Left Lung Transplantation Research Articles

Summary of perioperative analgesia and sedation management of 19 lung transplant recipients

Objective: To summarize and explore the management experience of postoperative analgesia and sedation in lung transplant recipients. Methods: A total of 19 cases of lung transplantation were performed in Renmin Hospital of Wuhan University from December 2016 to December 2020, and all of them were transferred back to intensive care unit after surgery, the clinical data were retrospectively analyzed. Results: Among the 19 patients, the main diagnoses were chronic obstructive pulmonary disease in 5 cases, idiopathic pulmonary fibrosis in 6 cases, bronchiectasis in 2 cases, pneumoconiosis in 4 cases, Kartagener syndrome in 1 case and COVID-19 pneumonia with advanced pulmonary fibrosis in 1 case. There were 12 cases of double lung transplantation, and 7 cases of unilateral lung transplantation in (4 cases of left single lung transplantation and 3 cases of right single lung transplantation). Nine patients used ECMO to complete the operation, and 5 cases took ECMO back to the intensive care unit. All patients were treated with opioid analgesia, mainly sufentanil at a dose of 0.2-0.3 μg/(kg•h), midazolam and propofol are mainly used as sedatives at doses of 0.02-0.1 mg/(kg•h) and 0.3-0.4 mg/(kg•h), respectively, and the Richmond agitation sedation scale was -3.01±1.32 within 24 hours after operation. The main postoperative adverse events were delirium (1 case) and respiratory depression (1 case). There were 6 deaths during the perioperative period. One case died of multi-drug resistant bacteria infection, 1 case died of circulatory failure caused by active thoracic hemorrhage post-operation, the third case died of intraoperative cardiac arrest, and the other 3 cases were given up because of multiple organs failure. Conclusion: Analgesia and sedation is an important treatment for patients after lung transplantation. Choosing the depth of sedation according to the functional state of organs of lung transplant recipients and implementing the sedation strategy aiming at organ function protection is helpful to maintain the stability of cardiopulmonary function after lung transplantation. © 2021, Editorial Board of Medical Journal of Wuhan University. All right reserved.

Summary of perioperative hemodynamic management of 19 lung transplant recipients

Objective: To summarize and discuss the experience of perioperative hemodynamic management of lung transplant recipients. Methods: A total of 19 lung transplant recipients from December 2016 to December 2020 were investigated in Renmin Hospital of Wuhan University, all of which were transferred to the intensive care unit for further monitoring and treatment, and their clinical data were retrospectively analyzed. Results: The 19 lung transplant recipients included 5 cases of chronic obstructive pulmonary disease (COPD), 5 cases of idiopathic pulmonary fibrosis (IPF), 4 cases of pneumoconiosis, 2 cases of bronchiectasis, 1 case of later lung fibrosis associated with COVID-19, 1 case of connective tissue disease-related pulmonary fibrosis, and 1 case of Kartagener syndrome. Twelve cases adopted double lung transplantation, while seven cases reveived unilateral lung transplantation (4 cases of left single lung transplantation and 3 cases of right single lung transplantation). There were 6 deaths during the perioperative period. One case died of multi-drug resistant bacteria infection, one case died of circulatory failure caused by active thoracic hemorrhage post-operation, the third case died of intraoperative cardiac arrest, and the other 3 cases were given up because of multiple organs failure. The remaining 13 cases were cured and discharged. Of the 19 recipients, 14 received vasopressors. The total and daily fluid output of the recipients in 3 postoperation days were greater than the input volume (P<0.05). Conclusion: Lung transplantation is an effective method for the treatment of end-stage lung disease. The hemodynamic management is a keypoint during perioperative period. It is import to maintain the blood volume as low as possible under the premise of systemic perfusion, limit the amount of fluid, choose albumin or plasma to increase the colloidal osmotic pressure, and strengthen the maintenance of right heart function. These abobe measures may improve the prognosis of lung transplant recipients. © 2021, Editorial Board of Medical Journal of Wuhan University. All right reserved.

Lipoxin A4 attenuates the lung ischaemia reperfusion injury in rats after lung transplantation

