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Definitions for chronic lung allograft dysfunction (CLAD) phenotypes were recently revised (2019 ISHLT consensus). Post-CLAD onset phenotype transition may occur as a result of change in obstruction, restriction, or RAS-like opacities (RLO). We aimed to assess the prevalence and prognostic implications of these transitions. This was a single-center, retrospective cohort study of bilateral lung transplants performed in 2009-2015. CLAD phenotypes were determined per ISHLT guidelines. CLAD phenotype transition was defined as a sustained change in obstruction, restriction or RLO. We specifically focused on phenotype changes based on RLO emergence. Association of RLO development with time to death or retransplant were assessed using Kaplan-Meier and Cox proportional hazards models. Among 211 patients with CLAD, 47 (22.2%) experienced a phenotype transition. Nineteen patients developed RLO. Development of RLO phenotype after CLAD onset was associated with a shorter time to death/retransplant when considering the entire CLAD patient cohort (HR = 4.00, CI 2.74-5.83, P

BackgroundThe published experience of lung transplantation in acute respiratory distress syndrome (ARDS) is limited. The aim of this study was to investigate the contemporary results of lung transplantation attempts in ARDS in major European centres.MethodsWe conducted a retrospective multicentre cohort study of all patients listed for lung transplantation between 2011 and 2019. We surveyed 68 centres in 22 European countries. All patients admitted to the waitlist for lung transplantation with a diagnosis of “ARDS/pneumonia” were included. Patients without extracorporeal membrane oxygenation (ECMO) or mechanical ventilation were excluded. Patients were followed until 1 October 2020 or death. Multivariable analysis for 1-year survival after listing and lung transplantation was performed.Results55 centres (81%) with a total transplant activity of 12 438 lung transplants during the 9-year period gave feedback. 40 patients with a median age of 35 years were identified. Patients were listed for lung transplantation in 18 different centres in 10 countries. 31 patients underwent lung transplantation (0.25% of all indications) and nine patients died on the waitlist. 90% of transplanted patients were on ECMO in combination with mechanical ventilation before lung transplantation. On multivariable analysis, transplantation during 2015–2019 was independently associated with better 1-year survival after lung transplantation (OR 10.493, 95% CI 1.977–55.705; p=0.006). 16 survivors out of 23 patients with known status (70%) returned to work after lung transplantation.ConclusionsLung transplantation in highly selected ARDS patients is feasible and outcome has improved in the modern era. The selection process remains ethically and technically challenging.

CASE PRESENTATION: A 63-year-old man with a left single lung transplant for end-stage combined restrictive and obstructive lung disease developed persistent pulmonary infiltrates and recurrent gram-negative bacteremia post-transplant. Bronchoalveolar lavage fluid revealed a nematode on Papanicolau staining compatible with Strongyloides stercoralis larvae on day 50 post-transplant. Although Strongyloides serology performed post-transplant was negative, a retrospective review of the medical record revealed marked peripheral blood eosinophilia on several occasions before transplantation. Despite reduction in immunosuppression and treatment with albendazole and ivermectin, the patient developed another episode of Escherichia coli bacteremia. He died 3 months post-transplant from pulmonary and neurological complications. DIAGNOSIS: Strongyloides hyper-infection. DISCUSSION: Strongyloides hyper-infection syndrome is known to occur in immunocompromised patients, but it has only been reported once in a lung transplant recipient. This case illustrates the importance of screening for parasitic infections before transplantation in patients with marked eosinophilia, especially among immigrants from countries in which Strongyloides is endemic. Hyper-infection syndrome may appear years after infection in the context of immunosuppression or immunodeficiency. This case also highlights the association between Strongyloides hyper-infection and bacteremia with enteric organisms.

BACKGROUND Procuring a good quality transbronchial-biopsy sample is essential for diagnosing acute cellular rejection after lung transplantation (LT). Insufficient transbronchial-biopsy samples are graded "AX." We hypothesized that AX samples may be associated with a higher risk for chronic lung allograft dysfunction (CLAD) or death/retransplant, through a potential anatomic or physiologic underlying pulmonary process or because of undiagnosed acute cellular rejection episodes. METHODS We conducted a single-center, retrospective, cohort study drawn from all consecutive adult, first, bilateral LT between 1999 and 2015. We reviewed all biopsies obtained within the first year posttransplant and compared outcomes of patients with ≥1 AX to patients with no AX. Association of any AX or percent AX with time to CLAD or death/retransplant was assessed using Cox Proportional Hazards models. RESULTS The cohort consisted of 809 patients with a median of 6 (interquartile range 5-6) biopsies and 16.7% (interquartile range 0-25) AX samples within the first year posttransplant. Four hundred thirty-nine (54.3%) subjects had ≥1 AX sample obtained within the time period. Median time to CLAD or death/retransplant, from 1 year posttransplant, was 761 (320, 1587) and 1200 (662, 2308) days, respectively. In the multivariable analysis, there was no difference in risk for CLAD (hazard ratio = 1.05, 95% confidence interval, 0.87-1.28, P = 0.60), or death/retransplant (hazard ratio = 1.14, 95% confidence interval, 0.92-1.42, P = 0.24) between patients with ≥1 AX biopsy versus none. Among subjects with ≥1 AX, having >50% AX biopsies was not associated with outcome. CONCLUSIONS This is the first study to demonstrate that AX biopsies are not associated with an increased risk of CLAD or death/retransplant after LT and may not require to repeat the biopsy.

BACKGROUND Invasive pulmonary aspergillosis (IPA) is a significant cause of morbidity and mortality in lung transplant recipients (LTRs). It is unclear how a targeted prophylaxis/ preemptive antifungal therapy strategy impacts the incidence of IPA beyond the first-year posttransplant. METHODS This is a retrospective cohort of LTRs from January 2010 to December 2014. We included all LTRs who survived beyond the first year and followed them until death or 4 years postoperatively. Incidence of probable/proven IPA and Aspergillus colonization were assessed as per International Society for Heart and Lung Transplantation (ISHLT) criteria. Patients with risk factors, positive Aspergillus cultures, or galactomannan (GM) received targeted prophylaxis/preemptive therapy within the first-year posttransplant. RESULTS During the study period, 350 consecutive LTRs underwent 1078 bronchoscopies. Positive bronchoalveolar lavage for GM or Aspergillus cultures was reported for 15% (52/350) of LTRs between 2 and 4 years after transplantation. Among them, the median time to positive Aspergillus culture or GM positivity was 703 days (interquartile range, 529-754 d). The incidence rate of IPA and Aspergillus colonization was 30 of 1000 patient-y, and 63 of 1000 patient-y, respectively. The mortality rate was significantly higher in patients with IPA than without IPA (107/1000 patient-years versus 18/1000 patient-years; P

