lower compared with bronchiolitis obliterans syndrome post allogenic hematopoietic stem cell transplantation, but similar to restrictive allograft syndrome post lung transplantation, showing a lower proportion of airway obstruction (20-35%), decreased number of terminal bronchioles per lung (p < 0.01), and parenchymal fibrosis. We observed similarities in the airway and parenchymal morphometric changes in lung graft vs. host disease and with chronic lung allograft dysfunction following lung transplantation, suggesting similar pathophysiological mechanisms.

Purpose of Review: Chronic lung allograft dysfunction (CLAD) has been recently introduced as an umbrella-term encompassing all forms of chronic pulmonary function decline posttransplant with bronchiolitis obliterans syndrome and restrictive allograft syndrome as the most important subtypes. Differential diagnosis and management, however, remains complicated., Recent Findings: Herein, we provide an overview of the different diagnostic criteria (pulmonary function, body plethysmography and radiology) used to differentiate bronchiolitis obliterans syndrome and restrictive allograft syndrome, their advantages and disadvantages as well as potential problems in making an accurate differential diagnosis. Furthermore, we discuss recent insights in CLAD management and treatment and advances in the search for accurate biomarkers of CLAD., Summary: Careful dissection of CLAD phenotypes is of utmost importance to assess patient prognosis, but uniform diagnostic criteria are desperately needed. There is a long way ahead, but the first steps towards this goal are now taken; tailored individualized therapy will be the golden standard to treat CLAD in the future, but randomized placebo-controlled and multicentre trials are needed to identify new and powerful therapeutic agents.

Background: Chronic lung allograft dysfunction (CLAD) is the single most important factor limiting long-term survival after lung transplantation (LTx). Azithromycin has been shown to improve CLAD-free and long-term survival, yet the possible impact on early lung allograft function is unclear., Methods: A prospective, randomized, double-blind, placebo-controlled trial of pre-transplant and prompt post-transplant azithromycin treatment was performed at the University Hospitals Leuven. In each arm, 34 patients, transplanted between October 2013 and October 2015, were included for analysis. Study drug was added to standard of care and was administered once before LTx (1,000 mg of azithromycin or placebo) and every other day from Day 1 until Day 31 after LTx (250 mg of azithromycin or placebo). Primary outcome was an anticipated 15% improvement of forced expiratory volume in 1 second (FEV 1 , percent predicted) during the first 3 months post-LTx. Secondary end-points included length of intubation, days on ventilator, duration of intensive care unit and hospital stay, prevalence and severity of primary graft dysfunction, acute rejection, infection, and CLAD-free and overall survival., Results: FEV 1 was not significantly different between the 2 groups (p = 0.41). Patients treated with azithromycin demonstrated less airway inflammation, with lower bronchoalveolar lavage (BAL) neutrophilia and BAL interleukin-8 protein levels at Day 30 (p = 0.09 and p = 0.04, respectively) and Day 90 (p = 0.002 and p = 0.08, respectively) after LTx. Other secondary outcomes were not significantly different between placebo and azithromycin groups., Conclusions: Pre-transplant and prompt post-transplant azithromycin treatment was not able to improve early lung allograft function. However, the known anti-inflammatory properties of azithromycin were confirmed (NCT01915082)., (Copyright © 2018 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Long-term survival after lung transplantation (LTx) is hampered by chronic lung allograft dysfunction (CLAD). Our study evaluated the prevalence and prognostic importance of obstructive and restrictive CLAD phenotypes, with or without an identifiable underlying cause, to validate the recently proposed classification system for CLAD., Methods: Data for patients who underwent LTx between 2004 and 2015 with a minimal survival of 180 days post-LTx were retrospectively collected. Double LTx patients with CLAD (defined as a persistent forced expiratory volume in 1 second decline of ≥ 20% compared with baseline) were subsequently classified according to obstructive (forced expiratory volume in 1 second /forced vital capacity [FVC] < 70%, total lung capacity > 90%, and FVC > 80%) or restrictive (total lung capacity ≤ 90% or FVC ≤ 80%) pulmonary function and to the presence of an unknown (bronchiolitis obliterans syndrome [BOS]/restrictive allograft syndrome [RAS]) or known (non-BOS/non-RAS) underlying cause., Results: After a median of 3.2 years, CLAD developed in 39% of double LTx patients (n = 219), of which 20% (n = 43) had an identifiable cause. Survival was worse in patients with restrictive CLAD (26%) compared with obstructive CLAD (64%; p < 0.0001). Non-BOS patients suffered from inferior survival compared with BOS patients (p = 0.0016), whereas there was no significant difference in survival between RAS and non-RAS (p = 0.17). Patients who evolved from an obstructive (BOS) to a restrictive (RAS) phenotype (10%) experienced better survival than RAS patients and a worse outcome compared with BOS patients (p < 0.0001)., Conclusions: Given the differences in outcome, accurate diagnosis of CLAD phenotypes is important, because this helps to inform patients about their prognosis, to reveal underlying pathogenesis, to identify homogenous patient populations for clinical trials, and to guide future therapeutic approaches., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: The advice of a dynamic multidisciplinary discussion (MDD) is believed to be important in the diagnosis of interstitial lung diseases (ILDs). However, to what extent MDD diagnoses differ from the preliminary diagnoses before formal workup and MDD (preMDD diagnoses) is still insufficiently studied., Methods: We compared preMDD and MDD diagnoses in patients discussed at the Leuven University Hospitals MDDs between January 2005 and December 2015., Results: Of 938 consecutive patients discussed in an MDD, 755 (80.5%) received a specific diagnosis. From the 183 patients with unclassifiable ILD, 150 patients (16.0%) received suggestions concerning further investigations to establish a definite diagnosis. In 191 patients (41.9% of patients with a preMDD diagnosis), the MDD changed the diagnosis. In 384 patients (79.5% of patients without preMDD diagnosis), MDD provided a diagnosis when the referring physician did not. MDD diagnosis showed a trend toward better prognostic discrimination between idiopathic pulmonary fibrosis and other ILDs compared with preMDD diagnosis (Harrell C-index, 0.666 vs 0.631; P = .08), which was particularly clear in patients with discordant MDD and preMDD diagnoses (hazard ratio, 2.68 vs 0.84; P = .012 vs .768)., Conclusions: The MDD provided a definite diagnosis in 80.5% of presented cases, suggesting further investigations in almost all others. Given the high number of patients without preMDD diagnosis, the rate of change in preMDD diagnoses (41.9% of patients with a preMDD diagnosis) probably is an underestimation. The better prognostic discrimination among ILDs by using MDD indicates the added value of MDD in ILD., (Copyright © 2018 American College of Chest Physicians. All rights reserved.)

