Chronic Allograft Research Articles

Cell death in lung transplantation. The roles of apoptosis, necroptois, and pyroptosis

Abstract Objective For patients with end stage lung disease, lung transplantation (Ltx) is the unique treatment option. Nevertheless, a large number of lung allografts fail, because of acute or chronic rejection. Innate immune responses following Ltx play a critical role in the development of primary graft dysfunction, and ultimately promote the development of chronic lung allograft dysfunction, leading to increased mortality after lung transplantation. Here, we focus on the mechanisms responsible for disruption of the cells membranes integrity, resulting in the release of Damage Associated Molecular Patterns (DAMPs) and activation of cell death pathways triggering cell injury in lungs with different preservation status. Methods Rat lungs were exposed to cold ischemia (CI group, n=9) or warm ischemia (WI group, n=9). In CI group, after Perfadex flushing, and hypothermic preservation (4 h) left lung was transplanted. In WI group, after 1 h of in situ WI, flashing and 3 h cold preservation the left lung was transplanted. Lung mechanics were determined during reperfusion. Recipients were sacrificed at 30, 60 and 120 min after Ltx. Bronchoalveolar lavage (BAL) was performed on the grafts to measure markers of cellular injury, and cytokines. Cell death markers were determined in graft tissue. Biological samples were kept at -80°C for additional analysis. Results Compared to CI, WI group displayed significantly decreased graft function associated with increased activation of pyroptotic cell death (NLRP3, caspase1, IL-1β) pathway, whereas apoptotic (caspas3 and caspase7) and necroptotic (RIP1, RIP3, MLKL) cell death pathways activation were similar in both groups. WI group showed more important cellular damage with DAMPs release (LDH, sRAGE, HMGB) and inflammation (CXCL1, IL1-β, IL-33). Conclusion Our results suggest that pyroptosis could play a critical role in the development of early graft dysfunction in lungs subjected to warm ischemia. Inhibition of pyroptotic pathway could be a strategy to improve damaged donor lungs.

PD-0176 Efficacy and safety of total lymphoid irradiation in chronic lung allograft dysfunction phenotypes

PD-0176 Efficacy and safety of total lymphoid irradiation in chronic lung allograft dysfunction phenotypes

Survival After Lung Transplantation for Chronic Hypersensitivity Pneumonitis: Results From a Large International Cohort Study.

Repeated exposure to antigens via inhalation is the primary cause of hypersensitivity pneumonitis, a form of interstitial pneumonia. The chronic form of hypersensitivity pneumonitis leads to progressive loss of respiratory function; lung transplantation is the only therapeutic option for chronically ill patients. The ESTS Lung Transplantation Working Group conducted a retrospective multicentred cohort study to increase the body of knowledge available on this rare indication for lung transplantation. Data were collected for every patient who underwent lung transplant for hypersensitivity pneumonitis in participating centres between December 1996 and October 2019. Primary outcome was overall survival; secondary outcome was freedom from chronic lung allograft dysfunction. A total of 114 patients were enrolled from 9 centres. Almost 90% of patients were diagnosed with hypersensitivity pneumonitis before transplantation, yet the antigen responsible for the infection was identified in only 25% of cases. Eighty per cent of the recipients received induction therapy. Survival at 1, 3, and 5years was 85%, 75%, and 70%, respectively. 85% of the patients who survived 90days after transplantation were free from chronic lung allograft dysfunction after 3years. The given study presents a large cohort of HP patients who underwent lung transplants. Overall survival rate is higher in transplanted hypersensitivity pneumonitis patients than in those suffering from any other interstitial lung diseases. Hypersensitivity pneumonitis patients are good candidates for lung transplantation.

Markers of rejection of a lung allograft: state of the art.

Chronic lung allograft dysfunction (CLAD) affects approximately 50% of all lung transplant recipients by 5 post-operative years and is the leading cause of death in lung transplant recipients. Early CLAD diagnosis or ideally prediction of CLAD is essential to enable early intervention before significant lung injury occurs. New technologies have emerged to facilitate biomarker discovery, including epigenetic modification and single-cell RNA sequencing. This review examines new and existing technologies for biomarker discovery and the current state of research on biomarkers for identifying lung transplant rejection.