Background Lung ischaemia reperfusion injury (LIRI) is the major cause of primary lung dysfunction after lung transplantation. Lipoxin A4 inhibits the oxidative stress and inflammation. This study aimed to evaluate the potential protective effect of lipoxin A4 on LIRI in rats. Methods SD (Sprague-Dawley) rats were randomised into the sham, LIRI and LA4 groups. Rats in the sham group received anaesthesia, thoracotomy and intravenous injection of saline, while those in the LIRI or LA4 group received left lung transplantation and intravenous injection of saline or lipoxin A4, respectively. After 24 h of reperfusion, the PaO2/FiO2 (Partial pressure of O2 to fraction inspiratory O2), wet/dry weight ratios and protein levels in lungs were measured to assess the alveolar capillary permeability. The oxidative stress response and inflammation were examined. The histological and apoptosis analyses of lung tissues were performed via HE staining (Haematoxylin-eosin staining) and TUNEL assay, respectively. The effects of lipoxin A4 on the endothelial viability and tube formation of hypoxaemia and reoxygenation-challenged rat pulmonary microvascular endothelium cells were determined. Results Lipoxin A4 significantly ameliorated the alveolar capillary permeability, reduced the oxidative stress and inflammation in transplanted lungs. The histological injury and apoptosis of lung tissues were also alleviated by lipoxin A4. In vitro lipoxin A4 treatment promoted the endothelial tube formation and improved the endothelial viability. Conclusion Lipoxin A4 protects LIRI after lung transplantation in rats, and its therapeutic effect is associated with the properties of anti-inflammation, anti-oxidation, and endothelium protection. Key messages: Lung transplantation is a treatment approach for the patients with lung disease. LIRI is the major cause of postoperative primary lung dysfunction. Lipoxins A4 exhibits strong anti-inflammatory properties.

Pulmonary vein stenosis after lung transplantation: a case report and literature review

Pulmonary vein stenosis (PVS) is a rare event following lung transplantation which increases the risk of morbidity and mortality. Early detection and rapid treatment of this condition is crucial for its management. Although several reports on PVS have been published, there is little consensus regarding its diagnosis and the methods of management. Here we present our experience with PVS. A 31-year-old man received a left lung transplant for chronic hypersensitivity pneumonitis. One year after his single-lung transplant, he began to develop persistent progressive hypoxemia. Computed tomography (CT) of the chest showed left pleural effusion and thickening of the interlobular septa. The results of bronchoscopy and transbronchial biopsies excluded the possibility of acute rejection or infection. The pleural effusion was transudative with lymphocyte predominance. Computed tomography angiography (CTA) in the left atrium and pulmonary veins demonstrated obvious stenosis of both the upper and lower left pulmonary veins (LLPVs) at the transplant anastomotic site. The patient underwent a catheter-guide stent implantation into the stenotic segment of the upper left pulmonary vein (ULPV), and his pleural effusion and hypoxemia problems were ameliorated. Ten months after the intervention, the patient was in excellent clinical condition. In a literature review, we discuss the importance of identifying PVS early after transplantation, the utility of CTA for diagnosis and the use of pulmonary vein stenting intervention. This review provides a basis for further diagnostic strategies and treatments for PVS following lung transplantation.

Functional, Metabolic and Morphologic Results of Ex Vivo Donor Lung Perfusion with a Perfluorocarbon-Based Oxygen Carrier Nanoemulsion in a Large Animal Transplantation Model.

Background: Ex vivo lung perfusion (EVLP) is a technology that allows the re-evaluation of questionable donor lung before implantation and it has the potential to repair injured donor lungs that are otherwise unsuitable for transplantation. We hypothesized that perfluorocarbon-based oxygen carrier, a novel reconditioning strategy instilled during EVLP would improve graft function. Methods: We utilized perfluorocarbon-based oxygen carrier (PFCOC) during EVLP to recondition and improve lung graft function in a pig model of EVLP and lung transplantation. Lungs were retrieved and stored for 24 h at 4 °C. EVLP was done for 6 h with or without PFCOC. In the transplantation groups, left lung transplantation was done after EVLP with or without PFCOC. Allograft function was assessed by means of pulmonary gas exchange, lung mechanics and vascular pressures, histology and transmission electron microscopy (TEM). Results: In the EVLP only groups, physiological and biochemical markers during the 6-h perfusion period were comparable. However, perfusate lactate potassium levels were lower and ATP levels were higher in the PFCOC group. Radiologic assessment revealed significantly more lung infiltrates in the controls than in the PFCOC group (p = 0.04). In transplantation groups, perfusate glucose consumption was higher in the control group. Lactate levels were significantly lower in the PFCOC group (p = 0.02). Perfusate flavin mononucleotide (FMN) was significantly higher in the controls (p = 0.008). Post-transplant gas exchange was significantly better during the 4-h reperfusion period in the PFCOC group (p = 0.01). Plasma IL-8 and IL-12 levels were significantly lower in the PFCOC group (p = 0.01, p = 0.03, respectively). ATP lung tissue levels at the end of the transplantation were higher and myeloperoxidase (MPO) levels in lung tissue were lower in the PFCOC group compared to the control group. In the PFCOC group, TEM showed better tissue preservation and cellular viability. Conclusion: PFCOC application is safe during EVLP in lungs preserved 24 h at 4 °C. Although this strategy did not significantly affect the EVLP physiology, metabolic markers of the donor quality such as lactate production, glucose consumption, neutrophil infiltration and preservation of mitochondrial function were better in the PFCOC group. Following transplantation, PFCOC resulted in better graft function and TEM showed better tissue preservation, cellular viability and improved gas transport.

