Immunological diversity in phenotypes of chronic lung allograft dysfunction: a comprehensive immunohistochemical analysis.

Chronic rejection after organ transplantation is defined as a humoral- and cell-mediated immune response directed against the allograft. In lung transplantation, chronic rejection is nowadays clinically defined as a cause of chronic lung allograft dysfunction (CLAD), consisting of different clinical phenotypes including restrictive allograft syndrome (RAS) and bronchiolitis obliterans syndrome (BOS). However, the differential role of humoral and cellular immunity is not investigated up to now. Explant lungs of patients with end-stage BOS (n = 19) and RAS (n = 18) were assessed for the presence of lymphoid (B and T cells) and myeloid cells (dendritic cells, eosinophils, mast cells, neutrophils, and macrophages) and compared to nontransplant control lung biopsies (n = 21). All myeloid cells, with exception of dendritic cells, were increased in RAS versus control (neutrophils, eosinophils, and mast cells: all P < 0.05, macrophages: P < 0.001). Regarding lymphoid cells, B cells and cytotoxic T cells were increased remarkably in RAS versus control (P < 0.001) and in BOS versus control (P < 0.01). Interestingly, lymphoid follicles were restricted to RAS (P < 0.001 versus control and P < 0.05 versus BOS). Our data suggest an immunological diversity between BOS and RAS, with a more pronounced involvement of the B-cell response in RAS characterized by a structural organization of lymphoid follicles. This may impact future therapeutic approaches.

A decade of extended-criteria lung donors in a single center: was it justified?

Despite a worldwide need to expand the lung donor pool, approximately 75% of lung offers are not accepted for transplantation. We investigated the impact of liberalizing lung donor acceptance criteria during the last decade on the number of effective transplants and early and late outcomes in our center. All 514 consecutive lung transplants (LTx) performed between Jan 2000 and Oct 2011 were included. Donors were classified as matching standard criteria (SCD; n = 159) or extended criteria (ECD; n = 272) in case they fulfilled at least one of the following criteria: age >55 years, PaO2 /FiO2 at PEEP 5 cmH2 O < 300 mmHg at time of offer, presence of abnormalities on chest X-ray, smoking history, presence of aspiration, presence of chest trauma, or donation after circulatory death. Outcome parameters were primary graft dysfunction (PGD) grade at 0, 12, 24, and 48 h after LTx, time to extubation, stay in intensive care unit (ICU), early and late infection, acute rejection and bronchiolitis obliterans syndrome (BOS), and survival. Two hundred and seventy-two recipients (63.1%) received ECD lungs. PGD grade at T0 was similar between groups, while at T12 (<0.01), T24 (<0.01), and T48 (<0.05), PGD3 was observed more often in ECDs. ICU stay (P < 0.05) was longer in ECDs compared with SCDs. Time to extubation, respiratory infections, acute rejection, lymphocytic bronchiolitis, BOS, and survival were not different between groups. Accepting ECDs contributed in increasing the number of lung transplants performed in our center. Although this lung donor strategy has an impact on early postoperative outcome, liberalizing criteria did not influence long-term outcome after LTx.

Do we need to cool the lung graft after ex vivo lung perfusion? A preliminary study.

BACKGROUND: After normothermic ex vivo lung perfusion (EVLP), pulmonary grafts are usually flush-cooled and stored on ice until implantation although evidence for this practice lacks. We compared outcomes between 2 post-EVLP preservation strategies in a porcine left single-lung transplantation model. MATERIAL AND METHODS: After cold flush and 2-h EVLP, donor lungs were prepared and split. In [C], (n = 5) lungs cooled on device to 15°C were preserved in ice-water; in [W] (n = 5), lungs were disconnected from EVLP at 37°C and kept at room temperature. The left lung was transplanted in a recipient animal. Posttransplant, 6 h-monitoring included hourly assessment of pulmonary vascular resistance, pulmonary artery pressure, plateau airway pressure, compliance, and oxygenation before and after exclusion of the right lung. Lung biopsies and bronchoscopy with bronchoalveolar lavage (BAL) were performed at retrieval, at the end of EVLP (R lung), and 1 and 6 h after reperfusion (L lung). RESULTS: Lungs in [W] showed the highest compliance (P < 0.05) and the lowest plateau airway pressure (not statistically significant) throughout the whole reperfusion period. Oxygenation and pulmonary artery pressure were similar between groups. Pulmonary vascular resistance was stable in [C], but rose after reperfusion in [W]. Histologic signs of lung injury and BAL neutrophilia were more pronounced in [C] at 1 h (not statistically significant and P < 0.05, respectively). BAL cytokine levels and lung tissue expression of intercellular adhesion molecule 1 did not differ between groups. CONCLUSIONS: Normothermic preparation after EVLP results in similar graft performances compared with lung cooling after EVLP.

