Donor age over 55 is associated with worse outcome in lung transplant recipients with idiopathic pulmonary fibrosis.

BACKGROUND: Lung transplantation (LTx) remains the only efficient treatment for selected patients with end-stage pulmonary disease. The age limit for the acceptance of donor organs in LTx is still a matter of debate. We here analyze the impact of donor organ age and the underlying pulmonary disease on short- and long-term outcome and survival after LTx. METHODS: Donor and recipient characteristics of LTx recipients at our institution between 03/2003 and 12/2021 were analyzed. Statistical analysis was performed using SPSS and GraphPad software. RESULTS: In 230 patients analyzed, donor age ≥ 55 years was associated with a higher incidence of severe primary graft dysfunction (PGD2/3) (46% vs. 31%, p = 0.03) and reduced long-term survival after LTx (1-, 5- and 10-year survival: 75%, 54%, 37% vs. 84%, 76%, 69%, p = 0.006). Notably, this was only significant in recipients with idiopathic pulmonary fibrosis (IPF) (PGD: 65%, vs. 37%, p = 0.016; 1-, 5-, and 10-year survival: 62%, 38%, 16% vs. 80%, 76%, 70%, p = 0.0002 respectively). In patients with chronic obstructive pulmonary disease (COPD), donor age had no impact on the incidence of PGD2/3 or survival (21% vs. 27%, p = 0.60 and 68% vs. 72%; p = 0.90 respectively). Moreover, we found higher Torque-teno virus (TTV)-DNA levels after LTx in patients with IPF compared to COPD (X2 = 4.57, p = 0.033). Donor age ≥ 55 is an independent risk factor for reduced survival in the whole cohort and patients with IPF specifically. CONCLUSIONS: In recipients with IPF, donor organ age ≥ 55 years was associated with a higher incidence of PGD2/3 and reduced survival after LTx. The underlying pulmonary disease may thus be a relevant factor for postoperative graft function and survival. TRIAL REGISTRATION NUMBER DKRS: DRKS00033312.

Murine orthotopic lung transplant models: A comprehensive overview of genetic mismatch degrees and histopathological insights into chronic lung allograft dysfunction.

Currently, lung transplantation outcome remains inferior compared to other solid organ transplantations. A major cause for limited survival after lung transplantation is chronic lung allograft dysfunction. Numerous animal models have been developed to investigate chronic lung allograft dysfunction to discover adequate treatments. The murine orthotopic lung transplant model has been further optimized over the last years. However, different degrees of genetic mismatch between donor and recipient mice have been used, applying a single, minor, moderate, and major genetic mismatch. This review aims to reassess the existing murine mismatch models and provide a comprehensive overview, with a specific focus on their eventual histopathological presentation. This will be crucial to leverage this model and tailor it according to specific research needs.

Increased Donor Organ Size and Age is Associated with Reduced Survival in Female Lung Transplant Recipients.

BACKGROUND: Organ selection in lung transplantation (LTx) is still controversial. We here analyze the impact of mismatches in size, age, and gender on early and long-term outcome after LTx. METHODS: Retrospective analysis of donor and recipient characteristics of patients who underwent double LTx between March 2003 and December 2021. Statistical analysis was performed using SPSS and GraphPad software. RESULTS: Two hundred three patients were included (94 women and 109 men). In the whole cohort, oversizing donor organs 10% to 20% compared to the recipients' predicted total lung capacity led to a decreased incidence of severe Primary Graft Dysfunction grades 2 and 3 (2/3; 15% vs 41%, P = .03), and further oversizing > 20% was associated with reduced long-term survival (hazard ratio, 2.33, P = .011). Analyzing donor and recipient age, we found that increased donor age correlated with reduced long-term survival (P = .013). In this cohort, female recipients received older organs (median 57 vs 46 years, P = .0003) and had a higher incidence of > 20% oversizing (13% vs 4%, P = .019) of donor lungs, which resulted in a significantly reduced long-term survival (P = .02) compared with male recipients. Median Lung Allocation Scores were similar in both groups. CONCLUSION: Mismatch of donor age and size can be important for organ function and survival in LTx recipients. Particularly female recipients seem to have a higher risk for unfavorable long-term outcome when transplanting organs of increased size and age. Multicenter studies are warranted to further address this question. TRIAL REGISTRATION NUMBER: (DKRS): 00033312.

