Primary Graft Dysfunction Group Research Articles

Predictors of Grade 3 Primary Graft Dysfunction in Lung Transplant Recipients

<h3>Purpose</h3> Primary graft dysfunction (PGD) remains a feared complication and contributes to significant morbidity and mortality following lung transplantation. The goal of this study was to evaluate factors associated with grade 3 PGD at a large volume lung transplant center. <h3>Methods</h3> We conducted retrospective review of all adult lung transplant recipients performed at University of California Los Angeles from January 1999 to August 2021, including data on donor and recipient baseline characteristics, laboratory values, and operative variables. The primary outcome was grade 3 PGD at 48 or 72 hours after lung transplantation. Donor and recipient factors associated with grade 3 PGD were examined with multivariable logistic regression. <h3>Results</h3> Of 1230 lung transplants performed during the study period with adequate PGD data, grade 3 PGD at 48 or 72 hours occurred in 86(7.0%) recipients. Recipients who developed grade 3 PGD were less likely male(49% vs 60%, p<0.04), white(56% vs 69%, p=0.04), and diagnosis groups A(15% vs 21%, p<0.01) and C (1% vs 5%, p<0.01). They were more likely to be diabetic(31% vs 22%, p=0.04), receive double lungs(65% vs 53%, p=0.04), and be completed on cardiopulmonary bypass(76% vs 64%, p=0.04). Recipients who developed grade 3 PGD also had higher BMI(27±4 vs 25±4 kg/m², p<0.01), PA pressures (50±21 vs 41±16 mmHg systolic and 21±10 vs 18±8 mmHg diastolic, p<0.01) and longer ischemic times (5.4±1.7 vs 4.7±1.3 hours, p<0.01). The grade 3 PGD group also had a lower proportion of male donors(52% vs 66%, p<0.01). On multivariable logistic regression, factors associated with increased odds of grade 3 PGD were recipient BMI (aOR 1.11, 95% CI 1.04-1.17), increasing PA systolic pressure (aOR 1.02 per mmHg, 95% CI 1.01-1.03), and increasing ischemic time (aOR 1.40 per hr, 95% CI 1.19-1.64). Male donors (aOR 0.49, 95% CI 0.30-0.79) were associated with lower odds of grade 3 PGD. The c-statistic for the multivariable model was 0.73. <h3>Conclusion</h3> Increasing recipient BMI, PA systolic pressures, and ischemic time were associated with developing grade 3 PGD 48 or 72 hours after lung transplantation, whereas male donors were protective in our single center study. These variables may help inform donor and recipient selection to reduce the risk of PGD following lung transplantation.

Recipient, Surgical, and Donor Factors Leading to Primary Graft Dysfunction Following Lung Transplantation

<h3>Purpose</h3> Primary graft dysfunction (PGD) is a major cause of early mortality following lung transplantation (LT). The International Society for Heart and Lung Transplantation (ISHLT) subdivides PGD into 3 grades of increasing severity. Majority studies have assessed risk factors for PGD focusing on only grade 3. In this study, we sought to identify recipient, donor and surgical risk factors specifically associated with grade 3 PGD after LT. We also analyzed the incidence of morbidity and postoperative outcomes. <h3>Methods</h3> This is a retrospective review of an institutional lung transplant database. We included consecutive LT recipients from March 2018 through September 2021. Patients were stratified into three cohorts: those who had no PGD after LT, those who had grade 1 or 2 PGD, and those who had grade 3 PGD after LT. PGD was defined according to modified ISHLT criteria. Recipient, donor and surgical variables were analyzed by multivariate Cox analysis with severe PGD as the response. Variables significant in univariate Cox modeling (p<0.20) were subject to multivariable analysis. <h3>Results</h3> In total, 151 patients were included in the study. PGD occurred in 45.6% of the cohort (n = 69) of whom 33.3% (n = 23) had severe PGD. One-year survival was reduced in recipients with grade 3 PGD but not in those with grade 1 or 2 PGD. Multivariable analysis identified three factors as severe PGD; one recipient factor: gender, and two surgical factors: longer operating time and more red blood cell transfusions. Post-LT complications in patients without PGD and with PGD were similar, with the exception of acute kidney injury which was higher in with grade 3 PGD patients (p<0.001). Intensive care unit stay and overall hospital stay were significantly longer in both of grade 1 or 2 and grade 3 PGD group (p<0.001). Grade 3 PGD was the only independent risk factor for mortality (HR = 8.45, 95% CI = 1.55-45.95, p = 0.01). <h3>Conclusion</h3> Risk factors for grade 1 or 2 PGD are distinct from grade 3 PGD. Given the decreased survival in LT recipients with grade 3 PGD, continued research is needed to understand the patho-physiology of PGD and develop effective management strategies.