POS-822 SODIUM-GLUCOSE CO-TRANSPORTER 2 INHIBITORS (SGLT2i); SHORT-TERM OUTCOME IN DIABETIC KIDNEY TRANSPLANT RECIPIENTS

The recent positive data on the use of sodium glucose co-transporter inhibitors (SGLT2i) in the last few years, begged the question of whether their positive outcomes can be seen in kidney transplant recipients, where we are faced with even more pronounced cardiovascular risk factors than the general population , as we got better in improving graft and patients survival in the short term , we are still falling behind in improving long term patients and graft survival with the unsolved problem of losing patients with a functioning graft from cardiovascular disease and its complication or losing the graft from chronic allograft changes due to difficult to control metabolic aspects namely Obesity , diabetes and blood pressure .

Noninvasive Assessment of Interstitial Fibrosis and Tubular Atrophy in Renal Transplant by Combining Point-Shear Wave Elastography and Estimated Glomerular Filtration Rate.

The purpose of this study was to evaluate the feasibility of the combination of point-shear wave elastography (p-SWE) and estimated glomerular filtration rate (eGFR) for assessing different stages of interstitial fibrosis and tubular atrophy (IF/TA) in patients with chronic renal allograft dysfunction (CAD). From September 2020 to August 2021, 47 patients who underwent renal biopsy and p-SWE examinations were consecutively enrolled in this study. The areas under the receiver operating characteristic curves (AUCs) were calculated to evaluate overall accuracy and to identify the optimal cutoff values for different IF/TA stages. A total of 43 patients were enrolled in this study. The renal cortical stiffness and eGFR showed a significant difference between IF/TA Grade 0–1 and Grade 2–3 (p < 0.001). Additionally, renal stiffness and eGFR were independent predictors for moderate-to-severe IF/TA (Grade ≥ 2) according to multiple logistic regression analysis. The combination of p-SWE and eGFR, with an optimal cutoff value of −1.63, was superior to eGFR alone in assessing moderate-to-severe interstitial fibrosis (AUC, 0.86 vs. 0.72, p = 0.02) or tubular atrophy (AUC, 0.88 vs. 0.74, p = 0.02). There was no difference between p-SWE and eGFR in assessing moderate-to-severe IF/TA (AUC, 0.85 vs. 0.79, p = 0.61). Therefore, combining p-SWE and eGFR is worthy of clinical popularization and application.

Single Nucleotide Polymorphisms of IL-33 Gene Correlated with Renal Allograft Fibrosis in Kidney Transplant Recipients.

Background Nowadays, renal allograft survival is confined by the development of allograft fibrosis. Previous studies have reported interleukin-33 (IL-33) upregulated significantly in patients with chronic renal allograft dysfunction, and it could induce renal tubular epithelial to mesenchymal transition (EMT), which eventually contributed to renal allograft fibrosis. Our study intended to detect the underlying association between single nucleotide polymorphisms (SNPs) of IL-33 gene and renal allograft fibrosis in kidney transplant recipients. Methods We collected blood samples from 200 renal transplant recipients for the identification of SNPs and transplanted kidney tissue samples for identifying differentially expressed genes (DEGs). Intersection of SNP-related genes and DEGs was conducted for further analysis. Relationships between these SNPs and renal allograft fibrosis were evaluated by the inheritance models. Immunohistochemical (IHC) staining and western blotting (WB) were used to detect the expression of IL-33 and the markers of EMT in human kidney tissues obtained from control and chronic renal allograft dysfunction (CAD) patients. In vitro, we detected the progressions of EMT-related markers and the levels of MAPK signaling pathway mediators after transfecting IL-33 mutant plasmids in HK2 cells. Results Three intersected genes including IL-33 genes were significantly expressed. IL-33 expression was validated in kidney tissues by IHC and WB. Thirty-nine IL-33-related SNPs were identified in targeted sequencing, in which 26 tagger SNPs were found by linkage disequilibrium analysis for further analysis. General linear models indicated sirolimus administration significantly influenced renal allograft fibrosis (P < 0.05), adjustment of which was conducted in the following analysis. By multiple inheritance model analyses, SNP rs10975519 of IL-33 gene was found closely related to renal allograft fibrosis (P < 0.005). Furthermore, HK2 cells transfected with mutated plasmid of rs10975519 showed stronger mobility and migration ability. Moreover, IL-33 mutant plasmids could promote the IL-33-induced EMT through the sustained activation of p38 MAPK signaling pathway in HK2 cells. Conclusion In our study, rs10975519 on the IL-33 gene was found to be statistically associated with the development of renal allograft fibrosis in kidney transplant recipients. This process may be related to the IL-33-induced EMT and sustained activation of p38 MAPK signaling pathway.