Background: Telomere shortening has been associated with several lung diseases. However, telomere length is generally measured in peripheral blood leucocytes rather than in lung tissue, where disease occurs. Consequently, telomere dynamics have not been established for the normal human lung nor for diseased lung tissue. We hypothesized an age- and disease-dependent shortening of lung tissue telomeres., Methods: At time of (re-)transplantation or autopsy, 70 explant lungs were collected: from unused donors (normal, n = 13) and patients with cystic fibrosis (CF, n = 12), chronic obstructive pulmonary disease (COPD, n = 11), chronic hypersensitivity pneumonitis (cHP, n = 9), bronchiolitis obliterans syndrome (BOS) after prior transplantation (n = 11) and restrictive allograft syndrome (RAS) after prior transplantation (n = 14). Lungs were inflated, frozen and then scanned using CT. Four tissue cores from distinct lung regions were sampled for analysis. Disease severity was evaluated using CT and micro CT imaging. DNA was extracted from the samples and average relative telomere length (RTL) was determined using real-time qPCR., Results: The normal lungs showed a decrease in RTL with age (p < 0.0001). Of the diseased lungs, only BOS and RAS showed significant RTL decrease with increasing lung age (p = 0.0220 and p = 0.0272 respectively). Furthermore, we found that RTL showed considerable variability between samples within both normal and diseased lungs. cHP, BOS and RAS lungs had significant shorter RTL in comparison with normal lungs, after adjustment for lung age, sex and BMI (p < 0.0001, p = 0.0051 and p = 0.0301 respectively). When investigating the relation between RTL and regional disease severity in CF, cHP and RAS, no association was found., Conclusion: These results show a progressive decline in telomere length with age in normal, BOS and RAS lungs. cHP, BOS and RAS lungs demonstrated shorter RTL compared to normal lungs. Lung tissue RTL does not associate with regional disease severity within the lung. Therefore, tissue RTL does not seem to fully reflect peripheral blood telomere length.

Bronchiolitis obliterans syndrome (BOS) remains the major problem which precludes long-term survival after lung transplantation. Previously, an open label pilot study from our group demonstrated a possible beneficial effect of montelukast in progressive BOS patients with low airway neutrophilia (<15%), and already on azithromycin treatment, in whom the further decline in pulmonary function was attenuated. This was, however, a non-randomized and non-placebo controlled trial. The study design is a single center, prospective, interventional, randomized, double blind, placebo-controlled trial, with a two arm parallel group design and an allocation ratio of 1:1. Randomization to additional montelukast (10 mg/day, n = 15) or placebo (n = 15) was performed from 2010 to 2014 at the University Hospitals Leuven (Leuven, Belgium) in all consecutive patients with late-onset (>2years posttransplant) BOS ≥1. Primary end-point was freedom from graft loss 1 year after randomization; secondary end-points were acute rejection, lymphocytic bronchiolitis, respiratory infection rate; and change in FEV1, airway and systemic inflammation during the study period. Graft loss at 1 y and 2y was similar in both groups (respectively p = 0. 981 and p = 0.230). Montelukast had no effect on lung function decline in the overall cohort. However, in a post-hoc subanalysis of BOS stage 1 patients, montelukast attenuated further decline of FEV1 during the study period, both in absolute (L) (p = 0.008) and % predicted value (p = 0.0180). A linear mixed model confirmed this association. Acute rejection, lymphocytic bronchiolitis, respiratory infections, systemic and airway inflammation were comparable between groups over the study period. This randomized controlled trial showed no additional survival benefit with montelukast compared to placebo, although the study was underpowered. The administration of montelukast was associated with an attenuation of the rate of FEV1 decline, however, only in recipients with late-onset BOS stage 1.

Background: Insults to the airway epithelium play a key role in constrictive bronchiolitis after lung transplantation, the typical hallmark of chronic rejection. Our hypothesis is that immunosuppressives might affect airway integrity., Methods: A biculture of human bronchial epithelial cells and lung microvascular endothelial cells was exposed to immunosuppressives (serum through levels) for 24 hours or 4 days. Cytotoxicity, transepithelial electrical resistance (TEER), and permeability was measured after exposure to monotherapies and combination therapies. Apoptosis, oxidative stress, inflammation (IL-8), real-time polymerase chain reaction for epithelial-to-mesenchymal transition and tight junction proteins were assessed in exposed cells., Results: Mycophenolate mofetil (MMF) and combination therapies including MMF, at serum trough levels and higher, are toxic for the human bronchial epithelial cells after 4-day exposure. Moreover, already after 24 hours, TEER of cells exposed to MMF decreases and permeability increases. MMF did not induce apoptosis, oxidative stress, loss of tight junctions or production of IL-8 after 24 hours, but possibly induces epithelial-to-mesenchymal transition in epithelial cells. MMF was detectable at both sides of the biculture and was also present in bronchoalveolar lavage of lung transplantation patients. Other immunosuppressives were not toxic, neither changed TEER or permeability., Conclusions: Our findings suggest that MMF is present in the airways of lung transplant patients and might affect the structural integrity of the airway, which needs further investigation and validation in the clinical setting.