ASPERGILLUS EMPYEMA IN A LUNG TRANSPLANT PATIENT

SESSION TITLE: Medical Student/Resident Chest Infections Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Fungal empyema thoracis is an uncommon entity with reported mortality rates as high as 73% [1]. Here we report a case of aspergillus empyema with associated cutaneous lesion in a lung transplant patient. CASE PRESENTATION: A 70 year old man who had undergone left lung transplant 5 years prior for chronic hypersensitivity pneumonitis, on immune suppressive therapy with tacrolimus, mycophenolate and prednisone presented with 3 months of weight loss, generalized weakness and confusion. He noted a stable chronic cough productive of clear phlegm, without dyspnea, hemoptysis, fever or night sweats. Approximately 3 months prior to presentation, while undergoing treatment for squamous cell carcinoma of the scalp, he had an anterior chest wall mass excised, histopathology notable for severe acute inflammation and narrow septate hyphal elements. Serum and bronchoalveolar lavage fluid galactomannan levels at that time were not detected, and treatment with systemic antifungals was deferred. On hospitalization, he was well-appearing with normal oxyhemoglobin saturation on room air. Limited bedside ultrasound examination demonstrated a large multi-loculated pleural effusion. Computed tomography imaging revealed severe traction bronchiectasis and fibrosis of native right lung and a large right sided pleural effusion. Diagnostic thoracentesis yielded a hazy yellow exudate with a pH 6.99, LDH of 1462 U/L, total protein 2.2 g/dL, and glucose 256 mg/dL. Fluid culture revealed 2+ Aspergillus fumigatus, consistent with a diagnosis of aspergillus fumigatus. He underwent treatment with oral isavuconazole and intrapleural tPA/dornase alpha via a pleural pigtail catheter. Unfortunately, the effusion persisted; surgical options were reviewed with patient, who elected to defer surgery and discharge home with hospice. DISCUSSION: Aspergillus empyema thoracis is an uncommon disease which mostly occurs in patients with established empyema or bronchiectectatic cavities and a bronchopleural or pleurocutaneous fistula [2]. In our case, early manifestations of invasive aspergillosis were subtle, and diagnosis elusive until the disease was advanced. CONCLUSIONS: Fungal empyema thoracis is an important differential consideration for pleural effusion in patients with chronic immune suppression, solid organ or hematologic malignancy. Mortality for this condition is high, particularly if not recognized and treated appropriately. Reference #1: Ko, SC et al. Fungal empyema thoracis: an emerging clinical entity. Chest, 2000; 117(6):1672-8. Reference #2: Zhang, W. et al. Pleural aspergillosis complicated by recurrent pneumothorax: a case report. J Med Case Rep, 2010. 4: p 180. DISCLOSURES: No relevant relationships by Nicholas Braus, source=Web Response No relevant relationships by Timothy Rowe, source=Web Response

DYSPNEA UNVEILED BY HANDS: A CHALLENGING CASE OF RAPIDLY PROGRESSIVE INTERSTITIAL LUNG DISEASE

SESSION TITLE: Medical Student/Resident Diffuse Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Antisynthetase syndrome (ASS) is a rare autoimmune condition characterized by antibodies directed against amino-acyl-tRNA synthetase along with clinical features of myositis, arthritis, Raynaud’s phenomenon and interstitial lung disease (ILD). We present a case of rapidly progressive ASS associated ILD. CASE PRESENTATION: A 40-year-old African American woman with past medical history of smoking and prior hospitalization for presumed pneumonia presented to the emergency department with complaints of ongoing but worsening cough and dyspnea for more than four months. She was hypoxic and lung examination revealed bilateral fine crackles. Chest imaging revealed patchy mixed consolidation and ground-glass opacities at the lung bases (figure 1). Her course worsened needing mechanical ventilation. Given the clinical picture and imaging findings raising concerns for ILD, she underwent VATS/lung biopsy, which revealed pinkish fibrous plugs: Masson bodies, concerning for organizing pneumonia (figure 2). Autoimmune work including ANA and rheumatoid factor was negative. She continued to decline despite broad-spectrum antibiotics and high dose steroids and had to be placed on VV-ECMO for severe ARDS. Hyperkeratosis and hyperpigmentation of her hands were later noted, raising concerns for an autoimmune process. A myositis panel was done, which revealed positive Anti-PL12 antibodies. Lung function recovery was sub-optimal despite ECMO support for 85 days, IVIG, plasma exchange and cyclophosphamide therapy. She had to undergo single left lung transplantation. She eventually was discharged home on immunosuppressants after five months of hospitalization. Her explanted lung showed features of non-specific interstitial pneumonia. She has done well for more than 2 years post-transplant with amelioration in the imaging findings of her native right lung and with no signs of graft rejection. The final diagnosis was rapidly progressive ASS associated ILD with progression to ARDS requiring single lung transplantation. DISCUSSION: ASS is a rare group of idiopathic inflammatory myopathies, characterized by the presence of seven different myositis-specific antisynthetase antibodies with Anti-Jo1 being the most common one. Anti-PL12 antibody type is associated with a severe form of ILD. ANA antibodies are typically negative and hence a high index of suspicion for ASS is warranted. Literature about the management of ASS-ILD is sparse but anecdotal experience favors steroids as first-choice agents and other immunosuppressive agents, plasma exchange therapy, and even lung transplantation in severe and refractory cases. CONCLUSIONS: Our case of ASS-ILD with anti-PL12 antibodies shows the rapid progression of the ILD despite aggressive immunosuppressive therapy and highlights the importance of identification, aggressive therapy and the role of VV-ECMO with lung transplantation as an option for refractory cases. Reference #1: Connors GR, Christopher-Stine L, Oddis CV, et al. Interstitial lung disease associated with the idiopathic inflammatory myopathies: what progress has been made in the past 35 years? Chest. 2010;138:1464–1474. Reference #2: Esposito AC, Gige TC, Miot HA. Syndrome in question: antisynthetase syndrome (anti-PL-7). An Bras Dermatol. 2016;91(5):683-685. DOI:10.1590/abd1806-4841.20164449 Reference #3: Witt LJ, Curran JJ, Strek ME. The Diagnosis and Treatment of Antisynthetase Syndrome. Clin Pulm Med. 2016;23(5):218-226. DOI:10.1097/CPM.0000000000000171 DISCLOSURES: No relevant relationships by Anas Alameh, source=Web Response No relevant relationships by Ansaam Daoud, source=Web Response No relevant relationships by Sujith Modugula, source=Web Response No relevant relationships by Lokesh Venkateshaiah, source=Web Response No relevant relationships by Elizabeth Verghese, source=Web Response

