Report of the ISHLT Working Group on Primary Lung Graft Dysfunction, part I: Definition and grading-A 2016 Consensus Group statement of the International Society for Heart and Lung Transplantation. J Heart Lung Transplant. 2017;36:1097-1103. [PMID: 28942784 DOI: 10.1016/j.healun.2017.07.021]

Update on the immunological mechanisms of primary graft dysfunction and chronic lung allograft dysfunction

PURPOSE OF REVIEW

Primary graft dysfunction (PGD) and chronic lung allograft dysfunction (CLAD) are the leading causes of graft loss in lung transplant recipients. The development of mouse lung transplant models has allowed for the genetic dissection of cellular and molecular pathways that prevent graft survival. This review provides an overview into recent mechanistic insights into PGD and CLAD.

RECENT FINDINGS

Mouse orthotopic lung transplant models and investigations of human lung transplant recipeints have revealed new molecular and cellular targets that promote PGD and CLAD. Donor and recipient-derived innate immune cells promote PGD and CLAD. PGD is driven by communication between classical monocytes and tissue-resident nonclassical monocytes activating alveolar macrophages to release chemokines that recruit neutrophils. Products of cell damage trigger neutrophil NET release, which together with NK cells, antibodies and complement, that further promote PGD. The development of CLAD involves circuits that activate B cells, CD8 + T cells, classical monocytes, and eosinophils.

SUMMARY

Effective targeted management of PGD and CLAD in lung transplant recipient to improve their long-term outcome remains a critical unmet need. Current mechanistic studies and therapeutic studies in mouse models and humans identify new possibilities for prevention and treatment.

Xenotransplantation of Mitochondria: A Novel Strategy to Alleviate Ischemia-Reperfusion Injury during Ex Vivo Lung Perfusion

Ischemia-reperfusion injury (IRI) plays a crucial role in the development of primary graft dysfunction (PGD) following lung transplantation. A promising novel approach to optimize donor organs before transplantation and reduce the incidence of PGD is mitochondrial transplantation. In this study, we explored the delivery of isolated mitochondria in 4 hour ex vivo lung perfusion (EVLP) before transplantation as a means to mitigate IRI. To provide a fresh and viable source of mitochondria, as well as to streamline the workflow without the need for donor muscle biopsies, we investigated the impact of autologous, allogeneic and xenogeneic mitochondrial transplantation. In the xenogeneic settings, isolated mitochondria from mouse liver were utilized while autologous and allogeneic sources came from pig skeletal muscle biopsies. Treatment with mitochondrial transplantation increased the P/F ratio and reduced pulmonary peak pressure of the lungs during EVLP, compared to lungs without any mitochondrial transplantation, indicating IRI mitigation. Extensive investigations using advanced light and scanning electron microscopy did not reveal evidence of acute rejection in any of the groups, indicating safe xenotransplantation of mitochondria. Future work is needed to further explore this novel therapy for combating IRI in lung transplantation, where xenotransplantation of mitochondria may serve as a fresh, viable source to reduce IRI.

Analysis of Perioperative Factors Leading to Postoperative Pulmonary Complications, Graft Injury and Increased Postoperative Mortality in Lung Transplantation

OBJECTIVES

Postoperative complications such as postoperative pulmonary complications (PPCs) and other organ complications are associated with increased morbidity and mortality after successful lung transplantation and have a detrimental effect on patient recovery. The aim of this study was to investigate perioperative risk factors for in-hospital mortality and postoperative complications with a focus on PPC and graft injury in patients undergoing lung transplantation DESIGN: Single-center retrospective cohort study of 173 patients undergoing lung transplantation SETTING: University Hospital, Medical Center Freiburg.

MAIN RESULTS

In the stepwise multivariate regression analysis, donor age >60 years (odds ratio [OR], 1.85; 95% confidence interval [CI], 1.27-2.81), intraoperative extracorporeal membrane oxygenation (OR, 2.4; 95% CI, 1.7-3.3), transfusion of >4 red blood cell concentrates (OR, 3.1; 95% CI, 1.82-5.1), mean pulmonary artery pressure of >30 mmHg at the end of surgery (OR, 3.5; 95% CI, 2-6.3), the occurrence of postoperative graft injury (OR, 4.1; 95% CI, 2.8-5.9), PPCs (OR, 2.1; 95% CI, 1.7-2.6), sepsis (OR, 4.5; 95% CI, 2.8-7.3), and Kidney disease Improving Outcome grading system stage 3 acute renal failure (OR, 4.3; 95% CI, 2.4-7.7) were associated with increased in hospital mortality, whereas patients with chronic obstructive pulmonary disease had a lower in-hospital mortality (OR, 1.6; 95% CI, 1.4-1.9). The frequency and number of PPCs correlated with postoperative mortality.

CONCLUSIONS

Clinical management and risk stratification focusing on the underlying identified factors that could help to improve patient outcomes.

Alterations in circulating measures of Th2 immune responses pre-lung transplant associates with reduced primary graft dysfunction

Primary graft dysfunction (PGD) is a complication of lung transplantation that continues to cause significant morbidity. The Th2 immune response has been shown to counteract tissue-damaging inflammation. We hypothesized that Th2 cytokines/chemokines in blood would be associated with protection from PGD. Utilizing pretransplant sera from the multicenter clinical trials in organ transplantation study, we evaluated Th2 cytokines/chemokines in 211 patients. Increased concentrations of Th2 cytokines were associated with freedom from PGD, namely IL-4 (odds ratio [OR] 0.66 [95% confidence interval {CI} 0.45-0.99], p = 0.043), IL-9 (OR 0.68 [95% CI 0.49-0.94], p = 0.019), IL-13 (OR 0.73 [95% CI 0.55-0.96], p = 0.023), and IL-6 (OR 0.74 [95% CI 0.56-0.98], p = 0.036). Multivariable regression performed for each cytokine, including clinically relevant covariables, confirmed these associations and additionally demonstrated association with IL-5 (OR 0.57 [95% CI 0.36-0.89], p = 0.014) and IL-10 (OR 0.55 [95% CI 0.32-0.96], p = 0.035). Higher levels of Th2 immune response before lung transplant appear to have a protective effect against PGD, which parallels the Th2 role in resolving inflammation and tissue injury. Pretransplant cytokine assessments could be utilized for recipient risk stratification.

The effect of rewarming ischemia on tissue transcriptome and metabolome signatures: a clinical observational study in lung transplantation

BACKGROUND

In lung transplantation (LuTx), various ischemic phases exist, yet the rewarming ischemia time (RIT) during implantation has often been overlooked. During RIT, lungs are deflated and exposed to the body temperature in the recipient's chest cavity. Our prior clinical findings demonstrated that prolonged RIT increases the risk of primary graft dysfunction. However, the molecular mechanisms of rewarming ischemic injury in this context remain unexplored. We aimed to characterize the rewarming ischemia phase during LuTx by measuring organ temperature and comparing transcriptome and metabolome profiles in tissue obtained at the end versus the start of implantation.

METHODS

In a clinical observational study, 34 double-LuTx with ice preservation were analyzed. Lung core and surface temperature (n=65 and 55 lungs) was measured during implantation. Biopsies (n=59 lungs) were wedged from right middle lobe and left lingula at start and end of implantation. Tissue transcriptomic and metabolomic profiling were performed.

RESULTS

Temperature increased rapidly during implantation, reaching core/surface temperatures of 21.5°C/25.4°C within 30min. Transcriptomics showed increased pro-inflammatory signaling and oxidative stress at the end of implantation. Upregulation of NLRP3 and NFKB1 correlated with RIT. Metabolomics indicated elevated levels of amino acids, hypoxanthine, uric acid, cysteineglutathione disulfide alongside decreased levels of glucose and carnitines. Arginine, tyrosine, and 1-carboxyethylleucine showed correlation with incremental RIT.

CONCLUSIONS

The final rewarming ischemia phase in LuTx involves rapid organ rewarming, accompanied by transcriptomic and metabolomic changes indicating pro-inflammatory signaling and disturbed cell metabolism. Limiting implantation time and lung cooling represent potential interventions to alleviate rewarming ischemic injury.

Bloodless lung transplantation: Comparison between 2 central venoarterial extracorporeal membrane oxygenation anticoagulation strategies and their impact on lung transplant outcomes

OBJECTIVE

To report differences between 2 anticoagulation protocols during venoarterial extracorporeal membrane oxygenation (VA-ECMO) intraoperative support and their effects on outcomes after lung transplantation.

METHODS

We performed a retrospective analysis of patients undergoing double-lung transplantation with intraoperative VA-ECMO from January 1, 2016, to December 30, 2023. Two distinct anticoagulation protocols were in place during this period. One included targeted activated clotting time >180 seconds at all times with protamine reversal after decannulation. The second included 75 units per kilogram of heparin at the time of cannulation with no redosing plus a tranexamic acid infusion after ECMO initiation.

RESULTS

A total of 116 patients (46 low heparin, 70 standard) were included in the analysis. Cannulation strategies and ECMO circuit were equivalent between the groups. The low-dose heparin protocol group had a shorter surgical time (7.28 hours vs 8.53 hours, P < .001) and required significantly less intraoperative packed red blood cells (median 0 vs 4.37 units, P < .001), fresh-frozen plasma (median 0 vs 2 units, P < .001), platelets (median 0 vs 1 units, P < .001), cryoprecipitate (median 0 vs 0 units, P < .001), and total blood products (median 0 vs 9 units, P < .001) compared with the standard group. There were no differences in rates of deep vein thrombosis (P = .13), airway dehiscence (P > .99), pneumonia (P = .38), or acute kidney injury requiring renal-replacement therapy (P = .59). There was no difference in rates of severe grade 3 primary graft dysfunction at 72 hours after transplant (P = .42).