Background: Primary graft dysfunction (PGD) is considered to be the end result of an inflammatory response targeting the new lung allograft after transplant. Previous research has indicated that MAPC cell therapy might attenuate this injury by its paracrine effects on the pro-/anti-inflammatory balance. This study aims to investigate the immunoregulatory capacities of MAPC cells in PGD when administered in the airways., Methods: Lungs of domestic pigs (n = 6/group) were subjected to 90 minutes of warm ischemia. Lungs were cold flushed, cannulated on ice and placed on EVLP for 6 hours. At the start of EVLP, 40 ml of an albumin-plasmalyte mixture was distributed in the airways (CONTR group). In the MAPC cell group, 150 million MAPC cells (ReGenesys/Athersys, Cleveland, OH, USA) were added to this mixture. At the end of EVLP, a physiological evaluation (pulmonary vascular resistance, lung compliance, PaO 2 /FiO 2 ), wet-to-dry weight ratio (W/D) sampling and a multiplex analysis of bronchoalveolar lavage (BAL) (2 × 30 ml) was performed., Results: Pulmonary vascular resistance, lung compliance, PaO 2 /FiO 2 and W/D were not statistically different at the end of EVLP between both groups. BAL neutrophilia was significantly reduced in the MAPC cell group. Moreover, there was a significant decrease in TNF-α, IL-1β and IFN-γ in the BAL, but not in IFN-α; whereas IL-4, IL-10 and IL-8 were below the detection limit., Conclusions: Although no physiologic effect of MAPC cell distribution in the airways was detected during EVLP, we observed a reduction in pro-inflammatory cytokines and neutrophils in BAL in the MAPC cell group. This effect on the innate immune system might play an important role in critically modifying the process of PGD after transplantation. Further experiments will have to elucidate the immunoregulatory effect of MAPC cell administration on graft function after transplantation.

Objectives: To describe the CT changes in patients with restrictive allograft syndrome (RAS) after lung transplantation, before and after clinical diagnosis., Methods: This retrospective study included 22 patients with clinical diagnosis of RAS. Diagnosis was based on a combination of forced expiratory volume (FEV1) decline (≥20 %) and total lung capacity (TLC) decline (≥10 %). All available CT scans after transplantation were analyzed for the appearance and evolution of lung abnormalities., Results: In 14 patients, non-regressing nodules and reticulations predominantly affecting the upper lobes developed an average of 13.9 months prior to the diagnosis of RAS. Median graft survival after onset of non-regressing abnormalities was 33.5 months, with most patients in follow-up (9/14). In eight patients, a sudden appearance of diffuse consolidations mainly affecting both upper and lower lobes was seen an average of 2.8 months prior to the diagnosis of RAS. Median graft survival was 6.4 months after first onset of non-regressing abnormalities, with graft loss in most patients (6/8)., Conclusions: RAS has been previously described as a homogenous group. However, our study shows two different groups of RAS-patients: one with slow progression and one with fast progression. The two groups show different onset and progression patterns of CT abnormalities., Key Points: • RAS is the newest discovered form of chronic lung allograft dysfunction (CLAD). • RAS is not a homogenous group, as survival varies greatly between patients. • In this study, we see two different CT onset and progression patterns. • These two different CT patterns also correlate with a different survival rate.

Despite donor organ shortage, a large proportion of possible donor lungs are declined for transplantation. Criteria for accepting/declining lungs remain controversial because of the lack of adequate tools to aid in decision-making. We collected, air-inflated, and froze a large series of declined/unused donor lungs and subjected these lung specimens to CT examination. Affected target regions were scanned by using micro-CT. Lungs from 28 donors were collected. Two lungs were unused, six were declined for non-allograft-related reasons (collectively denominated nonallograft declines, n = 8), and 20 were declined because of allograft-related reasons. CT scanning demonstrated normal lung parenchyma in only four of eight nonallograft declines, while relatively normal parenchyma was found in 12 of 20 allograft-related declines. CT and micro-CT examinations confirmed the reason for decline in most lungs and revealed unexpected (unknown from clinical files or physical inspection) CT abnormalities in other lungs. CT-based measurements showed a higher mass and density in the lungs with CT alterations compared with lungs without CT abnormalities. CT could aid in the decision-making to accept or decline donor lungs which could lead to an increase in the quantity and quality of lung allografts., (© 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Recently, antibody mediated rejection (AMR) has been associated with a higher incidence of chronic lung allograft dysfunction (CLAD) and mortality after lung transplantation (LTx). We investigated markers related to AMR and matrix remodeling in CLAD, with special attention for its two phenotypes being bronchiolitis obliterans syndrome (BOS) and restrictive CLAD (rCLAD)., Methods: Immunoglobulins (IgA, IgE, IgG1-IgG4, total IgG and IgM) and complement (C4d and C1q) were quantified in lung lavage samples at the moment of BOS (n=15) or RAS (n=16) diagnosis; and were compared to stable transplant patients who served as control (n=14). Also, airway remodeling and metalloproteinases (MMPs) were investigated via zymography and gelatin degradation. The presence of DSA was additionally assessed in blood., Results: Total IgG, IgG1-IgG4 and IgM were increased in rCLAD versus control (p<0.001) and BOS patients (p<0.01). IgA and IgE were increased in rCLAD compared to control (respectively p<0.05 and p<0.01), but not to BOS. Total IgG and IgE were increased in BOS versus control (respectively p<0.01 and p<0.05). Complement proteins were exclusively present in rCLAD and correlated positively with immunoglobulins. Additionally, in blood, DSA were more present in rCLAD (p=0.041). MMP-9 levels increased in RAS and BOS versus control (p<0.001) and MMP-9 induced gelatin degradation was only increased in BOS compared to control (p<0.01)., Conclusion: We demonstrated increased levels of immunoglobulins and complement proteins dominantly present in rCLAD. This leads to the belief that antibodies and AMR might play a more important role in rCLAD compared to BOS. Therefore, anti B-cell therapy could offer beneficial therapeutic effects in patients diagnosed with rCLAD, which needs further research., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Rationale: After repeated cycles of lung infection and inflammation, patients with cystic fibrosis (CF) evolve to respiratory insufficiency. Although histology and imaging have provided descriptive information, a thorough morphometric analysis of end-stage CF lung disease is lacking., Objectives: To quantify the involvement of small and large airways in end-stage CF., Methods: Multidetector computed tomography (MDCT) and micro-CT were applied to 11 air-inflated CF explanted lungs and 7 control lungs to measure, count, and describe the airway and parenchymal abnormalities in end-stage CF lungs. Selected abnormalities were further investigated with thin section histology., Measurements and Main Results: On MDCT, CF explanted lungs showed an increased median (interquartile range) number (631 [511-710] vs. 344 [277-349]; P = 0.003) and size of visible airways (cumulative airway diameter 217 cm [209-250] vs. 91 cm [80-105]; P < 0.001) compared with controls. Airway obstruction was seen, starting from generation 6 and increasing to 40 to 50% of airways from generation 9 onward. Micro-CT showed that the total number of terminal bronchioles was decreased (2.9/ml [2.6-4.4] vs. 5.3/ml [4.8-5.7]; P < 0.001); 49% were obstructed, and the cross-sectional area of the open terminal bronchioles was reduced (0.093 mm(2) [0.084-0.123] vs. 0.179 mm(2) [0.140-0.196]; P < 0.001). On micro-CT, 41% of the obstructed airways reopened more distally. This remodeling was confirmed on histological analysis. Parenchymal changes were also seen, mostly in a patchy and peribronchiolar distribution., Conclusions: Extensive changes of dilatation and obstruction in nearly all airway generations were observed in end-stage CF lung disease.