Plasma Levels of Histidine-Rich Glycoprotein are Associated with the Development of Primary Graft Dysfunction after Lung Transplantation

<h3>Purpose</h3> Histidine-rich glycoprotein (HRG) is a 75 kDa plasma glycoprotein produced in and secreted from the liver. Recently, supplementary HRG treatment has been shown to inhibit acute respiratory distress syndrome (ARDS) and prevent septic lethality. The pathogenesis of primary graft dysfunction (PGD) after lung transplantation (LT) could be similar to that of ARDS. However, the relationship between plasma levels of HRG and PGD after LT remains unknown. <h3>Methods</h3> Blood samples were collected from a total of 68 patients who underwent LT, including the patients with PGD grade 0-1 (the non-PGD group, n = 43), those with PGD grade 2 (the moderate PGD group, n = 18) and those with PGD grade 3 (the severe PGD group, n = 7) at 72 hours after LT. Plasma levels of HRG were quantified using ELISA and compared among the three groups. Appropriate cut-off values of HRG levels were set for overall survival (OS) after LT. <h3>Results</h3> The median follow-up period was 1208 (286-2982) days. Plasma levels of HRG at 72 hours after LT in the severe PGD group were significantly lower than those of the other groups (the non-PGD group vs. the severe PGD group, P = 0.042; the moderate PGD group vs. the severe PGD group, P = 0.040) (Fig. 1). An ROC analysis of the performance of plasma levels of HRG as a marker of overall survival yielded an AUC of 0.61 at a threshold level of 34.4 µg/mL. Patients with plasma levels of HRG ≥ 34.4 µg/mL showed significantly better OS and chronic lung allograft dysfunction (CLAD) free survival than those with plasma levels of HRG < 34.4 µg/mL (OS, P = 0.037; CLAD-free survival, P = 0.046) (Fig. 2). <h3>Conclusion</h3> Plasma level of HRG at 72 hours after LT was associated with the development of PGD, suggesting its usefulness as a predictor of the development of CLAD and survival after LT.

Characterization of Plasma-Derived Exosomes from Patient with Primary Graft Dysfunction after Lung Transplantation

Purpose Recipient responses to primary graft dysfunction (PGD) after lung transplantation (LTx) have important implications for the fate of the allograft. Exosomes, small circulating vesicles, are considered critical mediators of intercellular information and play a role in injury-induced tissue repair processes in multiple physiological systems. Identifying the potential molecular components that contribute to patient-specific responses may lead to new strategies for LTx. Therefore, we seek to elucidate differences in plasma-derived exosomes gene expression in subjects who develop PGD after LTx. Methods Plasma-derived exosomes RNA expression was measured before and 72h after LTx in 6 consented age, sex, commodities, and primary diagnosis matched subjects (PGD n=3; Non-PGD n=3). RNA seq was normalized with the TMM normalization algorithm, and differential expression was performed by edgeR. Differential expressed genes with a p-value 1.5 were considered significant. Gene set enrichment analysis (GSEA) was applied by g: Profiler and genome.jp. PGD was defined as PGD3 at 48-72 hours after reperfusion. Results Compared to the baseline, the PGD group at 72h presented 251 genes with increased relative expression and 27 with decreased relative expression. The same comparison showed 86/16 genes with increased/decreased relative expression respectively in the non-PGD group (Table 1). GSEA in the PGD group identified 327 gene ontology (GO) terms associated with the upregulated gene set, some of these GO associations, such as morphogenesis of epithelium, epithelium development, TNF signaling pathway, MAPK signaling pathway, cytokine-cytokine receptor interaction, Th1 and Th2 cell differentiation, leukocyte transendothelial migration were exclusively found in the PGD group. In the non-PGD group, 237 GO terms were significantly associated with the upregulated gene set, such as HIF-1, tight junction, GO was not observed in the PGD. Conclusion We demonstrated that the RNA content from plasma-derived exosomes and preliminary investigation using GSEA associated with the differentially expressed genes in PGD patients is different from non-PGD patients. Our findings suggest a potential role of exosome-carried RNA in the pathogenesis of PGD. Future investigations are needed to confirm the findings.

Are Those with Primary Graft Dysfunction More Likely to Have Acute Cellular Rejection or Donor-Specific Antibodies after Heart Transplantation?

