Preoperative Plasma Club (Clara) Cell Secretory Protein Levels Are Associated With Primary Graft Dysfunction After Lung Transplantation

Inherent recipient factors, including pretransplant diagnosis, obesity and elevated pulmonary pressures, are established primary graft dysfunction (PGD) risks. We evaluated the relationship between preoperative lung injury biomarkers and PGD to gain further mechanistic insight in recipients. We performed a prospective cohort study of recipients in the Lung Transplant Outcomes Group enrolled between 2002 and 2010. Our primary outcome was Grade 3 PGD on Day 2 or 3. We measured preoperative plasma levels of five biomarkers (CC‐16, sRAGE, ICAM‐1, IL‐8 and Protein C) that were previously associated with PGD when measured at the postoperative time point. We used multivariable logistic regression to adjust for potential confounders. Of 714 subjects, 130 (18%) developed PGD. Median CC‐16 levels were elevated in subjects with PGD (10.1 vs. 6.0, p < 0.001). CC‐16 was associated with PGD in nonidiopathic pulmonary fibrosis (non‐IPF) subjects (OR for highest quartile of CC‐16: 2.87, 95% CI: 1.37, 6.00, p = 0.005) but not in subjects with IPF (OR 1.38, 95% CI: 0.43, 4.45, p = 0.59). After adjustment, preoperative CC‐16 levels remained associated with PGD (OR: 3.03, 95% CI: 1.26, 7.30, p = 0.013) in non‐IPF subjects. Our study suggests the importance of preexisting airway epithelial injury in PGD. Markers of airway epithelial injury may be helpful in pretransplant risk stratification in specific recipients. The authors demonstrate a relationship between perioperative CC‐16 blood levels and an increased risk of primary lung allograft dysfunction, particularly in those without idiopathic pulmonary fibrosis as a pretransplant diagnosis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102697/1/ajt12541.pd

The relationship between plasma lipid peroxidation products and primary graft dysfunction after lung transplantation is modified by donor smoking and reperfusion hyperoxia

BACKGROUND: Donor smoking history and higher fraction of inspired oxygen (FIO2) at reperfusion are associated with primary graft dysfunction (PGD) after lung transplantation. We hypothesized that oxidative injury biomarkers would be elevated in PGD, with higher levels associated with donor exposure to cigarette smoke and recipient hyperoxia at reperfusion. METHODS: We performed a nested case-control study of 72 lung transplant recipients from the Lung Transplant Outcomes Group cohort. Using mass spectroscopy, F2-isoprostanes and isofurans were measured in plasma collected after transplantation. Cases were defined in 2 ways: grade 3 PGD present at day 2 or day 3 after reperfusion (severe PGD) or any grade 3 PGD (any PGD). RESULTS: There were 31 severe PGD cases with 41 controls and 35 any PGD cases with 37 controls. Plasma F2-isoprostane levels were higher in severe PGD cases compared with controls (28.6 pg/ml vs 19.8 pg/ml, p = 0.03). Plasma F2-isoprostane levels were higher in severe PGD cases compared with controls (29.6 pg/ml vs 19.0 pg/ml, p = 0.03) among patients reperfused with FIO2 >40%. Among recipients of lungs from donors with smoke exposure, plasma F2-isoprostane (38.2 pg/ml vs 22.5 pg/ml, p = 0.046) and isofuran (66.9 pg/ml vs 34.6 pg/ml, p = 0.046) levels were higher in severe PGD compared with control subjects. CONCLUSIONS: Plasma levels of lipid peroxidation products are higher in patients with severe PGD, in recipients of lungs from donors with smoke exposure, and in recipients exposed to higher Fio2 at reperfusion. Oxidative injury is an important mechanism of PGD and may be magnified by donor exposure to cigarette smoke and hyperoxia at reperfusion

Protein Quantitative Trait Loci Analysis Identifies Genetic Variation in the Innate Immune Regulator TOLLIP

The authors previously identified plasma plasminogen activator inhibitor-1 (PAI-1) level as a quantitative lung injury biomarker in primary graft dysfunction (PGD). They hypothesized that plasma levels of PAI-1 used as a quantitative trait could facilitate discovery of genetic loci important in PGD pathogenesis. A two-stage cohort study was performed. In stage 1, they tested associations of loci with PAI-1 plasma level using linear modeling. Genotyping was performed using the Illumina CVD Bead Chip v2. Loci meeting a p &lt; 5 × 10(-4) cutoff were carried forward and tested in stage 2 for association with PGD. Two hundred ninety-seven enrollees were evaluated in stage 1. Six loci, associated with PAI-1, were carried forward to stage 2 and evaluated in 728 patients. rs3168046 (Toll interacting protein [TOLLIP]) was significantly associated with PGD (p = 0.006). The increased risk of PGD for carrying at least one copy of this variant was 11.7% (95% confidence interval 4.9-18.5%). The false-positive rate for individuals with this genotype who did not have PGD was 6.1%. Variants in the TOLLIP gene are associated with higher circulating PAI-1 plasma levels and validate for association with clinical PGD. A protein quantitative trait analysis for PGD risk prioritizes genetic variations in TOLLIP and supports a role for Toll-like receptors in PGD pathogenesis