Chronic lung allograft dysfunction (CLAD) remains the major barrier to long-term success after lung transplantation. This report compares gross and microscopic features of lungs removed from patients receiving a redo-transplant as treatment for CLAD. Lungs donated by patients with either the bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS) phenotype of CLAD and appropriate control lungs (eight per group) were air-inflated, frozen solid and kept frozen while a multi-detector computed tomography (MDCT) was obtained. The lung was then cut into 2-cm thick transverse slices and sampled for micro-CT and histopathology. The MDCT showed reduced lung volume with increased lung weight and density in RAS versus BOS and control (p<0.05). Although pre-terminal bronchioles were obstructed in both phenotypes, RAS lungs showed a reduction of pre-terminal bronchioles (p<0.01). Micro-CT and matched histopathology showed that RAS was associated with reduced numbers of terminal bronchioles/lung compared to BOS and controls (p<0.01), with expansion of the interstitial compartment and obliteration of the alveolar airspaces by fibrous connective tissue. RAS is associated with greater destruction of both pre-terminal and terminal bronchioles. Additionally, the interstitial compartments are expanded and alveolar airspaces are obliterated by accumulation of fibrous connective tissue., (Copyright ©ERS 2015.)

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality and resource use worldwide. The goal of this official American Thoracic Society (ATS)/European Respiratory Society (ERS) Research Statement is to describe evidence related to diagnosis, assessment, and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management. Clinicians, researchers and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarised, and then salient knowledge gaps were identified. Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulated via discussion and consensus. Great strides have been made in the diagnosis, assessment and management of COPD, as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS research statement highlights the types of research that leading clinicians, researchers and patient advocates believe will have the greatest impact on patient-centred outcomes., (Copyright ©ATS/ERS 2015.)

Bronchiolitis obliterans syndrome (BOS) is a major complication of lung transplantation that is associated with poor survival. The International Society for Heart and Lung Transplantation, American Thoracic Society, and European Respiratory Society convened a committee of international experts to describe and/or provide recommendations for 1) the definition of BOS, 2) the risk factors for developing BOS, 3) the diagnosis of BOS, and 4) the management and prevention of BOS. A pragmatic evidence synthesis was performed to identify all unique citations related to BOS published from 1980 through to March, 2013. The expert committee discussed the available research evidence upon which the updated definition of BOS, identified risk factors and recommendations are based. The committee followed the GRADE (Grading of Recommendation, Assessment, Development and Evaluation) approach to develop specific clinical recommendations. The term BOS should be used to describe a delayed allograft dysfunction with persistent decline in forced expiratory volume in 1 s that is not caused by other known and potentially reversible causes of post-transplant loss of lung function. The committee formulated specific recommendations about the use of systemic corticosteroids, cyclosporine, tacrolimus, azithromycin and about re-transplantation in patients with suspected and confirmed BOS. The diagnosis of BOS requires the careful exclusion of other post-transplant complications that can cause delayed lung allograft dysfunction, and several risk factors have been identified that have a significant association with the onset of BOS. Currently available therapies have not been proven to result in significant benefit in the prevention or treatment of BOS. Adequately designed and executed randomised controlled trials that properly measure and report all patient-important outcomes are needed to identify optimal therapies for established BOS and effective strategies for its prevention., (©ERS 2014.)