<h3>Purpose</h3> Primary graft dysfunction (PGD) is a leading cause of early morbidity and mortality following heart transplantation (HT). We sought to determine the association between PGD and incidence of acute cellular rejection (ACR) and development of <i>de novo</i> donor specific antibodies (DSA) within two years post-HTx. <h3>Methods</h3> Consecutive adult HT recipients (n=351) from 1/2010 to 7/2018 at a single center were included. Multi-organ and re-transplants were excluded. Definition of moderate and severe PGD was based on the 2014 ISHLT consensus, which includes dependence on extracorporeal membrane oxygenation or intra-aortic balloon pump. The primary outcome was the incidence of ACR (ISHLT grade 2R or 3R) and the development of <i>de novo</i> DSA (mean fluorescence intensity >500) within 2 years post-HTx. <h3>Results</h3> The cohort was predominantly male (70.6%), with a mean age of 54.1±12.5 years; 34.6% had a durable left ventricular assist device as a bridge to HTx. There were 33 (9.1%) cases of moderate or severe PGD. HLA was assessed in a mean of 15 and 24 samples per patient in those with and without PGD respectively. At two years, patients with PGD had lower incidence of development of <i>de novo</i> DSA against HLA-C (1.6 vs. 3.2%, p=0.047), DP (1.3 vs. 4.3%, p=0.002), DQ (3.3% vs. 11.8%, p<0.001), DR (4.9 vs. 12.4%, p<0.001) compared to patients without PGD (Table 1). In patients with and without PGD, there were 7 and 8 endomyocardial biopsies performed per patient, respectively within two years post-HTx. Patients with PGD had similar incidence of ISHLT 2R or 3R ACR compared to those without PGD (5.3% vs. 3.1%, p=0.07). Finally, there was no difference in PGD among patients who received empiric treatment for ACR without positive endomyocardial biopsy results (3.1% in PGD vs. 3.7% in no PGD, p=0.47). <h3>Conclusion</h3> Development of <i>de novo</i> DSA was lower in the PGD group and there was no difference in overall incidence of ACR in patients with and without PGD at 2 years post-HTx.

Use of donor-derived-cell-free DNA as a marker of early allograft injury in primary graft dysfunction (PGD) to predict the risk of chronic lung allograft dysfunction (CLAD)

Primary graft dysfunction (PGD) is a risk factor for chronic lung allograft dysfunction (CLAD). However, the association between PGD and degree of allograft injury remains poorly defined. In this study, we leverage a novel biomarker for allograft injury, percentage donor-derived cell-free DNA (%ddcfDNA), to study the association between PGD, degree of allograft injury, and the development of CLAD. This prospective cohort study recruited 99 lung transplant recipients and collected plasma samples on days 1, 3, and 7 for %ddcfDNA measurements. Clinical data on day 3 was used to adjudicate for PGD. %ddcfDNA levels were compared between PGD grades. In PGD patients, %ddcfDNA was compared between those who developed CLAD and those who did not. On posttransplant day 3, %ddcfDNA was higher in PGD than in non-PGD patients (median [IQR]: 12.2% [8.2, 22.0] vs 8.5% [5.6, 13.2] p = 0.01). %ddcfDNA correlated with the severity grade of PGD (r = 0.24, p = 0.02). Within the PGD group, higher levels of %ddcfDNA correlated with increased risk of developing CLAD (log OR(SE) 1.38 (0.53), p = 0.009). PGD patients who developed CLAD showed ∼2-times higher %ddcfDNA levels than patients who did not develop CLAD (median [IQR]: 22.4% [11.8, 27.6] vs 9.9% [6.7, 14.9], p = 0.007). PGD patients demonstrated increased early posttransplant allograft injury, as measured by %ddcfDNA, in comparison to non-PGD patients, and these high %ddcfDNA levels were associated with subsequent development of CLAD. This study suggests that %ddcfDNA identifies PGD patients at greater risk of CLAD than PGD alone.

Abstract 14108: Does Primary Graft Dysfunction Increase First Year Intimal Thickness After Heart Transplantation?

Introduction: Primary graft dysfunction (PGD) has been reported in between 7-30% of heart transplant recipients with severe PGD known to have poor outcome. Due to graft dysfunction and potential for endothelial cell injury, it is not known whether all grades of PGD can increase first year intimal thickening, which may be a harbinger for clinical cardiac allograft vasculopathy (CAV). Methods: Between 2010 and 2017, we assessed 769 heart transplant patients and divided them into those patients with mild PGD (n=12), moderate PGD (n=35), severe PGD (n=36) and no PGD (n=686). Endpoints included 3-year survival and freedom from angiographic CAV (stenosis ≥30%) and non-fatal major adverse cardiac events (NF-MACE: myocardial infarction, percutaneous coronary intervention, new congestive heart failure, pacemaker/implantable cardioverter-defibrillator placement, stroke); and 1-year freedom from any treated rejection (ATR), acute cellular rejection (ACR), antibody mediated rejection (AMR). First year intravascular ultrasound (IVUS) was performed at baseline 4-8 weeks and at 1 year after transplant. IVUS parameters included first-year average change in MIT and change in MIT ≥0.5mm. Results: First year change in average MIT and MIT ≥0.5mm and 3-year freedom from CAV were not significantly different in all groups. The severe PGD group compared to all groups had significantly lower 3-year survival and freedom from NF-MACE. There was lower freedom from various types of rejection in the PGD groups compared to the no PGD group. Specifically, 1-year freedom from ACR was significantly lower in the mild PGD group compared to the moderate PGD group and the no PGD group (see table). Conclusions: PGD grades do not appear to lead to increased first year intimal thickening or angiographic CAV at 3 years. Lower freedom from ACR in the mild PGD group and ATR in the severe PGD group will need further study. Larger numbers of patients are needed to confirm these findings.