CONCLUSIONS

Our low-dose heparin VA-ECMO protocol for intraoperative support during lung transplantation led to a significant reduction of blood product use. Although this did not translate to a reduced rates of grade 3 primary graft dysfunction, the low-dose heparin protocol was associated with similar postoperative outcomes.

Differences in chronic lung allograft dysfunction between deceased-donor lung transplantation and living-donor lobar lung transplantation

OBJECTIVE

To explore the characteristics and prognostic impact of chronic lung allograft dysfunction (CLAD) after deceased-donor lung transplantation and living-donor lobar lung transplantation, wherein the lower lobes from 2 donors are usually transplanted into one recipient.

METHODS

The clinical data of 123 deceased-donor and 67 living-donor lung transplantations performed in adult patients at our institution between June 2008 and September 2019 were retrospectively reviewed. The cumulative incidence of CLAD was evaluated on a per-recipient and per-donor graft basis using the Kaplan-Meier method.

RESULTS

A smaller number of human leukocyte antigen mismatches, shorter ischemic time, and lower incidence of grade 3 primary graft dysfunction were observed in living-donor transplantation than in deceased-donor transplantation (P < .001). Restrictive allograft syndrome-type CLAD occurred in 9 (20.9%) of 43 patients with CLAD after deceased-donor transplantation and 9 (45.0%) of 20 patients with CLAD after living-donor transplantation. CLAD occurred unilaterally in 15 patients (75.0%) after bilateral living-donor transplantation. Despite the greater incidence of restrictive allograft syndrome-type CLAD after living-donor transplantation, the overall survival rates after the transplantation and survival rates after the onset of CLAD were comparable between the patients receiving deceased-donor transplants and living-donor transplants. The cumulative incidence of CLAD per recipient was similar between recipients of deceased-donor and the living-donor transplants (P = .32). In the per-donor graft analysis, the cumulative incidence of CLAD was significantly lower in the living-donor grafts than in the deceased-donor grafts (P = .003).

CONCLUSIONS

The manifestation of CLAD after living-donor lobar lung transplantation is unique and differs from that after deceased-donor lung transplantation.

Angiotensin-converting enzyme 2 activation attenuates inflammation and oxidative stress in brain death donor followed by rat lung transplantation

Brain death (BD) provides most of the donor organs destined for lung transplantation (LTx). However, the organs may be affected by inflammatory and oxidative processes. Based on this, we hypothesize that the angiotensin-converting enzyme 2 (ACE2) activation can reduce the lung injury associated with LTx. 3 h after BD induction, rats were injected with saline (BD group) or an ACE2 activator (ACE2a group; 15 mg/kg-1) and kept on mechanical ventilation for additional 3 h. A third group included a control ventilation (Control group) prior to transplant. After BD protocol, left LTx were performed, followed by 2 h-reperfusion. ACE2 activation was associated with better oxygenation after BD management (p = 0.01), attenuating edema (p = 0.05) followed by the reduction in tissue resistance (p = 0.01) and increase of respiratory compliance (p = 0.02). Nrf2 expression was also upregulated in the ACE2a group (p = 0.03). After transplantation, ACE2a group showed lower levels of TNF-α (p = 0.02), IL-6 (p = 0.001), IL-1β (p = 0.01), ROS (p = 0.004) and MDA (p = 0.002), in addition to higher CAT activity (p = 0.04). In conclusion, our study suggests that ACE2 activation improves anti-inflammatory and antioxidant activity in a model of LTx.

Donor age over 55 is associated with worse outcome in lung transplant recipients with idiopathic pulmonary fibrosis

BACKGROUND

Lung transplantation (LTx) remains the only efficient treatment for selected patients with end-stage pulmonary disease. The age limit for the acceptance of donor organs in LTx is still a matter of debate. We here analyze the impact of donor organ age and the underlying pulmonary disease on short- and long-term outcome and survival after LTx.

METHODS

Donor and recipient characteristics of LTx recipients at our institution between 03/2003 and 12/2021 were analyzed. Statistical analysis was performed using SPSS and GraphPad software.

RESULTS

In 230 patients analyzed, donor age ≥ 55 years was associated with a higher incidence of severe primary graft dysfunction (PGD2/3) (46% vs. 31%, p = 0.03) and reduced long-term survival after LTx (1-, 5- and 10-year survival: 75%, 54%, 37% vs. 84%, 76%, 69%, p = 0.006). Notably, this was only significant in recipients with idiopathic pulmonary fibrosis (IPF) (PGD: 65%, vs. 37%, p = 0.016; 1-, 5-, and 10-year survival: 62%, 38%, 16% vs. 80%, 76%, 70%, p = 0.0002 respectively). In patients with chronic obstructive pulmonary disease (COPD), donor age had no impact on the incidence of PGD2/3 or survival (21% vs. 27%, p = 0.60 and 68% vs. 72%; p = 0.90 respectively). Moreover, we found higher Torque-teno virus (TTV)-DNA levels after LTx in patients with IPF compared to COPD (X2 = 4.57, p = 0.033). Donor age ≥ 55 is an independent risk factor for reduced survival in the whole cohort and patients with IPF specifically.

CONCLUSIONS

In recipients with IPF, donor organ age ≥ 55 years was associated with a higher incidence of PGD2/3 and reduced survival after LTx. The underlying pulmonary disease may thus be a relevant factor for postoperative graft function and survival.

TRIAL REGISTRATION NUMBER DKRS

DRKS00033312.

Loss of Nr4a1 ameliorates endothelial cell injury and vascular leakage in lung transplantation from circulatory-death donor

BACKGROUND

Ischemia-reperfusion injury (IRI) stands as a major trigger for primary graft dysfunction (PGD) in lung transplantation (LTx). Especially in LTx from donation after cardiac death (DCD), effective control of IRI following warm ischemia (WIRI) is crucial to prevent PGD. This study aimed to identify the key factors affecting WIRI in LTx from DCD.

METHODS

Previously reported RNA-sequencing dataset of lung WIRI was reanalyzed to identify nuclear receptor subfamily 4 group A member 1 (NR4A1) as the immediate early gene for WIRI. Dynamics of NR4A1 expression were verified using a mouse hilar clamp model. To investigate the role of NR4A1 in WIRI, a mouse model of LTx from DCD was established using Nr4a1 knockout (Nr4a1-/-) mice.

RESULTS

NR4A1 was located around vascular cells, and its protein levels in the lungs increased rapidly and transiently during WIRI. LTｘ from Nr4a1-/- donors significantly improved pulmonary graft function compared to wild-type donors. Histological analysis showed decreased microvascular endothelial cell death, neutrophil infiltration, and albumin leakage. Evans blue permeability assay demonstrated maintained pulmonary microvascular barrier integrity in grafts from Nr4a1-/- donors, correlating with diminished pulmonary edema. However, NR4A1 did not significantly affect the inflammatory response during WIRI, and IRI was not suppressed when a wild-type donor lung was transplanted into the Nr4a1-/- recipient.

CONCLUSIONS

Donor NR4A1 plays a specialized role in the positive regulation of endothelial cell injury and microvascular hyperpermeability. These findings demonstrate the potential of targeting NR4A1 interventions to alleviate PGD and improve outcomes in LTx from DCD.

Case Report: Optimal utilization of marginal lung allografts by considering donor-recipient PGD risk compatibility and by mitigating allograft and recipient inflammatory risk

Reducing the risk of high-grade primary graft dysfunction (PGD) is vital to achieve acceptable short- and long-term outcomes for recipients following lung transplantation. However, the utilization of injured lung allografts, which may confer a higher risk of PGD, must be considered due to the disparity between the increasing number of patients requiring lung transplantation and the limited donor pool. We describe a case in which highly marginal lung allografts were utilized with a good post-transplant outcome. Donor-recipient PGD risk compatibility was taken into consideration. Normothermic ex vivo lung perfusion (EVLP) was utilized to functionally assess the allografts. A second cold ischemia time following EVLP was avoided by converting the EVLP mode to a hypothermic oxygenated perfusion setup from which the lungs were transplanted directly. We attempted to mitigate lung ischemia-reperfusion injury in the recipient by employing cytokine adsorption both during the EVLP and intraoperatively during the implant procedure. In this case report, we describe our hypothermic oxygenated perfusion setup on EVLP for the first time. Furthermore, we describe the utilization of cytokine adsorption in two phases of the same transplant process.

Impact of Angiotensin Blockade on Development of Chronic Lung Allograft Dysfunction

Background: The renin-angiotensin-aldosterone system (RAAS) is responsible for a multitude of physiological functions, including immunological effects such as promotion of TGF-β and upregulation of IL-6 and IL-8 which are also implicated in the development of chronic lung allograft dysfunction (CLAD). Blockade of the RAAS pathway in pre-clinical models has demonstrated a decrease in these cytokines and pulmonary neutrophil recruitment. Objective: This study sought to evaluate whether use of RAAS inhibitor (RAASi) in lung transplant recipients impacted CLAD-free survival. Methods: In this retrospective, single-center study, 35 lung transplant recipients who received a RAASi post-transplant were compared to 70 lung transplant recipients not exposed to a RAASi and were followed for up to 5 years post-transplant. Results: The incidence of CLAD did not differ based on RAASi treatment (34.3% in RAASi vs 38.6%, P-value .668). This was confirmed with a multivariable Cox proportional hazards model with RAASi initiation as a time-varying covariate (RAASi hazard ratio of 1.01, P-value .986). Incidence of hyperkalemia and acute kidney injury were low in the RAASi group. Conclusions: This study demonstrated no association between post-transplant RAASi use and decreased risk of CLAD development. RAASi were also well tolerated in this patient population.