Protocol for orthotopic single-lung transplantation in mice as a tool for lung metastasis studies.

The transplantation model provides the opportunity to assess the relevance of a molecule of interest for tumor cell extravasation by using a respective genetically modified donor animal. Here, we present a protocol for orthotopic single-lung transplantation in mice as a tool for lung metastasis studies. We describe steps for animal preparation, lung transplantation, and tumor cell injection. We then detail procedures for the direct comparison of tumor cell spreading between the genetically modified left lung and the naive right lung parenchyma. For complete details on the use and execution of this protocol, please refer to Giannou et al. (2023).1.

Endoscopic Lung Volume Reduction Prior to Lung Transplantation Does Not Increase Postoperative Pulmonary Complications.

INTRODUCTION: Lung transplantation (LTx) remains the only therapeutic option for selected patients with end-stage lung disease. In comparison to surgical lung volume reduction, few data exist on the risks and benefits of pretransplant endoscopic lung volume reduction (eLVR). Here, we investigate the risk of postoperative pulmonary complications (PPCs) after LTx in patients with emphysematous lung disease bridged with eLVR until transplantation. METHODS: Eighty-two patients with emphysematous lung disease who underwent double-LTx (DLTx) were included and retrospectively evaluated. Statistical analysis was performed using SPSS and GraphPad Prism software. RESULTS: 28/82 patients underwent eLVR prior to DLTx. eLVR patients spent comparable time on the waitlist; however, they were older at the time of DLTx (median 60 vs. 58 years, p = 0.02). Both groups showed comparable 90-day (92%) and long-term survival (eLVR 1-/5-/10-year survival: 92/88/77%, vs. control: 89/77/67%, p = 0.5). The odds for PPCs were similar in patients with and without eLVR (OR 0.7; 95% CI: 0.3-1.7), as well as major perioperative surgical and cardiovascular complications. In the entire cohort, we found ≥1 PPC to be a risk factor for death within 90 days (OR 9.7, 95% CI: 1.3-110). Among the PPCs, pneumonia (HR 4.6 95% CI: 1.1-14.9, p = 0.02) and ARDS (HR 11.2 95% CI: 1.6-229.2, p = 0.04) were identified as independent risk factors for reduced long-term survival. CONCLUSIONS: eLVR does not increase the risk for PPCs, surgical complications, or reduced survival after LTx in patients with emphysematous lung disease and can serve as a bridge to LTx.

Biased IL-2 signals induce Foxp3-rich pulmonary lymphoid structures and facilitate long-term lung allograft acceptance in mice.

Transplantation of solid organs can be life-saving in patients with end-stage organ failure, however, graft rejection remains a major challenge. In this study, by pre-conditioning with interleukin-2 (IL-2)/anti-IL-2 antibody complex treatment biased toward IL-2 receptor α, we achieved acceptance of fully mismatched orthotopic lung allografts that remained morphologically and functionally intact for more than 90 days in immunocompetent mice. These allografts are tolerated by the actions of forkhead box p3 (Foxp3)+ regulatory T (Treg) cells that home to the lung allografts. Although counts of circulating Treg cells rapidly return to baseline following cessation of IL-2 treatment, Foxp3+ Treg cells persist in peribronchial and peribronchiolar areas of the grafted lungs, forming organized clusters reminiscent of inducible tertiary lymphoid structures (iTLS). These iTLS in lung allografts are made of Foxp3+ Treg cells, conventional T cells, and B cells, as evidenced by using microscopy-based distribution and neighborhood analyses. Foxp3-transgenic mice with inducible and selective deletion of Foxp3+ cells are unable to form iTLS in lung allografts, and these mice acutely reject lung allografts. Collectively, we report that short-term, high-intensity and biased IL-2 pre-conditioning facilitates acceptance of vascularized and ventilated lung allografts without the need of immunosuppression, by inducing Foxp3-controlled iTLS formation within allografts.

Tissue resident iNKT17 cells facilitate cancer cell extravasation in liver metastasis via interleukin-22.