Chronic lung allograft dysfunction.

Lung transplantation remains the only cure for selected patients with advanced irreversible lung diseases. More than 4000 lung transplants are performed worldwide annually. In the last two decades, significant advances have been made in this arena, the most impactful being a modest but improved survival of the recipients. Unfortunately majority of recipients still succumb to chronic lung allograft dysfunction (CLAD), and it remains the most common cause of death after the first year of transplantation. Below is a concise review of the current definition of CLAD, including the various phenotypes, anda brief discussion of the tools available for itsdiagnosis and management.

Effect of preoperative long-term use of corticosteroids on the development of post-transplant lymphoproliferative disorders after lung transplantation: a single-center experience in Japan.

Post-transplant lymphoproliferative disorder (PTLD) is a major complication of lung transplantation (LTx). However, few studies on PTLD in Asian populations have been reported. We explored the characteristics of Japanese PTLD cases after LTx. We retrospectively reviewed 195 cases of LTx at our institute. We summarized the clinical experiences of 7 PTLD cases and analyzed the patient characteristics and survival outcomes of patients with (n = 7) and without (n = 188) PTLD. All PTLD patients were taking corticosteroids preoperatively (p = 0.0030), and the duration of preoperative corticosteroid therapy was significantly longer in the PTLD group (p = 0.0064) than in the non-PTLD group. The overall survival after LTx was significantly worse in the PTLD group (p = 0.027) than in the non-PLTD group. Among the three patients who died within 1year after the PTLD onset, two died of opportunistic infections without residual PTLD lesions. Chronic lung allograft dysfunction (CLAD) or bronchiolitis obliterans at an autopsy were diagnosed after PTLD treatment in four cases. Long-term preoperative corticosteroid therapy may be a risk factor for PTLD after LTx. Opportunistic infections are lethal complications of PTLD, regardless of the effectiveness of PTLD treatment. CLAD occurs at a high rate after PTLD treatment, and close monitoring is required.

Respiratory Viruses in Solid Organ Transplant Recipients.

Solid organ transplantation is often lifesaving, but does carry an increased risk of infection. Respiratory viral infections are one of the most prevalent infections, and are a cause of significant morbidity and mortality, especially among lung transplant recipients. There is also data to suggest an association with acute rejection and chronic lung allograft dysfunction in lung transplant recipients. Respiratory viral infections can appear at any time post-transplant and are usually acquired in the community. All respiratory viral infections share similar clinical manifestations and are all currently diagnosed using nucleic acid testing. Influenza has good treatment options and prevention strategies, although these are hampered by resistance to neuraminidase inhibitors and lower vaccine immunogenicity in the transplant population. Other respiratory viruses, unfortunately, have limited treatments and preventive methods. This review summarizes the epidemiology, clinical manifestations, therapies and preventive measures for clinically significant RNA and DNA respiratory viruses, with the exception of SARS-CoV-2. This area is fast evolving and hopefully the coming decades will bring us new antivirals, immunologic treatments and vaccines.

COVID-19 in chronic rejection allograft kidney transplant: a case report

COVID-19 in chronic rejection allograft kidney transplant: a case report

Ex Vivo Lung Perfusion: A Platform for Donor Lung Assessment, Treatment and Recovery

Lung transplantation offers a lifesaving therapy for patients with end-stage lung disease but its availability is presently limited by low organ utilization rates with donor lungs frequently excluded due to unsuitability at assessment. When transplantation does occur, recipients are then vulnerable to primary graft dysfunction (PGD), multitudinous short-term complications, and chronic lung allograft dysfunction. The decision whether to use donor lungs is made rapidly and subjectively with limited information and means many lungs that might have been suitable are lost to the transplant pathway. Compared to static cold storage (SCS), ex vivo lung perfusion (EVLP) offers clinicians unrivalled opportunity for rigorous objective assessment of donor lungs in conditions replicating normal physiology, thus allowing for better informed decision-making in suitability assessments. EVLP additionally offers a platform for the delivery of intravascular or intrabronchial therapies to metabolically active tissue aiming to treat existing lung injuries. In the future, EVLP may be employed to provide a pre-transplant environment optimized to prevent negative outcomes such as primary graft dysfunction (PGD) or rejection post-transplant.

