Elevated Plasma Clara Cell Secretory Protein Concentration Is Associated with High‐Grade Primary Graft Dysfunction

Primary graft dysfunction (PGD) is the leading cause of early posttransplant morbidity and mortality after lung transplantation. Clara cell secretory protein (CC16) is produced by the nonciliated lung epithelium and may serve as a plasma marker of epithelial cell injury. We hypothesized that elevated levels of CC16 would be associated with increased odds of PGD. We performed a prospective cohort study of 104 lung transplant recipients. Median plasma CC16 levels were determined at three time points: pretransplant and 6 and 24 h posttransplant. The primary outcome was the development of grade 3 PGD within the first 72 h after transplantation. Multivariable logistic regression was performed to evaluate for confounding by donor and recipient demographics and surgical characteristics. Twenty‐nine patients (28%) developed grade 3 PGD within the first 72 h. The median CC16 level 6 h after transplant was significantly higher in patients with PGD [13.8 ng/mL (IQR 7.9, 30.4 ng/mL)] than in patients without PGD [8.2 ng/mL (IQR 4.5, 19.1 ng/mL)], p = 0.02. Elevated CC16 levels were associated with increased odds of PGD after lung transplantation. Damage to airway epithelium or altered alveolar permeability as a result of lung ischemia and reperfusion may explain this association.     

Elevated plasma long pentraxin-3 levels and primary graft dysfunction after lung transplantation for idiopathic pulmonary fibrosis

Primary graft dysfunction (PGD) after lung transplantation may result from ischemia reperfusion injury (IRI). The innate immune response to IRI may be mediated by Toll-like receptor and IL-1-induced long pentraxin-3 (PTX3) release. We hypothesized that elevated PTX3 levels were associated with PGD. We performed a nested case control study of lung transplant recipients with idiopathic pulmonary fibrosis (IPF) or chronic obstructive pulmonary disease (COPD) from the Lung Transplant Outcomes Group cohort. PTX3 levels were measured pretransplant, and 6 and 24 h postreperfusion. Cases were subjects with grade 3 PGD within 72 h of transplantation and controls were those without grade 3 PGD. Generalized estimating equations and multivariable logistic regression were used for analysis. We selected 40 PGD cases and 79 non-PGD controls. Plasma PTX3 level was associated with PGD in IPF but not COPD recipients (p for interaction < 0.03). Among patients with IPF, PTX3 levels at 6 and 24 h were associated with PGD (OR = 1.6, p = 0.02 at 6 h; OR = 1.4, p = 0.008 at 24 h). Elevated PTX3 levels were associated with the development of PGD after lung transplantation in IPF patients. Future studies evaluating the role of innate immune activation in IPF and PGD are warranted.     

Soluble Adhesion Molecules During Ex Vivo Lung Perfusion Are Associated With Posttransplant Primary Graft Dysfunction

Ex vivo lung perfusion (EVLP) enables assessment of marginal donor lungs for transplantation. We aimed to discover biomarkers in EVLP perfusate that could predict development of primary graft dysfunction (PGD). From September 2008 to August 2013, 100 clinical EVLPs were performed. Eleven patients developed PGD grade 3 within 72 h after transplant. The non‐PGD group consisted of 34 patients without PGD grade 3. Nonbilateral lung transplants or transplant after extracorporeal life support were excluded from analyses. Soluble intercellular adhesion molecule 1 (sICAM‐1), soluble VCAM‐1 (sVCAM‐1), and soluble E selectin (sE‐selectin) levels, as markers of endothelial activation, were measured in the perfusate of EVLP by enzyme‐linked immunosorbent assay and were correlated with clinical outcome. Levels of sICAM‐1 at 1 h and sVCAM‐1 at 1 and 4 h were significantly higher in the PGD group compared with the non‐PGD group. The sE selectin levels were not statistically different between the study groups. Higher levels of sVCAM‐1 at 1 and 4 h were statistically significantly associated with PGD either alone or after adjustment for other PGD risk factors. These adhesion molecules may help identify donor lungs at higher risk of PGD during EVLP.     