Occurrence of metastatic eccrine porocarcinoma in an immunosuppressed patient

BackgroundEccrine porocarcinoma is a rare malignancy accounting for 0.005 to 0.01% of all cutaneous tumors. However, its etiology is not well established. Herein we are reporting the occurrence of metastatic porocarcinoma of the back in a patient with a history of multiple cutaneous malignancies and chronic immunosuppression.Case presentationA 79-year-old male with a history of long-term immunosuppressive therapy for left lung transplantation and multiple cutaneous malignancies including melanoma, presented with an enlargening plaque on the right upper back. Biopsy demonstrated an infiltrative epithelial tumor with aggressive histology and ductal formation. Immunohistochemical stains for p63, CK-5/6, and CEA were diffusely positive, while CK-7 and CK-20 were negative. A diagnosis of eccrine porocarcinoma was made. He underwent complete wide excision with negative margins of the right upper back in January 2018. In November 2018, he was found to have a right posterior shoulder mass, positive right axillary lymph nodes, superficial right upper back soft tissue masses and lymphangitic carcinomatosis involving the left lung. He was transitioned to comfort care and subsequently passed from metastatic disease in December 2018.ConclusionThe occurrence of eccrine porocarcinoma in a patient on long term immunosuppressive therapy for lung transplantation suggests a possible role for chronic immunosuppression in the induction of a subset of eccrine porocarcinomas, as in other cutaneous malignancies.

Protective Effects of a Hydrogen-Rich Preservation Solution in a Canine Lung Transplantation Model

Molecular hydrogen (H2) has protective effects against ischemia-reperfusion injury in various organs. Because they are easier to transport and safer to use than inhaled H2, H2-rich solutions are suitable for organ preservation. In this study, we examined the protective effects of an H2-rich solution for lung preservation in a canine left lung transplantation (LTx) model. Ten beagles underwent orthotopic left LTx after 23 hours of cold ischemia followed by reperfusion for 4 hours. Forty-five minutes after reperfusion, the right main pulmonary artery was clamped to evaluate the function of the implanted graft. The beagles were divided into two groups: control group (n= 5), and H2 group (n= 5). In the control group, the donor lungs were flushed and immersed during cold preservation at 4°C using ET-Kyoto solution, and in the H2 group, these were flushed and immersed using H2-rich ET-Kyoto solution. Physiologic assessments were performed during reperfusion. After reperfusion, the wet-to-dry ratios were determined, and histology examinations were performed. Significantly higher partial pressure of arterial oxygen and significantly lower partial pressure of carbon dioxide were observed in the H2 group than in the control group (P= .045 and P < .001, respectively). The wet-to-dry ratio was significantly lower in the H2 group than in the control group (P= .032). Moreover, in histology examination, less lung injury and fewer apoptotic cells were observed in the H2 group (P < .001 and P < .001, respectively). Our results demonstrated that the H2-rich preservation solution attenuated ischemia-reperfusion injury in a canine left LTx model.