Summary Background A substantial proportion of organ donors test positive for hepatitis C virus (HCV) infection. To date, only a few studies have evaluated the safety of using lungs from these donors for transplantation, and no direct interventions to donor organs have been done with the aim of preventing HCV transmission via organ transplantation. We aimed to assess the safety and efficacy of lung transplantation in humans from HCV-positive donors to HCV-negative recipients after application of ex-vivo lung perfusion (EVLP) plus ultraviolet C (UVC) perfusate irradiation. Methods We did a single centre, prospective, open-label, non-randomised trial in which donor lungs from HCV-viraemic donors (HCV-positive) were transplanted into HCV-negative recipients at Toronto General Hospital, University Health Network (Toronto, ON, Canada). Donors were younger than 65 years old and tested positive for HCV by nucleic acid testing. Donors who tested positive for hepatitis B virus, HIV, human T-lymphotropic virus 1 or 2 were excluded. Recipients were on the lung transplant waiting list without significant liver disease (stage 2 fibrosis or higher were excluded) or active HCV infection. Before implantation, all HCV-positive donor lungs were treated with EVLP with or without UVC perfusate irradiation to reduce the concentration of HCV RNA and infectivity. For the first week after transplantation, patients' HCV RNA blood concentrations were measured once daily, then once per week for 12 weeks. All patients received 12 weeks of oral sofosbuvir 400 mg plus velpatasvir 100 mg, starting at least 2 weeks after transplantation. The primary endpoint was a composite of survival and HCV-free status at 6 months after transplantation in all patients who received HCV-positive lungs. Patient outcomes such as survival, time in hospital, and incidence of acute rejection were compared between those receiving HCV-positive lungs and all patients who received HCV-negative lung transplants during the study period. The study is registered with ClinicalTrials.gov, NCT03112044. Findings From Oct 1, 2017, to Nov 1, 2018, 209 patients had a transplantation; of 27 donors who were HCV-positive and initially considered, 22 were suitable for transplantation. The remaining 187 donors were HCV-negative. Before implantation, 11 of the HCV-positive donor lungs were treated with EVLP alone and the other 11 were treated with EVLP plus UVC. Lung disease, urgency status, and positive donor-recipient HLA crossmatch were similar between the patients who received HCV-positive and HCV-negative lungs. 20 (91%) patients in the HCV-positive group developed HCV viraemia within the first week after transplantation and had sofosbuvir plus velpatasvir treatment, starting at a median of 21 days after transplantation (IQR 16·76–24·75). Donor organ treatment with EVLP plus UVC was associated with significantly lower recipient viral loads in blood within the first week after transplantation than with EVLP alone (median of 167 IU/mL [IQR 20–12 000] vs 4390 IU/mL [1170–112 000] at day 7; p=0·048) and prevented transmission in two (18%) of 11 patients. All 20 infected patients achieved negative HCV PCR within 6 weeks of treatment initiation. The primary endpoint of survival and HCV-free status at 6 months after transplantation was achieved in 19 (86%) of 22 patients in the HCV-positive group. 6-month survival was 95% in recipients receiving lungs from HCV-viraemic donors versus 94% in recipients receiving lungs from HCV-negative donors. The most common grade 3–4 adverse events in the HCV-positive group were respiratory complications (five [23%]) and infections (four [18%]). Serious adverse events requiring admission to hospital occurred in ten (45%) patients. One (5%) patient who did not develop HCV infection died at day 31 from multiorgan failure related to pseudomonas sepsis. Two patients presented with HCV relapse within 3 months after sofosbuvir plus velpatasvir completion and required retreatment. Interpretation Early and intermediate clinical outcomes were not significantly different between patients receiving viraemic HCV donor lungs and HCV-negative donor lungs. Donor organ treatment with UVC perfusate irradiation during EVLP significantly decreased HCV viral loads within the first 7 days after transplantation and shows the proof-of-concept for a novel approach of minimising viral load ex vivo before transplantation, with intent of preventing donor–recipient transmission. Funding Canadian Institutes of Health Research.

Funding Information: Supported by the Helsinki University Hospital , the Sigrid Juselius Foundation , the Academy of Finland , Finska Läkaresällskapet , the Research and Science Foundation of Farmos , The Paulo Foundation , Jalmari and Rauha Ahokas Foundation , Aarne Koskelo Foundation , Päivi and Sakari Sohlberg Foundation , Finnish Pulmonary Association , Biomedicum Helsinki Foundation , Jane and Aatos Erkko Foundation , and the University of Helsinki . Funding Information: Supported by the Helsinki University Hospital, the Sigrid Juselius Foundation, the Academy of Finland, Finska L?kares?llskapet, the Research and Science Foundation of Farmos, The Paulo Foundation, Jalmari and Rauha Ahokas Foundation, Aarne Koskelo Foundation, P?ivi and Sakari Sohlberg Foundation, Finnish Pulmonary Association, Biomedicum Helsinki Foundation, Jane and Aatos Erkko Foundation, and the University of Helsinki. Publisher Copyright: © 2022 American Society for Investigative Pathology Obliterative bronchiolitis (OB) after lung transplantation is a nonreversible, life-threatening complication. Herein, the role of vascular endothelial growth factor receptor (Vegfr)-1 and -2 was investigated in the development of obliterative airway disease (OAD), an experimental model for OB. The nonimmunosuppressed recipients underwent transplantation with fully major histocompatibility complex mismatched heterotopic tracheal allografts and received Vegfr1 and -2-specific monoclonal antibodies either alone or in combination, or rat IgG as a control. The treatment with Vegfr1- or -2-blocking antibody significantly decreased intragraft mRNA expression of natural killer cell activation markers early after transplantation. This was followed by reduced infiltration of Cd11b thorn cells and Cd4 thorn T cells as well as down-regulated mRNA expression of proinflammatory chemokines and profibrotic growth factors. However, blocking of both Vegfr1 and -2 was necessary to reduce luminal occlusion. Furthermore, concomitant inhibition of the calcineurin activation pathway almost totally abolished the development of OAD. This study proposes that blocking of Vegf receptors blunted natural killer cell and innate immune responses early after transplantation and attenuated the development of OAD. The results of this study suggest that further studies on the role of Vegfr1 and -2 blocking in development of obliterative airway lesions might be rewarding. (Am J Pathol 2022, 192: 254-269; https://doi.org/10.1016/ j.ajpath.2021.10.018)

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease characterized by progressive and excessive accumulation of myofibroblasts and extracellular matrix in the lung. Connective-tissue growth factor (CTGF) is known to exacerbate pulmonary fibrosis in radiation-induced lung fibrosis, and in this study, we show the upregulation of CTGF from a rat lung fibrosis model induced by adenovirus vector encoding active TGF-β1 (AdTGF-β1), and also in patients with IPF. The expression of CTGF was upregulated in vascular smooth muscle cells cultured from fibrotic lungs on days 7 or 14 as well as endothelial cells sorted from fibrotic lungs on day 14 or 28 respectively. These findings suggest the role of different cells in maintaining the fibrotic phenotype during fibrogenesis. Treatment of fibroblasts with recombinant CTGF along with TGF-β increases pro-fibrotic markers in fibroblasts, confirming the synergistic effect of recombinant CTGF with TGF-β in inducing pulmonary fibrosis. Also, fibrotic extracellular matrix upregulated the expression of CTGF, as compared to normal extracellular matrix, suggesting that not only profibrotic mediators but also a profibrotic environment contributes to fibrogenesis. We also showed that pamrevlumab, a CTGF inhibitory antibody, partially attenuates fibrosis in the model. These results suggest that pamrevlumab could be an option for the treatment of pulmonary fibrosis.