Plasma Cytokines and Chemokines in Primary Graft Dysfunction Post-Lung Transplantation

Primary graft dysfunction (PGD) after lung transplantation causes significant morbidity and mortality. We aimed to determine the role of cytokines and chemokines in PGD. This is a multicenter case–control study of PGD in humans. A Luminex analysis was performed to determine plasma levels of 25 chemokines and cytokines before and at 6, 24, 48 and 72 h following allograft reperfusion in 25 cases (grade 3 PGD) and 25 controls (grade 0 PGD). Biomarker profiles were evaluated using a multivariable logistic regression and generalized estimating equations. PGD cases had higher levels of monocyte chemotactic protein-1 (MCP-1)/chemokine CC motif ligand 2 (CCL2) and interferon (IFN)-inducible protein (IP-10)/chemokine CXC motif ligand 10 (CXCL10) (both p < 0.05), suggesting recruitment of monocytes and effector T cells in PGD. In addition, PGD cases had lower levels of interleukin (IL-13) (p = 0.05) and higher levels of IL-2R (p = 0.05). Proinflammatory cytokines, including tumor necrosis factor (TNF)-α, and IFN-γ decreased to very low levels after transplant in both PGD cases and controls, exhibiting no differences between the two groups. These findings were independent of clinical variables including diagnosis in multivariable analyses, but may be affected by cardiopulmonary bypass. Profound injury in clinical PGD is distinguished by the upregulation of selected chemokine pathways, which may useful for the prediction or early detection of PGD if confirmed in future studies.     

供肝热缺血与肝移植术后肺损伤关系的实验研究

目的：探讨心脏停搏供体肝移植中，供肝热缺血与肝移植术后肺损伤的关系。方法：实验以供肝获取前经历的心脏停搏时间0、30和60min分为3组，分别为有心跳组（HB组）、心脏停搏30min组（NHBD－30组）和心跳停搏60min组（NHBD－60组），而后行大鼠原位肝移植。比较术后血清中肿瘤坏死因子（TNF）－α细胞间粘附分子－1（ICAM－1）的变化，并观察肺组织病理和肺组织中ICAM－1免疫组织化学表达。结果：随着供肝热缺血时间的延长，肺组织损害也逐渐回重，术后血清中TNF－α和ICAM－1的值呈上升趋势，各组间差异有显著性。术后6h NHBD-60组出现肺组织中ICAM－1的强表达。结论：在心脏停搏供体肝移植中，TNF－α和ICAM－1的表达上调与术后肺组织损伤有关。     

Elevated donor plasminogen activator inhibitor‐1 levels and the risk of primary graft dysfunction

Primary graft dysfunction (PGD) following lung transplantation is associated with elevated recipient plasma levels of plasminogen activator inhibitor‐1 (PAI‐1) and the receptor for advanced glycation end products (RAGE). However, the significance of these biomarkers in the donor plasma is uncertain. We hypothesized that elevated donor plasma levels of PAI‐1 and RAGE would be associated with recipient PGD. We carried out a prospective unmatched case‐control study of double‐lung transplant recipients between May 2014 and September 2015. We compared donor plasma levels of PAI‐1 and RAGE using rank‐sum tests and t tests, in 12 recipients who developed PGD grade 2 or 3 within 72 hours postoperatively with 13 recipients who did not. Recipients who developed PGD had higher donor plasma levels of PAI‐1 than recipients who did not (median 2.7 ng/mL vs 1.4; P = .03). Recipients with PGD also had numerically higher donor plasma levels of RAGE than recipients without PGD, although this difference did not achieve statistical significance (median 1061 pg/mL vs 679; P = .12). Systemic inflammatory responses in the donor, as reflected by elevated plasma levels of PAI‐1, may contribute to the risk of developing PGD. Rapid biomarker assessment of easily available plasma samples may assist in donor lung selection and risk stratification.     

The Role of TGF‐β in the Association Between Primary Graft Dysfunction and Bronchiolitis Obliterans Syndrome

Primary graft dysfunction (PGD) is a possible risk factor for bronchiolitis obliterans syndrome (BOS) following lung transplantation; however, the mechanism for any such association is poorly understood. Based on the association of TGF‐β with acute and chronic inflammatory disorders, we hypothesized that it might play a role in the continuum between PGD and BOS. Thus, the association between PGD and BOS was assessed in a single‐center cohort of lung transplant recipients. Bronchoalveolar lavage fluid concentrations of TGF‐β and procollagen collected within 24 h of transplantation were compared across the spectrum of PGD, and incorporated into Cox models of BOS. Immunohistochemistry localized expression of TGF‐β and its receptor in early lung biopsies posttransplant. We found an association between PGD and BOS in both bilateral and single lung recipients with a hazard ratio of 3.07 (95% CI 1.76–5.38) for the most severe form of PGD. TGF‐β and procollagen concentrations were elevated during PGD (p < 0.01), and associated with increased rates of BOS. Expression of TGF‐β and its receptor localized to allograft infiltrating mononuclear and stromal cells, and the airway epithelium. These findings validate the association between PGD and the subsequent development of BOS, and suggest that this association may be mediated by receptor/TGF‐β biology.     