Evaluating lung injury at increasing time intervals in a murine brain death model.

INTRODUCTION: Only 15%-25% of brain death (BD) donors match the ideal donor criteria for lung transplantation. Lung injury may evolve in the hours after onset of brain death, but the evolution over time has not been well studied in lung. The aim of this study was to evaluate lung injury at different time points after BD using a murine model. MATERIALS AND METHODS: Male C57BL6/J mice (8-10 wk) were anesthetized, tracheotomized, and mechanically ventilated. Mice were randomly assigned to six groups (n=8/group): 1 h, 3 h, and 6 h sham ([SH1], [SH3], [SH6]) and 1 h, 3 h, and 6 h brain death ([BD1], [BD3], [BD6]). BD was gradually induced by a subdural balloon catheter. Heart rate and mean arterial pressure were continuously monitored. At the end of the experiment, bronchoalveolar lavage was performed and the left lung was excised for histopathologic analysis. RESULTS: The Cushing reflex was characterized by a rapid increase in heart rate and mean arterial pressure after balloon inflation in BD animals. An increase in percentage of neutrophils was seen with a longer follow-up period (P<0.05). Interleukin 6 and interleukin 10 levels in bronchoalveolar lavage progressively increased with longer time intervals after BD ([BD1] versus [BD6]; P<0.01). Histologic signs of lung injury (congestion, hemorrhage, and neutrophilic influx) were more pronounced in [BD3] and [BD6] compared with the other groups; however, this difference did not reach statistical significance. CONCLUSION: Three hours after brain death, significant signs of inflammation and lung injury were seen compared with sham-operated animals. This murine BD model gives us opportunities for further mechanistic studies regarding treatment of BD-related donor lung injury.

Fluoro-D-glucose-micro positron emission tomography as a diagnostic tool to confirm brain death in a murine donor lung injury model.

PURPOSE: Because brain death (BD)-related donor lung injury is still poorly understood, a reliable mouse model can help in understanding the immunologic mechanisms behind this lung injury. The purpose of our study was to validate BD in mice using small-animal positron emission tomography. PROCEDURES: BD was induced in male Balb/c mice (27.1 ± 0.9 g) with an intracranial balloon catheter inflated rapidly (<1 min) [BD](R) or gradually (36 ± 5 min) [BD](G), and compared with sham-operated [SH] and control animals [C] (n = 6/group). Ten minutes after balloon insertion 10.4 ± 1.0 MBq 2-deoxy-2-[(18)F]-fluoro-D-glucose ((18)FDG) was administered intravenously and static images were performed and quantified. RESULTS: Coronal, sagittal, and transaxial sections of cerebral (18)FDG activity revealed significant differences when comparing [BD](R) and [BD](G) with [C] and [SH] animals. No significant (18)FDG uptake was visually detectable in [BD](R) and [BD](G). The percentage injected dose showed significant differences between BD groups and [C] and [SH] (P < 0.0001). No significant difference was seen between [C] versus [SH] nor between [BD](R)versus [BD](G) (P > 0.05). CONCLUSIONS: (18)FDG micro positron emission tomography imaging is a valuable tool to demonstrate brain functionality and can therefore be used as a surrogate test to confirm BD in mice.

Interleukin-17 receptor polymorphism predisposes to primary graft dysfunction after lung transplantation.

BACKGROUND: Primary graft dysfunction (PGD), with an incidence of 11% to 57%, is a major cause of morbidity and mortality within the first 30 days after lung transplantation (LTx). In this study, we postulate that recipient genetic variants in interleukin-17 and -23 receptor genes (IL-17R and IL-23R, respectively) may predispose LTx recipients to an increased risk for developing PGD. METHODS: Seven genetic variants of IL-17R and IL-23R were successfully genotyped in 431 lung transplant recipients. Our primary end-point was PGD and secondary end-points were time to extubation, intensive care unit (ICU) stay, bronchoalveolar lavage neutrophilia and serum C-reactive protein. RESULTS: The AA genotype of the rs882643 genetic variant of IL-17R was associated with higher PGD grades at 0 hour (adjusted p = 0.042), 12 hours (adjusted p = 0.013) and 48 hours (adjusted p = 0.0092) after LTx. The GG genotype of the rs2241049 genetic variant of IL-17R was associated with higher PGD grades at 48 hours (adjusted p = 0.0067) after LTx. For both genetic variants, no association was found with extubation time, ICU stay, post-operative BAL neutrophilia, serum CRP, chronic lung allograft dysfunction (CLAD) or graft loss. CONCLUSION: Both genetic variants of IL-17R (rs882643 and rs2241049) were associated with PGD. This confirms a genetic predisposition toward PGD and suggests a role of IL-17 in driving neutrophilia in PGD.