During metastasis, cancer cells invade, intravasate, enter the circulation, extravasate, and colonize target organs. Here, we examined the role of interleukin (IL)-22 in metastasis. Immune cell-derived IL-22 acts on epithelial tissues, promoting regeneration and healing upon tissue damage, but it is also associated with malignancy. Il22-deficient mice and mice treated with an IL-22 antibody were protected from colon-cancer-derived liver and lung metastasis formation, while overexpression of IL-22 promoted metastasis. Mechanistically, IL-22 acted on endothelial cells, promoting endothelial permeability and cancer cell transmigration via induction of endothelial aminopeptidase N. Multi-parameter flow cytometry and single-cell sequencing of immune cells isolated during cancer cell extravasation into the liver revealed iNKT17 cells as source of IL-22. iNKT-cell-deficient mice exhibited reduced metastases, which was reversed by injection of wild type, but not Il22-deficient, invariant natural killer T (iNKT) cells. IL-22-producing iNKT cells promoting metastasis were tissue resident, as demonstrated by parabiosis. Thus, IL-22 may present a therapeutic target for prevention of metastasis.

Independent risk factors for an increased incidence of thromboembolism after lung transplantation.

BACKGROUND: Thromboembolism (TE) after lung transplantation (LTX) is associated with increased morbidity and mortality. The aim of this study is to analyze the incidence and outcome of venous and arterial thromboembolic complications and to identify independent risk factors. PATIENTS AND METHODS: We retrospectively analyzed the medical records of 221 patients who underwent LTX at our institution between 2002 and 2021. Statistical analysis was performed using SPSS and GraphPad software. RESULTS: 74 LTX recipients (33%) developed TE. The 30-days incidence and 12-months incidence were 12% and 23%, respectively. Nearly half of the patients (48%) developed pulmonary embolism, 10% ischemic stroke. Arterial hypertension (p = 0.006), a body mass index (BMI) > 30 (p = 0.006) and diabetes mellitus (p = 0.041) were independent predictors for TE. Moreover, a BMI of > 25 at the time of transplantation was associated with an increased risk for TE (43% vs. 32%, p = 0.035). At the time of LTX, 65% of the patients were older than 55 years. An age > 55 years also correlated with the incidence of TE (p = 0.037) and these patients had reduced overall post-transplant survival when the event occurred within the first postoperative year (59% vs. 72%, p = 0.028). CONCLUSIONS: The incidence of TE after LTX is high, especially in lung transplant recipients with a BMI > 25 and an age > 55 years as well as cardiovascular risk factors closely associated with the metabolic syndrome. As these patients comprise a growing recipient fraction, intensified research should focus on the risks and benefits of regular screening or a prolonged TE prophylaxis in these patients. Trial registration number DKRS: 00021501.

Targeting cluster of differentiation 26 / dipeptidyl peptidase 4 (CD26/DPP4) in organ fibrosis.

Cluster of differentiation 26 (CD26)/dipeptidyl peptidase 4 (DPP4) is an exopeptidase that is expressed as a transmembrane protein in many organs but also present in a circulating soluble form. Beyond its enzymatic and costimulatory activity, CD26/DPP4 is involved in the pathogenesis of chronic fibrotic diseases across many organ types, such as liver cirrhosis, kidney fibrosis and lung fibrosis. Organ fibrosis is associated with a high morbidity and mortality, and there are no causative therapies that can effectively attenuate the progress of the disease. Growing evidence suggests that inhibiting CD26/DPP4 can modulate the profibrotic tissue microenvironment and thus reduce fibrotic changes within affected organs. This review summarizes the role of CD26/DPP4 in fibroproliferative disorders and highlights new opportunities for an antifibrotic treatment by CD26/DPP4 inhibition. As a major advantage, CD26/DPP4 inhibitors have been in safe and routine clinical use in type 2 diabetes for many years and thus qualify for repurposing to repurpose as a promising therapeutic against fibrosis. LINKED ARTICLES: This article is part of a themed issue on Translational Advances in Fibrosis as a Therapeutic Target. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.22/issuetoc.