Background: Restrictive allograft syndrome (RAS) has recently been defined as a novel phenotype of chronic lung allograft dysfunction (CLAD) after lung transplantation. The goal was to describe computed tomographic (CT) changes of RAS patients and to correlate this with spirometry and survival., Methods: All 24 established RAS patients at our center were retrospectively included. CT scans from pre-CLAD, CLAD, post-CLAD and late-CLAD subjects were systematically evaluated by a blinded observer using a semi-quantitative scoring system. Changes in CT patterns were correlated with spirometry and survival., Results: The most prominent CT features at diagnosis of CLAD as compared with pre-CLAD were appearance of central (p = 0.020) and peripheral ground glass opacities (p = 0.052), as well as septal and non-septal lines (p = 0.020). Survival after diagnosis of CLAD was only associated with the absolute value of forced vital capacity (FVC) at diagnosis (R = 0.46 and p = 0.021), and not with any CT alterations. Evolution of CT abnormalities after diagnosis of CLAD included significant increases in (traction) bronchiectasis (p < 0.0001), central (p = 0.051) and peripheral (p = 0.0002) consolidation, architectural deformation (p = 0.0002), volume loss (p = 0.0004) and hilus retraction (p = 0.0036). The absolute FVC decrease post-CLAD diagnosis correlated with CT alterations., Conclusions: In the early stages of RAS, central and peripheral ground glass opacities are the most prominent feature on CT, whereas, in later stages, bronchiectasis, traction, central and peripheral consolidation, architectural deformation, volume loss and hilus retraction are more pronounced. CT changes, however, could not predict survival, whereas FVC at diagnosis of CLAD seems to be the best predictor of survival., (Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Eosinophils are involved in the pathophysiology of many respiratory diseases, but the exact role of eosinophilia in lung transplantation has not been thoroughly investigated., Methods: We performed a retrospective analysis of our transplanted patients between 2001 and 2011, with a minimum follow-up of 1 year. Using a cutoff of ≥2% eosinophilia in bronchoalveolar lavage (BAL) fluid, chronic lung allograft dysfunction (CLAD)-free survival and overall survival was compared between 66 patients demonstrating at least one BAL with eosinophils ≥2% and 253 control patients (never BAL ≥2%)., Results: Patients with increased BAL eosinophilia demonstrated worse CLAD-free and overall survival (both P<0.0001) compared with controls. Eosinophilic BAL predisposed to development of bronchiolitis obliterans syndrome but particularly to restrictive allograft syndrome (P<0.0001). After correction for covariates, the association between eosinophilic BAL and CLAD but equally death remained significant (P=0.0047 and 0.0011). Blood eosinophil and C-reactive protein levels were also elevated at the time of eosinophilic BAL., Conclusion: BAL eosinophilia ≥2% is associated with poor outcome in our lung transplant patients as demonstrated by worse CLAD-free and overall survival. Interestingly, increased BAL eosinophilia may be specifically associated with the development of restrictive allograft syndrome, which needs further prospective investigation.

Introduction: Only 15%-25% of brain death (BD) donors match the ideal donor criteria for lung transplantation. Lung injury may evolve in the hours after onset of brain death, but the evolution over time has not been well studied in lung. The aim of this study was to evaluate lung injury at different time points after BD using a murine model., Materials and Methods: Male C57BL6/J mice (8-10 wk) were anesthetized, tracheotomized, and mechanically ventilated. Mice were randomly assigned to six groups (n=8/group): 1 h, 3 h, and 6 h sham ([SH1], [SH3], [SH6]) and 1 h, 3 h, and 6 h brain death ([BD1], [BD3], [BD6]). BD was gradually induced by a subdural balloon catheter. Heart rate and mean arterial pressure were continuously monitored. At the end of the experiment, bronchoalveolar lavage was performed and the left lung was excised for histopathologic analysis., Results: The Cushing reflex was characterized by a rapid increase in heart rate and mean arterial pressure after balloon inflation in BD animals. An increase in percentage of neutrophils was seen with a longer follow-up period (P<0.05). Interleukin 6 and interleukin 10 levels in bronchoalveolar lavage progressively increased with longer time intervals after BD ([BD1] versus [BD6]; P<0.01). Histologic signs of lung injury (congestion, hemorrhage, and neutrophilic influx) were more pronounced in [BD3] and [BD6] compared with the other groups; however, this difference did not reach statistical significance., Conclusion: Three hours after brain death, significant signs of inflammation and lung injury were seen compared with sham-operated animals. This murine BD model gives us opportunities for further mechanistic studies regarding treatment of BD-related donor lung injury., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose of Review: During a classical lung transplantation procedure, there is no attempt to restore the bronchial circulation, giving rise to ischemia of the mucosa with initial loss of ciliated function. This might compromise the ciliary function and the infection defense mechanisms of the airways., Recent Findings: Although initially the airways are characterized by ischemia (epithelial sloughing), later on, there seems to be a restoration of the ciliary function and up to now, there is no clear evidence that there is an increased risk of infectious episodes due to the lack of bronchial circulation, although this has not extensively been investigated., Summary: Local pulmonary defense mechanisms after lung transplantation without bronchial revascularization seem to be preserved at least in a stable condition. Whether the loss of bronchial circulation has a negative impact when complications develop (such as bronchiolitis obliterans syndrome) remains speculative.