RATIONALE Cytomegalovirus (CMV)-seronegative recipients receiving a seropositive allograft (D+/R-) are at a high risk of developing CMV disease. Our program increased the duration of CMV prophylaxis from 6 to 9 months in May 2013. Here, we present the impact on the incidence of CMV infection, disease, side effects, rejection, and other factors. METHODS Retrospective cohort of 241 CMV (D+/R-) patients transplanted between January 1, 2008, and December 31, 2017. Blood CMV testing was done according to protocol. All patients received ganciclovir/valganciclovir as prophylaxis. We compared the incidence and timing of CMV infection and disease up to 6 months after cessation of prophylaxis between patients who received 9 months (May 2013 onwards) and a historical control group who received 6 months of prophylaxis (prior to May 2013). CMV infection was defined as detectable CMV viremia in the absence of symptoms. CMV disease was defined as CMV syndrome or tissue-invasive disease. Side effects of prophylaxis and CMV resistance were recorded. RESULTS A total of 116 patients were included in the 6-month group and 125 in the 9-month group. The extended 9-month CMV prophylaxis delayed the onset of CMV infection (median time to CMV infection after lung transplantation 295 vs 353 days, P

Long-term outcomes after lung transplantation remain inferior to those of other solid organ groups. The significance of eosinophils detected on transbronchial biopsies (TBBx) after lung transplantation and their relationship to long-term outcomes remain unknown. A retrospective single-center cohort study was performed of patients transplanted between January 01, 2001, and July 31, 2018, who had at least 1 TBBx with evaluable parenchymal tissue. Multivariable Cox proportional hazard models were used to assess the associations between eosinophil detection and: all-cause mortality and Chronic Lung Allograft Dysfunction (CLAD). 8887 TBBx reports from 1440 patients were reviewed for the mention of eosinophils in the pathology report. 112 (7.8%) patients were identified with eosinophils on at least one TBBx. The median (95% CI) survival time for all patients was 8.28 (7.32-9.31) years. Multivariable analysis, adjusted for clinical variables known to affect post-transplant outcomes, showed that the detection of eosinophils was independently associated with an increased risk of death (HR 1.51, 95% CI 1.24-1.85, p < 0.01) and CLAD (HR 1.35, 95% CI 1.07-1.70, P = 0.01). Eosinophils detected in TBBx are associated with an increased risk of CLAD and death. There may be benefit in specifically reporting the presence of eosinophils in TBBx reports and incorporating their presence in clinical decision-making.

Background Letermovir, a new viral terminase complex inhibitor, has been approved for the prevention of cytomegalovirus (CMV) infection in hematopoietic stem cell transplant patients. However, data on the efficacy and safety of letermovir for the treatment of CMV infection in transplant recipients remain scarce. Methods We performed a single-center retrospective study of stem cell and organ transplant recipients who received letermovir for the treatment of CMV infection from November 2017 to October 2018. Results Six patients were included and five were evaluable. All received letermovir in the context of a refractory or resistant CMV infection including asymptomatic CMV viremia (n=3), CMV syndrome (n=1) and CMV pneumonitis and colitis (n=1). The three asymptomatic patients experienced a decrease of the viral load to less than 200 IU/mL after letermovir therapy. One patient displayed a partial viral load response (2 log of viral load reduction) but a good clinical response, and one who received a suboptimal dose of letermovir experienced an increase of viremia. There were no treatment-related adverse effects. Conclusion We demonstrate mixed efficacy in patients with refractory CMV infection suggesting that letermovir may be a useful therapeutic adjunct, potentially in combination with other antivirals.

Although lung transplant is a life-saving therapy for some patients, primary graft dysfunction (PGD) is a leading cause of mortality and morbidity soon after a transplant. Ischemia reperfusion injury is known to be one of the most critical factors in PGD development. PGD is by definition an acute lung injury syndrome that occurs during the first 3 d following lung transplantation. To successfully translate laboratory discoveries to clinical practice, a reliable and practical large animal model is critical. This protocol describes a surgical technique for swine lung transplantation and postoperative management for a further 3 d post transplant. The protocol includes the background and rationale, required supplies, and a detailed description of the donor operation, transplant surgery, postoperative care, and sacrifice surgery. A pig lung transplant model is reliably produced in which the recipients survive for 3 d post transplant. This 3-d survival model can be used by lung transplant researchers to assess the development of PGD and to test therapeutic strategies targeting PGD. In total, the protocol requires 5 h for the surgeries, plus ~2 h in total for the postoperative care.

Background Ex-vivo lung perfusion (EVLP), a technique for donor lung assessment, also represents a platform for donor lung repair and immunomodulation. α 1 -Anti-trypsin (A1AT), a medication used to treat emphysema in A1AT-deficient patients, has anti-inflammatory properties and has been shown to attenuate ischemia–reperfusion injury in rat and pig lung transplants . The objective of this study was to determine whether administration of A1AT during EVLP can improve donor lung quality after prolonged hypothermic preservation. Methods Pig donor lungs were retrieved, preserved at 4°C for 24 hours, and then subjected to normothermic EVLP for 12 hours using the Toronto protocol. The treatment group (n = 6) received 3 mg/ml A1AT (Zemaira) in the EVLP perfusate, acellular Steen solution. The control group (n = 6) was perfused with Steen solution only. Physiologic functions and gas exchange were measured hourly. Pulmonary edema, lung injury, apoptosis and inflammatory mediators were evaluated in lung tissues and perfusate. Results A1AT treatment significantly reduced pulmonary arterial pressure , pulmonary vascular resistance and airway pressure changes from the baseline when compared with controls. A1AT treatment significantly improved both dynamic and static pulmonary compliance , and change in partial pressure of oxygen (ΔPO 2 ) between the left atrium and the pulmonary artery. Furthermore, A1AT treatment also significantly reduced pulmonary edema (wet-to-dry ratio), pulmonary cell apoptosis and pro-inflammatory cytokine levels (interleukin-1α and -8) in the perfusate. Conclusion Treatment of 24-hour-preserved pig donor lungs with A1AT during EVLP resulted in improved physiologic function, reduced pulmonary edema and inflammation and decreased cell death. Our findings suggest that treatment of donor lungs during EVLP with A1AT is a promising strategy to attenuate early lung injury and improve donor lung function before lung transplantation.

BackgroundChronic lung allograft dysfunction (CLAD) is the principal cause of graft failure in lung transplant recipients and prognosis depends on CLAD phenotype. We used a machine learning computed tomography (CT) lung texture analysis tool at CLAD diagnosis for phenotyping and prognostication compared with radiologist scoring.MethodsThis retrospective study included all adult first double lung transplant patients (January 2010–December 2015) with CLAD (censored December 2019) and inspiratory CT near CLAD diagnosis. The machine learning tool quantified ground-glass opacity, reticulation, hyperlucent lung and pulmonary vessel volume (PVV). Two radiologists scored for ground-glass opacity, reticulation, consolidation, pleural effusion, air trapping and bronchiectasis. Receiver operating characteristic curve analysis was used to evaluate the diagnostic performance of machine learning and radiologist for CLAD phenotype. Multivariable Cox proportional hazards regression analysis for allograft survival controlled for age, sex, native lung disease, cytomegalovirus serostatus and CLAD phenotype.Results88 patients were included (57 bronchiolitis obliterans syndrome (BOS), 20 restrictive allograft syndrome (RAS)/mixed and 11 unclassified/undefined) with CT a median 9.5 days from CLAD onset. Radiologist and machine learning parameters phenotyped RAS/mixed with PVV as the strongest indicator (area under the curve (AUC) 0.85). Machine learning hyperlucent lung phenotyped BOS using only inspiratory CT (AUC 0.76). Radiologist and machine learning parameters predicted graft failure in the multivariable analysis, best with PVV (hazard ratio 1.23, 95% CI 1.05–1.44; p=0.01).ConclusionsMachine learning discriminated between CLAD phenotypes on CT. Both radiologist and machine learning scoring were associated with graft failure, independent of CLAD phenotype. PVV, unique to machine learning, was the strongest in phenotyping and prognostication.