High-Affinity Cu(I)-Chelator with Potential Anti-Tumorigenic Action-A Proof-of-Principle Experimental Study of Human H460 Tumors in the CAM Assay.

Human lung cancer ranks among the most frequently treated cancers worldwide. As copper appears critical to angiogenesis and tumor growth, selective removal of copper represents a promising strategy to restrict tumor growth. To this end, we explored the activity of the novel high-affinity membrane-permeant Cu(I) chelator PSP-2 featuring a low-zeptomolar dissociation constant. Using H460 human lung cancer cells, we generated small tumors on the chorioallantoic membrane of the chicken embryo (CAM assay) and studied the effects of topical PSP-2 application on their weight and vessel density after one week. We observed a significant angiosuppression along with a marked decrease in tumor weight under PSP-2 application compared to controls. Moreover, PSP-2 exposure resulted in lower ki67+ cell numbers at a low dose but increased cell count under a high dose. Moreover, HIF-1α+ cells were significantly reduced with low-dose PSP-2 exposure compared to high-dose and control. The total copper content was considerably lower in PSP-2 treated tumors, although statistically not significant. Altogether, PSP-2 shows promising potential as an anti-cancer drug. Nevertheless, further animal experiments and application to different tumor types are mandatory to support these initial findings, paving the way toward clinical trials.

Probing Vasoreactivity and Hypoxic Phenotype in Different Tumor Grafts Grown on the Chorioallantoic Membrane of the Chicken Embryo In Ovo Using MRI.

Tumor grafts grown on the chorioallantoic membrane (CAM) of chicken embryos represent a transition between cell culture and mammalian in vivo models. Magnetic resonance imaging (MRI) started to harness this potential. Functional gas challenge is feasible on the CAM. Using quantitative T1 and T2* mapping, we characterized the response of MC-38 colon, A549, and H460 adeno-carcinoma cell grafts to hypercapnic (HC) and hypercapnic-hyperoxic (HCHO) gas challenges, pertaining to the grafts' vascular and oxygenation phenotypes. MR imaging revealed that larger T1 and T2* were located in the center of H460 and MC-38 tumors. Quantitative analysis showed a significant reduction in T1 and a significant increase in T2* in response to HCHO for A549 grafts, while H460 and MC-38 tumors did not respond to either gas challenge. Different tumor grafts respond differentially to HC and HCHO conditions. A549 tumor grafts, with higher vessel density and smaller tumor diameter compared with H460 and MC-38 grafts, had a significant response in T1 for HCHO and T2* increased slightly during HC and significantly under HCHO, consistent with a normoxic phenotype and functional vasoreactivity. Therefore, gas challenges enable differential characterization of tumor grafts with respect to their vascular and oxygenation status.

Hybrid nanocomposite as a chest wall graft with improved vascularization by copper oxide nanoparticles.

Chest wall repair can be necessary after tumor resection or chest injury. In order to cover or replace chest wall defects, autologous tissue or different synthetic materials are commonly used, among them the semi-rigid gold standard Gore-Tex® and prolene meshes. Synthetic tissues include composite materials with an organic and an inorganic component. On the basis of previously reported hybrid nanocomposite poly-lactic-co-glycolic acid amorphous calcium phosphate nanocomposite (PLGA/aCaP), a CuO component was incorporated to yield (60%/35%/5%). This graft was tested in vitro by seeding with murine adipose-derived stem cells (ASCs) for cell attachment and migration. The graft was compared to PLGA/CaCO3 and PLGA/hydroxyapatite, each providing the inorganic phase as nanoparticles. Further characterization of the graft was performed using scanning electron microscopy. Furthermore, PLGA/aCaP/CuO was implanted as a chest wall graft in mice. After 4 weeks, total cell density, graft integration, extracellular matrix components such as fibronectin and collagen I, the cellular inflammatory response (macrophages, F4/80 and lymphocytes, CD3) as well as vascularization (CD31) were quantitatively assessed. The nanocomposite PLGA/aCaP/CuO showed a good cell attachment and cells migrated well into the pores of the electrospun meshes. Cell densities did not differ between PLGA/aCaP/CuO and PLGA/CaCO3 or PLGA/hydroxyapatite, respectively. When applied as a chest wall graft, adequate stability for suturing into the thoracic wall could be achieved. Four weeks post-implantation, there was an excellent tissue integration without relevant fibrotic changes and a predominating collagen I matrix deposition within the graft. Slightly increased inflammation, reflected by increased infiltration of macrophages could be observed. Vascularization of the graft was significantly enhanced when compared with PLGA/aCaP (no CuO). We conclude that the hybrid nanocomposite PLGA/aCaP/CuO is a viable option to be used as a chest wall graft. Surgical implantation of the material is feasible and provides stability and enough flexibility. Proper tissue integration and an excellent vascularization are characteristics of this biodegradable material.