Right single lung transplantation or double lung transplantation compared with left single lung transplantation in chronic obstructive pulmonary disease

Although single and double lung transplantation outcomes for chronic obstructive pulmonary disease (COPD) have been investigated, right and left single lung transplants have never been rigorously compared to evaluate disease-specific differences. Single lung transplants for COPD often have hyperinflation of the contralateral native lung, which may be more pronounced in left lung transplants. Using the United Network for Organ Sharing registry, we conducted a retrospective cohort study of 5,585 adults who underwent lung transplantation for COPD from May 4, 2005 to June 30, 2017. Subjects were followed until March 2019. Post-transplant survival was compared using Cox proportional hazards and Royston and Parmar's flexible parametric survival models. We adjusted for donor and recipient factors with known or plausible associations with survival. Lung transplant recipients who received a left single lung transplant for COPD had an increased risk of post-transplant death when compared with those who received a right single lung transplant for COPD (hazard ratio [HR]: 1.24, 95% CI: 1.08-1.48, p = 0.002). Survival did not differ significantly between double lung transplant and right single lung transplant recipients (HR: 0.88, 95% CI: 0.77-1.02, p = 0.086). Adjusted 5-year survival was 57.8% (95% CI: 55.7-60.1) for double lung recipients, 56.7% (95% CI: 55.4-58.0) for right single lung recipients, and 50.9% (95% CI: 47.2-55.0) for left single lung recipients. In COPD, right single lung transplantation was associated with improved post-transplant survival compared with left single lung transplantation, and no significant difference in post-transplant survival compared with double lung transplantation was found. In light of the ongoing donor lung shortage, preferential allocation of right single lungs to patients with COPD should be considered.

Ex Vivo Lung Perfusion Improves the Inflammatory Signaling Profile of the Porcine Donor Lung Following Transplantation.

Primary graft dysfunction and allograft rejection represent major caveats to successful lung transplantation. Reducing inflammation in donor lungs before transplantation may improve outcomes. Evidence exists that ex vivo lung perfusion (EVLP) can alter the donor lung environment, although the mechanisms remain unclear. This study aimed to characterize the inflammatory signaling profile of the lung following standard and EVLP transplant and delineate the immediate impact on the recipient circulation. Female recipient pigs (n = 12) were randomized to undergo left lung transplantation from male donors either using the gold standard protocol (static cold storage) or following 3 hours of EVLP. The relative phosphorylation of 44 phosphokinases and the relative expression of 35 apoptosis-related molecules were profiled within the donor lung 24 hours posttransplantation. A global profile of mitochondrial salvage and cell survival was observed in the EVLP lung tissue compared with lungs undergoing standard transplantation. This included increased phosphorylation of downstream prosignaling kinases, including ERK1/2 and FAK. In addition, there was upregulated expression of the antiapoptotic proteins Bcl-2, HSP-70, LIVIN, and PON2 with downregulation of apoptosis inducing mitochondrial associated molecules, including clusterin, cytochrome C, and HTRA2/OMI. In the early postoperative period, there were significantly lower levels of circulating mitochondrial DNA in recipients receiving EVLP lungs compared with a standard transplant (P = 0.016). Genomic DNA did not differ between groups, with donor DNA undetectable at all time points. EVLP alters the inflammatory signaling profile of the donor lung before transplantation, with a global cell survival and antiapoptotic signature.

A Simplified Continuous Two-stitch Suture for Bronchial Anastomosis of Left Single Lung Transplant in Dogs.

Large animal models are essential to pre-clinical trials of pulmonary transplantation and bronchial anastomosis poses a great technical challenge to the procedure. Presented here is a simplified continuous two-stitch suture technique into bronchial anastomosis during the course of left single lung transplantation in canine. Animals were divided into three groups with each group having 6 animals. Left single lung transplantation in canine was performed to assess the feasibility of using this technique for bronchial anastomosis. In the control groups, all anastomoses were done by using traditional technique. Allograft functions and hemodynamic parameters were monitored during a 3-h reperfusion period. Quality of bronchial healing and airway complications were assessed by bronchoscopic surveillance after transplantation. We successfully completed left lung transplantation in 18 dogs, and all the dogs survived the procedures. The new technique substantially simplified the procedures for bronchial anastomosis and greatly reduced the time for bronchial anastomosis (P<<0.01) and the ischemic time of the grafts (P<0.05) compared to the control group. The continuous two-stitch suture attenuated the tissue injury to allografts and led to better blood gas exchange function as compared to the control group (P<0.05). Good bronchial healing (Grade I) was observed in all the groups. A canine left single lung transplantation model is feasible by using the novel suture technique, and the new technique is as safe as the traditional method. The technique is easy to learn, particularly for less experienced operators. Simpler and time-saving, the technique has great potential to be widely employed in clinical lung transplantation.

LPS-induced Airway-centered Inflammation Leading to BOS-like Airway Remodeling Distinct From RAS-like Fibrosis in Rat Lung Transplantation.