Risk factors for early primary graft dysfunction after lung transplantation: a registry study

Abstract: Background: Primary graft dysfunction (PGD) is a leading cause of early morbidity and mortality in lung transplantation. We sought to identify risk factors for PGD using the United Network for Organ Sharing/International Society for Heart and Lung Transplant (UNOS/ISHLT) Registry. Methods: A total of 6984 lung transplants between 1994 and 2002 were available for analysis. Potential risk factors were tested for association with PGD and multivariable logistic regression was applied to adjust for confounding. Results: The overall incidence of PGD was 10.7% (95% CI 9.9–11.4). In multivariable analyses, factors independently associated with PGD were donor age >45 yr (p < 0.001); donor head trauma (p = 0.03); recipient body mass index >25 kg/m² (p = 0.005); recipient female gender (p = 0.001); use of Eurocollins preservation solution (p = 0.001); single lung transplant (p = 0.005); increased ischemic time (p < 0.001); and elevated recipient pulmonary artery systolic pressure at transplant (p < 0.001). Recipient transplant diagnosis was strongly associated with PGD, with primary or secondary pulmonary hypertension (p < 0.001 for both), and idiopathic (p < 0.001) or secondary pulmonary fibrosis (p = 0.011) as significant and independent risk factors for PGD. Conclusions: Risk factors for PGD in the UNOS/ISHLT registry are consistent with prior smaller studies. Recipient, donor, and therapy variables are independently associated with PGD, as defined in a large registry.     

Primary Graft Dysfunction and Mortality Following Lung Transplantation: A Role for Proadrenomedullin Plasma Levels

Primary graft dysfunction (PGD) after lung transplantation (LT) is a heterogeneous syndrome that comprises clinical presentations with diverse grades of severity. Proadrenomedullin (proADM) levels may be associated with PGD and may enhance its relationship with outcomes. We prospectively included 100 LT recipients. Plasma levels of proADM were measured at 24, 48 and 72 h after admission to the intensive care unit (ICU). We assessed their relationship with PGD grade and ICU mortality. Fifty patients (50%) presented grade 3 PGD at ICU admission. Twenty‐two patients (22%) developed grade 3 PGD at 72 h, the only grade associated with higher mortality (odds ratio 6.84, 95% confidence interval [CI] 1.47–38.44). ProADM levels measured at 24 h (3.25 vs. 1.61 nmol/L; p = 0.016) and 72 h (2.17 vs. 1.35 nmol/L; p = 0.011) were higher in these patients than the rest of the population. When we added the individual predictive utility of grade 3 PGD at 72 h for ICU mortality (area under the curve [AUC] 0.72, 95% CI 0.53–0.90) to that of ProADM at 72 h, the predictive value of the model improved (AUC 0.81, 95% CI 0.65–0.97). Higher levels of proADM measured following LT are associated with grade 3 PGD at 72 h. ProADM enhances the association of this entity with mortality.     

The Perioperative Lung Transplant Virome: Torque Teno Viruses Are Elevated in Donor Lungs and Show Divergent Dynamics in Primary Graft Dysfunction

Primary graft dysfunction (PGD) is a principal cause of early morbidity and mortality after lung transplantation, but its pathogenic mechanisms are not fully clarified. To date, studies using standard clinical assays have not linked microbial factors to PGD. We previously used comprehensive metagenomic methods to characterize viruses in lung allografts >1 mo after transplant and found that levels of Anellovirus, mainly torque teno viruses (TTVs), were significantly higher than in nontransplanted healthy controls. We used quantitative polymerase chain reaction to analyze TTV and shotgun metagenomics to characterize full viral communities in acellular bronchoalveolar lavage from donor organs and postreperfusion allografts in PGD and non‐PGD lung transplant recipient pairs. Unexpectedly, TTV DNA levels were elevated 100‐fold in donor lungs compared with healthy adults (p = 0.0026). Although absolute TTV levels did not differ by PGD status, PGD cases showed a smaller increase in TTV levels from before to after transplant than did control recipients (p = 0.041). Metagenomic sequencing revealed mainly TTV and bacteriophages of respiratory tract bacteria, but no viral taxa distinguished PGD cases from controls. These findings suggest that conditions associated with brain death promote TTV replication and that greater immune activation or tissue injury associated with PGD may restrict TTV abundance in the lung.     