653 LAPAROSCOPIC TOUPET FUNDOPLICATION RARELY INFLUENCES THE DECLINE IN FEV1 SEEN AFTER LUNG TRANSPLANT

Abstract Lung allografts have the shortest survival of any solid organ transplant. The leading cause of chronic lung allograft dysfunction (CLAD) is bronchiolitis obliterans syndrome (BOS). The aetiology of BOS remains poorly understood, with infections, immunosuppression and gastro-oesophageal reflux disease (GORD) amongst the proposed co-factors. A recent systematic review of GORD and BOS examined six retrospective case series with relatively small numbers and conflicting results. Our dataset is the largest cohort reported to date. Methods Retrospective review of a prospectively maintained database containing 149 consecutive lung transplant recipients undergoing laparoscopic Toupet fundoplication. A single expert surgeon (&amp;gt;5000 procedures) with published high-quality long-term outcomes in the non-transplant population did the operations. All were referred with symptoms of GORD and/or positive 24-hour ambulatory pH study. FEV1 was measured at three time points before (6, 3 and 1 month) and after (3, 6 and 12 months) surgery. Data were analysed using random intercept generalised linear (mixed) models to examine changes in FEV1 across time, as well as graphical methods (least squares method for FEV1 trendlines and two-tailed t-test). Results Median age was 56 (IQR 44–66) years; 84/149 were male. 132 had bilateral sequential single lung transplantation. The underlying pathologies were representative—emphysema, cystic fibrosis, interstitial lung disease. 8 patients died within 6 months of fundoplication. Using a linear mixed model there was no significant change in FEV1 across time after surgery compared with the last pre-operative measurement (p = 0.48). A significant reduction in FEV1 was seen in those undergoing fundoplication after CLAD was diagnosed (1.47 L, 95% CI 1.21–1.72, p &amp;lt; 0.001). There was no change in trajectory of FEV1 when trendlines for each patient were analysed (p = 0.777). Conclusion As with any solid organ transplant, lung allografts unfortunately suffer failure with time. Laparoscopic Toupet fundoplication performed in a high-volume centre by an experienced surgeon did not appear to alter this. In particular, once CLAD is diagnosed it seems that the decline in function (FEV1) is accelerated and cannot be salvaged by fundoplication. A minority of patients had their declining FEV1 stabilised or improved by surgery, but it is not yet possible to predict response.

Визначення рівня субпопуляцій лімфоцитів периферичної крові для діагностики хронічної реакції відторгнення ниркових алотрансплантатів