Localization of inflammatory stimuli may direct lung allografts to different phenotypes of chronic dysfunction, such as bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS). We hypothesized that airway stimulation with lipopolysaccharide (LPS) in rats leads to airway-centered inflammation similar to human BOS. Rat left lung transplantation was conducted (donor: Brown Norway, recipient: Lewis). Allotransplant recipients received cyclosporine A (CsA) until postoperative day 56 with airway instillation of LPS (Allo-LPS, n = 8), phosphate buffered saline (Allo-PBS, n = 5) from days 35 to 46 (3 times a wk), or no further treatment (n = 4). Some allotransplant recipients received CsA until day 14 and were immunosuppression free after day 15 until day 56. Bronchial and pleural fibrosis were semiquantified; alveolar fibrosis was evaluated with a histological scale. The Allo-LPS group had significantly increased International Society for Heart and Lung Transplantation rejection grades (grade A, P = 0.005; grade B, P = 0.004), bronchial obstructive proportion (0.34 ± 0.04% [Allo-LPS] versus 0.11 ± 0.04% [Allo-PBS], P = 0.006), and airway resistance (3.05 ± 1.78 cm H2O·s/mL [Allo-LPS] versus 0.83 ± 0.58 cm H2O·s/mL [Allo-PBS], P = 0.007) compared with other groups. Allotransplant recipients that underwent a short course of CsA developed RAS-like fibrosis involving the airways, alveoli, and pleura. Airway instillation of LPS in allografts under immunosuppression resulted in BOS-like airway-centered inflammation and fibrosis distinct from RAS-like diffuse fibrosis, which was induced by a shortened course of immunosuppression. We propose novel animal models for BOS and RAS after lung transplantation.

Transplantation of Bioengineered Lungs Created From Recipient-Derived Cells Into a Large Animal Model

The use of bioartificial lungs may represent a breakthrough for the treatment of end-stage lung disease. The present study aimed to evaluate the feasibility of transplanting bioengineered lungs created from autologous cells. Porcine decellularized lung scaffolds were seeded with porcine recipient-derived airway and vascular cells. The porcine recipient-derived cells were collected from lung tissue obtained by pulmonary wedge resection. Following culture of autologous cells in the scaffolds, the resulting grafts were unilaterally transplanted into porcine recipients (n = 3). Allograft left unilateral lung transplantation was performed in the control group (n = 3). Left unilateral transplantation of decellularized grafts was also performed in a separate control group (n = 2). In vivo functions were assessed for 2 hours after transplantation. Histologic evaluation and immunostaining showed the presence of airway and vascular cells in the bioengineered lungs. No animals survived in the decellularized transplant group, whereas all animals survived in the bioengineered transplant and allotransplant groups. However, bioengineered lung grafts showed marked bullous changes. The oxygen exchange was comparable between the bioengineered lung graft transplant and allograft transplant groups. However, the carbon dioxide gas exchange of the bioengineered lung graft transplant group was significantly lower than that of the allograft transplant group at 2 hours after transplantation (4.10 ± 0.87 mm Hg vs 24.7 ± 10.1 mm Hg, P = 0.02). Transplantation of bioartificial lung grafts created from autologous cells was feasible in the super-acute phase. However, bullous changes and poor carbon dioxide gas exchange remain limitations of this method.

Insights from the UNOS Database on the Impact of Laterality on Outcomes in Lung Transplantation: Left is Not Always Right in Single Lung Transplantation

Lung transplantation remains an established therapy for end stage lung disease. It is well known that double lung transplant recipients have a survival advantage over single lung transplant (SLTxp) recipients. There is a gap in knowledge regarding how laterality might affect survival in these recipients. We hypothesized that recipients who need a single left lung transplant might have shorter wait times and improved survival compared to right. This is a retrospective analysis of de-identified data from the UNOS registry. SLTxp adult recipients who were transplanted for COPD and IPF diagnoses were queried from January 2006 to September 2018. Group comparisons were made with chi-square for categorical and student's t-test for continuous variables. The univariate odds ratios, obtained using logistical regression, was adjusted for the presence of confounders. Survival using Kaplan-Meier survival curve was examined. The final study cohort consisted of 6,730 recipients who received a SLT for COPD or IPF. Total number of SLT during this period included: IPF right (n=2054) vs left (n=2568) and COPD right (n=1029) vs left (n=1079) respectively. Median time from transplant to follow-up was 23.5 months. The difference in the wait list times in both cohorts, COPD and IPF was statistically significant between right and left lung recipients (IPF: Left 99.6 vs Right: 96.7 days; COPD: Left: 226 vs Right 233 days). In the IPF lung transplant recipients no difference in survival was observed between right vs left lung transplantation. (Figure A) In the COPD cohort, right lung recipients had a better post-transplant survival (Figure B). The wait time for both cohorts, COPD and IPF was longer for right vs left lung recipients. Compared to left lung recipients, Right LT recipients for COPD reported better survival but this difference in survival was not seen in the IPF cohort. The reason for this survival advantage needs to be studied further.