Lung transplantation has become an invaluable approach for the treatment of end-stage respiratory diseases. However, survival after lung transplant remains limited due to chronic lung allograft dysfunction (CLAD), a fibrotic process affecting the airway and/or parenchymal compartments of the lung graft leading to a significant and persistent deterioration in lung function [1, 2]. With our accelerating understanding of CLAD, it has become evident that CLAD is a heterogeneous process comprised of multiple patterns of physiological and radiological features, which have strong implications for post-CLAD survival [3]. Footnotes This manuscript has recently been accepted for publication in the European Respiratory Journal . It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article. Conflict of interest: Dr. Levy has nothing to disclose. Conflict of interest: Dr. Huszti has nothing to disclose. Conflict of interest: Dr. Berra has nothing to disclose. Conflict of interest: Dr. Renaud-Picard has nothing to disclose. Conflict of interest: Dr. Kawashima has nothing to disclose. Conflict of interest: Dr. Takahagi has nothing to disclose. Conflict of interest: Dr. Moshkelgosha has nothing to disclose. Conflict of interest: Dr. Ghany has nothing to disclose. Conflict of interest: Dr. Fuchs has nothing to disclose. Conflict of interest: Dr. Chow has nothing to disclose. Conflict of interest: Dr. Keshavjee has nothing to disclose. Conflict of interest: Dr. Singer has nothing to disclose. Conflict of interest: Dr. Tikkanen has nothing to disclose. Conflict of interest: Dr. Martinu has nothing to disclose.

RationaleThe diffusing capacity of the lung for carbon monoxide corrected for haemoglobin (DLCOcor) measures gas movement across the alveolar–capillary interface. We hypothesised that DLCOcor is a sensitive measure of injurious allograft processes disrupting this interface.ObjectivesTo determine the prognostic significance of the DLCOcor trajectory on chronic lung allograft dysfunction (CLAD) and survival.MethodsA retrospective analysis was conducted of all bilateral lung transplant recipients at a single centre, between January 1998 and January 2018, with one or more DLCOcor measurements. Low baseline DLCOcor was defined as the failure to achieve a DLCOcor >75% predicted. Drops in DLCOcor were defined as >15% below recent baseline.Results1259 out of 1492 lung transplant recipients were included. The median (range) time to peak DLCOcor was 354 (181–737) days and the mean±sdDLCOcor was 80.2±21.2% pred. Multivariable analysis demonstrated that low baseline DLCOcor was significantly associated with death (hazrd ratio (HR) 1.68, 95% CI 1.27–2.20; pDLCOcor was not independently associated with CLAD after adjustment for low baseline forced expiratory volume in 1 s or forced vital capacity. Any DLCOcor declines ≥15% were significantly associated with death, independent of concurrent spirometric decline. Lower percentage predicted DLCOcor values at CLAD onset were associated with shorter post-CLAD survival (HR 0.75 per 10%-unit change, pConclusionLow baseline DLCOcor and post-transplant declines in DLCOcor were significantly associated with survival, independent of spirometric measurements. We propose that DLCOcor testing may allow identification of a subphenotype of baseline and chronic allograft dysfunction not captured by spirometry. There may be benefit in routine monitoring of DLCOcor after lung transplantation to identify patients at risk of poor outcomes.

Purpose The majority of potential donor lungs are not being used. The primary reason for underutilization is the concern for primary graft dysfunction (PGD). There is currently no clinically available therapy for PGD. Alpha 1 antitrypsin (A1AT) is a serine protease inhibitor with anti-inflammatory and cytoprotective properties. We and others have shown benefits of A1AT in small and large animal lung transplant studies. Before performing clinical trials, evidence of therapeutic efficacy in human lungs would be valuable. We tested the effect of A1AT given during ex vivo lung perfusion (EVLP) to human lungs rejected for transplantation. Methods Double lung blocks rejected for transplantation (n=8) were divided and placed on separate EVLP circuits for 12h. Lungs were randomly assigned to receive A1AT or placebo, with the contralateral lung serving as control for the treated lung. Outcome measures included: hourly physiologic lung function, perfusate loss, wet-dry weight ratio, inflammatory mediators, endothelin-1 (ET-1), and zonula occludens tight junction protein‐1 (ZO‐1, immunofluorescence staining). Results The A1AT-treated group demonstrated significantly better lung function: higher pO2 and compliance (Fig A), lower pulmonary artery pressure (-0.4 mmHg p= 0.04) and vascular resistance (-30.4 dynes·s cm−5 p= 0.01). Perfusate loss, a surrogate for lung permeability, was lower in the A1AT group, as was the wet-dry ratio (Fig B). A1AT also decreased ET-1 levels in perfusate (Fig C) and increased ZO-1 expression on endothelial cells (Fig D). Conclusion In this study we demonstrated that human A1AT was able to improve the quality of severly injuried human lungs, likely through endothelial cell protection. The encouraging results justify a clinical trial, in order to improve donor lung quality and clinical outcomes in lung transplantation. Our study also illustrates that testing selected drugs on injured human lungs on EVLP is a viable strategy prior to clinical application.

Purpose Previous studies suggest Chronic Lung Allograft Dysfunction (CLAD) subtypes with RAS-like opacities (RLO) (i.e. persistent parenchymal or pleural fibrosis) at CLAD onset to have worse survival. However, the significance of transitions between CLAD subtypes remains obscure. Methods This was a single center, retrospective cohort study of consecutive adult, first bilateral lung transplants from 2010-2015. Patients with CLAD were classified into ISHLT phenotypes BOS, RAS, Mixed, undefined and some remained unclassified. We defined phenotype transition as a change of at least one of three determinants: obstruction, restriction or RLO. Association of phenotype transition with time to death or retransplant starting at CLAD onset or transition date was assessed using Cox PH models. Multivariable models included age and CMV mismatch. Results Of 173 patients with CLAD, 108 patients with no RLO and 28 with RLO at CLAD onset did not change phenotype. 37 patients (21.3%) had a phenotype transition at a median time of 329 days (IQR 166-591) post CLAD onset. 15 patients without RLO (12 BOS, 2 undefined, 1 unclassified) developed RLO and changed phenotype to RAS (1), mixed (7), or undefined (7). 22 patients had a phenotype transition owing to a change in the ventilatory defect pattern (10 with RLO and 12 without RLO). Patients who developed RLO after CLAD onset had a non-significant trend towards worse survival from CLAD onset (HR=1.29, p=0.7) and also from transition date (HR=3.45, p=0.1) compared to patients who transitioned to a phenotype without RLO (Fig 1A), probably due to small number of patients. Survival after RLO emergence did not differ between patients with RLO at CLAD onset and patients who developed RLO post CLAD onset (HR=1.69, p=0.17 (Fig 1B). Conclusion Our study shows that phenotype transition is a relatively common phenomenon, although a transition to RAS-like opacities occurred in only 9% of CLAD patients. The poor survival from emergence of RAS-like opacities appears to be similar regardless of timing relative to CLAD onset.