Improving lung allograft function in the early post-operative period through the inhibition of pyroptosis

Lung transplantation is the only definitive therapy for end-stage pulmonary disease. Less than 20 % of offered lungs are successfully transplanted due to a limited ischemic time window and poor donor lung quality manifested by pulmonary edema, hypoxia, or trauma. Therefore, poor donor organ recovery and utilization are significant barriers to wider implementation of the life-saving therapy of transplantation. While ischemia reperfusion injury (IRI) is often identified as the underlying molecular insult leading to immediate poor lung function in the post-operative period, this injury encompasses several pathways of cellular injury in addition to the recruitment of the innate immune system to the site of injury to propagate this inflammatory cascade. Pyroptosis is a central molecular inflammatory pathway that is the most significant contributor to injury in this early post-operative phase. Pyroptosis is another form of programmed cell death and is often associated with IRI. The mitigation of pyroptosis in the early post-operative period following lung transplantation is a potential novel way to prevent poor allograft function and improve outcomes for all recipients. Here we detail the pyroptotic pathway, its importance in lung transplantation, and several therapeutic modalities that can mitigate this harmful inflammatory pathway.

Outcomes of controlled DCDD lung transplantation after thoraco-abdominal vs abdominal normothermic regional perfusion: The Spanish experience

BACKGROUND

Thoraco-abdominal normothermic regional perfusion (TA-NRP) has emerged as a strategy for evaluating and recovering the heart in controlled donation after the circulatory determination of death (cDCDD). However, its impact on lung grafts remains largely unknown. We aimed to assess the impact of TA-NRP on the outcomes of recipients of cDCDD lungs.

METHODS

This is a retrospective, multicenter, nationwide study describing the outcomes of cDCDD lung transplants (LTs) performed in Spain from January 2021 to November 2023. Patients were divided in 2 groups based on the recovery technique: TA-NRP with the simultaneous recovery of the heart vs abdominal NRP (A-NRP) without simultaneous heart recovery. The primary endpoint was the incidence of Primary Graft Dysfunction (PGD) grade 3 at 72 hours. Secondary endpoints included the overall incidence of PGD, days on mechanical ventilation, intensive care unit (ICU) and hospital length of stay, early survival rates, and mid-term outcomes.

RESULTS

Two hundred and eighty three cDCDD LTs were performed during the study period, 28 (10%) using TA-NRP and 255 (90%) using A-NRP. No differences were observed in the incidence of PGD grade 3 at 72 hours between the TA-NRP and the A-NRP group (0% vs 7.6%; p = 0.231), though the overall incidence of PGD was significantly lower with TA-NRP (14.3% vs 41.5%; p = 0.005). We found no significant differences between the groups regarding other post-transplant outcome variables.

CONCLUSIONS

TA-NRP allows the simultaneous recovery of both the heart and the lungs in the cDCDD scenario with appropriate LT outcomes comparable to those observed with the A-NRP approach.

Predicting Primary Graft Dysfunction in Lung Transplantation: Machine Learning-Guided Biomarker Discovery

BACKGROUND –

There is an urgent need to better understand the pathophysiology of primary graft dysfunction (PGD) so that point-of-care methods can be developed to predict those at risk. Here we utilize a multiplex multivariable approach to define cytokine, chemokines, and growth factors in patient-matched biospecimens from multiple biological sites to identify factors predictive of PGD.

METHODS –

Biospecimens were collected from patients undergoing bilateral LTx from three distinct sites: donor lung perfusate, post-transplant bronchoalveolar lavage (BAL) fluid (2h), and plasma (2h and 24h). A 71-multiplex panel was performed on each biospecimen. Cross-validated logistic regression (LR) and random forest (RF) machine learning models were used to determine whether analytes in each site or from combination of sites, with or without clinical data, could discriminate between PGD grade 0 (n = 9) and 3 (n = 8).

RESULTS –

Using optimal AUROC, BAL fluid at 2h was the most predictive of PGD (LR, 0.825; RF, 0.919), followed by multi-timepoint plasma (LR, 0.841; RF, 0.653), then perfusate (LR, 0.565; RF, 0.448). Combined clinical, BAL, and plasma data yielded strongest performance (LR, 1.000; RF, 1.000). Using a LASSO of the predictors obtained using LR, we selected IL-1RA, BCA-1, and Fractalkine, as most predictive of severe PGD.

CONCLUSIONS –

BAL samples collected 2h post-transplant were the strongest predictors of severe PGD. Our machine learning approach not only identified novel cytokines not previously associated with PGD, but identified analytes that could be used as a point-of-care cytokine panel aimed at identifying those at risk for developing severe PGD.

Post-lung transplant outcomes of connective tissue disease-related interstitial lung diseases compared with idiopathic interstitial pneumonia: a single-center experience in Japan

OBJECTIVES

The aim of this study was to investigate the outcomes of lung transplantation for connective tissue disease-related interstitial lung disease (CTD-ILD) conducted at our institution, compared with those for idiopathic interstitial pneumonias (IIPs).

METHODS

We retrospectively reviewed patients with CTD-ILD and IIPs who underwent lung transplantation at our hospital from July 2015 to October 2023. We compared patients' backgrounds, early complications within 28 days post-transplant (CTCAE grade 3 or higher), postoperative courses, and prognoses between the two groups.

RESULTS

The CTD-ILD group (n = 19) and the IIPs group (n = 56) were compared. The CTD-ILD group had significantly higher preoperative use of corticosteroids and antifibrotic agents, mean pulmonary arterial pressure, anti-human leukocyte antigen antibody positivity, and donor age (p < 0.05). In addition, the CTD-ILD group had significantly longer operation times (579.0 vs 442.5 min), longer stays in the intensive care unit (17.0 vs 9.0 days) and hospital (58.0 vs 44.0 days); required more tracheostomies (57.9 vs 25.0%); and experienced more respiratory (52.6 vs 25.0%) and gastrointestinal (42.1 vs 8.9%) complications (p < 0.05). However, there were no significant differences in overall survival, nor chronic lung allograft dysfunction (CLAD)-free survival between the two groups.

CONCLUSION

Perioperative complications, notably respiratory and gastrointestinal complications, were prevalent after lung transplantation among CTD-ILD patients. Despite this, long-term survival rates were comparable to those observed in IIP cases.

Comparing right- versus left-first implantation in off-pump sequential double-lung transplantation: an observational cohort study

OBJECTIVES

Historically, the perfusion-guided sequence suggests to first transplant the side with lowest lung perfusion. This sequence is thought to limit right ventricular afterload and prevent acute heart failure after first pneumonectomy. As a paradigm shift, we adopted the right-first implantation sequence, irrespective of lung perfusion. The right donor lung generally accommodates a larger proportion of the cardiac output. We hypothesized that the right-first sequence reduces the likelihood of oedema formation in the firstly transplanted graft during second-lung implantation. Our objective was to compare the perfusion-guided and right-first sequence for intraoperative extracorporeal membrane oxygenation (ECMO) need and primary graft dysfunction (PGD).

METHODS

A retrospective single-centre cohort study (2008-2021) including double-lung transplant cases (N = 696) started without ECMO was performed. Primary end-points were intraoperative ECMO cannulation and PGD grade 3 (PGD3) at 72 h. Secondary end-points were patient and chronic lung allograft dysfunction-free survival. In cases with native left lung perfusion ≤50% propensity score adjusted comparison of the perfusion-guided and right-first sequence was performed.

RESULTS

When left lung perfusion was ≤50%, right-first implantation was done in 219 and left-first in 189 cases. Intraoperative escalation to ECMO support was observed in 10.96% of right-first versus 19.05% of left-first cases (odds ratio 0.448; 95% confidence interval 0.229-0.0.878; P = 0.0193). PGD3 at 72 h was observed in 8.02% of right-first versus 15.64% of left-first cases (0.566; 0.263-1.217; P = 0.1452). Right-first implantation did not affect patient or chronic lung allograft dysfunction-free survival.

CONCLUSIONS

The right-first implantation sequence in off-pump double-lung transplantation reduces need for intraoperative ECMO cannulation with a trend towards less PGD grade 3.

Baseline lung allograft dysfunction after bilateral deceased-donor lung transplantation: A single-center experience in Japan

BACKGROUND

Baseline lung allograft dysfunction (BLAD) refers to a condition in which a lung transplant recipient does not achieve normal pulmonary function (i.e., forced expiratory volume in 1 s or forced vital capacity of <80% of predicted values). Although BLAD is reportedly associated with a poor prognosis, the condition has not been examined in Japanese patients.

METHODS

In this study, we retrospectively examined 38 Japanese adults who underwent bilateral lung transplantation from 2015 to 2022 in a single center.

RESULTS

Twenty-one (55%) patients met the criteria for BLAD. No significant differences were found in recipient or donor factors between the BLAD and non-BLAD groups, but the donor-recipient ratio of the predicted vital capacity was lower in the BLAD group (p = 0.009). The intensive care unit length of stay, ventilator duration, and blood loss during transplant surgery were significantly higher in the BLAD group (p < 0.05). No significant difference was found in survival. The median observation period was significantly shorter in the BLAD than non-BLAD group (744 vs.1192 days, respectively; p = 0.031). The time to reach the normal threshold of pulmonary function after lung transplantation varied among the patients, ranging from 6 months to 4 years.