Successful Transplantation of Porcine Lungs Following 3 Days of Preservation Using a Modified Cold Static Method Paired with Intermittent Normothermic Ex Vivo Lung Perfusion (EVLP)

We have recently showed the superiority of 10°C cold static preservation (CSP) compared to standard 4°C. Despite that, CSP cannot be prolonged unlimited. Here, we hypothesized that combining CSP at 10°C with 2 short cycles of normothermic EVLP (a "recharge" period) would further extend donor lung preservation. Donor lungs (n=3) from Yorkshire pigs (28-35kg) were flushed with 4°C LPD and subsequently preserved using 10°C CSP and intermittent normothermic EVLP (Fig 1A). After a total of 72h of preservation, a left lung transplant was performed followed by 4h of reperfusion. At 4h of reperfusion, isolated graft assessment was performed by clamping the contralateral pulmonary artery and bronchus. To evaluate the contribution of the EVLP recharge periods, 2 control lungs were preserved solely with 10°C CSP for 72h and assessed using normothermic EVLP. After 3-days of preservation, post-transplant graft function was excellent. Systemic P/F ratio after excluding the contra-lateral lung was 430 ± 57 mmHg. Lung function was also stable during the intermittent EVLP periods (Fig 1B) and after transplantation (Fig 1C). No pulmonary edema was observed in the bronchoscopic assessment after transplant. Lungs preserved purely in CSP for 72h were assessed on EVLP and failed immediately with the development of massive pulmonary edema. We demonstrate for the first time the feasibility of 3-day lung preservation leading to excellent early post-transplant outcomes. Further experiments are being performed to confirm these positive findings and underlying mechanisms. The combination of a modified CSP method (10°C) and intermittent EVLP can open new opportunities to further prolong organ preservation and provide time for advanced lung treatments and repair.

Extended Pig-to-Baboon Lung Xenograft Survival

In baboons, lungs from galactosyl transferase knock-out (GTKO) pigs expressing human complement regulatory proteins (hCPRP: hCD46, hCD55) exhibit elevated pulmonary vascular resistance and loss of vascular barrier function within hours. Here we summarize efforts over ten years to understand and prevent these phenomena. Orthotopic left single lung transplantation was performed using GTKO.hCPRP lungs with additional expression of one or more thromboregulatory (hEPCR, hTBM, hTFPI, hCD39) and anti-inflammatory genes (HO-1, HLA-E, hCD47), and β4Gal carbohydrate xenoantigen knock-down (KD), in various combinations. Anti-inflammatory drugs (steroids, sC1Inh, anti-histamine, anti-thromboxane, A1AT, sTNFR, αIL-6, αIL-8, PSGL-1, αMac1), antibody adsorption (AbAds) using donor pig kidneys, and donor pretreatment with chlodronate liposomes were progressively added in recent years. Transient life-supporting GTKO.hCD46 lung function was consistently observed with either hEPCR (alone [n=6] or with hCD55 [6], HO-1 [2], or hCD47 [1]); with hTBM (alone [3] or with HO-1 [1] or CD47 [1]); or with hCD55.hTFPI.CD47 [11]. Although recipient survival was occasionally extended to 2 [n=6] or even 8 days [1], loss of xenograft vascular barrier function and systemic inflammation typically occurred within 24-48 hours. Consistent recipient survival beyond 12 hours was only observed with hEPCR and hTBM co-expression [n=12] in combination with one or more additional genetic modifications (HO-1 [2], CD47.HO-1 [3], hCD55 [2], hCD55.hCD39 [3], or β4GalKD.hCD47 [2]), including 7 and 9 day survivals with selectin/integrin blockade, A1AT, and liposomes. β4GalKD.hCD47, liposome pretreatment, recipient splenectomy, and AbAds were associated with prolonged recipient survival to 31 days in one instance. Graft demise beyond 2 days was association with elaboration of anti-non-Gal antibody whether using conventional or αCD40-based immunosuppression. Consistent life-supporting lung xenograft function and increasingly frequent recipient survival >2d reflect significant progress in understanding the remaining barriers to clinical translation. We identify a pivotal role for dysregulated coagulation and multiple proinflammatory mechanisms in the loss of vascular barrier function which is associated with lung xenograft failure, and the need for more effective immunosuppression.