Protein Quantitative Trait Loci Analysis Identifies Genetic Variation in the Innate Immune Regulator TOLLIP in Post–Lung Transplant Primary Graft Dysfunction Risk

The authors previously identified plasma plasminogen activator inhibitor‐1 (PAI‐1) level as a quantitative lung injury biomarker in primary graft dysfunction (PGD). They hypothesized that plasma levels of PAI‐1 used as a quantitative trait could facilitate discovery of genetic loci important in PGD pathogenesis. A two‐stage cohort study was performed. In stage 1, they tested associations of loci with PAI‐1 plasma level using linear modeling. Genotyping was performed using the Illumina CVD Bead Chip v2. Loci meeting a p < 5 × 10−4 cutoff were carried forward and tested in stage 2 for association with PGD. Two hundred ninety‐seven enrollees were evaluated in stage 1. Six loci, associated with PAI‐1, were carried forward to stage 2 and evaluated in 728 patients. rs3168046 (Toll interacting protein [TOLLIP]) was significantly associated with PGD (p = 0.006). The increased risk of PGD for carrying at least one copy of this variant was 11.7% (95% confidence interval 4.9–18.5%). The false‐positive rate for individuals with this genotype who did not have PGD was 6.1%. Variants in the TOLLIP gene are associated with higher circulating PAI‐1 plasma levels and validate for association with clinical PGD. A protein quantitative trait analysis for PGD risk prioritizes genetic variations in TOLLIP and supports a role for Toll‐like receptors in PGD pathogenesis.Plasma plasminogen activator inhibitor‐1 quantitative trait analysis prioritizes genetic variations in TOLLIP for posttransplant primary graft dysfunction and supports a role for Toll‐like receptors in primary graft dysfunction pathogenesis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134189/1/ajt13525.pd

Genetic Variation in the Prostaglandin E2 Pathway Is Associated with Primary Graft Dysfunction

RationaleBiologic pathways with significant genetic conservation across human populations have been implicated in the pathogenesis of primary graft dysfunction (PGD). The evaluation of the role of recipient genetic variation in PGD has thus far been limited to single, candidate gene analyses.ObjectivesWe sought to identify genetic variants in lung transplant recipients that are responsible for increased risk of PGD using a two-phase large-scale genotyping approach.MethodsPhase 1 was a large-scale candidate gene association study of the multicenter, prospective Lung Transplant Outcomes Group cohort. Phase 2 included functional evaluation of selected variants and a bioinformatics screening of variants identified in phase 1.Measurements and main resultsAfter genetic data quality control, 680 lung transplant recipients were included in the analysis. In phase 1, a total of 17 variants were significantly associated with PGD, four of which were in the prostaglandin E2 family of genes. Among these were a coding variant in the gene encoding prostaglandin E2 synthase (PTGES2; P = 9.3 × 10(-5)) resulting in an arginine to histidine substitution at amino acid position 298, and three variants in a block containing the 5' promoter and first intron of the PTGER4 gene (encoding prostaglandin E2 receptor subtype 4; all P &lt; 5 × 10(-5)). Functional evaluation in regulatory T cells identified that rs4434423A in the PTGER4 gene was associated with differential suppressive function of regulatory T cells.ConclusionsFurther research aimed at replication and additional functional insight into the role played by genetic variation in prostaglandin E2 synthetic and signaling pathways in PGD is warranted

Variation in PTX3 Is Associated with Primary Graft Dysfunction after Lung Transplantation

RationaleElevated long pentraxin-3 (PTX3) levels are associated with the development of primary graft dysfunction (PGD) after lung transplantation. Abnormalities in innate immunity, mediated by PTX3 release, may play a role in PGD pathogenesis.ObjectivesOur goal was to test whether variants in the gene encoding PTX3 are risk factors for PGD.MethodsWe performed a candidate gene association study in recipients from the multicenter, prospective Lung Transplant Outcomes Group cohort enrolled between July 2002 and July 2009. The primary outcome was International Society for Heart and Lung Transplantation grade 3 PGD within 72 hours of transplantation. Targeted genotyping of 10 haplotype-tagging PTX3 single-nucleotide polymorphisms (SNPs) was performed in lung transplant recipients. The association between PGD and each SNP was evaluated by logistic regression, adjusting for pretransplantation lung disease, cardiopulmonary bypass use, and population stratification. The association between SNPs and plasma PTX3 levels was tested across genotypes in a subset of recipients with idiopathic pulmonary fibrosis.Measurements and main resultsSix hundred fifty-four lung transplant recipients were included. The incidence of PGD was 29%. Two linked 5' region variants, rs2120243 and rs2305619, were associated with PGD (odds ratio, 1.5; 95% confidence interval, 1.1 to 1.9; P = 0.006 and odds ratio, 1.4; 95% confidence interval, 1.1 to 1.9; P = 0.007, respectively). The minor allele of rs2305619 was significantly associated with higher plasma PTX3 levels measured pretransplantation (P = 0.014) and at 24 hours (P = 0.047) after transplantation in patients with idiopathic pulmonary fibrosis.ConclusionsGenetic variants of PTX3 are associated with PGD after lung transplantation, and are associated with increased PTX3 plasma levels