CONCLUSIONS

The characteristics of these Japanese patients with BLAD were similar to those of other patients in previous reports. The effects of the observation period and donor-recipient age discrepancy on BLAD require further exploration.

Ex vivo lung perfusion in donation after circulatory death: A post hoc analysis of the Normothermic Ex Vivo Lung Perfusion as an Assessment of Extended/Marginal Donors Lungs trial

OBJECTIVE

Donation after circulatory death (DCD) donors offer the ability to expand the lung donor pool and ex vivo lung perfusion (EVLP) further contributes to this ability by allowing for additional evaluation and resuscitation of these extended criteria donors. We sought to determine the outcomes of recipients receiving organs from DCD EVLP donors in a multicenter setting.

METHODS

This was an unplanned post hoc analysis of a multicenter, prospective, nonrandomized trial that took place during 2011 to 2017 with 3 years of follow-up. Patients were placed into 3 groups based off procurement strategy: brain-dead donor (control), brain-dead donor evaluated by EVLP, and DCD donors evaluated by EVLP. The primary outcomes were severe primary graft dysfunction at 72 hours and survival. Secondary outcomes included select perioperative outcomes, and 1-year and 3-years allograft function and quality of life measures.

RESULTS

The DCD EVLP group had significantly higher incidence of severe primary graft dysfunction at 72 hours (P = .03), longer days on mechanical ventilation (P < .001) and in-hospital length of stay (P = .045). Survival at 3 years was 76.5% (95% CI, 69.2%-84.7%) for the control group, 68.3% (95% CI, 58.9%-79.1%) for the brain-dead donor group, and 60.7% (95% CI, 45.1%-81.8%) for the DCD group (P = .36). At 3-year follow-up, presence observed bronchiolitis obliterans syndrome or quality of life metrics did not differ among the groups.

CONCLUSIONS

Although DCD EVLP allografts might not be appropriate to transplant in every candidate recipient, the expansion of their use might afford recipients stagnant on the waitlist a viable therapy.

A Multi-Center International Analysis of Lung Transplantation Outcomes in Patients With COVID-19

INTRODUCTION

Lung transplantation has become increasingly utilized in patients with COVID-19. While several single-center and UNOS database studies have been published on lung transplants (LTs) for end-stage lung disease (ESLD) from Coronavirus disease 2019 (COVID-19), there is a lack of multi-center and international data.

METHODS

This is a multicenter analysis from 11 high-volume lung transplant centers in the United States and Europe. Data were collected through the Multi-Institutional ECLS Registry and stratified by ESLD due to COVID-19 versus other etiologies. Demographics and clinical variables were compared using Chi-square test and Fisher's exact test. Survival was assessed by Kaplan-Meier curves and compared by log-rank test with propensity score matching.

RESULTS

Of 1606 lung transplant recipients, 46 (2.9%) were transplanted for ESLD from COVID-19 compared to 1560 (97.1%) without a history of COVID-19. Among COVID-19 patients, 30 (65.2%) had COVID-19-associated ARDS and 16 (34.8%) had post-COVID-19 fibrosis. COVID-19 patients had higher lung allocation scores (78.0 vs. 44.4, p < 0.0001), had severely limited functional status (37.0% vs. 2.9%, p < 0.0001), had higher preoperative ECMO usage (65.2% vs. 5.4%, p < 0.0001), and spent less time on the waitlist (32 vs. 137 days, p < 0.0001). A 30-day survival was comparable between COVID-19 and non-COVID-19 patients before (100% vs. 98.7%, p = 0.39) and after propensity matching (p = 0.15).

CONCLUSIONS

Patients who received LTs due to COVID-19 had short-term survival comparable to that of patients without COVID-19. Our findings support the idea that lung transplantation should be considered for select patients with ESLD due to COVID-19.

CD94+ natural killer cells potentiate pulmonary ischaemia-reperfusion injury

BACKGROUND

Pulmonary ischaemia-reperfusion injury (IRI) is a major contributor to poor lung transplant outcomes. We recently demonstrated a central role of airway-centred natural killer (NK) cells in mediating IRI; however, there are no existing effective therapies for directly targeting NK cells in humans.

METHODS

We hypothesised that a depleting anti-CD94 monoclonal antibody (mAb) would provide therapeutic benefit in mouse and human models of IRI based on high levels of KLRD1 (CD94) transcripts in bronchoalveolar lavage samples from lung transplant patients.

RESULTS

We found that CD94 is highly expressed on mouse and human NK cells, with increased expression during IRI. Anti-mouse and anti-human mAbs against CD94 showed effective NK cell depletion in mouse and human models and blunted lung damage and airway epithelial killing, respectively. In two different allogeneic orthotopic lung transplant mouse models, anti-CD94 treatment during induction reduced early lung injury and chronic inflammation relative to control therapies. Anti-CD94 did not increase donor antigen-presenting cells that could alter long-term graft acceptance.

CONCLUSIONS

Lung transplant induction regimens incorporating anti-CD94 treatment may safely improve early clinical outcomes.

Pre-transplant Anemia as a Marker of Short-term Outcomes in Lung Transplant Recipients

BACKGROUND

Anemia is a risk factor for increased morbidity and mortality in multiple medical conditions, yet the impact of pretransplant anemia in patients with advanced lung disease on post-transplant outcomes remains under-explored. We sought to determine whether pretransplant anemia serves as a marker of altered inflammation in the host and associates with short-term outcomes following lung transplantation.

STUDY DESIGN AND METHODS

We performed a single-center, retrospective analysis of 238 lung transplant recipients. We assessed for risk factors of pretransplant anemia and identified associations with short-term post-transplant outcomes.

RESULTS

Pretransplant anemia was associated with increased intraoperative transfusion of packed red blood cells and a trend towards increased index hospital length of stay and 1-year mortality. Conversely, pretransplant anemia was associated with a decreased incidence of acute cellular rejection.

CONCLUSION

These preliminary data suggest that anemia may be a biomarker of altered inflammation in the host recipient and influences post-transplant outcomes.

Outcomes of extracorporeal membrane oxygenation cannulation strategy in lung transplantation: A retrospective cohort study

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) with different cannulation strategies is determined according to surgical position and patient condition. However, no cannulation guidelines have been proposed. This retrospective study assessed the outcomes of diverse ECMO cannulation strategies in patients undergoing lung transplantation (LTx).

METHODS

Data of patients undergoing intraoperative veno-arterial ECMO-assisted LTx were retrospectively collected from December 1st, 2015 to October 31st, 2021. Patients were classified into three groups based on the different cannulation strategies: femoral artery-femoral vein (F-F)-ECMO, axillary artery-femoral vein (A-F)-ECMO, and ascending aorta-femoral vein (AAO-F)-ECMO. The F-F-ECMO, A-F-ECMO, and AAO-F-ECMO groups comprised 34, 44, and 30 patients, respectively.

MAIN RESULTS

The AAO-F-ECMO group exhibited a significantly shorter duration of postoperative ECMO therapy (3 vs. 2 vs. 0 days, P < 0.01).the level of postoperative proBNP was lower on the third and seventh days (P < 0.001). AAO-F-ECMO patients had a significantly lower incidence of postoperative infections, heart failure, and bleeding (P < 0.05). Similar outcomes were observed in postoperative survival rates among the three groups (P > 0.05).

CONCLUSIONS

Ascending aorta-femoral vein ECMO can provide sufficient and effective aerobic blood to perfuse organs with fewer side effects than cannulation in the femoral artery-femoral vein or axillary artery-femoral vein.

Amniotic fluid-derived mesenchymal stem cells reduce inflammation and improve lung function following transplantation in a porcine model

BACKGROUND

Lung transplantation is hindered by low donor lung utilization rates. Infectious complications are reasons to decline donor grafts due to fear of post-transplant primary graft dysfunction. Mesenchymal stem cells are a promising therapy currently investigated in treating lung injury. Full-term amniotic fluid-derived lung-specific mesenchymal stem cell treatment may regenerate damaged lungs. These cells have previously demonstrated inflammatory mediation in other respiratory diseases, and we hypothesized that treatment would improve donor lung quality and postoperative outcomes.

METHODS

In a transplantation model, donor pigs were stratified to either the treated or the nontreated group. Acute respiratory distress syndrome was induced in donor pigs and harvested lungs were placed on ex vivo lung perfusion (EVLP) before transplantation. Treatment consisted of 3 doses of 2 × 106 cells/kg: one during EVLP and 2 after transplantation. Donors and recipients were assessed on clinically relevant parameters and recipients were followed for 3 days before evaluation for primary graft dysfunction (PGD).

RESULTS

Repeated injection of the cell treatment showed reductions in inflammation seen through lowered immune cell counts, reduced histology signs of inflammation, and decreased cytokines in the plasma and bronchoalveolar lavage fluid. Treated recipients showed improved pulmonary function, including increased PaO2/FiO2 ratios and reduced incidence of PGD.

CONCLUSIONS

Repeated injection of lung-specific cell treatment during EVLP and post transplant was associated with improved function of previously damaged lungs. Cell treatment may be considered as a potential therapy to increase the number of lungs available for transplantation and the improvement of postoperative outcomes.