Complement Inhibition as Potential Novel Therapy for Antibody-Mediated Rejection after Lung Transplantation in Murine Antibody-Mediated Rejection Model

Antibody-mediated rejection (AMR) can induce acute or chronic graft failure in organ transplantations. There are few reports regarding AMR in lung transplant, and no reports of effective therapy for AMR after lung transplant. This study aimed to verify the efficacy of anti-complement 5(anti-C5), which is reported to prevent AMR in kidney transplant, in an AMR-enhanced mouse model after lung transplant. As allograft model, BALB/c (Major histocompatibility complex; MHC H2b) and C57BL/6 (MHC H2b) were used for donor and recipient in order to detect and enhance AMR. Skin transplants were performed to pre-sensitize, and subsequently, orthotopic left lung transplants were performed 14 days after skin transplant. The mice were treated with anti-C5 (40mg/kg/day) (n=5), or cyclosporine (CyA, 10mg/kg/day) /methylprednisolone (mPSL, 1.6mg/kg/day) (n=5), or anti-C5/CyA/mPSL (n=5), or with isotype-matched irrelevant control mAb (n=5) subcutaneously until sacrifice. The mice were sacrificed 2 days after lung transplant and evaluated for histopathology, including acute rejection score, C4d immunostaining, and donor-specific antibody (DSA) in serum. The mice with anti-C5 showed significantly lower C5 in serum compared with the mice with isotype control (1472.50±110.44 vs. 2081.87±75.17 pg/ml, p=0.002). The mice treated with anti-C5 and anti-C5/CyA/mPSL showed significantly lower rejection A score (0.63±0.23; p=0.002, 0.59±0.22; p=0.001) compared with the mice with isotype control (2.58±0.35). All groups showed C4d deposition on vascular endothelium and DSA in serum. Anti-C5 effectively prevented AMR against transplanted allogeneic lung in the pre-sensitized murine model, in which AMR was strongly augmented.

Rapid Activation of Pro-Lymphangiogenic Phenotype and Consequent Increase of Lymphatic Density Occurs during the Development of Chronic Lung Allograft Dysfunction

Lung transplant shows poor long-term survival due to chronic lung allograft dysfunction (CLAD). VEGF-C/VEGFR3 signaling may regulate lymphatic vessel activation and initiate alloimmunity after transplantation. However, its role in CLAD development remains unclear. The CLAD model was established in mouse orthotopic left lung transplantation with a single mismatch (HLA-A2 knock-in C57BL/6 to C57BL/6). The allografts were collected at 14, 28 and 56d after surgery. Syngeneic transplantations were used as control. We analyzed the change of lymphatic density, lymphatic phenotype and the activation of pro-lymphangiogenic genes during CLAD development. We found increased expression of PROX-1 7d after transplantation in CLAD model. We further observed a significant increase of lymphatic vessel density 56d after transplantation in CLAD model. The trend of increased lymphatic activation reached no significance (Figure 1). Our results show that lung transplantation leads to the rapid activation of pro-lymphangiogenic phenotype with consequent increase of lymphatic vessel density in CLAD model. The early activation of lymphangiogensis during the CLAD development may stimulate chronic alloimmune response. VEGF-C/VEGFR3 inhibition during lung transplant might therefore prevent CLAD.

Development of a Pre-Implantation Regulatory T Cell-Permissive Immunosuppression Protocol in a Rat Model of Ex Vivo Lung Perfusion Followed by Lung Transplantation

CD4+CD25highFoxp3+ regulatory T cells (Treg) can establish immunologic tolerance in animal models. We have developed a method to deliver recipient-derived Tregs to donor lungs during ex-vivo lung perfusion (EVLP). Our goal is to maximize the effectiveness of this therapy by developing a Treg-permissive post transplant immunosuppression protocol. We hypothesized that combination therapy with interleukin-2 (IL-2)/anti-IL-2 antibody complexes (IL-2c) and tacrolimus (Tac) would facilitate the expansion of endogenous Tregs and attenuate acute rejection, thus creating an environment permissive to Treg therapy. We performed rat left lung transplantation (LTx) experiments using Fischer 344 (F344, RT-1lv1) donors and Wistar Kyoto (WKy, RT-1l) recipients with or without antecedent 3h EVLP. Animals received: no treatment (NT); IL-2c (a single low [30ug] or high [60ug] dose) alone; Tac (0.1mg/kg/day, 7 doses) alone; or both IL-2c and Tac, intraperitoneally starting on the day of transplantation. Allografts that underwent EVLP had lower acute rejection grades in IL-2c/Tac-treated rats than in NT and Tac-treated rats (A Grade p = 0.046; B Grade p = 0.064; Fig1). In contrast, there were no differences among these groups in allografts that had not undergone EVLP. In the grafts, the frequency of CD4+CD25highFoxp3+ cells increased in both low and high dose IL-2c/Tac groups compared with Tac group, regardless of EVLP (p = 0.012, p = 0.107; Fig 2). Although the frequency of CD4+CD25+Foxp3- effector T cells also increased with high dose IL-2c in the non-EVLP group, this was not seen with EVLP (p = 0.804) (Fig 2). Despite the presence of Tac, IL-2c increased Tregs in the graft after transplantation and attenuated acute rejection in EVLP-treated lungs. This work lays the groundwork for pre-implantation allograft-directed regulatory T cell therapy.