Cell-free DNA in human ex vivo lung perfusate as a potential biomarker to predict the risk of primary graft dysfunction in lung transplantation

BackgroundCell-free DNA (cfDNA), such as mitochondrial DNA (mtDNA) and nuclear DNA (nuDNA), are known to be released from injured cells and as such have been explored as biomarkers for tissue injury in different clinical settings. Ex vivo lung perfusion (EVLP) has been developed as an effective technique for marginal donor lung functional assessment. We hypothesized that the level of cfDNA in EVLP perfusate may reflect tissue injury and thus can be developed as a biomarker to quantify the degree of donor lung injury or predict the development of primary graft dysfunction (PGD) after lung transplantation (LTx). MethodsThe perfusate from 62 donor lungs transplanted at our institution between May 2010 and December 2015 was sampled for cfDNA at 1 and 4 hours of perfusion. Sequences of genes encoding nicotinamide adenine dinucleotide dehydrogenase 1 (NADH-1) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were used to represent mtDNA and nuDNA, respectively. Levels were quantified by real-time polymerase chain reaction and correlated with clinical outcome after LTx. ResultsIn our entire cohort, 14 patients developed PGD grade 3 (PGD3) within 72 hours after LTx. The non-PGD group included 48 patients (PGD0-1). Concentrations of mtDNA in the perfusate of the PGD3 group were significantly higher than those in non-PGD group at 1 hour of EVLP (1874 ± 844 vs 1259 ± 885 copies/μL; P = .011). The perfusate of the PGD3 group had significantly higher levels of nuDNA compared with the non-PGD group at both 1 hour (1498 ± 1895 vs 675 ± 391 copies/μL; P = .008) and 4 hours (4521 ± 5810 vs 1764 ± 1494 copies/μL; P = .001). In donation after cardiac death (DCD) cases, mtDNA levels were significantly higher in the PGD3 group compared with the non-PGD group at 1 hour of EVLP (2060 ± 997 vs 1184 ± 782 copies/μL; P = .040), and the levels of nuDNA were significantly higher in the PGD3 group compared with the non-PGD group at both 1 hour (1021 ± 495 vs 606 ± 305 copies/μL; P = .041) and 4 hours (2358 ± 1028 vs 1185 ± 967 copies/μL; P = .006). In donation after brain death (DBD) cases, cfDNA scores did not show a significant difference. ConclusionsWe found that the amount of cfDNA, especially nuDNA, in EVLP perfusate was higher in the severe PGD group (PGD3) compared with the non-PGD group. This proof-of-concept study supports the concept that the analysis of cfDNA levels in EVLP perfusate can help estimate the damage to donor lungs before implantation. Larger studies are needed to validate this concept.

Primary graft dysfunction after heart transplantation: Outcomes and resource utilization.

A unified definition of primary graft dysfunction (PGD) after heart transplantation was adopted in 2014, with moderate and severe PGD defined as a need for mechanical circulatory support. While risk factors for PGD are well identified, outcomes and resource utilization have not been well-studied. We examined the resource utilization and associated costs with PGD. All adult heart transplantations (2001-2016) from a statewide Society of Thoracic Surgery database were analyzed by dividing them into two groups-with PGD (requiring mechanical circulatory support) and without PGD. Of the 718 heart transplants, 110 (15.3%) patients developed PGD. Prevalence of PGD for the study duration ranged from 3.7% to 22.7% with no significant trend. The most frequently used mechanical circulatory support device was intra-aortic balloon pump (88%), followed by extracorporeal membrane oxygenation (17%), and catheter-based circulatory support devices (3%). There were no significant differences in demographics or preoperative variables between the two groups. Resource utilization such as total intensive care unit hours, ventilation hours, reoperation for bleeding, blood product transfusions, and length of stay were significantly higher in the PGD group. Postoperative complications were also higher in PGD group including operative mortality (31.8% vs 3.8%, P < .0001). The median cost of heart transplantation was significantly higher in the PGD group $229 482 ($126 044-$388 889) vs $101 788 ($72 638-$181 180) P < .0001. Primary graft dysfunction following heart transplantation developed in 15% of patients. Patients with PGD had significantly higher complications, resource utilization, and mortality. Preventive measures to address the development of PGD would reduce resource utilization and improve outcomes.

Elevated pre-transplant left ventricular end-diastolic pressure increases primary graft dysfunction risk in double lung transplant recipients.