Clinical Risk Factors for Primary Graft Dysfunction after Lung Transplantation

RationalePrimary graft dysfunction (PGD) is the main cause of early morbidity and mortality after lung transplantation. Previous studies have yielded conflicting results for PGD risk factors.ObjectivesWe sought to identify donor, recipient, and perioperative risk factors for PGD.MethodsWe performed a 10-center prospective cohort study enrolled between March 2002 and December 2010 (the Lung Transplant Outcomes Group). The primary outcome was International Society for Heart and Lung Transplantation grade 3 PGD at 48 or 72 hours post-transplant. The association of potential risk factors with PGD was analyzed using multivariable conditional logistic regression.Measurements and main resultsA total of 1,255 patients from 10 centers were enrolled; 211 subjects (16.8%) developed grade 3 PGD. In multivariable models, independent risk factors for PGD were any history of donor smoking (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2-2.6; P = 0.002); FiO2 during allograft reperfusion (OR, 1.1 per 10% increase in FiO2; 95% CI, 1.0-1.2; P = 0.01); single lung transplant (OR, 2; 95% CI, 1.2-3.3; P = 0.008); use of cardiopulmonary bypass (OR, 3.4; 95% CI, 2.2-5.3; P &lt; 0.001); overweight (OR, 1.8; 95% CI, 1.2-2.7; P = 0.01) and obese (OR, 2.3; 95% CI, 1.3-3.9; P = 0.004) recipient body mass index; preoperative sarcoidosis (OR, 2.5; 95% CI, 1.1-5.6; P = 0.03) or pulmonary arterial hypertension (OR, 3.5; 95% CI, 1.6-7.7; P = 0.002); and mean pulmonary artery pressure (OR, 1.3 per 10 mm Hg increase; 95% CI, 1.1-1.5; P &lt; 0.001). PGD was significantly associated with 90-day (relative risk, 4.8; absolute risk increase, 18%; P &lt; 0.001) and 1-year (relative risk, 3; absolute risk increase, 23%; P &lt; 0.001) mortality.ConclusionsWe identified grade 3 PGD risk factors, several of which are potentially modifiable and should be prioritized for future research aimed at preventative strategies. Clinical trial registered with www.clinicaltrials.gov (NCT 00552357)

Clinical Risk Factors for Primary Graft Dysfunction after Lung Transplantation

Rationale: Primary graft dysfunction (PGD) is the main cause of early morbidity and mortality after lung transplantation. Previous studies have yielded conflicting results for PGD risk factors. Objectives: We sought to identify donor, recipient, and perioperative risk factors for PGD. Methods: We performed a 10-center prospective cohort study enrolled between March 2002 and December 2010 (the Lung Transplant Outcomes Group). The primary outcome was International Society for Heart and Lung Transplantation grade 3 PGD at 48 or 72 hours post-transplant. The association of potential risk factors with PGD was analyzed using multivariable conditional logistic regression. Measurements and Main Results: A total of 1,255 patients from 10 centers were enrolled; 211 subjects (16.8%) developed grade 3 PGD. In multivariable models, independent risk factors for PGD were any history of donor smoking (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2–2.6; P = 0.002); Fi(O(2)) during allograft reperfusion (OR, 1.1 per 10% increase in Fi(O(2)); 95% CI, 1.0–1.2; P = 0.01); single lung transplant (OR, 2; 95% CI, 1.2–3.3; P = 0.008); use of cardiopulmonary bypass (OR, 3.4; 95% CI, 2.2–5.3; P < 0.001); overweight (OR, 1.8; 95% CI, 1.2–2.7; P = 0.01) and obese (OR, 2.3; 95% CI, 1.3–3.9; P = 0.004) recipient body mass index; preoperative sarcoidosis (OR, 2.5; 95% CI, 1.1–5.6; P = 0.03) or pulmonary arterial hypertension (OR, 3.5; 95% CI, 1.6–7.7; P = 0.002); and mean pulmonary artery pressure (OR, 1.3 per 10 mm Hg increase; 95% CI, 1.1–1.5; P < 0.001). PGD was significantly associated with 90-day (relative risk, 4.8; absolute risk increase, 18%; P < 0.001) and 1-year (relative risk, 3; absolute risk increase, 23%; P < 0.001) mortality. Conclusions: We identified grade 3 PGD risk factors, several of which are potentially modifiable and should be prioritized for future research aimed at preventative strategies. Clinical trial registered with www.clinicaltrials.gov (NCT 00552357)