The mortality rate for individuals on the wait list for lung transplant is 15% to 25%, and still only 20% of lungs from multiorgan donors are used for lung transplant. The lung donor pool may be increased by assessing and reconditioning high-risk extended criteria donor lungs with ex vivo lung perfusion (EVLP), with similar short-term outcomes.To assess the long-term outcomes of transplant recipients of donor lungs treated with EVLP.This retrospective cohort single-center study was conducted from August 1, 2008, to February 28, 2017, among 706 recipients of donor lungs not undergoing EVLP and 230 recipients of donor lungs undergoing EVLP.Donor lungs undergoing EVLP.The incidence of chronic lung allograft dysfunction and allograft survival during the 10-year EVLP era were the primary outcome measures. Secondary outcomes included donor characteristics, maximum predicted percentage of forced expiratory volume in 1 second, acute cellular rejection, and de novo donor-specific antibody development.This study included 706 patients (311 women and 395 men; median age, 50 years [interquartile range, 34-61 years]) in the non-EVLP group and 230 patients (85 women and 145 men; median age, 46 years [interquartile range, 32-55 years]) in the EVLP group. The EVLP group donors had a significantly lower mean (SD) Pao2:fraction of inspired oxygen ratio than the non-EVLP group donors (348 [108] vs 422 [88] mm Hg; P .001), higher prevalence of abnormal chest radiography results (135 of 230 [58.7%] vs 349 of 706 [49.4%]; P = .02), and higher proportion of smoking history (125 of 204 [61.3%] vs 322 of 650 [49.5%]; P = .007). More recipients in the EVLP group received single-lung transplants (62 of 230 [27.0%] vs 100 of 706 [14.2%]; P .001). There was no significant difference in time to chronic lung allograft dysfunction between the EVLP and non-EVLP group (70% vs 72% at 3 years; 56% vs 56% at 5 years; and 53% vs 36% at 9 years; log-rank P = .68) or allograft survival between the EVLP and non-EVLP groups (73% vs 72% at 3 years; 62% vs 58% at 5 years; and 50% vs 44% at 9 years; log-rank P = .97) between the 2 groups. All secondary outcomes were similar between the 2 groups.Since 2008, 230 of 936 lung transplants (24.6%) in the Toronto Lung Transplant Program were performed after EVLP assessment and treatment. Use of EVLP-treated lungs led to an increase in the number of patients undergoing transplantation, with comparable long-term outcomes.

BACKGROUND Chronic lung allograft dysfunction (CLAD) is a heterogeneous condition. Characterization of CLAD phenotypes is essential to enhance the understanding of pathogenesis and guide new therapies. The study objective was to validate the new International Society for Heart and Lung Transplantation (ISHLT) CLAD classification system and further explore patients who do not fall into the defined CLAD sub-categories. METHODS We performed a single-center, retrospective cohort study of adult, first, bilateral lung transplants performed from 2010 to 2015. Patients with CLAD were classified on the basis of the 2019 ISHLT consensus document. CLAD phenotypes and other potential predictors of survival after CLAD onset were assessed using Kaplan–Meier and Cox proportional hazards models. RESULTS Among the 174 subjects with CLAD, 104 (59.8%) had bronchiolitis obliterans syndrome (BOS), 16 (9.2%) restrictive allograft syndrome (RAS), 9 (5.2%) mixed, and 19 (10.9%) undefined phenotype. A total of 26 patients (14.9%) did not match any of these 4 categories and remained unclassified. Allograft survival post-CLAD onset was longer for patients with BOS (median, 500 days) than patients with RAS (median, 372 days) or mixed (median, 328 days). The 45 patients (26.8%) with undefined/unclassified phenotype were combined and recategorized on the basis of the presence or absence of characteristic RAS-like opacities on chest imaging; those with RAS-like opacities had significantly worse allograft survival than patients with BOS (hazard ratio, 2.14; 95% confidence interval, 1.17–3.93; p = 0.014) and similar survival to RAS or mixed phenotype. CONCLUSIONS The new ISHLT CLAD phenotype classification is informative with regards to post-CLAD outcomes. Chest imaging demonstrating persistent parenchymal or pleural fibrosis may be used for risk-stratification of patients who do not match the major CLAD phenotypes.

Chronic lung allograft dysfunction (CLAD) remains the leading cause of late death after lung transplantation. Epithelial injury is thought to be a key event in the pathogenesis of CLAD. M30 and M65 are fragments of cytokeratin-18 released specifically during epithelial cell apoptosis and total cell death, respectively. We investigated whether M30 and M65 levels in bronchoalveolar lavage (BAL) correlate with CLAD subtypes: restrictive allograft syndrome (RAS) versus bronchiolitis obliterans syndrome (BOS). BALs were obtained from 26 patients with established CLAD (10 RAS, 16 BOS) and 19 long-term CLAD-free controls. Samples with concurrent infection or acute rejection were excluded. Protein levels were measured by ELISA. Variables were compared using Kruskal-Wallis, Mann-Whitney U test and Chi-squared tests. Association of M30 and M65 levels with post-CLAD survival was assessed using a Cox PH models. M65 levels were significantly higher in RAS compared to BOS and long-term CLAD-free controls and correlated with worse post-CLAD survival. Lung epithelial cell death is enhanced in patients with RAS. Detection of BAL M65 may be used to differentiate CLAD subtypes and as a prognostic marker in patients with established CLAD. Understanding the role of epithelial cell death in CLAD pathogenesis may help identify new therapeutic targets to improve outcome.

Cytomegalovirus (CMV) infection and development of CMV drug resistance can cause significant morbidity and mortality in patients with lung transplantation (LTX). We investigated the incidence of CMV drug resistance in adult patients with LTX and characterized this patient group and its outcomes.We analyzed a single-center retrospective cohort of 735 patients who received LTX between January 2012 and October 2017. We assessed the incidences of CMV UL97 and UL54 genotyping for clinically suspected drug resistance and confirmed drug resistance. Case-matched controls (3 control patients for each resistant patient) were identified by matching for CMV serological status, development of CMV disease or significant viremia (≥3,000 IU/ml), and transplantation date.The incidence of drug-resistant CMV was 1.98% (11/556) in donor and/or recipient CMV-positive patients and 4.7% (7/150) in donor-positive/recipient-negative patients. Altogether, 27 patients were tested for drug resistance, and 11 strains were resistant, 8 sensitive, and 8 inconclusive. No differences in immunosuppression, acute rejection, or pre-transplant sensitization were seen between case-matched groups. The peak CMV viral load and mean duration of viremia were significantly higher in the resistant group (324,000 vs. 117,000 mean IU/ml, p = 0.048 and 140 vs. 55 days, p0.001, respectively). The resistant group had increased overall mortality after onset of viremia compared with controls (3-year mortality 70% vs. 30%; p = 0.01).Drug-resistant CMV infection is rare, but patients who develop it have decreased overall survival. Peak CMV viral load and duration of CMV viremia were associated with development of resistant CMV infection.