Актуальність. Однією з основних причин втрат ниркових алотрансплантатів (НАТ) у віддалені строки після трансплантації є прогресуюча хронічна дисфункція ниркового алотрансплантата (ХДНА), причиною розвитку якої в 20–60 % випадків є хронічне відторгнення (ХВ). Діагностика причин дисфункції трансплантата базується на морфологічному дослідженні, яке через інвазивність має ряд недоліків. Тому великий інтерес являє пошук неінвазивних методів діагностики стану НАТ, зокрема, дослідження клітинної ланки імунної відповіді. Мета. Дослідження відносної кількості субпопуляцій лімфоцитів периферичної крові та їх співвідношення в реципієнтів у віддаленому періоді після трансплантації нирки, оцінювання інформативності цих показників для діагностики ХВ НАТ. Матеріали та методи. Досліджено рівні субпопуляцій лімфоцитів (Т-клітини, Т-хелпери, Т-цитотоксичні, Т-активовані, T-NK-клітини, В-клітини, NK-клітини) у 43 реципієнтів НАТ залежно від перебігу віддаленого післяопераційного періоду та стану алотрансплантата через 1–9 років після алотрансплантації нирки, які були розподілені згідно з морфологічною верифікацією діагнозу на дві групи. Група 1 — 23 хворі із задовільною функцією НАТ без ознак відторгнення; група 2 — 20 хворих із ХДНА, обумовленою хронічною реакцією відторгнення (ХРВ) за даними пункційної біопсії. До контрольної групи увійшли 23 здорові донори, чиї показники становили референтний коридор. Результати. Дані аналізу показали підвищення середніх рівнів Т-активованих лімфоцитів у групах 1 та 2 щодо контрольної (8,9 ± 2,0; 8,4 ± 2,4; 6,8 ± 2,1 відповідно). Також виявлено зниження середніх показників рівнів T-NK-клітин (2,4 ± 2,0) та В-клітин (9,6 ± 2,0) у групі 2 щодо показників групи 1 (5,6 ± 1,8 та 12,4 ± 2,4 відповідно). Аналіз індексів співвідношення між окремими субпопуляційними одиницями лімфоцитів показав статистично вірогідну значущість різниці між індексом Т-клітини/T-NK-клітини (22,53 vs 46,89 в групах 1 та 2 відповідно; p &lt; 0,05) та індексом Т-активовані/В-клітини (1,14 vs 4,17 в групах 1 та 2 відповідно; p &lt; 0,05). При цьому чутливість індексу Т-клітини/T-NK-клітини становила 70 %, специфічність — 60 %. Чутливість індексу Т-активовані/В-клітини дорівнювала 55 %, специфічність — 50 %. Висновки. Зниження рівня T-NK-клітин ближче до нижнього порогового значення референтного коридора і, відповідно, співвідношення Т-клітини/T-NK-клітини в межах 44,49–49,29 (46,89 ± 2,40) у віддаленому післятрансплантаційному періоді може бути додатковою ознакою ХРВ як причини прогресуючої дисфункції НАТ.

Experience with Alpha-1 Proteinase Replacement Post-Lung Transplantation in Alpha-1 Antitrypsin Deficiency: A Single Center Case Series

Alpha-1 antitrypsin deficiency (AATD) accounts for approximately 5% of lung transplants (LTx) performed annually. No studies have addressed the potential benefit of ongoing alpha-1 proteinase inhibitor (A1-PI) replacement to AATD patients post-LTx. Our primary objective was to assess potential benefits of continually administering A1-PI from pre- to post-transplantation for AATD LTx recipients. A retrospective case series was performed on AATD LTx recipients between 2002 and 2018. Data reviewed included date of A1-PI initiation, pulmonary function tests, and surveillance bronchoscopies. Endpoints included the change of forced expiratory volume in one-second (FEV1), infective episodes, chronic lung allograft dysfunction (CLAD), and acute rejection episodes. Out of the 13 AATD LTx recipients, 6 continually received A1-PI beginning prior to transplant (Group 1), and 7 were re-introduced to Α1-PI a number of years after LTx (Group 2). After two years, Group 1 experienced a median FEV1% predicted decline of 0.0%, and Group 2 experienced a median decline of 15.0%. No differences noted in frequency of infective episodes. One patient in Group 1 developed CLAD about 2.5 years post-LTx, whereas all Group 2 patients developed CLAD at a mean of 5.4 years post-LTx. No Group 1 patients experienced acute lung rejection episodes noted from surveillance bronchoscopies, corresponding data not available for Group 2. We report that the continual use of Α1-PI in AATD LTx recipients is associated with better maintenance and stabilization of lung function and potentially less acute lung rejection episodes early post-LTx. Prospective studies should be performed to confirm possible benefits.