Primary graft dysfunction (PGD) represents ischemia‒reperfusion injury in the lung allograft, and elevated left ventricular end-diastolic pressure (LVEDP) may contribute to capillary leak. We tested whether pre-transplant LVEDP or pulmonary capillary wedge pressure (mPCWP) are related to PGD risk. We hypothesized that elevated LVEDP and mPCWP would increase PGD risk. We reviewed adult double lung transplant recipients at the University of Alberta Hospital from 2004 to 2016 with pre-transplant LVEDP measurements. The primary outcome was Grade 3 PGD at 48 to 72 hours post-transplant. We used regression analysis to assess the association between LVEDP and mPCWP with Grade 3 PGD risk, as well as agreement between these measurements. Three hundred thirty double lung transplant recipients were included in the study, and 63 (19%) developed Grade 3 PGD at 48 or 72 hours. Mean LVEDP was 16 ± 7 mm Hg in the Grade 3 PGD group and 12 ± 5 mm Hg in the non-PGD group (p < 0.0001). LVEDP >15 mm Hg was associated with an adjusted odds ratio (OR) of 3.83 (95% confidence interval [CI] 1.90 to 7.73, p < 0.0001), whereas mPCWP >15 mm Hg showed similar findings (adjusted OR 4.25 [1.83 to 9.86], p = 0.0008). Correlation and agreement between LVEDP and mPCWP were fair. Elevated pre-transplant LVEDP increases the risk of severe PGD after lung transplant, as does elevated mPCWP. These measurements appear to be complementary as markers of prospective PGD risk.

Evaluation of trazodone and quetiapine in patients with Alzheimer's type dementia and sleep disturbance

Primary graft dysfunction (PGD) represents ischemia‒reperfusion injury in the lung allograft, and elevated left ventricular end-diastolic pressure (LVEDP) may contribute to capillary leak. We tested whether pre-transplant LVEDP or pulmonary capillary wedge pressure (mPCWP) are related to PGD risk. We hypothesized that elevated LVEDP and mPCWP would increase PGD risk.We reviewed adult double lung transplant recipients at the University of Alberta Hospital from 2004 to 2016 with pre-transplant LVEDP measurements. The primary outcome was Grade 3 PGD at 48 to 72 hours post-transplant. We used regression analysis to assess the association between LVEDP and mPCWP with Grade 3 PGD risk, as well as agreement between these measurements.Three hundred thirty double lung transplant recipients were included in the study, and 63 (19%) developed Grade 3 PGD at 48 or 72 hours. Mean LVEDP was 16 ± 7 mm Hg in the Grade 3 PGD group and 12 ± 5 mm Hg in the non-PGD group (p < 0.0001). LVEDP >15 mm Hg was associated with an adjusted odds ratio (OR) of 3.83 (95% confidence interval [CI] 1.90 to 7.73, p < 0.0001), whereas mPCWP >15 mm Hg showed similar findings (adjusted OR 4.25 [1.83 to 9.86], p = 0.0008). Correlation and agreement between LVEDP and mPCWP were fair.Elevated pre-transplant LVEDP increases the risk of severe PGD after lung transplant, as does elevated mPCWP. These measurements appear to be complementary as markers of prospective PGD risk.

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.

Risk factors and outcome of primary graft dysfunction after lung transplantation in Korea.

Primary graft dysfunction (PGD) is a severe, acute and post-transplantation lung injury associated with early morbidity and mortality. We aimed to identify clinical risk factors for PGD, as well as the outcome of PGD after lung transplantation in Korea. We retrospectively analyzed lung transplant patients in a South Korean Hospital. The primary outcome was grade 3 PGD, defined according to the International Society for Heart and Lung Transplantation criteria. We compared grade 0-2 PGD group to grade 3 PGD group to identify the risk factors and outcome of grade 3 PGD. Sixty-one patients were enrolled; 16 (26.2%) developed grade 3 PGD. Univariate analysis revealed higher body mass index (BMI) and history of smoking, extracorporeal membrane oxygenation (ECMO) before transplantation in recipients, and an extended intraoperative ischemic time as risk factors for grade 3 PGD. In multivariate analysis, independent risk factors for PGD were higher BMI in recipients [odds ratio (OR), 1.286; P=0.043] and total intraoperative ischemic time (OR, 1.028; P=0.007). As compared to grade 0-2 PGD, grade 3 PGD was significantly associated with a higher re-operation rate (grade 0-2 PGD vs. grade 3 PGD, 22.2% vs. 50.0%; P=0.036), prolonged ventilator apply (median: 6.0 vs. 14.5 days; P=0.044), a longer intensive care unit stay (median: 9.0 vs. 17.0 days; P=0.041), and a higher rate of renal replacement therapy (RRT) (17.8% vs. 62.5%; P=0.002) after transplantation. Patients who developed grade 3 PGD had higher re-operation rate, longer ventilator apply, longer intensive care unit stay, higher rate of RRT, with higher BMI and total intraoperative ischemic time being the significant risk factor. These findings may allow physicians to modify risk factors before development of PGD.