Mitigating the risk of inflammatory type primary graft dysfunction by applying an integrated approach to assess, modify and match risk factors in lung transplantation

Long-term outcome following lung transplantation remains one of the poorest of all solid organ transplants with a 1- and 5-year survival of 85% and 59% respectively for adult lung transplant recipients and with 50% of patients developing chronic lung allograft dysfunction (CLAD) in the first 5 years following transplant. Reducing the risk of inflammatory type primary graft dysfunction (PGD) is vital for improving both short-term survival following lung transplantation and long-term outcome due to the association of early inflammatory-mediated damage to the allograft and the risk of CLAD. PGD has a multifactorial aetiology and high-grade inflammatory-type PGD is the result of cumulative insults that may be incurred in one or more of the three variables of the transplantation continuum: the donor lungs, the recipient and intraoperative process. We set out a conceptual framework which uses a fully integrated approach to this transplant continuum to attempt to identify and, where possible, modify specific donor, recipient and intraoperative PGD risk with the goal of reducing inflammatory-type PGD risk for an individual recipient. We also consider the concept and risk-benefit of matching lung allografts and recipients on the basis of donor and recipient PGD-risk compatibility. The use of ex vivo lung perfusion (EVLP) and the extended preservation of lung allografts on EVLP will be explored as safe, non-injurious EVLP may enable extensive inflammatory testing of specific donor lungs and has the potential to provide a platform for targeted therapeutic interventions on lung allografts.

The Role of Ficolins in Lung Injury

BACKGROUND

Respiratory diseases seriously threaten human health worldwide, and lung injury is an important component of respiratory disease. Complement activation is an important function of the innate immune system. Complement activation helps the body defend against invasion by external microorganisms, whereas excessive complement activation can exacerbate tissue damage or lead to unwanted side effects. Ficolins are a class of immune-related proteins in the lectin pathway that play important roles in the body's immune defense. Although individual ficolins are not well understood, current information suggests that ficolins may play an important regulatory role in lung injury.

SUMMARY

Several studies have shown that ficolins are involved in the immune response in the lung, particularly in the response to infectious and inflammatory processes.

KEY MESSAGES

This review summarizes the role of ficolins in lung injury. Ficolins may influence the development and repair of lung injury by recognizing and binding pathogenic microorganisms, modulating the inflammatory response, and promoting the clearance of immune cells. In addition, ficolins are associated with the development and progression of lung diseases (such as pneumonia and ARDS) and may have an important impact on the pathophysiological processes of inflammatory diseases.

Machine learning model predicts airway stenosis requiring clinical intervention in patients after lung transplantation: a retrospective case-controlled study

BACKGROUND

Patients with airway stenosis (AS) are associated with considerable morbidity and mortality after lung transplantation (LTx). This study aims to develop and validate machine learning (ML) models to predict AS requiring clinical intervention in patients after LTx.

METHODS

Patients who underwent LTx between January 2017 and December 2019 were reviewed. The conventional logistic regression (LR) model was fitted by the independent risk factors which were determined by multivariate LR. The optimal ML model was determined based on 7 feature selection methods and 8 ML algorithms. Model performance was assessed by the area under the curve (AUC) and brier score, which were internally validated by the bootstrap method.

RESULTS

A total of 381 LTx patients were included, and 40 (10.5%) patients developed AS. Multivariate analysis indicated that male, pulmonary arterial hypertension, and postoperative 6-min walking test were significantly associated with AS (all P < 0.001). The conventional LR model showed performance with an AUC of 0.689 and brier score of 0.091. In total, 56 ML models were developed and the optimal ML model was the model fitted using a random forest algorithm with a determination coefficient feature selection method. The optimal model exhibited the highest AUC and brier score values of 0.760 (95% confidence interval [CI], 0.666-0.864) and 0.085 (95% CI, 0.058-0.117) among all ML models, which was superior to the conventional LR model.

CONCLUSIONS

The optimal ML model, which was developed by clinical characteristics, allows for the satisfactory prediction of AS in patients after LTx.

Analysis of Primary Graft Dysfunction (PGD) Risk Factors in Lung Transplantation (LuTx) Patients

BACKGROUND

Primary graft dysfunction (PGD) is a form of acute lung injury (ALI) that occurs within 72 h after lung transplantation (LuTx) and is the most common early complication of the procedure. PGD is diagnosed and graded based on the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen and chest X-ray results. PGD grade 3 increases recipient mortality and the chance of chronic lung allograft dysfunction (CLAD).

METHOD

The aim of this retrospective study was to identify new PGD risk factors. The inclusion criteria were met by 59 patients, who all received transplants at the same center between 2010 and 2018. Donor data were taken from records provided by the Polish National Registry of Transplantation and analyzed in three variants: PGD 1-3 vs. PGD 0, PGD 3 vs. PGD 0 and PGD 3 vs. PGD 0-2.

RESULTS

A multiple-factor logistic regression model was used to identify decreasing recipient age; higher donor BMI and higher donor central venous pressure (CVP) for the PGD (of the 1-3 grade) risk factor.

CONCLUSIONS

Longer cold ischemia time (CIT) and higher donor CVP proved to be independent risk factors of PGD 3.

Transcriptomic Signatures in Lung Allografts and Their Therapeutic Implications

Ex vivo lung perfusion (EVLP) is a well-established method of lung preservation in clinical transplantation. Transcriptomic analyses of cells and tissues uncover gene expression patterns which reveal granular molecular pathways and cellular programs under various conditions. Coupling EVLP and transcriptomics may provide insights into lung allograft physiology at a molecular level with the potential to develop targeted therapies to enhance or repair the donor lung. This review examines the current landscape of transcriptional analysis of lung allografts in the context of state-of-the-art therapeutics that have been developed to optimize lung allograft function.

Four decades of progress in heart-lung transplantation: Two hundred seventy-one cases at a single institution

OBJECTIVE

The objective of this study is to evaluate survival for combined heart-lung transplant (HLTx) recipients across 4 decades at a single institution. We aim to summarize our contemporary practice based on more than 271 HLTx procedures over 40 years.

METHODS

Data were collected from a departmental database and the United Network for Organ Sharing. Recipients younger than age 18 years, those undergoing redo HLTx, or triple-organ system transplantation were excluded, leaving 271 patients for analysis. The pioneering era was defined by date of transplant between 1981 and 2000 (n = 155), and the modern era between 2001 and 2022 (n = 116). Survival analysis was performed using cardinality matching of populations based on donor and recipient age, donor and recipient sex, ischemic time, and sex matching.

RESULTS

Between 1981 and 2022, 271 HLTx were performed at a single institution. Recipients in the modern era were older (age 42 vs 34 y; P < .001) and had shorter waitlist times (78 vs 234 days; P < .001). Allografts from female donors were more common in the modern era (59% vs 39%; P = .002). In the matched survival analysis, 30-day survival (97% vs 84%; P = .005), 1-year survival (89% vs 77%; P = .041), and 10-year survival (53% vs 26%; P = .012) significantly improved in the modern era relative to the pioneering era, respectively.

CONCLUSIONS

Long-term survival in HLTx is achievable with institutional experience and may continue to improve in the coming decades. Advances in mechanical circulatory support, improved maintenance immunosuppression, and early recognition and management of acute complications such as primary graft dysfunction and acute rejection have dramatically improved the prognosis for recipients of HLTx in our contemporary institutional experience.

National utilization, trends, and lung transplant outcomes of static versus portable ex vivo lung perfusion platforms

BACKGROUND

This study compared utilization and outcomes of the 2 widely utilized ex vivo lung perfusion (EVLP) platforms in the United States: a static platform and a portable platform.

METHODS

Adult (age 18 years or older) bilateral lung-only transplants utilizing EVLP between February 28, 2018, and December 31, 2022, in the United Network for Organ Sharing database were included. Predischarge acute rejection, intubation at 72 hours posttransplant, extracorporeal membrane oxygenation at 72 hours posttransplant, primary graft dysfunction grade 3 at 72 hours posttransplant, 30-day mortality, and 1-year mortality were evaluated using multivariable regressions.

RESULTS

Overall, 607 (6.3%) lung transplants during the study period used EVLP (51.2% static, 48.8% portable). Static EVLP was primarily utilized in the eastern United States, whereas portable EVLP was primarily utilized in the western United States. Static EVLP donors were more likely to be donation after circulatory death (33.4% vs 26.0%; P = .005), have a >20 pack-year smoking history (13.5% vs 6.5%; P = .005), and be extended criteria donors (92.3% vs 85.0%; P = .013), whereas portable EVLP donors were more likely to be older than age 55 years (14.2% vs 8.0%; P = .02). Transplants utilizing the static and portable platforms had similar risk of acute rejection, intubation at 72 hours, extracorporeal membrane oxygenation at 72 hours, primary graft dysfunction grade 3 at 72 hours, and posttransplant mortality at 30 days and 1 year (all P values > .05).

CONCLUSIONS

The static and portable platforms had significant differences in donor characteristics and geographic distributions of utilization. Despite this, posttransplant survival was similar between the 2 EVLP platforms.

Impaired esophagogastric junction relaxation and lung transplantation outcomes

The implications of impaired esophagogastric junction relaxation (i.e. esophagogastric junction outflow obstruction and achalasia) in lung transplants recipients (LTRs) are unclear. Thus, we examined the prevalence and clinical outcomes of LTRs with an abnormally elevated integrated relaxation pressure (IRP) on high-resolution manometry before lung transplantation (LTx). After IRB approval, we reviewed data on LTRs who underwent LTx between January 2019 and August 2022 with a preoperative median IRP >15 mmHg. Differences in overall survival and chronic lung allograft dysfunction (CLAD)-free survival between LTRs with a normalized median IRP after LTx (N-IRP) and those with persistently high IRP (PH-IRP) were assessed using Kaplan-Meier curves and the log-rank test. During the study period, 352 LTx procedures were performed; 44 (12.5%) LTRs had an elevated IRP before LTx, and 37 (84.1%) completed a postoperative manometry assessment (24 [70.6%] males; mean age, 65.2 ± 9.1 years). The median IRP before and after LTx was 18.7 ± 3.8 mmHg and 12 ± 5.6 mmHg, respectively (P < 0.001); the median IRP normalized after LTx in 24 (64.9%) patients. Two-year overall survival trended lower in the N-IRP group than the PH-IRP group (77.2% vs. 92.3%, P = 0.086), but CLAD-free survival (P = 0.592) and rates of primary graft dysfunction (P = 0.502) and acute cellular rejection (P = 0.408) were similar. An abnormally elevated IRP was common in LTx candidates; however, it normalized in roughly two-thirds of patients after LTx. Two-year survival trended higher in the PH-IRP group, despite similar rates of primary graft dysfunction and acute cellular rejection as well as similar CLAD-free survival between the groups.