Background: Dendritic cells (DC) linking innate and adaptive immune responses are present in human lungs, but the characterization of different subsets and their role in COPD pathogenesis remain to be elucidated. The aim of this study is to characterize and quantify pulmonary myeloid DC subsets in small airways of current and ex-smokers with or without COPD., Methods: Myeloid DC were characterized using flowcytometry on single cell suspensions of digested human lung tissue. Immunohistochemical staining for langerin, BDCA-1, CD1a and DC-SIGN was performed on surgical resection specimens from 85 patients. Expression of factors inducing Langerhans-type DC (LDC) differentiation was evaluated by RT-PCR on total lung RNA., Results: Two segregated subsets of tissue resident pulmonary myeloid DC were identified in single cell suspensions by flowcytometry: the langerin+ LDC and the DC-SIGN+ interstitial-type DC (intDC). LDC partially expressed the markers CD1a and BDCA-1, which are also present on their known blood precursors. In contrast, intDC did not express langerin, CD1a or BDCA-1, but were more closely related to monocytes.Quantification of DC in the small airways by immunohistochemistry revealed a higher number of LDC in current smokers without COPD and in COPD patients compared to never smokers and ex-smokers without COPD. Importantly, there was no difference in the number of LDC between current and ex-smoking COPD patients.In contrast, the number of intDC did not differ between study groups. Interestingly, the number of BDCA-1+ DC was significantly lower in COPD patients compared to never smokers and further decreased with the severity of the disease. In addition, the accumulation of LDC in the small airways significantly correlated with the expression of the LDC inducing differentiation factor activin-A., Conclusions: Myeloid DC differentiation is altered in small airways of current smokers and COPD patients resulting in a selective accumulation of the LDC subset which correlates with the pulmonary expression of the LDC-inducing differentiation factor activin-A. This study identified the LDC subset as an interesting focus for future research in COPD pathogenesis.

Clinical studies revealed that azithromycin reduces airway neutrophilia during chronic rejection after lung transplantation. Our aim was to investigate the possible effect of azithromycin on ischaemia-reperfusion injury. Azithromycin or water was administered to mice every other day during 2 weeks (n = 6/group). On the 14th day, the left lung was clamped to induce ischaemia (90 min). In two additional groups, animals underwent the same protocol, followed by 4 h of reperfusion. Two control groups were included with thoracotomy only. Inflammatory parameters and oxidative stress were measured in broncho-alveolar lavage of the left lung. Leukocytes, lymphocytes, neutrophils, 8-isoprostane and IL-1beta levels after ischaemia and reperfusion were significantly reduced in mice treated with azithromycin. There was a trend towards lower IL-6 and KC levels. A significant correlation was seen between 8-isoprostanes and neutrophils (Pearson r = 0.72; P = 0.0086), IL-6 (Pearson r = 0.84; P = 0.0006), KC (Pearson r = 0.88; P = 0.0002) and IL-1beta (Pearson r = 0.62; P = 0.0326). We conclude (i) that azithromycin reduces inflammation and oxidative stress in our IRI model, and (ii) that oxidative stress is correlated with the number of neutrophils and IL-6, KC and IL-1beta levels after ischaemia and reperfusion. Azithromycin should be further investigated as a novel drug to prevent lung ischaemia-reperfusion injury.

Background: Lungs donated after cardiac death (DCD) may significantly reduce current organ shortage. However, the warm ischemic period following circulatory arrest may enhance ischemia-reperfusion injury (IRI). We investigated the possible therapeutic effect of N-acetyl cysteine (NAC), a potent anti-oxidative agent on IRI in a porcine ex vivo lung reperfusion model., Materials and Methods: NAC (50 mg/kg) was nebulized to pigs (n = 6/group) prior to sacrifice (NAC-DCD). In DCD-NAC, animals received NAC 15 min after death. Control animals did not receive an aerosol (DCD). Interleukin (IL)-1beta, tumor necrosis factor-alpha, IL-8, lactate dehydrogenase activity and thiobarbituric acid reactive substances were measured and cells were counted in broncho-alveolar lavage from the right lung after a 3-h warm plus 1-h cold ischemic interval., Results: There were no differences in cells between groups, however cell death was lower in NAC-DCD (10.3 +/- 1.5%) and DCD-NAC (7.83 +/- 1.8%) compared to DCD (18.0 +/- 3.8%). IL-1beta levels (111.5 +/- 28.8 pg/mL and 92.2 +/- 51.0 pg/mL versus 250.3 +/- 56.6 pg/mL) and lactate dehydrogenase activity (1258.0 +/- 440.9 U/L and 1606.0 +/- 289.0 U/L versus 2848.0 +/- 760.9 U/L) were significantly lower in NAC-DCD and DCD-NAC compared with DCD, respectively. These postischemic inflammatory markers correlated with functional parameters upon reperfusion of the left lung, reported in a previous study., Conclusions: Administration of NAC prior to or shortly after circulatory arrest results in a marked reduction of inflammation during the warm ischemic phase.

Background: The warm ischemic period in non-heart-beating donor lungs may contribute to a higher degree of ischemia-reperfusion injury after lung transplantation. We investigated the impact and timing of administration of N-acetyl cysteine (NAC) on inflammatory parameters., Methods: Ischemia (I) was induced by clamping the hilum of the left lung for 90 minutes, and some protocols were followed by reperfusion (R) for 4 hours. Mice were divided into nine groups (n = 6/group): three control groups ([sham] (thoracotomy only), [I] and [I+R]); two groups with saline instillation only ([saline+I] and [saline+I+R]); and four experimental groups with NAC (50 mg/kg), administered by instillation ([NAC+I], [NAC+I+R] and [I+NAC+R]) or by aerosol ([NACaero+I+R]). Cell counts and protein levels in bronchoalveolar lavage (BAL) were determined., Results: NAC administered prior to hilar clamping led to a significant decrease in macrophages and lymphocytes and interleukin (IL)-1 beta levels after ischemia. NAC also resulted in significantly fewer macrophages, lymphocytes and neutrophils as well as IL-1 beta, keratinocyte cytokine (KC), monocyte chemoattractant protein (MCP)-1 and IL-6 levels in BAL taken after reperfusion., Conclusions: NAC treatment prior to warm ischemia attenuates inflammatory changes after both the ischemic and reperfusion periods.