B Cell Immunity in Lung Transplant Rejection - Effector Mechanisms and Therapeutic Implications.

Allograft rejection remains the major hurdle in lung transplantation despite modern immunosuppressive treatment. As part of the alloreactive process, B cells are increasingly recognized as modulators of alloimmunity and initiators of a donor-specific humoral response. In chronically rejected lung allografts, B cells contribute to the formation of tertiary lymphoid structures and promote local alloimmune responses. However, B cells are functionally heterogeneous and some B cell subsets may promote alloimmune tolerance. In this review, we describe the current understanding of B-cell-dependent mechanisms in pulmonary allograft rejection and highlight promising future strategies that employ B cell-targeted therapies.

[Congenital Malformations of the Lung - an Overview]. / Angeborene Fehlbildungen der Lunge ­ eine Übersicht.

Congenital pulmonary malformations comprise a heterogenous group of rare developmental diseases. The most common malformations are the tracheal bronchus, bronchial atresia, bronchogenic cyst, pulmonary sequestration, congenital lobar emphysema, and congenital pulmonary airway malformation. Due to their space-consuming effect, patients suffer early postnatal respiratory distress which generally requires immediate surgical resection. The management of asymptomatic lesions remains subject to debate, but early elective surgery is generally recommended to avoid respiratory and infectious complications at a later time point.We here provide a comprehensive review in which we present causes, clinical presentation and therapeutic options for the most prominent congenital malformations of the airways and lung parenchyma.

Balancing the Risk of Adverse Events against the Efficacy of Immunotherapy in Advanced Thymic Epithelial Tumors.

Thymic epithelial tumors (TETs) are rare thoracic malignancies with a favorable prognosis when complete surgical resection can be achieved. Therapeutic options for advanced, irresectable, or recurrent disease are limited and currently, a therapeutic standard treatment beyond platinum-based chemotherapy is undefined. Immune checkpoint inhibitors are effective against TETs, however their use is associated with a serious risk of immune-mediated toxicity. In this article, we highlight new insights regarding markers of predictive value for both treatment efficacy and risk of adverse effects in immune checkpoint inhibitor treatment for thymic epithelial tumors.

CD26 as a target against fibrous formation in chronic airway rejection lesions.

AIMS: Chronic lung allograft dysfunction (CLAD) after lung transplantation (Tx) is the clinical result of chronic airway rejection lesions (CARL), histomorphologically described as either obliterative remodeling of small airways or alveolar fibroelastosis, or as a combination of both. We here investigated the CD26-inhibitory effect on CD26-expressing CARL. MAIN METHODS: CARL were induced by BALB/c â†’ C57BL/6 mouse Tx under mild immunosuppression. CARL-related pro-fibrotic mediators were determined by RT-qPCR and western blotting (WB), EMT and ERK markers by WB. CD26 co-expression by immunofluorescence. CD26 was inhibited by Vildagliptin, gene depleted by CD26-/- mice. Primary lung fibroblasts were employed for ex vivo analyses. Samples from lung transplant patients with CLAD were analyzed by immunohistochemistry. KEY FINDINGS: CARL revealed a significantly higher expression of profibrotic proteins vs. normal lungs (p < 0.05). CD26 and EMT co-expressed in CARL with significantly higher Vimentin, Slug, Hif-1α, α-SMA expression vs. normal lungs (p < 0.05). Vildagliptin decreased the expression of α-SMA and N-cadherin in wild type (WT) lung fibroblasts (p < 0.05). Primary lung fibroblasts from WT and CD26-/- mice treated with TGF-ß1, IFN-γ, and FGF showed a reduction of EMT protein expression, proliferation, and reduced activation of ERK in CD26-/- mice vs. WT mice. CD26-positive cells were found in patient samples with CLAD in areas of loose fibrosis, but not in areas of dense fibrosis. SIGNIFICANCE: CD26 is expressed in CARL-developing lung transplants and CD26-inhibition downregulates fibrosis-forming mediators and fibroblast proliferation. CD26 thus qualifies as a target to attenuate the development of CARL mainly via modulation of ERK and the EMT pathway.