Circulating Cell Death Biomarkers May Predict Survival in Human Lung Transplantation.

Immediate graft performance after lung transplantation is associated with short- and long-term clinical outcomes. However, the biologic mechanism that determines outcomes is not fully understood. To investigate the impact of cell death signals at 24 and 48 hours after lung transplantation on short- and long-term clinical outcomes. Plasma samples were collected pretransplantation and at 24 and 48 hours after transplant from 60 bilateral lung transplant recipients. Ten patients had primary graft dysfunction (PGD) grade 3 (PaO2/FiO2 ratio <200 or on extracorporeal membrane oxygenation support) at 72 hours after transplant (PGD group). The remaining 50 patients were defined as the control group. Levels of plasma M30 (signifying epithelial apoptosis), M65 (signifying epithelial apoptosis plus necrosis), and high-mobility group box 1 protein (HMGB-1; signifying necrosis of all cell types) were measured by ELISA and correlated with clinical outcomes. Survival analyses were performed using Kaplan-Meier curves and Cox proportional hazards regression. Prediction accuracy of markers was assessed by calculated area under the curve of receiver operating characteristic graph. The PGD group had significantly higher M30 and M65 levels at 24 and 48 hours after transplant compared with the control group. There was no significant difference in HMGB-1. Area under the curve for 1-year survival was 0.86, 0.93, and 0.51 for M30, M65, and HMGB-1 at 48 hours, respectively. Survival analysis showed that higher M30 and M65 levels at 24 and 48 hours were significantly associated with worse survival. M65 at 48 hours remained significant even after adjustment for PGD. HMGB-1 was not significantly associated with survival. Recipient plasma concentration of epithelial cell death markers (M30, M65) after lung transplantation is negatively correlated with early graft performance and long-term survival.

Biomarkers of cellular apoptosis and necrosis in donor myocardium are not predictive of primary graft dysfunction.

Primary graft dysfunction (PGD) is a life-threatening complication among heart transplant recipients and a major cause of early mortality. Although the pathogenesis of PGD is still unclear, ischemia/reperfusion injury has been identified as a predominant factor. Both necrosis and apoptosis contribute to the loss of cardiomyocytes during ischemia/reperfusion injury, and this loss of cells can ultimately lead to PGD. The aim of our prospective study was to find out whether cell death, necrosis and apoptosis markers present in the donor myocardium can predict PGD. The prospective study involved 64 consecutive patients who underwent orthotopic heart transplantation at our institute between September 2010 and January 2013. High-sensitive cardiac troponin T (hs-cTnT) as a marker of minor myocardial necrosis was detected from arterial blood samples before the donor's pericardium was opened. Apoptosis (caspase-3, active + pro-caspase-3, bcl-2, TUNEL) was assessed from bioptic samples taken from the right ventricle prior graft harvesting. In our study, 14 % of transplant recipients developed PGD classified according to the standardized definition proposed by the ISHLT Working Group. We did not find differences between the groups in regard to hs-cTnT serum levels. The mean hs-cTnT value for the PGD group was 57.4+/-22.9 ng/l, compared to 68.4+/-10.8 ng/l in the group without PGD. The presence and severity of apoptosis in grafted hearts did not differ between grafts without PGD and hearts that subsequently developed PGD. In conclusion, our findings did not demonstrate any association between measured myocardial cell death, necrosis or apoptosis markers in donor myocardium and PGD in allograft recipients. More detailed investigations of cell death signaling pathways in transplanted hearts are required.

(247) - Ex-Vivo Lung Perfusate Cell Death Markers May Predict Long Term Outcomes After Transplantation