Rationale: Chronic obstructive pulmonary disease (COPD) is characterized by chronic airway inflammation. It is unclear if dendritic cells (DC) participate in this inflammatory process., Objectives: To evaluate the presence of DC in small airways of patients with COPD., Methods: We evaluated DC infiltration in small airways by immunohistochemistry in patients with COPD (stage I-IV), never-smokers, and smokers without COPD. Chemokine ligand 20 (CCL20, the most potent chemokine in attracting DC) was determined in total lung by RT-PCR and in induced sputum by enzyme-linked immunsorbent assay. Chemokine receptor 6 (CCR6, the receptor for CCL20) expression on human pulmonary DC was evaluated by RT-PCR and flow cytometry., Measurements and Main Results: There is a significant increase in DC number in the epithelium (p = 0.007) and adventitia (p = 0.009) of small airways of patients with COPD compared with never-smokers and smokers without COPD. DC number in epithelium and adventitia increases along with disease severity. CCL20 mRNA expression in total lung and CCL20 protein levels in induced sputum are significantly higher in patients with COPD compared with never-smokers (p = 0.034 for CCL20 mRNA and p = 0.0008 for CCL20 protein) and smokers without COPD (p = 0.016 for CCL20 mRNA and p = 0.001 for CCL20 protein). DC isolated from human lung express CCR6 both at mRNA and at protein level., Conclusions: This is the first description of airway infiltration by DC in COPD. Moreover, interaction between CCL20 and CCR6 provides a possible mechanism for accumulation of DC in the lungs in COPD.

Objective: The use of non-heart-beating donors (NHBD) has been advocated as an alternative to overcome the critical organ shortage in lung transplantation despite the warm ischemic period that may result in primary graft dysfunction. On the contrary, brain death in the heart-beating donor (HBD) may be an underestimated risk factor for donor lung injury. We postulated that 60 min of warm ischemia in the NHBD is less detrimental to the lung than the pathophysiological changes after brain death in the HBD. In this study we compared the quality of lungs from HBD versus NHBD in an isolated reperfusion model., Methods: Pigs (n=10 per group) were divided into three groups. In group I (HBD), brain death was induced by acute inflation of an intracranial epidural balloon catheter. In group II (CONTROL), the balloon was not inflated. In group III (NHBD), cardiac arrest was induced by myocardial fibrillation. After 5 h of in situ mechanical ventilation, lungs in HBD and CONTROL were preserved with a cold antegrade flush. In NHBD, unflushed grafts were explanted after 1 h of warm ischemia and 4 h of topical cooling in the cadaver. Graft performance was evaluated during 1 h in an isolated ventilation and reperfusion model. Extravascular lung water content (EVLW) was calculated. All data are reported as mean+/-SEM., Results: A significant autonomic storm was observed in HBD following balloon inflation. During ex vivo assessment, pulmonary vascular resistance (PVR) at 60 min in HBD (2634+/-371 dynes cm(-5)) was significantly higher as compared with that of CONTROL and NHBD (1894+/-137 dynes s cm(-5) and 1268+/-111 dynes s cm(-5), respectively; p<0.05). Plateau airway pressure (Plateau AwP) was also higher in HBD (17+/-1cmH2O) compared with that of CONTROL (12+/-1 cmH2O; p<0.05) and NHBD (14+/-1 cmH2O; not significant). No significant differences were observed between HBD, CONTROL and NHBD in EVLW (79+/-1%, 79+/-0% and 78+/-1%, respectively), and in PO2/FiO2 (564+/-58 mmHg, 622+/-14 mmHg and 578+/-26 mmHg, respectively)., Conclusions: These data indicate that 1-h warm ischemic lungs in our model are less susceptible to ischemia-reperfusion injury than lungs retrieved 5 h after brain death. This study further supports the use of lungs from NHBD for pulmonary transplantation.

Background: The use of non-heart-beating donors (NHBDs) for lung transplantation is a possible alternative for increasing the number of organs available. The warm ischemic period after circulatory arrest may contribute to a higher degree of primary graft dysfunction, resulting from ischemia-reperfusion injury (IRI). A better understanding of the role of inflammatory cells during the warm ischemic interval may be useful for developing new therapeutic strategies against IRI., Methods: Mice were divided in 7 groups (n = 6/group). In 3 groups, ischemia was induced by clamping the hilum of the left lung for 30, 60 or 90 minutes (Groups [30I], [60I] or [90I], respectively). In 3 more groups, the lung was reperfused for 4 hours after identical ischemic intervals (Groups [30I+R], [60I+R] or [90I+R], respectively). Surgical impact was evaluated in a sham group ([sham]). Total and differential cell counts and interleukin-1beta (IL-1beta) protein levels in bronchoalveolar lavage (BAL) were determined and their correlations were investigated., Results: Total cell, macrophage and lymphocyte numbers and IL-1beta protein levels increased progressively with longer ischemic intervals. A significant rise in BAL macrophages and lymphocytes was observed between [60I] and [90I] (p < 0.01 and p < 0.001, respectively). BAL neutrophils only increased after reperfusion with longer ischemic intervals. A positive correlation was found in the ischemic groups between IL-1beta levels and the number of macrophages (r = 0.62; p = 0.0012) and the number of lymphocytes (r = 0.68; p = 0.0002). A positive correlation was found in the reperfusion groups between IL-1beta levels and the number of neutrophils (r = 0.48; p = 0.044)., Conclusions: This study demonstrates for the first time that BAL macrophages and lymphocytes increase significantly during warm ischemia and correlate with IL-1beta levels.

Listeria monocytogenes is an important bacterial pathogen in immunocompromised patients, the elderly, pregnant women and transplant patients, but until now it has not been reported in lung transplants. We report the first case of listeriosis in a lung transplant recipient who presented with a pleural effusion 8 days after transplantation. After the introduction of a thorax drain and the administration of intravenous antibiotics during 3 weeks, the patient recovered completely. This case highlights the increased risk for uncommon respiratory infections in lung transplant patients and examines the specific management of listeria pleuritis.