BACKGROUND Low-level CMV DNAemia is common and in the absence of treatment may either progress to higher viral loads that require therapy, or may spontaneously resolve. The clinical predictors of progression and spontaneous viral clearance are not well defined. METHODS We performed a retrospective cohort study of organ transplant recipients who had untreated low-level CMV DNAemia (

Acute cellular rejection (ACR) is a significant risk factor for chronic lung allograft dysfunction (CLAD). Although clinically manifest and higher grade (≥A2) ACR is generally treated with augmented immunosuppression, management of minimal (grade A1) ACR remains controversial. In our program, patients with subclinical and spirometrically stable A1 rejection (StA1R) are routinely not treated with augmented immunosuppression. We hypothesized that an untreated first StA1R does not increase the risk of CLAD or death compared to episodes of spirometrically stable no ACR (StNAR). The cohort was drawn from all consecutive adult, first, bilateral lung transplantations performed between 1999 and 2017. Biopsies obtained in the first-year posttransplant were paired with (forced expiratory volume in 1 second FEV1 ). The first occurrence of StA1R was compared to a time-matched StNAR. The risk of CLAD or death was assessed using univariable and multivariable Cox proportional hazards models. The analyses demonstrated no significant difference in risk of CLAD or death in patients with a first StA1R compared to StNAR. This largest study to date shows that, in clinically stable patients, an untreated first A1 ACR in the first-year posttransplant is not significantly associated with an increased risk for CLAD or death. Watchful-waiting approach may be an acceptable tactic for stable A1 episodes in lung transplant recipients.

Purpose Chronic Lung Allograft Dysfunction (CLAD) is a heterogeneous disease. Three major phenotypes: bronchiolitis obliterans syndrome (BOS), restrictive allograft syndrome (RAS) and mixed phenotype, are defined based on combinations of lung physiology and chest imaging. Total lung capacity (TLC)≤90% of baseline is used to define RAS/Mixed; however, many centers do not routinely obtain TLC and use instead forced vital capacity (FVC)≤80%. The objective of the current study was to assess the diagnostic accuracy of FVC≤80% for determining RAS/Mixed in a large center that routinely monitors both TLC and FVC. Methods This was a retrospective cohort study of all consecutive adult, first, bilateral lung transplants performed 2010-2015. All patients with CLAD were included. Spirometry, lung volumes, and chest imaging were available. RAS/mixed were determined based on 2019 ISHLT definitions using TLC≤90% and the presence of RAS-like opacities. Sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic accuracy of FVC≤80% combined with RAS-like opacities for diagnosis of RAS/Mixed were computed. Results A total of 174 patients developed CLAD: 25(14.4%) met criteria for RAS/mixed by TLC. The sensitivity, specificity, PLR, NLR and diagnostic accuracy for FVC to determine RAS/Mixed was 84.0% (95%CI 63.9-95.5), 95.3% (95%CI 90.6-98.1), 17.9 (95%CI 8.5-37.6), 0.17 (95%CI 0.07-0.41) and 93.7% (95%CI 89.0-96.8). Conclusion Low FVC has an overall good diagnostic value for estimating RAS/mixed phenotype. Given the high specificity, it is possible to rule in RAS/mixed phenotype with spirometry. However, it cannot be ruled out confidently based on spirometry alone. In CLAD patients with a clinical suspicion of RAS/mixed phenotype and a preserved FVC, measurement of TLC is important for a more accurate diagnosis.

Purpose Bronchiolitis obliterans syndrome (BOS), restrictive allograft syndrome (RAS), and mixed are major phenotypes of CLAD. In previous, older studies, CMV viremia has been associated with reduced survival. We hypothesized that, in a more modern era of CMV prophylaxis, CMV viremia would remain associated with death, but also represent a risk factor for CLAD and specifically RAS/mixed phenotype. Methods This is a retrospective cohort study of all consecutive adult, first, bilateral-/single-lung transplants performed 2010-2016 who had ≥4 pulmonary function tests and ≥1 CMV-PCR measurement. CMV-PCR levels were divided into 3 categories: undetectable, Results Of 645 patients, 257 developed CLAD (143 BOS, 44 RAS/mixed, 66 undefined/unclassified) and 388 were CLAD-free at last follow-up. In univariate analysis, CMV-PCR≥1000 IU/mL was a significant risk factor for CLAD (HR 1.33, p=0.05). In multivariate analysis, CMV-PCR was not a significant risk factor for CLAD, whereas CMV serostatus mismatch was (Table). CMV-PCR was not a significant risk factor for RAS/mixed (CMV-PCR Conclusion CMV viremia was significantly associated with death/re-transplantation. Conversely, CMV viremia was not strongly associated with CLAD or RAS/mixed, while CMV serostatus mismatch was. CMV serostatus mismatch may have an impact on CLAD through mechanisms independent of viremia. In light of these paradoxical results, we are further assessing the relationship between immunosuppression, immune function, and CMV.

Purpose Lung and heart-lung transplant candidates and recipients are susceptible to mycobacterial infections that can cause morbidity and mortality. We characterized the incidence, clinical characteristics and treatment of mycobacterial findings and assessed their impact on patient outcomes. Methods We conducted a retrospective review of patients who underwent lung or heart-lung transplantation in our center between June 1988 and May 2020 and identified patients with mycobacterial findings, in most cases positive sputum or bronchoscopy sample cultures. Pre-transplant patients are screened for mycobacterial infections with bronchoscopy and sputum samples. Post-transplant patients undergo surveillance bronchoscopies several times during the first post-transplant year, annually thereafter, and when clinically warranted. The decision to initiate anti-mycobacterial treatment is based on clinical, radiologic and mycobacterial sample results, with the aim to treat mycobacterial disease and monitor colonization. Results In a cohort of 355 patients, 15/355 (4.2%) patients had a pre-transplant mycobacterial finding and 9/15 received anti-mycobacterial treatment. In one patient, mycobacterium tuberculosis infection recurred post-transplant. No deaths were related to mycobacterial infections in patients with a pre-transplant mycobacterial finding. In post-transplant patients, 27/355 (7.6%) patients had a mycobacterial finding and 5/27 received anti-mycobacterial treatment. One patient died due to disseminated mycobacterium abscessus infection. Mycobacterial findings pre- or post-transplant did not affect overall patient survival compared to non-infected patients (Log Rank p = 0.312). Conclusion Mycobacterial findings are rare in patients undergoing lung or heart-lung transplantation, and do not seem to affect overall survival of patients. Most post-transplant mycobacterial findings represent colonization, but disseminated mycobacterial infection may be fatal.