Purpose: Ex-Vivo Lung Perfusion (EVLP) is an emerging technology to reas- sess marginal donor lungs for transplantation. We have previously reported that cell death related perfusate bio-markers in EVLP are potentially predic- tive for primary graft dysfunction (PGD). Our objective was to investigate whether EVLP perfusate cell death markers could be used to predict post- transplant long term survival. Methods: Caspase-cleaved cytokeratin 18 (M30) and HMGB-1 levels in the perfusate of EVLP of marginal donor lungs were measured by quantitative enzyme linked immunosorbent assay, and were correlated with short and long term clinical outcome. Results: From 100 sequential clinical EVLP cases, 79 lungs were selected to be transplanted. Recipients that were bridged with pre-transplant extra- corporeal life support system were excluded from this analysis. 11 patients (PGD group) developed PGD 3 at any time within 72 h after transplant following bilateral lung transplant (BLTx). 34 patients (Control group) did not develop PGD grade 3 after BLTx. Levels of M30 were signifi- cantly higher in PGD group compared to Control group at 1 h (Control 53.9±15.9 vs. PGD 73.3± 24.9 U/L, p= 0.004) and 4 h (Control 72.4±40.0 vs. PGD 137.0±146.6 U/L; p= 0.04) of EVLP . The increase of HMGB-1 from 1 h to 4 h of EVLP (delta HMGB-1) in PGD group was signifi- cantly higher than Control (Control 7.2±16.8 vs. PGD 37.0±25.4 ng/ml; p= 0.0002). Uni variate Cox regression analysis revealed that higher M30 at 1 h (HR= 1 .03 (95%CI 1.004-1.058) per 1 U/L; p= 0 .025) and 4 h (HR= 1.009 (95%CI 1.002-1.016) per 1 U/L; p= 0.009), and higher delta HMGB-1 (HR= 1.033 (95%CI 1.006-1.061) per 1 ng/ml; p= 0.016) are sig- nificantly predictive for survival. After adjustment for PGD using bivariate cox regression analyses, M30 at 4h remained significant (p= 0.04) and the other markers were not statistically significant (M30 at 1 h; p= 0.13; delta HMGB-1; p= 0 .10). The significance of M30 at 4 h seen after adjustment for PGD may suggest that the marker provides additional predictive power for survival above that predicted by PGD status alone. Conclusion: We have demonstrated a correlation of cell death markers in the EVLP perfusate with PGD outcome and long term survival. Further research and validation is required to determine which of these biomarkers will be important in repertoire for real time predictive evaluation of the ex vivo perfused donor lung.

(834) - Primary Graft Dysfunction After Cardiac Transplantation Following Continuous-Flow Left Ventricular Device Support

Primary graft dysfunction (PGD) is the most catastrophic complication after cardiac transplantation. However, little is known about PGD in patients who are bridged with contemporary continuous-flow left ventricular assist devices (LVAD). Between May 2004 and December 2013, 145 patients underwent cardiac transplantation after continuous-flow LVAD support as a bridge to transplant at our center. Degree of PGD was classified into mild, moderate, and severe according to recently published the International Society for Heart and Lung Transplantation consensus statement. The mean age of the study cohort was 54 ± 14 years, 81% were male, and 35% were ischemic etiology. The median duration of LVAD support before transplantation was 205 days. Thirty-six patients (25%) developed PGD (mild 4, moderate 22, severe 10) within 24 hours after transplantation. For severe PGD, biventricular assist device was used in all patients. Mean left ventricular ejection fraction immediately after transplantation was 57 ± 5.6% in non-PGD, 45 ± 9.5% in mild/moderate PGD, and 13 ± 10% in severe PGD group (p<0.0001). In-hospital mortality in non-PGD, mild/moderate PGD, and severe PGD were 5.5%, 7.7%, and 60%, respectively (p=0.002). The 1-year post-transplant survival in non-PGD, mild/moderate PGD, and severe PGD were 91%, 92%, and 25%, respectively (p<0.0001). PGD after bridge with continuous-flow LVAD is common. Patients who developed severe PGD had a dismal outcome. A multi-center study including large cohort is warranted to extend our findings.

Apoptosis, Not Necrosis, during Ex-Vivo Lung Perfusion Is Correlated with Severe PGD

Purpose We hypothesized that a donor lung which develops more apoptosis during ex-vivo lung perfusion (EVLP) tends to experience severer primary graft dysfunction (PGD) after transplant and that cell death markers in perfusate can be used for prediction of subsequent PGD3. Methods and Materials This is a single-institution retrospective case-control study. A correlation of the outcome of recipients after EVLP and cell death markers in EVLP perfusate was investigated. From 2008 to 2012, 77 high-risk donor lungs were subjected to normothermic acellular EVLP for 4 to 6 hours. Lungs were judged for transplantation based on physiological assessment. The cases (PGD group, N=8) were patients who developed PGD 3 within 72h after lung transplant. The matched controls (Control group, N=8) were selected from patients who had PGD 0, 1 or 2 within 72 h after transplant. Matching factors were recipient age, gender and lung disease. A matched design was used to minimize biases of recipient factors affecting the outcome. Cell death markers including M30, M65 and HMGB-1 were measured with ELISA in perfusate at 1h and the end of EVLP. Results M30 which indicates epithelial apoptosis didn’t show a significant difference between two groups in perfusate at 1h. However, M30 in PGD group was significantly higher compared to Control group at the end of EVLP (p=0.015). M30 at the end of EVLP increased significantly compared to 1 h (p=0.016). M65 which indicates epithelial apoptosis and necrosis didn’t show a significant difference between two groups in both time-points. HMGB-1, which is a mediator of inflammation / immune response and released from dead cells, was significantly higher in PGD group at the end (p=0.035) but not at 1h of EVLP. Using ROC curve, AUC of M30 at the end of EVLP was 0.84 (95%CI: 0.62-1.06, p=0.035) and AUC of HMGB-1 at the end of EVLP was 0.85 (95%CI: 0.64-1.06, p=0.029). Conclusions Epithelial cell apoptosis is related to subsequent PGD3, but necrosis didn’t correlate with PGD severity. M30 and HMGB-1 are predictive perfusate markers for PGD3.