MO919THE INTERPLAY BETWEEN IL-6 AND IL-17 MIGHT PLAY A SIGNIFICANT ROLE IN CHRONIC ANTIBODY MEDIATED REJECTION IN RENAL ALLOGRAFT RECIPIENTS

Abstract Background and Aims Chronic antibody-mediated rejection (CABMR) plays a critical role in kidney allograft loss and consider among one of the most important barriers that is responsible for late term graft loss. Previously we believed that alloreactive T-cell and de-novo DSA responsible for late term graft loss but recent study suggested that not only immune cell, non-immune cells like fibroblast also plays important role in chronic inflammation and allograft rejection via IL-6 amplifier loop (IL-6+IL-17). The interaction between non-immune tissues/cells and the immune system plays a critical role in chronic inflammation and late graft rejection. In chronic inflammation IL-6 enhance the production of acute phase proteins, T cell Subset differentiation, Maturation of Plasma cells, Generation of cellular and humoral immune responses and Control the transition from acute to chronic inflammation by changing the nature of leucocyte infiltration (from neutrophils to monocyte). We sought to see whether IL-6 and IL-17A mediated synergistic activation of inflammation amplifier is operational in CABMR. Method Recruitment of patients according to Banff 2017criteria and biopsy was taken from consented patients and establishment of fibroblast culture from renal biopsy of patients with CABMR. Fibroblast culture from CABMR patients were cultured to purity and pre stimulated with IL-6 (20ng/ µl), IL-17(50ng/ µl), IL-6 plus IL-17 for 24 hours and culture supernatant were collected for IL-6 ELISA to see synergistic activation. Serum IL-6, MCP1 and CCL20 levels of Healthy control (HC), CABMR and Non-CABMR patients and MCP1, CCL20 level in culture supernatant were measured by ELISA. m-RNA expression of IL-6, MCP1, CCL20 and SOCS3 gene were measured by real time PCR (Syber-green method) One-way ANOVA and Non-parametric Student t tests (two-tailed) were used for the statistical analysis of differences between groups. Results In comparison to IL-6 and IL-17 alone these cytokines synergistically induced more IL-6 production from renal fibroblasts. (Fig 1) also, we found that concentrations of effectors of inflammation amplifiers like IL-6, CCL-20 &amp; MCP-1 in sera were significantly higher in CABMR patients compared to Non rejection patients, while their concentration in culture supernatant was higher when fibroblast cell stimulated with IL-6 and IL-17 together as compared either IL-6 or IL-17 alone. (Fig 2) Gene expression analysis of IL-6, MCP1 and CCL20 was significant higher (p&amp;lt;0.001) with synergistic activation of IL-6 and IL-17 as compared to either IL-6 or IL-17 alone, while SOCS3 gene expression was downregulated. (Fig 3) There was significant reduction in IL-6 concentration in culture supernatant with IL-6 and IL-17 inhibitor together (Fig 4) and m-RNA expression of IL-6 and MCP-1 was significantly reduced. (Fig 5) Conclusion CABMR is perpetuated by inflammation amplifier loop or synergistic induction of IL-6 and IL-17. Inhibition of IL-6 with Anti-IL-6 (Tocilizumab) and IL-17 with Anti-IL-17 reduces the tissue injury marker (IL-6, MCP1, CCL20) and allograft rejection.

An Integrated Transcriptomic Approach to Identify Molecular Markers of Calcineurin Inhibitor Nephrotoxicity in Pediatric Kidney Transplant Recipients.

Calcineurin inhibitors are highly efficacious immunosuppressive agents used in pediatric kidney transplantation. However, calcineurin inhibitor nephrotoxicity (CNIT) has been associated with the development of chronic renal allograft dysfunction and decreased graft survival. This study evaluated 37 formalin-fixed paraffin-embedded biopsies from pediatric kidney transplant recipients using gene expression profiling. Normal allograft samples (n = 12) served as negative controls and were compared to biopsies exhibiting CNIT (n = 11). The remaining samples served as positive controls to validate CNIT marker specificity and were characterized by other common causes of graft failure such as acute rejection (n = 7) and interstitial fibrosis/tubular atrophy (n = 7). MiRNA profiles served as the platform for data integration. Oxidative phosphorylation and mitochondrial dysfunction were the top molecular pathways associated with overexpressed genes in CNIT samples. Decreased ATP synthesis was identified as a significant biological function in CNIT, while key toxicology pathways included NRF2-mediated oxidative stress response and increased permeability transition of mitochondria. An integrative analysis demonstrated a panel of 13 significant miRNAs and their 33 CNIT-specific gene targets involved with mitochondrial activity and function. We also identified a candidate panel of miRNAs/genes, which may serve as future molecular markers for CNIT diagnosis as well as potential therapeutic targets.