Purpose Airway epithelial injury is thought to be a key event in the pathogenesis of Chronic lung allograft dysfunction (CLAD). We investigated whether markers of epithelial activity and injury in bronchoalveolar lavage (BAL) correlate with CLAD diagnosis and major CLAD phenotypes: bronchiolitis obliterans syndrome (BOS) vs. restrictive allograft syndrome (RAS)-related phenotypes (including RAS, mixed phenotype, and all other patients with RAS-like opacities). Methods CLAD status and phenotypes were retrospectively determined in a cohort of all consecutive adult, first, bilateral lung transplants performed 2010-2015. All patients with RAS-related phenotypes were included and 1:1 matched with BOS patients based on time from transplant to CLAD-onset. CLAD-free subjects were used as controls. Proteins that maintain the barrier function of the airway epithelial mucosa (club cell secretory protein (CCSP), surfactant protein-D (SP-D) and epithelial mucins: MUC1, MUC5AC, MUC5B, MUC16), as well as epithelial cell death markers (M30&M65 representing apoptosis and overall death, respectively), were measured in BAL obtained within 6-months from CLAD onset using a double-sandwich ELISA or a multiplex bead assay. Protein levels were compared using Kruskal-Wallis and Mann-Whitney-U-test. Association between protein levels and graft survival was assessed using Cox proportional hazards models, adjusted for CMV serology mismatch status and phenotype. Results Fifty-four CLAD (27 BOS, 11 RAS, 7 mixed, 9 others with RAS-like opacities) patients and 26 CLAD-free controls were included. Median BAL levels were significantly higher in patients with CLAD compared to CLAD-free controls for M30 (124.5 vs. 88.9), MUC1 (6.8 vs. 3.28) and MUC16 (121.0 vs. 31.1). When comparing CLAD phenotypes, M30 was significantly higher in patients with RAS-related phenotypes compared to BOS (160.9 vs. 114.6). In multivariable models, levels of M30 and MUC5B were associated with allograft survival after CLAD onset independent of phenotype (P Conclusion Airway epithelial mucin and cell death markers are enhanced in the BAL fluid of patients with CLAD and can assist in differentiating between CLAD phenotypes. Abnormal airway mucin expression and epithelial cell death may be involved in the airway inflammatory response of CLAD and thus aid in future selection of targeted therapies.

Purpose Allograft infection after lung transplant (LTx) has a significant impact on outcome and has been associated with chronic lung allograft dysfunction (CLAD). Commensal bacteria (CB) are commonly isolated from bronchoalveolar lavages (BAL) in LTx recipients but the clinical significance is unknown. Our objective was to evaluate the association of high growth of CB (≥106 CFU/L) in BAL cultures with subsequent infection or CLAD. Methods We conducted a single-center, retrospective, cohort study of consecutive adult, first bilateral LTx performed 2010-2017. Patients who had no evidence of BAL infection and were alive and CLAD-free throughout the first 6-months post-transplant were included. Infection was defined as the presence of treatment-requiring pathogens in BAL. Outcomes of patients with ≥1CB within the first 6-months post-transplant were compared to patients with no CB isolation episodes within the same time interval. Association of CB with subsequent clinically significant BAL infections using logistic regression models and with time to CLAD was assessed using Cox Proportional Hazards models. Results The study cohort consisted of 202 patients with a median of 7 (IQR 7, 8) bronchoscopies per patient. Seventy of the 202 (34.7%) had subsequent BAL infection at some point post-transplant. Median time to CLAD was 497 days (IQR 131, 1043). Fifty-four (26.7%) patients had at least one episode of CB within the first 6-months post-transplant. In a multivariable analysis accounting for age, sex, primary lung disease, acute rejection score and CMV-mismatch, there was no difference in risk for subsequent infections (OR=0.83, 95% CI 0.40-1.69, P=0.60) or CLAD (HR=0.97, 95% CI 0.50-1.87, P=0.92) between patients with ≥1CB episode versus none. Conclusion We found that in the absence of specific infectious pathogens, isolation of commensal bacteria from BAL of LTx recipients during the first 6-months is not associated with an increased risk of subsequent infections or development of CLAD.

Purpose Chronic lung allograft dysfunction (CLAD) is a heterogeneous condition. Characterization of CLAD phenotypes is essential to enhance the understanding of pathogenesis and guide new therapies. The study objective was to validate the 2019 ISHLT CLAD classification system and further explore patients who do not fall into the defined CLAD sub-categories. Methods We performed a single-center, retrospective cohort study of adult, first, bilateral lung transplants performed 2010-2015. Classification of CLAD phenotypes was based on the 2019 ISHLT consensus document. Survival after CLAD onset was assessed using Kaplan-Meier and Cox proportional hazards models. Results Among the 174 subjects with CLAD, 104 (59.8%) had bronchiolitis obliterans syndrome (BOS), 16 (9.2%) restrictive allograft syndrome (RAS), 9 (5.2%) mixed and 19 (10.9%) undefined phenotype. Twenty-six patients (14.9%) did not match any of these four categories and remained unclassified. Allograft survival post-CLAD onset was longer for patients with BOS (median, 500 days) than patients with RAS (median, 372 days) or mixed (median, 328 days). The remaining 45 (25.9%) patients were combined and re-categorized based on the presence or absence of characteristic RAS-like opacities on chest imaging: those with RAS-like opacities at CLAD onset had significantly worse allograft survival compared to patients with BOS (HR=2.14, 95% CI 1.17-3.93, P=0.014) and similar survival to RAS or mixed phenotype. Conclusion The new ISHLT CLAD phenotype classification is informative with regards to post-CLAD outcomes. Chest imaging demonstrating persistent parenchymal or pleural fibrosis may be used for the risk-stratification of patients who do not match the major CLAD phenotypes.

Purpose There are contradictory reports on outcomes after bilateral lung transplant (BLT) vs. single lung transplant (SLT) in patients with COPD, which may be confounded by differences in allocation preferences and patient care between programs. We report outcomes of SLT vs. BLT for COPD at our center. Methods We retrospectively analyzed COPD patients who underwent SLT and BLT between Jan 2008 and Dec 2018. Pre- and post-transplant characteristics were compared between groups with chi‐square and t-tests. Unadjusted Kaplan‐Meier survival estimates were used to compare differences in freedom from CLAD (2019 ISHLT criteria) and allograft survival with log‐rank tests. Results 276 patients with COPD underwent LT (233 BLT and 43 SLT). SLTs were older than BLTs [median 63y (IQR 59-69) vs. 61y (IQR 57-67) p=0.04]. There were no other differences in baseline characteristics. SLTs had younger donors [median 27y (IQR 23-49) vs. 36y (IQR 22-53) p=0.01] and more often underwent EVLP [49% vs. 29% p=0.01]. BLTs required more intraoperative ECMO [14% vs. 2.3% p=0.03] and blood transfusion [40% vs. 19% p=0.02]. Mean post-transplant hospital and ICU length of stay was similar between groups [BLT 29.1d (95%CI 27.1-34.9) vs. SLT 23.5d (95% CI 19.6-27.5) p=0.11], and [BLT 6.8d (95%CI 5.3-8.1) vs. SLT 5.4d (95% CI 3.7-7.1) p=0.36]. Postoperative FEV1 and FVC were better in BLT [2.75L (95% CI 2.2-3.39) vs. 1.63L (95% CI 1.39-1.92) p Conclusion BLT for COPD resulted in better postoperative lung function and exercise capacity, but no significant differences in freedom from CLAD and allograft survival. There was a trend toward improved longer-term survival with BLT for COPD.