The Utility of Classical Parameters of Uncontrolled Non-Heart-Beating Donors to Avoid Primary Graft Dysfunction and Ischemic Cholangiopathy: Are They Still Valid?

Introduction: The acceptance of non-heart-beating donors (NHBD) emerges as a consequence of the shortage of organs and increased mortality in the waiting list. The use of these grafts implies a higher risk of primary graft dysfunction (PGD) as well as ischemic cholangiopathy (IC). Classically, liver function tests (LFT) (AST-ALT) and ischemia times, as well as the macroscopic aspect of the liver are used as determining factors in accepting these organs. Patients and methods: Between January 2006 and December 2011, we performed 380 OLT. 48 of these transplants were NHBD (Maastricht type II). We analyzed factors implied in relationship to LFT and the times with ECMO. Results: We present 48 liver recipients from uncontrolled NHBD, with a mean age of 58.1 ± 9.3 (36-71) years, and a male:female ratio of 3.8:1. The mean age of donor was 39 ± 9.3 years. The indications for transplant were: HCV infection + hepatocarcinoma (HCC) 27.1%, alcoholic cirrhosis (AC) 20.8%, HCV alone 20.8% with a total percentage of HCV of 60.4% and HCC of 43.8%. PGD was observed in 5 patients, and IC in 16. In relation to predictive factors for PGD, no statistical differences were found with respect to the mean values of cold ischemia and warm ischemia times in both groups. We also didn't find statistical differences with respect to times in ECMO, fluid flux in ECMO, nor in the transfusion of red blood cells and plasma in ECMO. No statistical differences were seen with respect to time of cardiac arrest, which paradoxically was lower in those with PGD, who also presented shorter time of cardiopulmonary resuscitation (CPR) and out-of-hospital CPR. We observed differences with respect to LFT: AST at start of ECMO: 503 U/l in PGD group vs 150 in non-PGD patients (p=0.000); ALT at the start of ECMO 462 vs 160 (p=0.000). No differences were observed with respect to total bilirrubin levels, prothrombin time (PT), activated partial thromboplastin time (aPTT) and blood pH. Considering the predictive factors for IC, no statistical differences were observed with respect to the mean values of cold ischemia times and warm ischemia times in both groups. Differences were observed with respect to a higher necessity of red blood cells in ECMO in patients with CI, although not statistically significant. No differences were observed with regard to flux parameters in ECMO, in the CPR times, nor in the analytical values. Conclusion: Taking into consideration these results, we should analyse the true value of these classical parameters in decision making, especially that only an association with elevated LFT was observed for dysfunction. Thus new parameters should be considered for the evaluation of these livers.

Primary graft dysfunction does not lead to increased cardiac allograft vasculopathy in surviving patients

Early injury is associated with the development of cardiac allograft vasculopathy in heart transplantation. We examined whether adult heart transplant recipients surviving primary graft dysfunction were more susceptible to the development of cardiac allograft vasculopathy than their nonprimary graft dysfunction counterparts. A total of 857 patients who underwent heart transplantation between January 1994 and December 2008 at our institution were reviewed. Primary graft dysfunction was defined as the need for extracorporeal membrane oxygenation, open chest, or intra-aortic balloon pump placement within 72 hours of transplantation. Cardiac allograft vasculopathy was defined as ≥50% coronary artery stenosis in any vessel. Allograft survival was defined by patient death or need for retransplantation. Completed follow-up was available for 32 patients in the primary graft dysfunction group and 701 patients in the nonprimary graft dysfunction group. Mean recipient ages (56 years vs 55 years, respectively; P = .50) and ischemic times (220 minutes vs 208 minutes, respectively; P = .35) were similar. Donor age was significantly higher in the primary graft dysfunction group (38 years vs 32 years, P = .02). Five-year survivals for the primary graft dysfunction and nonprimary graft dysfunction groups were 46.9% versus 78.9% (P < .001). Conditional 5-year survivals in patients surviving the first year were 78.9% and 88.3% for the primary graft dysfunction and nonprimary graft dysfunction groups, respectively (P = .18). Within a 30-day postoperative period, there were more deaths in the primary graft dysfunction group (28.1% vs 2.3%, P < .0001) and more retransplants (6.25% vs 0%, P = .002). Of the patients surviving past 30 days, only 2 (8.7%) of the primary graft dysfunction patients developed cardiac allograft vasculopathy versus 144 (21.0%) in the nonprimary graft dysfunction group (P < .001). Primary graft dysfunction was associated with lower 30-day, 1-year, and 5-year allograft survival rates. Surviving patients, however, did not show increased tendency toward cardiac allograft vasculopathy development.