Ex Vivo Lung Perfusion and Primary Graft Dysfunction Following Lung Transplantation: A Contemporary United Network for Organ Sharing Database Analysis

Background: Primary graft dysfunction (PGD) has detrimental effects on recipients following lung transplantation. Here, we determined the contemporary trends of PGD in a national database, factors associated with the development of PGD grade 3 (PGD3) and ex vivo lung perfusion's (EVLP) effect on this harmful postoperative complication. Methods: The United Network for Organ Sharing database was queried from 2015 to 2023, and recipients were stratified into No-PGD, PGD1/2, or PGD3. The groups were analyzed with comparative statistics, and survival was determined with Kaplan-Meier methods. Multivariable Cox regression was used to determine factors associated with increased mortality. PGD3 recipients were then stratified based on EVLP use prior to transplantation, and a 3:1 propensity match was performed to determine outcomes following transplantation. Finally, logistic regression models based on select criteria were used to determine risk factors associated with the development of PGD3 and mortality within 1 year. Results: A total of 21.4% of patients were identified as having PGD3 following lung transplant. Those with PGD3 suffered significantly worse perioperative morbidity, mortality, and had worse long-term survival. PGD3 was also independently associated with increased mortality. Matched EVLP PGD3 recipients had significantly higher use of ECMO postoperatively; however, they did not suffer other significant morbidity or mortality as compared to PGD3 recipients without EVLP use. Importantly, EVLP use prior to transplantation was significantly associated with decreased likelihood of PGD3 development, while having no significant association with early mortality. Conclusions: EVLP is associated with decreased PGD3 development, and further optimization of this technology is necessary to expand the donor pool.

L-Alanyl-L-Glutamine Alleviated Ischemia-Reperfusion Injury and Primary Graft Dysfunction in Rat Lung Transplants

BACKGROUND

Concern of ischemia-reperfusion injury reduces utilization of donor lungs. We hypothesized adding L-alanyl-L-glutamine (L-AG) to preservation solution may protect donor lungs from ischemia-reperfusion injury through its multiple cytoprotective effects.

METHODS

A lung transplantation cell culture model was used on human lung epithelial cells and pulmonary microvascular endothelial cells, and the effects of adding different concentrations of L-AG on basic cellular function were tested. Rat donor lungs were preserved at 4 °C with 8 mmol/L L-AG for 12 h followed by 4 h reperfusion or monitored for 3 d. Lung function, lung histology, inflammation, and cell death biomarker were tested. Computerized tomography scan was used and metabolomic analysis was performed on lung tissues.

RESULTS

Cold preservation with L-AG improved cell viability and inhibited apoptosis in cell culture. Rat donor lungs treated with L-AG during cold storage showed decreased peak airway pressure, higher dynamic compliance and oxygenation ability, reduced lung injury, apoptosis, and oxidative stress during reperfusion. L-AG treatment significantly changed 130 metabolites during reperfusion, with enhanced amino acid biosynthesis and tricarboxylic acid cycle. Furthermore, cold storage with L-AG decreased primary graft dysfunction grade, improved oxygenation, reduced pulmonary atelectasis, sign of infection, and pneumothorax in a rat left lung transplant 3-d survival model.

CONCLUSIONS

Adding L-AG to cold preservation solution reduced lung injury and alleviated primary graft dysfunction by inhibiting inflammation, oxidative stress, and cell death with modified metabolic activities.

The impact of bleeding on outcomes following lung transplantation: a retrospective analysis using the universal definition of perioperative bleeding

BACKGROUND

Lung transplantation (LT) represents a high-risk procedure for end-stage lung diseases. This study describes the outcomes of patients undergoing LT that require massive transfusions as defined by the universal definition of perioperative bleeding (UDPB).

METHODS

Adult patients who underwent bilateral LT at a single academic center were surveyed retrospectively. Patients were grouped by insignificant, mild, or moderate perioperative bleeding (insignificant-to-moderate bleeders) and severe or massive perioperative bleeding (severe-to-massive bleeders) based on the UDPB classification. Outcomes included 1-year survival and primary graft dysfunction (PGD) of grade 3 at 72 h postoperatively. Multivariable models were adjusted for recipient age, sex, body mass index (BMI), Lung allocation score (LAS), preoperative hemoglobin (Hb), preoperative extracorporeal membrane oxygenation (ECMO) status, transplant number, and donor status. An additional multivariable model was created to find preoperative and intraoperative predictors of severe-to-massive bleeding. A p-value less than 0.05 was selected for significance.

RESULTS

A total of 528 patients were included, with 357 insignificant-to-moderate bleeders and 171 severe-to-massive bleeders. Postoperatively, severe-to-massive bleeders had higher rates of PGD grade 3 at 72 h, longer hospital stays, higher mortality rates at 30 days and one year, and were less likely to achieve textbook outcomes for LT. They also required postoperative ECMO, reintubation for over 48 h, tracheostomy, reintervention, and dialysis at higher rates. In the multivariate analysis, severe-to-massive bleeding was significantly associated with adverse outcomes after adjusting for recipient and donor factors, with an odds ratio of 7.73 (95% CI: 4.27-14.4, p < 0.001) for PGD3 at 72 h, 4.30 (95% CI: 2.30-8.12, p < 0.001) for 1-year mortality, and 1.75 (95% CI: 1.52-2.01, p < 0.001) for longer hospital stays. Additionally, severe-to-massive bleeders were less likely to achieve textbook outcomes, with an odds ratio of 0.07 (95% CI: 0.02-0.16, p < 0.001). Preoperative and intraoperative predictors of severe/massive bleeding were identified, with White patients having lower odds compared to Black patients (OR: 041, 95% CI: 0.22-0.80, p = 0.008). Each 1-unit increase in BMI decreased the odds of bleeding (OR: 0.89, 95% CI: 0.83-0.95, p < 0.001), while each 1-unit increase in MPAP increased the odds of bleeding (OR: 1.04, 95% CI: 1.02-1.06, p < 0.001). First-time transplant recipients had lower risk (OR: 0.16, 95% CI: 0.06-0.36, p < 0.001), whereas those with DCD donors had a higher risk of severe-to-massive bleeding (OR: 3.09, 95% CI: 1.63-5.87, p = 0.001).

CONCLUSION

These results suggest that patients at high risk of massive bleeding require higher utilization of hospital resources. Understanding their outcomes is important, as it may inform future decisions to transplant comparable patients.

Restoring discarded porcine lungs by ex vivo removal of neutrophil extracellular traps

BACKGROUND

By causing inflammation and tissue damage, neutrophil extracellular traps (NETs) constitute an underlying mechanism of aspiration-induced lung injury, a major factor of the low utilization of donor lungs in lung transplantation (LTx).

METHODS

To determine whether NET removal during ex vivo lung perfusion (EVLP) can restore lung function and morphology in aspiration-damaged lungs, gastric aspiration lung injury was induced in 12 pigs. After confirmation of acute respiratory distress syndrome, the lungs were explanted and assigned to NET removal connected to EVLP (treated) (n = 6) or EVLP only (nontreated) (n = 6). Hemodynamic measurements were taken, and blood and tissue samples were collected to assess lung function, morphology, levels of cell-free DNA, extracellular histones, and nucleosomes as markers of NETs, as well as cytokine levels.

RESULTS

After EVLP and NET removal in porcine lungs, PaO2/FiO2 ratios increased significantly compared to those undergoing EVLP alone (p = 0.0411). Treated lungs had lower cell-free DNA (p = 0.0260) and lower levels of extracellular histones in EVLP perfusate (p= 0.0260) than nontreated lungs. According to histopathology, treated lungs showed less immune cell infiltration and less edema compared with nontreated lungs, which was reflected in decreased levels of proinflammatory cytokines in EVLP perfusate and bronchoalveolar lavage fluid.

CONCLUSIONS

To conclude, removing NETs during EVLP improved lung function and morphology in aspiration-damaged donor lungs. The ability to remove NETs during EVLP could represent a new therapeutic approach for LTx and potentially expand the donor pool for transplantation.

Thoracic and vertebral deformities in lung transplantation: perioperative complications and long-term prognoses

BACKGROUND

Lung transplantation (LTx) is a crucial therapeutic strategy for patients suffering from end-stage respiratory diseases, necessitating precise donor-recipient size matching to ensure optimal graft function. While standard allocation protocols rely on predicted lung capacity based on factors such as sex, age, and height, a subset of patients with respiratory diseases presents an additional challenge - thoracic or vertebral deformities. These deformities can complicate accurate volume predictions and may impact the success of lung transplantation.