Mitochondrial damage–associated molecular patterns released by lung transplants are associated with primary graft dysfunction

Primary graft dysfunction (PGD) is a major limitation in short‐ and long‐term lung transplant survival. Recent work has shown that mitochondrial damage–associated molecular patterns (mtDAMPs) can promote solid organ injury, but whether they contribute to PGD severity remains unclear. We quantitated circulating plasma mitochondrial DNA (mtDNA) in 62 patients, before lung transplantation and shortly after arrival to the intensive care unit. Although all recipients released mtDNA, high levels were associated with severe PGD development. In a mouse orthotopic lung transplant model of PGD, we detected airway cell‐free damaged mitochondria and mtDNA in the peripheral circulation. Pharmacologic inhibition or genetic deletion of formylated peptide receptor 1 (FPR1), a chemotaxis sensor for N‐formylated peptides released by damaged mitochondria, inhibited graft injury. An analysis of intragraft neutrophil‐trafficking patterns reveals that FPR1 enhances neutrophil transepithelial migration and retention within airways but does not control extravasation. Using donor lungs that express a mitochondria‐targeted reporter protein, we also show that FPR1‐mediated neutrophil trafficking is coupled with the engulfment of damaged mitochondria, which in turn triggers reactive oxygen species (ROS)–induced pulmonary edema. Therefore, our data demonstrate an association between mtDAMP release and PGD development and suggest that neutrophil trafficking and effector responses to damaged mitochondria are drivers of graft damage.     

Recipient Vascular Endothelial Growth Factor Serum Levels Predict Primary Lung Graft Dysfunction

Primary graft dysfunction (PGD) is a severe complication in lung transplantation. Therapeutic strategies are limited and there exist no predictive markers for PGD. To investigate whether vascular endothelial growth factor (VEGF) that regulates vascular permeability could predict PGD, pretransplant VEGF serum concentrations were measured in 150 lung transplant patients and 12 controls by ELISA. PGD was scored from 0 to 3 using chest radiographs and PaO(2)/FiO(2) ratios according to the International Society for Heart and Lung Transplantation guidelines. The mean graft ischemia time was 5 h 47 min and the donors' PaO(2)/FiO(2) ratios were >300. PGD grades 0-3 occurred in 23%, 44%, 21%, and 11% of patients, respectively. Pre-operative VEGF serum concentrations were significantly higher in PGD grade 3 (p < 0.0001) versus grade 0-2 and controls. VEGF concentrations significantly predicted PGD grade 3 versus 0-2 in logistic regression analysis (p < 0.0001) and receiver operating analysis (AUC = 0.778). At a cut-off level of > or =650 pg/mL VEGF had 86% sensitivity and 62% specificity to identify PGD grade 3 versus 0-2. Pre-operative VEGF serum concentrations could identify lung transplant recipients with high PGD risk.     

Adipose Gene Expression Profile Changes With Lung Allograft Reperfusion

Obesity is a risk factor for primary graft dysfunction (PGD), a form of lung injury resulting from ischemia–reperfusion after lung transplantation, but the impact of ischemia–reperfusion on adipose tissue is unknown. We evaluated differential gene expression in thoracic visceral adipose tissue (VAT) before and after lung reperfusion. Total RNA was isolated from thoracic VAT sampled from six subjects enrolled in the Lung Transplant Body Composition study before and after allograft reperfusion and quantified using the Human Gene 2.0 ST array. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed enrichment for genes involved in complement and coagulation cascades and Jak‐STAT signaling pathways. Overall, 72 genes were upregulated and 56 genes were downregulated in the postreperfusion time compared with baseline. Long pentraxin‐3, a gene and plasma protein previously associated with PGD, was the most upregulated gene (19.5‐fold increase, p = 0.04). Fibronectin leucine‐rich transmembrane protein‐3, a gene associated with cell adhesion and receptor signaling, was the most downregulated gene (4.3‐fold decrease, p = 0.04). Ischemia–reperfusion has a demonstrable impact on gene expression in visceral adipose tissue in our pilot study of nonobese, non‐PGD lung transplant recipients. Future evaluation will focus on differential adipose tissue gene expression and the development of PGD after transplant.     

Objective Estimates Improve Risk Stratification for Primary Graft Dysfunction after Lung Transplantation

Primary graft dysfunction (PGD) is a major cause of early mortality after lung transplant. We aimed to define objective estimates of PGD risk based on readily available clinical variables, using a prospective study of 11 centers in the Lung Transplant Outcomes Group (LTOG). Derivation included 1255 subjects from 2002 to 2010; with separate validation in 382 subjects accrued from 2011 to 2012. We used logistic regression to identify predictors of grade 3 PGD at 48/72 h, and decision curve methods to assess impact on clinical decisions. 211/1255 subjects in the derivation and 56/382 subjects in the validation developed PGD. We developed three prediction models, where low‐risk recipients had a normal BMI (18.5–25 kg/m²), chronic obstructive pulmonary disease/cystic fibrosis, and absent or mild pulmonary hypertension (mPAP<40 mmHg). All others were considered higher‐risk. Low‐risk recipients had a predicted PGD risk of 4–7%, and high‐risk a predicted PGD risk of 15–18%. Adding a donor‐smoking lung to a higher‐risk recipient significantly increased PGD risk, although risk did not change in low‐risk recipients. Validation demonstrated that probability estimates were generally accurate and that models worked best at baseline PGD incidences between 5% and 25%. We conclude that valid estimates of PGD risk can be produced using readily available clinical variables.     