Background: The use of lungs from non-heart-beating donors (NHBD) might significantly alleviate the organ shortage. The tolerable warm ischemic period after cardiac arrest, however, is limited to approximately 1 hour. If the lung could be safely protected inside the cadaver, this time period may be prolonged. This would help to obtain family consent and to organize organ retrieval., Methods: Pigs (30.8 +/- 0.6 kg) were killed, left untouched for 3 hours, and divided into 3 groups. Nebulized N-acetyl cysteine (NAC) (300 mg), a precursor of the antioxidant agent glutathione, was administered during 10 minutes before death in Group I (NAC-NHBD, n = 6) and 15 minutes after death in Group II (NHBD-NAC, n = 6). In the control group, no aerosol was administered (NHBD, n = 6). After a warm ischemic interval of 3 hours, both lungs in all groups were topically cooled for 1 hour. Thereafter, the left lung was prepared for evaluation in an isolated reperfusion circuit. Hemodynamic, aerodynamic, and oxygenation parameters were measured. Wet-to-dry weight ratio (W/D) was calculated after reperfusion. The right lung was used to measure reduced glutathione (GSH) and oxidized glutathione (GSSG) levels (micromol/g) in lung homogenates and total protein levels in bronchial lavage fluid., Results: Pulmonary vascular resistance, mean airway pressure, and W/D were significantly decreased in NAC-NHBD (1930 +/- 144 Dynes x sec x cm(-5), 14.2 +/- 0.5 cm H2O, and 7.4 +/- 0.4; p < 0.01, 0.01, and 0.05, respectively) and NHBD-NAC (1837 +/- 180 Dynes x sec x cm(-5), 13.3 +/- 1.2 cm H2O, and 7.3 +/- 0.3; p < 0.01, 0.05, and 0.05, respectively) when compared with the control group (5051 +/- 530 Dynes x sec x cm(-5), 17 +/- 0.4 cm H2O, 8.5 +/- 0.1, respectively). GSH/GSSG ratio was significantly higher and protein levels were significantly lower in NAC-NHBD (1.7 +/- 0.1 and 1315 +/- 60 microg/ml; p < 0.05 and 0.05, respectively) and NHBD-NAC (1.7 +/- 0.2 and 1475 +/- 159 microg/ml; p < 0.05 and 0.05, respectively) when compared with the control group (1.2 +/- 0.1 and 2150 +/- 200 microg/ml)., Conclusions: Nebulized NAC administered before or shortly after death attenuates early ischemia reperfusion injury via upregulation of glutathione. NAC might be a promising tool to protect the pulmonary graft from both controlled and uncontrolled NHBD.

Background: The ideal preservation method during the warm ischemic period in the non-heart-beating donor (NHBD) remains unclear. In this study we compare the protective effect of ventilation vs cooling of the non-perfused pulmonary graft., Methods: Domestic pigs (30.8 +/- 0.35 kg) were divided into 3 groups. In Group I, lungs were flushed with cold Perfadex solution, explanted and stored in saline (4 degrees C) for 4 hours (HBD, n = 5). Pigs in the 2 study groups were killed by myocardial fibrillation and left untouched for 1 hour. Lungs in Group II were ventilated (NHBD-V, n = 5) for 3 hours. Lungs in Group III were topically cooled (NHBD-TC, n = 5) in situ for 3 hours with saline (6 degrees C) infused via intra-pleural drains. Thereafter, the left lungs from all groups were prepared for evaluation. In an isolated circuit the left lungs were ventilated and reperfused via the pulmonary artery (PA) with autologous, hemodiluted, deoxygenated blood. Hemodynamic, aerodynamic and oxygenation parameters were measured at 37.5 degrees C and a PA pressure of 20 mm Hg. The wet:dry weight ratio (W/D) was calculated after reperfusion., Results: Pulmonary vascular resistance, oxygenation index and W/D weight ratio were significantly worse in NHBD-V (3,774 +/- 629 dyn sec cm(-5), 3.43 +/- 0.5, 6.98 +/- 0.42, respectively) compared with NHBD-TC (1,334 +/- 140 dyn sec cm(-5), 2.47 +/- 0.14, 5.72 +/- 0.24, respectively; p < 0.01, p < 0.05 and p < 0.05, respectively) and HBD (1,130 +/- 91 dyn sec cm(-5), 2.25 +/- 0.09, 5.23 +/- 0.49, respectively; p < 0.01, p < 0.01 and p < 0.05, respectively groups). No significant differences were observed, however, in any of these parameters between NHBD-TC and HBD (p = 0.46, p = 0.35 and p = 0.12, respectively)., Conclusion: These results indicate that cooling of the pulmonary graft inside the cadaver is the preferred method in an NHBD protocol. It is also confirmed that 1 hour of warm ischemia does not diminish graft function upon reperfusion.

If lungs could be retrieved for transplantation after circulatory arrest, the shortage of donors might be significantly alleviated. An important issue in using lungs from these so-called non-heart-beating donors is the development of a technique to assess their quality prior to transplantation without jeopardizing the life of the recipient. In our laboratory we tested the reliability of an ex vivo model for such an evaluation. We used pig lungs from optimal control animals, in casu heart-beating donors. This model enabled us to preserve and evaluate lungs with perfect function up to 24 hours after death. The intermediate assessment is performed in an isolated circuit where the lungs are being ventilated and reperfused via the pulmonary artery (PA) with autologous and haemodiluted blood. Haemodynamic, aerodynamic and oxygenation parameters are measured at 37.5 degrees C and a maximum PA pressure of 20 mmHg. These data were correlated with premortem values. During this ex vivo evaluation, leukocyte depletion plays an important role since neutrophils have been recognized as critical components in the inflammatory cascade, which is responsible for graft dysfunction soon and long after transplantation.