METHODS

In this retrospective cohort study of patients who underwent LTx at Tohoku University Hospital between January 2007 and April 2022, with follow-up until October 2022, the primary objective was to assess the influence of thoracic and vertebral deformities on perioperative complications, emphasizing interventions, such as volume reduction surgery. The secondary objective aimed to identify any noticeable impact on long-term prognoses in recipients with these deformities.

RESULTS

Of 129 LTx recipients analyzed, 17.8% exhibited thoracic deformities, characterized by pectus excavatum, while 16.3% had vertebral deformities. Perioperative complications, requiring delayed chest closure, tracheostomy, and volume reduction surgery, were more prevalent in the deformity group. Thoracic deformities were notably associated with the need for volume reduction surgery. However, long-term prognoses did not differ significantly between patients with deformities and those without. Vertebral deformities did not appear to significantly impact perioperative or long-term outcomes.

CONCLUSIONS

This study highlights the prevalence of thoracic deformities in LTx recipients, correlating with increased perioperative complications, particularly the potential need for volume reduction surgery. Importantly, these deformities do not exert a significant impact on long-term prognoses. Additionally, patients with vertebral deformities, such as scoliosis and kyphosis, appear to be manageable in the context of LTx.

Is Night Surgery a Nightmare for Lung Transplantation?

Night work is frequently associated with sleep deprivation and is associated with greater surgical and medical complications. Lung transplantation (LT) is carried out both at night and during the day and involves many medical healthcare workers. The goal of the study was to compare morbidity and mortality between LT recipients according to LT operative time. We performed a retrospective, observational, single-center study. When the procedure started between 6 AM and 6 PM, the patient was allocated to the Daytime group. If the procedure started between 6 PM and 6 AM, the patient was allocated to the Nighttime group. Between January 2015 and December 2020, 253 patients were included. A total of 168 (66%) patients were classified into the Day group, and 85 (34%) patients were classified into the Night group. Lung Donors' general characteristics were similar between the groups. The 90-day and one-year mortality rates were similar between the groups (90-days: n = 13 (15%) vs. n = 26 (15%), p = 0.970; 1 year: n = 18 (21%) vs. n = 42 (25%), p = 0.499). Daytime LT was associated with more one-year airway dehiscence (n = 36 (21%) vs. n = 6 (7.1%), p = 0.004). In conclusion, among patients who underwent LT, there was no significant association between operative time and survival.

Phenotyping of primary graft dysfunction after lung transplantation by in-depth biomarker analysis

This editorial highlights the importance of research towards PGD-specific biomarkers, suggesting strategic sample collection and advanced analysis techniques to expand our knowledge of PGD mechanisms and potential phenotyping https://bit.ly/3UUElw0.

Oversizing lung allografts deteriorates outcomes in patients with pulmonary fibrosis

BACKGROUND

Lung transplantation is the only curative treatment for patients with end-stage pulmonary fibrosis. It is still under debate whether over- or undersizing of lung allografts is preferably performed regarding the postoperative outcome. We therefore analyzed our data using predicted total lung capacity to compare size mismatches.

METHODS

Patient records were retrospectively reviewed. Three groups were formed, 1 including patients with a donor-recipients pTLC ratio (DRPR) of <1.0 (undersized group), the second with a DRPR of ≥1.0 and <1.1 (size-matched group), and the third group with a DRPR of ≥1.1 (oversized group). Outcomes were evaluated using chi-square test and Kruskall-Wallis test as well as Kaplan-Meier analysis, competing risk analysis, and multivariable analysis, respectively.

RESULTS

Between January 2010 and May 2023, among the 1501 patients transplanted at our institution, 422 (28%) patients were included, 26 (2%) patients forming the oversized group (median DRPR: 1.14), 101 (7%) patients forming the size-matched group (median DRPR: 1.03), and 296 (20%) patients forming the undersized group (median DRPR: 0.92). Patients from the oversized group had a higher PGD grade 3 rate at 24 (p < 0.001), 48 (p < 0.001), and 72 (p = 0.039) hours after transplantation as well as a higher in-hospital mortality compared to the undersized group (p = 0.033). The long-term survival was also better in the undersized group compared to the oversized group (p = 0.011) and to the size-matched group (p = 0.01).

CONCLUSIONS

Oversizing lung allografts more than 10% deteriorated early postoperative outcomes and long-term survival in patients with pulmonary fibrosis.

Shah P, Mathew J, Kong H, Charya A, Luikart H, Aryal S, Nathan SD, Orens JB, Khush KK, Kyoo Jang M, Agbor-Enoh S. Baseline Lung Allograft Dysfunction After Bilateral Lung Transplantation Is Associated With an Increased Risk of Death: Results From a Multicenter Cohort Study

Background

A prior single-center, retrospective cohort study identified baseline lung allograft dysfunction (BLAD) as a risk factor for death in bilateral lung transplant recipients. In this multicenter prospective cohort study, we test the association of BLAD with death in bilateral lung transplant recipients, identify clinical risk factors for BLAD, and assess its association with allograft injury on the molecular level.

Methods

This multicenter, prospective cohort study included 173 bilateral lung transplant recipients that underwent serial pulmonary function testing and plasma collection for donor-derived cell-free DNA at prespecified time points. BLAD was defined as failure to achieve ≥80% predicted for both forced expiratory volume in 1 s and forced vital capacity after lung transplant, on 2 consecutive measurements at least 3 mo apart.

Results

BLAD was associated with increased risk of death (hazard ratio, 1.97; 95% confidence interval [CI], 1.05-3.69; P = 0.03) but not chronic lung allograft dysfunction alone (hazard ratio, 1.60; 95% CI, 0.87-2.95; P = 0.13). Recipient obesity (odds ratio, 1.69; 95% CI, 1.15-2.80; P = 0.04) and donor age (odds ratio, 1.03; 95% CI, 1.02-1.05; P = 0.004) increased the risk of developing BLAD. Patients with BLAD did not demonstrate higher log10(donor-derived cell-free DNA) levels compared with no BLAD (slope [SE]: -0.0095 [0.0007] versus -0.0109 [0.0007]; P = 0.15).

Conclusions

BLAD is associated with an increased risk of death following lung transplantation, representing an important posttransplant outcome with valuable prognostic significance; however, early allograft specific injury on the molecular level does not increase the risk of BLAD, supporting further mechanistic insight into disease pathophysiology.

Early Extubation: Who Qualifies Postoperatively in Lung Transplantation?

INTRODUCTION

Early extubation has been adopted in many settings within cardiothoracic surgery, with several advantages for patients. We sought to determine the association of timing of extubation in lung transplant recipients' short- and long-term outcomes.

METHODS

Adult, primary lung transplants were identified from the United Network for Organ Sharing database. Recipients were stratified based on the duration of postoperative ventilation: 1) None (NV); 2) <5 Days (<5D); and 3) 5+ Days (5+D). Comparative statistics were performed, and both unadjusted and adjusted survival were analyzed with Kaplan-Meier Methods and a Cox proportional hazard model. A multivariable model including recipient, donor, and transplant characteristics was created to examine factors associated with NV.

RESULTS

28,575 recipients were identified (NV = 960, <5D = 21,959, 5+D = 5656). The NV group had shorter median length of stay (P < 0.01) and lower incidence of postoperative dialysis (P < 0.01). The NV and <5D groups had similar survival, while 5+D recipients had decreased survival (P < 0.01). The multivariable model demonstrated increased donor BMI, center volume, ischemic time, single lung transplant, and transplantation between 2011 and 2015 were associated with NV (P < 0.01 for all). Use of donation after cardiac death donors and transplantation between 2016 and 2021 was associated with postoperative ventilator use.

CONCLUSIONS

Patients extubated early after lung transplantation have a shorter median length of stay without an associated increase in mortality. While not all patients are appropriate for earlier extubation, it is possible to extubate patients early following lung transplant. Further efforts are necessary to help expand this practice and ensure its' success for recipients.

Predictors of Cytomegalovirus Recurrence Following Cessation of Posttransplant Prophylaxis

INTRODUCTION

Cytomegalovirus (CMV) infection is associated with a poor prognosis after lung transplantation, and donor and recipient CMV serostatus is a risk factor for reactivation. CMV prophylaxis is commonly administered in the first year following transplantation to reduce CMV infection; however, the risk factors for long-term reactivation remain unclear. We investigated the timing and risk factors of CMV infection after prophylactic administration.

METHODS

This study was a retrospective review of the institutional lung transplantation database from June 2014 to June 2022. Data on patient characteristics, pretransplantation laboratory values, postoperative outcomes, and CMV infection were collected. Donor CMV-IgG-positive and recipient CMV-IgG-negative groups were defined as the CMV mismatch group.

RESULTS

During the study period, 257 patients underwent lung transplantation and received a prophylactic dose of valganciclovir hydrochloride for up to 1 y. CMV infection was detected in 69 patients (26.8%): 40 of 203 (19.7%) in the non-CMV mismatch group and 29 of 54 (53.7%) in the CMV mismatch group (P < 0.001). CMV infection after prophylaxis occurred at a median of 425 and 455 d in the CMV mismatch and non-CMV mismatch groups, respectively (P = 0.07). Multivariate logistic regression analysis revealed that preoperative albumin level (odds ratio [OR] = 0.39, P = 0.04), CMV mismatch (OR = 15.7, P < 0.001), and donor age (OR = 1.05, P = 0.009) were significantly associated with CMV infection.

CONCLUSIONS

CMV mismatch may have increased the risk of CMV infection after lung transplantation, which decreased after prophylaxis. In addition to CMV mismatch, low preoperative albumin level and donor age were independent predictors of CMV infection.