BAL neutrophilia in azithromycin-treated lung transplant recipients: Clinical significance.

BACKGROUND: Azithromycin decreases airway neutrophilia and can prevent chronic lung allograft dysfunction (CLAD) after lung transplantation (LTx). It also can be used to treat lymphocytic bronchiolitis, as it decreases the submucosal infiltrating IL-17 positive lymphocytes. Some patients, while receiving azithromycin, (re)develop increased airway neutrophilia, which we hypothesize to result in worse outcome and to be regulated by an IL-17-independent mechanism. METHODS: LTx recipients, transplanted between 2001 and 2012, were investigated and categorized in a study group of patients with increased broncho-alveolar lavage (BAL) neutrophilia (≥15%) and a matched control group with low BAL neutrophilia (<15%), both groups while already being on azithromycin treatment. CLAD-free and overall survival were compared between groups. Cell differentials and 33 proteins in BAL were analyzed to identify underlying mechanisms. RESULTS: The study group (n=72) demonstrated a significantly lower CLAD-free (p=0.015) and overall survival (p=0.041) compared to the control group (n=37). Absolute BAL neutrophils and eosinophils were increased in the study group, which was paralleled by elevated inflammatory cytokines (IL-1ß/IL-1Ra, IL-4 and IL-6) and chemokines (CXCL8/IL-8, CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1ß, CCL11/eotaxin) concentrations compared to the control group (all p<0.05). CONCLUSION: Patients with elevated airway neutrophilia despite azithromycin, experience worse CLAD-free and overall survival. In these patients, IL-1ß might play a central role giving rise to neutrophils, eosinophils, macrophages and B-cells. This provides an opportunity to further investigate the modulation of this pathway.

Multiplex protein profiling of bronchoalveolar lavage in idiopathic pulmonary fibrosis and hypersensitivity pneumonitis.

CONTEXT: Idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (HP) are diffuse parenchymal lung diseases characterized by a mixture of inflammation and fibrosis, leading to lung destruction and finally death. AIMS: The aim of this study was to compare different pathophysiological mechanisms, such as angiogenesis, coagulation, fibrosis, tissue repair, inflammation, epithelial damage, oxidative stress, and matrix remodeling, in both disorders using bronchoalveolar lavage (BAL). METHODS: at diagnosis, patients underwent bronchoscopy with BAL and were divided into three groups: Control (n = 10), HP (n = 11), and IPF (n = 11), based on multidisciplinary approach (clinical examination, radiology, and histology): Multiplex searchlight technology was used to analyze 25 proteins representative for different pathophysiological processes: Eotaxin, basic fibroblast growth factor (FGFb), fibronectin, hepatocyte growth factor (HGF), interleukine (IL)-8, IL-12p40, IL-17, IL-23, monocyte chemotactic protein (MCP-1), macrophage-derived chemokine (MDC), myeloperoxidase (MPO), matrix metalloproteinase (MMP)-8, MMP-9, active plasminogen activating inhibitor 1 (PAI-1), pulmonary activation regulated chemokine (PARC), placental growth factor (PlGF), protein-C, receptor for advanced glycation end products (RAGE), regulated on activation normal T cells expressed and secreted (RANTES), surfactant protein-C (SP-C), transforming growth factor-ß1 (TGF-ß1), tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue factor, thymic stromal lymphopoietin (TSLP), and vascular endothelial growth factor (VEGF). RESULTS: All patients suffered from decreased pulmonary function and abnormal BAL cell differential compared with control. Protein levels were increased in both IPF and HP for MMP-8 (P = 0.022), MMP-9 (P = 0.0020), MCP-1 (P = 0.0006), MDC (P = 0.0048), IL-8 (P = 0.013), MPO (P = 0.019), and protein-C (P = 0.0087), whereas VEGF was decreased (P = 0.0003) compared with control. HGF was upregulated in HP (P = 0.0089) and active PAI-1 was upregulated (P = 0.019) in IPF compared with control. Differences in expression between IPF and HP were observed for IL-12p40 (P = 0.0093) and TGF-ß1 (P = 0.0045). CONCLUSIONS: Using BAL, we demonstrated not only expected similarities but also important differences in both disorders, many related to the innate immunity. These findings provide new clues for further research in both disorders.