Jana Somers

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 cmH2O < 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.

Prophylactic Azithromycin Therapy After Lung Transplantation: Post hoc Analysis of a Randomized Controlled Trial.

Prophylactic azithromycin treatment has been demonstrated to improve freedom from bronchiolitis obliterans syndrome (BOS) 2 years after lung transplantation (LTx). In the current study, we re‐evaluated the long‐term effects of this prophylactic approach in view of the updated classification system for chronic lung allograft dysfunction (CLAD). A retrospective, intention‐to‐treat analysis of a randomized controlled trial comparing prophylactic treatment with placebo (n = 43) versus azithromycin (n = 40) after LTx was performed. Graft dysfunction (CLAD), graft loss (retransplantation, mortality), evolution of pulmonary function and functional exercise capacity were analyzed 7 years after inclusion of the last study subject. Following LTx, 22/43 (51%) patients of the placebo group and 11/40 (28%) patients of the azithromycin group ever developed CLAD (p = 0.043). CLAD‐free survival was significantly longer in the azithromycin group (p = 0.024). No difference was present in proportion of obstructive versus restrictive CLAD between both groups. Graft loss was similar in both groups: 23/43 (53%) versus 16/40 (40%) patients (p = 0.27). Long‐term pulmonary function and functional exercise capacity were significantly better in the azithromycin group (p < 0.05). Prophylactic azithromycin therapy reduces long‐term CLAD prevalence and improves CLAD‐free survival, pulmonary function, and functional exercise capacity after LTx.

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.

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.

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.

The role of recipient derived interleukin-17A in a murine orthotopic lung transplant model of restrictive chronic lung allograft dysfunction

The single most important cause of late mortality after lung transplantation is chronic lung allograft dysfunction (CLAD). However, the pathological development of CLAD was not as simple as previously presumed and subclassification phenotypes, bronchiolitis obliterans syndrome (BOS) and restrictive CLAD (rCLAD), have been introduced. We want to re-investigate how CLAD manifests in the murine orthotopic lung transplant model and investigate the role of interleukin 17A (IL-17A) within this model. Orthotopic LTx was performed in CB57BL/6, IL-17 WT and IL-17 KO mice. In a first experiment, CB57BL/6 mice receiving an isograft (CB57BL/6) or allograft (BALB/C) were compared. In a second experiment IL-17 WT and IL-17 KO mice (both CB57BL/6 background) received an allograft (BALB/C). Mice received daily immunosuppression with steroids and cyclosporine and were sacrificed 10weeks after transplantation for histopathological analysis by an experienced lung pathologist. After murine orthotopic lung transplantation, the allograft histopathologically presented features of human rCLAD (i.e. overt inflammation, pleural/parenchymal fibrosis and obliterative bronchiolitis). In the IL-17A KO group, less inflammation in the bronchovascular axis (p=0.03) was observed and a non-significant trend towards less bronchovascular fibrosis, pleural/septal inflammation and fibrosis, and parenchymal inflammation and fibrosis when compared to WT mice. The major mismatch orthotopic lung transplant model resembles features of human rCLAD. IL-17A mediated immunity is involved in the inflammatory component, but had little influence on the degree of fibrosis. Further mechanistic and therapeutic studies in this mouse model are needed to fully understand the mechanisms in rCLAD.

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-1β/IL-1Ra, IL-4 and IL-6) and chemokines (CXCL8/IL-8, CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, 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-1β 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.

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.