Early serum biomarkers to characterise different phenotypes of primary graft dysfunction after lung transplantation: a systematic scoping review

Background

Lung transplantation (LUTX) is often complicated by primary graft dysfunction (PGD). Plasma biomarkers hold potential for PGD phenotyping and targeted therapy. This scoping review aims to collect the available literature in search of serum biomarkers for PGD phenotyping.

Methods

Following JBI and PRISMA guidelines, we conducted a systematic review searching MEDLINE, Web of Science, EMBASE and The Cochrane Library for papers reporting the association between serum biomarkers measured within 72 h of reperfusion and PGD, following International Society for Heart and Lung Transplantation (ISHLT) guidelines. We extracted study details, patient demographics, PGD definition and timing, biomarker concentration, and their performance in identifying PGD cases.

Results

Among the 1050 papers screened, 25 prospective observational studies were included, with only nine conducted in the last decade. These papers included 1793 unique adult patients (1195 double LUTX, median study size 100 (IQR 44-119)). Most (n=21) compared PGD grade 3 to less severe PGD, but only four adhered to 2016 PGD definitions. Enzyme-linked immunosorbent assays and the multiplex bead array technique were utilised in 23 and two papers, respectively. In total, 26 candidate biomarkers were identified, comprising 13 inflammatory, three endothelial activation, three epithelial injury, three cellular damage and two coagulation dysregulation markers. Only five biomarkers (sRAGE, ICAM-1, PAI-1, SP-D, FSTL-1) underwent area under the receiver operating characteristic curve analysis, yielding a median value of 0.58 (0.51-0.78) in 406 patients (276 double LUTX).

Conclusions

Several biomarkers exhibit promise for future studies aimed at PGD phenotyping after LUTX. To uncover the significant existing knowledge gaps, further international prospective studies incorporating updated diagnostic criteria, modern platforms and advanced statistical approaches are essential.

Real-time lung weight measurement during clinical ex vivo lung perfusion

BACKGROUND

Real-time lung weight (LW) measurement is a simple and noninvasive technique for detecting extravascular lung water during ex vivo lung perfusion (EVLP). We investigated the feasibility of real-time LW measurement in clinical EVLP as a predictor of transplant suitability and post-transplant outcomes.

METHODS

In our clinical acellular EVLP protocol, real-time LW was measured in 117 EVLP cases from June 2019 to June 2022. The estimated LW gain at each time point was calculated using a scale placed under the organ chamber. The lungs were classified into 4 categories based on LW adjusted for height and compared between suitable and unsuitable cases. The relationship between estimated LW gain and primary graft dysfunction was also investigated.

RESULTS

The estimated LW gain during the EVLP significantly correlated with the LW gain (post-EVLP LW and pre-EVLP LW) measured on the back table (R2 = 0.61, p < 0.01). In the adjusted LW categories 2 to 4, the estimated LW gain at 0-1 hour after EVLP was significantly higher in unsuitable cases than in suitable cases. The area under the curve for the estimated LW gain was ≥0.80. Primary graft dysfunction grades 0 to 1 had a significantly lower estimated LW gain at 60 minutes than grades 2 to 3 (-43 vs 1 g, p < 0.01).

CONCLUSIONS

Real-time lung measurements can predict transplant suitability and post-transplant outcomes by the early detection of extravascular lung water during the initial 1 hour of EVLP.

Impact of Pre-Transplant Left Ventricular Diastolic Pressure on Primary Graft Dysfunction after Lung Transplantation: A Narrative Review

Lung transplantation (LT) constitutes the last therapeutic option for selected patients with end-stage respiratory disease. Primary graft dysfunction (PGD) is a form of severe lung injury, occurring in the first 72 h following LT and constitutes the most common cause of early death after LT. The presence of pulmonary hypertension (PH) has been reported to favor PGD development, with a negative impact on patients' outcomes while complicating medical management. Although several studies have suggested a potential association between pre-LT left ventricular diastolic dysfunction (LVDD) and PGD occurrence, the underlying mechanisms of such an association remain elusive. Importantly, the heterogeneity of the study protocols and the various inclusion criteria used to define the diastolic dysfunction in those patients prevents solid conclusions from being drawn. In this review, we aim at summarizing PGD mechanisms, risk factors, and diagnostic criteria, with a further focus on the interplay between LVDD and PGD development. Finally, we explore the predictive value of several diastolic dysfunction diagnostic parameters to predict PGD occurrence and severity.

Calcineurin Inhibitor in NEuRoloGically deceased donors to decrease kidney delayed graft function study: study protocol of the CINERGY Pilot randomised controlled trial

INTRODUCTION

Most solid organ transplants originate from donors meeting criteria for death by neurological criteria (DNC). Within the organ donor, physiological responses to brain death increase the risk of ischaemia reperfusion injury and delayed graft function. Donor preconditioning with calcineurin inhibition may reduce this risk.

METHODS AND ANALYSIS

We designed a multicentre placebo-controlled pilot randomised trial involving nine organ donation hospitals and all 28 transplant programmes in the Canadian provinces of Ontario and Québec. We planned to enrol 90 DNC donors and their approximately 324 organ recipients, totalling 414 participants. Donors receive an intravenous infusion of either tacrolimus 0.02 mg/kg over 4 hours prior to organ retrieval, or a matching placebo, while monitored in an intensive care unit for any haemodynamic changes during the infusion. Among all study organ recipients, we record measures of graft function for the first 7 days in hospital and we will record graft survival after 1 year. We examine the feasibility of this trial with respect to the proportion of all eligible donors enrolled and the proportion of all eligible transplant recipients consenting to receive a CINERGY organ transplant and to allow the use of their health data for study purposes. We will report these feasibility outcomes as proportions with 95% CIs. We also record any barriers encountered in the launch and in the implementation of this trial with detailed source documentation.

ETHICS AND DISSEMINATION

We will disseminate trial results through publications and presentations at participating sites and conferences. This study has been approved by Health Canada (HC6-24-c241083) and by the Research Ethics Boards of all participating sites and in Québec (MP-31-2020-3348) and Clinical Trials Ontario (Project #3309).

TRIAL REGISTRATION NUMBER

NCT05148715.

Lung transplantation following controlled hypothermic storage with a portable lung preservation device: first multicenter European experience

Introduction

Compared with traditional static ice storage, controlled hypothermic storage (CHS) at 4-10°C may attenuate cold-induced lung injury between procurement and implantation. In this study, we describe the first European lung transplant (LTx) experience with a portable CHS device.

Methods

A prospective observational study was conducted of all consecutively performed LTx following CHS (11 November 2022 and 31 January 2024) at two European high-volume centers. The LUNGguard device was used for CHS. The preservation details, total ischemic time, and early postoperative outcomes are described. The data are presented as median (range: minimum-maximum) values.

Results

A total of 36 patients underwent LTx (i.e., 33 bilateral, 2 single LTx, and 1 lobar). The median age was 61 (15-68) years; 58% of the patients were male; 28% of the transplantations had high-urgency status; and 22% were indicated as donation after circulatory death. In 47% of the patients, extracorporeal membrane oxygenation (ECMO) was used for perioperative support. The indications for using the CHS device were overnight bridging (n = 26), remote procurement (n = 4), rescue allocation (n = 2), logistics (n = 2), feasibility (n = 1), and extended-criteria donor (n = 1). The CHS temperature was 6.5°C (3.7°C-9.3°C). The preservation times were 11 h 18 (2 h 42-17 h 9) and 13 h 40 (4 h 5-19 h 36) for the first and second implanted lungs, respectively, whereas the total ischemic times were 13 h 38 (4 h 51-19 h 44) and 15 h 41 (5 h 54-22 h 48), respectively. The primary graft dysfunction grade 3 (PGD3) incidence rates were 33.3% within 72 h and 2.8% at 72 h. Intensive care unit stay was 8 (4-62) days, and the hospital stay was 28 (13-87) days. At the last follow-up [139 (7-446) days], three patients were still hospitalized. One patient died on postoperative day 7 due to ECMO failure. In-hospital Clavien-Dindo complications of 3b were observed in six (17%) patients, and 4a in seven (19%).

Conclusion

CHS seems safe and feasible despite the high-risk recipient and donor profiles, as well as extended preservation times. PGD3 at 72 h was observed in 2.8% of the patients. This technology could postpone LTx to daytime working hours. Larger cohorts and longer-term outcomes are required to confirm these observations.

Systemic Inflammation Differences in Brain-vs. Circulatory-Dead Donors: Impact on Lung Transplant Recipients

Brain death triggers a systemic inflammatory response. Whether systemic inflammation is different in lung donors after brain- (DBD) or circulatory-death (DCD) is unknown, but this may potentially increase the incidence of primary graft dysfunction (PGD) after lung transplantation. We compared the plasma levels of interleukin (IL)-6, IL-8, IL-10 and TNF-α in BDB and DCD and their respective recipients, as well as their relationship with PGD and mortality after LT. A prospective, observational, multicenter, comparative, cohort-nested study that included 40 DBD and 40 DCD lung donors matched and their respective recipients. Relevant clinical information and blood samples were collected before/during lung retrieval in donors and before/during/after (24, 48 and 72 h) LT in recipients. Incidence of PGD and short-term mortality after LT was recorded. Plasma levels of all determined cytokines were numerically higher in DBD than in DCD donors and reached statistical significance for IL-6, IL-10 and IL-8. In recipients with PGD the donor's plasma levels of TNF-α were higher. The post-operative mortality rate was very low and similar in both groups. DBD is associated with higher systemic inflammation than DCD donors, and higher TNF-α plasma levels in donors are associated with a higher incidence of PGD.