Purpose Surveillance bronchoscopies with bronchoalveolar lavage (BAL) and transbronchial biopsies (TBB) are used in the evaluation of patients after lung transplant to detect acute cellular rejection (ACR) or infection. We have previously shown that a focused BAL protein signature early post-transplant may predict CLAD or death in a subset of clinically-stable patients with A1-grade (minimal) ACR. The aim of the current study was to determine whether similar BAL markers would have similar predictive characteristics irrespective of ACR grade. Methods The cohort consisted of all adult, first, bilateral lung transplants performed 2010-2017. Clinical status was categorized as unstable or stable based on presence or absence of ≥10% concurrent drop in FEV1. Clinically stable patients with grade AX TBB (inadequate biopsies, which are not routinely treated at our center, thus avoiding the confounding effect of ACR treatment) during the first-year post-transplant, not preceded by ACR (grade A≥1 or grade B≥1) were included. IL6, S100A8, IL10, TNF-receptor1, IL-1α, pentraxin3 and CXCL10, previously shown to be associated with worse outcomes, were measured in the BAL using a multiplex bead assay. Association with subsequent CLAD or death was assessed using Cox proportional hazards models adjusted for age, sex, native lung disease, and CMV-mismatch. Results 107 patients matched the inclusion criteria with a stable AX occurring at a median time of 188 days (IQR 96-279) post-transplant. Median time from AX TBB to CLAD or death was 462 (IQR 330, 928) and 582 days (IQR 251-1410), respectively. In multivariable models, levels of CXCL10 and IL10 were associated with both CLAD development and death while IL6, S100A8 and pentraxin3 were only associated with death (P Conclusion A focused BAL protein signature in clinically stable patients with ungradable TBB, early post-transplant, may be informative in determining increased risk for worse outcome and may benefit from a more aggressive management strategy.

Summary of Objectives Chronic lung allograft dysfunction (CLAD) affects up to 70% of lung transplant (LTx) recipients and is the major impediment to long-term survival. CLAD is a retrospective diagnosis of exclusion when other causes for sustained drop of ≥20% of forced expiratory volume in 1s or forced vital capacity have been ruled out. No effective treatments exist, likely due to irreversible lung damage at diagnosis. Oscillometry (Osc) is a promising pulmonary function test that is particularly sensitive to changes in small airways, the site of CLAD onset. Our aim is to characterize Osc in patients with early CLAD. Methods In a prospective study that began in December 2017, all new double LTx recipients are enrolled for Osc prior to routine spirometry. Endpoints CLAD will be diagnosed according to ISHLT guidelines. By March 2020 we anticipate enrolment of 300 patients and 30 to have CLAD. We will compare Osc in CLAD patients with those who remain CLAD free after ≥6 mths follow-up. Univariate and mixed models will be used to examine spirometry vs Osc parameters of small airway disease: namely, X5 (reactance at 5Hz), Ax (area of reactance) and R5-19 (difference of resistance at 5 and 19 Hz). Receiver operating characteristic area under the curve (AUC) will be used to assess the predictive power of each. In interim analysis of patients enrolled by 31 July 2019, 13/197 had CLAD [all with bronchiolitis obliterans syndrome (BOS)], with median time of diagnosis at 24 wks post-LTx (range 10-59). Osc was abnormal and significantly different in CLAD vs. 87 CLAD-free recipients who had follow-up of ≥ 6 mths (median 40 wks). The mean Osc measurements at time of CLAD diagnosis vs last follow-up of CLAD-free patients are: X5 = -3.7 vs -2.1 cmH20.s/L, Ax = 31.6 vs 15.9 cmH20/L and R5-19 = 1.5 vs 0.8 cmH20.s/L (p

The development of de novo donor-specific HLA antibodies (dnDSA) after transplantation is associated with graft failure, mortality, and cost. There is no effective therapeutic intervention to prevent dnDSA or ameliorate associated injury. The aims of this study were to identify specific HLA factors associated with dnDSA development and to propose primary prevention strategies that could reduce the incidence of dnDSA without prohibitively limiting access to transplant. The investigation cohort included heart transplant recipients from 2008 to 2015 (n = 265). HLA typing was performed and HLA antibody testing was undertaken before and after transplantation. HLAMatchmaker analysis was performed for persistent dnDSA to identify potentially more immunogenic eplet differences. Validation was performed in recipients of lung transplants from 2008 to 2013 (n = 433). The majority of recipients with dnDSA had antibodies to identical eplet positions on DQ2 and DQ7. A high-risk epitope mismatch (found in DQA1*05 + DQB1*02/DQB1*03:01(7)) was associated with a 4.2- and 4.9-fold increased risk of dnDSA in heart and lung recipients respectively. HLA electrostatic potential modeling provided a plausible explanation for this observed immunogenicity. A theoretical allocation algorithm avoiding high-risk epitope mismatches was generated and predicted to reduce dnDSA by up to 72% without additional testing, eplet analysis, or cost.

The growing demand for suitable lungs for transplantation drives the quest for alternative strategies to expand the donor pool. The aim of this study is to evaluate the outcomes of lung transplantation (LTx) with donation after circulatory determination of death (DCDD) and the impact of selective ex vivo lung perfusion (EVLP). From 2007 to 2013, 673 LTx were performed, with 62 (9.2%) of them using DCDDs (seven bridged cases). Cases bridged with mechanical ventilation/extracorporeal life support were excluded. From 55 DCDDs, 28 (51%) underwent EVLP. Outcomes for LTx using DCDDs and donation after neurological determination of death (DNDD) donors were similar, with 1 and 5-year survivals of 85% and 54% versus 86% and 62%, respectively (p = 0.43). Although comparison of survival curves between DCDD + EVLP versus DCDD-no EVLP showed no significant difference, DCDD + EVLP cases presented shorter hospital stay (median 18 vs. 23 days, p = 0.047) and a trend toward shorter length of mechanical ventilation (2 vs. 3 days, p = 0.059). DCDDs represent a valuable source of lungs for transplantation, providing similar results to DNDDs. EVLP seems an important technique in the armamentarium to safely increase lung utilization from DCDDs; however, further studies are necessary to better define the role of EVLP in this context.

Ex-vivo lung perfusion (EVLP), a technique for donor lung assessment, also represents a platform for donor lung repair and immunomodulation. αPig donor lungs were retrieved, preserved at 4°C for 24 hours, and then subjected to normothermic EVLP for 12 hours using the Toronto protocol. The treatment group (n = 6) received 3 mg/ml A1AT (Zemaira) in the EVLP perfusate, acellular Steen solution. The control group (n = 6) was perfused with Steen solution only. Physiologic functions and gas exchange were measured hourly. Pulmonary edema, lung injury, apoptosis and inflammatory mediators were evaluated in lung tissues and perfusate.A1AT treatment significantly reduced pulmonary arterial pressure, pulmonary vascular resistance and airway pressure changes from the baseline when compared with controls. A1AT treatment significantly improved both dynamic and static pulmonary compliance, and change in partial pressure of oxygen (ΔPOTreatment of 24-hour-preserved pig donor lungs with A1AT during EVLP resulted in improved physiologic function, reduced pulmonary edema and inflammation and decreased cell death. Our findings suggest that treatment of donor lungs during EVLP with A1AT is a promising strategy to attenuate early lung injury and improve donor lung function before lung transplantation.

Intragraft DSA can be found in explanted lungs of patients with chronic lung allograft dysfunction in the absence of circulating DSA. New diagnostic approaches to assess for intragraft DSA may add to our diagnostic arsenal in treating AMR.http://bit.ly/31kS00b