Psychometric properties of the updated EORTC module for assessing quality of life in patients with lung cancer (QLQ-LC29): an international, observational field study.

BACKGROUND: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Lung Cancer 13 (QLQ-LC13) assesses quality of life (QOL) in patients with lung cancer and was the first EORTC module developed for use in international clinical trials. Since its publication in 1994, major treatment advances with possible effects on QOL have occurred. These changes called for an update of the module and its international psychometric validation. We aimed to investigate the scale structure and psychometric properties of the updated lung cancer module, QLQ-LC29, in patients with lung cancer. METHODS: This international, observational field study was done in 19 hospitals across 12 countries. Patients aged older than 18 years with a confirmed diagnosis of lung cancer and no other previous primary tumour, and who were mentally fit with sufficient language skills to understand and complete the questionnaire were included. Patients were asked during a hospital visit to fill in the paper versions of the core questionnaire EORTC QLQ-C30 plus QLQ-LC29, and investigators selected half of these patients to complete the questionnaire again 2-4 weeks later. Our primary aim was to assess the scale structure and psychometric properties of EORTC QLQ-LC29. We analysed scale structure using confirmatory factor analysis; reliability using Cronbach's α value (internal consistency) and intra-class coefficient (test-retest reliability); sensitivity using independent t tests stratified by Karnofsky performance status; and responsiveness to change over time by ANOVA. This study is registered with ClinicalTrials.gov, NCT02745691. FINDINGS: Between April 12, 2016, and Sept 26, 2018, 523 patients with a confirmed diagnosis of either non-small-cell lung cancer (n=442) or small-cell lung cancer (n=81) were recruited. Confirmatory factor analysis provided a solution composed of five multi-item scales (coughing, shortness of breath, fear of progression, hair problems, and surgery-related symptoms) plus 15 single symptom or side-effect items: χ2=370·233, root mean square error of approximation=0·075, and comparative-fit index=0·901. Cronbach's α for internal consistencies of all multi-item scales were above the threshold of 0·70. Intra-class coefficients for test-retest reliabilities ranged between 0·82 and 0·97. Three (shortness of breath, fear of progression, and hair problems) of the five multi-item scales showed responsiveness to change over time (p values <0·05), as did nine of 15 single symptom items. Four (coughing, shortness of breath, fear of progression, and surgery-related symptoms) of the five multi-item scales and ten of the 15 single symptom items were sensitive to known group differences (ie, lower vs higher Karnofsky performance status). INTERPRETATION: Results determined the psychometric properties of the updated lung cancer module, which is ready for use in international clinical studies. FUNDING: EORTC Quality of Life Group.

Novel Strategies for Endothelial Preservation in Lung Transplant Ischemia-Reperfusion Injury.

Lung ischemia reperfusion (IR) injury inevitably occurs during lung transplantation. The pulmonary endothelium is the primary target of IR injury that potentially results in severe pulmonary dysfunction. Over the last decades, various molecules, receptors, and signaling pathways were identified in order to develop treatment strategies for the preservation of the pulmonary endothelium against IR injury. We here review the latest and most promising therapeutic strategies for the protection of the endothelium against IR injury. These include the stabilization of the endothelial glycocalyx, inhibition of endothelial autophagy, inhibition of adhesion molecules, targeting of angiotensin-converting enzyme, and traditional viral and novel non-viral gene transfer approaches. Though some of these strategies proved to be promising in experimental studies, very few of these treatment concepts made the transfer into clinical application. This dilemma underscores the need for more experimental evidence for the translation into clinical studies to invent therapeutic concepts against IR injury-mediated endothelial damage.