Plasma Levels of N Terminal Pro-Brain Natriuretic Peptide as a Prognostic Value in Primary Graft Dysfunction and a Predictor of Mortality in the Immediate Postoperative Period of Lung Transplantation

Introduction and Objectives

Primary graft dysfunction (PGD) is a form of acute lung injury secondary to lung transplantation (LT). The objective of our study was to analyse N terminal pro-brain natriuretic peptide (NT-pro-BNP) as a prognostic marker of morbidity and mortality and its possible relationship with the development of PGD.

Materials and Methods

This prospective study of 50 consecutive lung transplantation patients used blood samples obtained at baseline, 24, 48, and 72 hours after admission. We analyzed the amino terminal fraction of the BNP prohormone (NT-pro-BNP). The development of PGD was defined following the criteria of the International Society for Heart and Lung Transplantation (ISHLT).

Results

In this study 72% of patients developed PGD at T24, 42% of whom had severe grade III. There was no relationship between the development of PGD at any grade and NT-pro-BNP levels. Elevated levels of NT-pro-BNP were accompanied by greater postoperative mortality (P < .05).     

Immediate postoperative inflammatory response predicts long-term outcome in lung-transplant recipients

OBJECTIVES Although lung transplantation is an accepted therapy for end-stage disease, recipient outcomes continue to be hindered by early primary graft dysfunction (PGD) as well as late rejection and bronchiolitis obliterans syndrome (BOS). We have previously shown that the pro-inflammatory cytokine response following transplantation correlates with the severity of PGD. We hypothesized that lung-transplant recipients with an increased inflammatory response immediately following surgery would also have a greater incidence of unfavorable long-term outcomes including rejection, BOS and ultimately death. METHODS A retrospective study of lung-transplant recipients (n?=?19) for whom serial blood sampling of cytokines was performed for 24?h following transplantation between March 2002 and June 2003 at a single institution. Long-term follow-up was examined for rejection, BOS and survival. RESULTS Thirteen single and six bilateral lung recipients were examined. Eleven (58%) developed BOS and eight (42%) did not. Subgroup analysis revealed an association between elevated IL-6 concentrations 4?h after reperfusion of the allograft and development of BOS (P?=?0.068). The correlation between IL-6 and survival time was found to be significant (corr?=?-0.46, P?=?0.047), indicating that higher IL-6 response had shorter survival following transplantation. CONCLUSIONS An elevation in interleukin (IL)-6 concentration immediately following lung transplantation is associated with a trend towards development of bronchiolitis obliterans, rejection and significantly decreased survival time. Further studies are warranted to confirm the correlation between the immediate inflammatory response, PGD and BOS. Identification of patients at risk for BOS based on the cytokine response after surgery may allow for early intervention.     

大鼠肺移植术后早期肺组织ICAM-1表达的变化

目的　研究大鼠肺移植术后早期肺组织细胞间粘附分子 1(ICAM 1)表达的变化。方法　用免疫组织化学 (SABC)法及设置内参照的半定量RT PCR方法 ,对移植肺获再灌注及通气 4h后肺组织的ICAM 1蛋白及其mRNA表达水平进行观察。实验组 (n =6 )肺经低钾右旋糖酐液 4℃保存12h后 ,行同种异体左肺原位移植。对照组 (n =6 )充分游离左侧肺动、静脉及支气管。免疫组织化学检测结果按阴性 (- )、可疑 (± )、弱阳性 ( )、阳性 ( )、强阳性 ( )进行记录。PCR产物电泳后扫描记录条带密度。结果　移植肺肺泡上皮及肺血管内皮细胞免疫着色显著较对照组深 (P<0 .0 1)。其ICAM 1mRNA与β actinmRNART PCR扩增产物相对密度值亦显著高于对照组 ,分别为 0 .873± 0 .0 44和 0 .44 2± 0 .0 37,P <0 .0 1。结论　肺移植术后早期肺组织ICAM 1表达上调 ,这种上调与ICAM 1mRNA增强有关。