The Role of Galectins in Chronic Lung Allograft Dysfunction

BackgroundGalectins are proteins that bind β-galactosides such as N-acetyllactosamine present in N-linked and O-linked glycoproteins and that seem to be implicated in inflammatory and immune responses as well as fibrotic mechanisms. This preliminary study investigated serum galectins as clinical biomarkers in lung transplant patients with chronic lung allograft dysfunction (CLAD), phenotype bronchiolitis obliterans syndrome (BOS).Materials and MethodsNineteen lung transplant patients [median age (IQR), 55 (45–62) years; 53% males] were enrolled in the study. Peripheral blood concentrations of galectins-1, 3 and 9 were determined with commercial ELISA kits.ResultsGalectin-1 concentrations were higher in BOS than in stable LTX patients (p = 0.0394). In logistic regression analysis, testing BOS group as dependent variable with Gal-1 and 3 as independent variables, area under the receiver operating characteristics (AUROC) curve was 98.9% (NPV 90% and PPV 88.9%, p = 0.0003). With the stable LTX group as dependent variable and Gal-1, 3 and 9 as independent variables, AUROC was 92.6% (NPV 100% and PPV 90%, p = 0.0023). In stable patients were observed an inverse correlation of Gal-3 with DLCO% and KCO%, and between Gal-9 and KCO%.ConclusionGalectins-1, 3 and 9 are possible clinical biomarkers in lung transplant patients with diagnostic and prognostic meaning. These molecules may be directly implicated in the pathological mechanisms of BOS. The hypothesis that they could be new therapeutic targets in BOS patients is intriguing and also worth exploring.

Lung transplantation for late-onset non-infectious chronic pulmonary complications of allogenic hematopoietic stem cell transplant

BackgroundLate onset non-infectious pulmonary complications (LONIPCs) following allogenic hematopoietic stem cell transplantation (allo-HSCT) confer a significant mortality risk. Lung transplantation (LTx) has the potential to provide survival benefit but the impact of prior allo-HSCT on post-LTx outcomes is not well studied.MethodsThis retrospective, single-centre cohort study assessed the post-LTx outcomes of adults with LONIPCs of allo-HSCT. Outcomes of LTx for LONIPCs were compared to propensity-score matched LTx controls (n = 38, non-HSCT) and recipients of re-LTx (n = 70) for chronic lung allograft dysfunction (CLAD).ResultsNineteen patients underwent DLTx for LONIPCs of allo-HSCT between 2003 and 2019. Post-LTx survival was 50% at 5-years. Survival to 1-year post-LTx was similar to matched controls (p = 0.473). Survival, conditional on 1-year survival, was lower in the allo-HSCT cohort (p = 0.034). An increased risk of death due to infection was identified in the allo-HSCT cohort compared to matched controls (p = 0.003). Compared to re-LTx recipients, the allo-HSCT cohort had superior survival to 1-year post-LTx (p = 0.034) but conditional 1-year survival was similar (p = 0.145).ConclusionThis study identifies an increased risk of post-LTx mortality in recipients with previous allo-HSCT, associated with infection. It supports the hypothesis that allo-HSCT LTx recipients are relatively more immunosuppressed than patients undergoing LTx for other indications. Optimisation of post-LTx immunosuppressive and antimicrobial strategies to account for this finding should be considered.

Potential novel biomarkers for chronic lung allograft dysfunction and azithromycin responsive allograft dysfunction

Chronic Lung Allograft Dysfunction (CLAD), manifesting as Bronchiolitis Obliterans Syndrome (BOS) or Restrictive Allograft Syndrome (RAS), is the main reason for adverse long-term outcome after Lung Transplantation (LTX). Until now, no specific biomarkers exist to differentiate between CLAD phenotypes. Therefore, we sought to find suitable cytokines to distinguish between BOS, RAS and Azithromycin Responsive Allograft Dysfunction (ARAD); and reveal potential similarities or differences to end-stage fibrotic diseases. We observed significantly increased Lipocalin-2 serum concentrations in RAS compared to BOS patients. In addition, in RAS patients immunohistochemistry revealed Lipocalin-2 expression in bronchial epithelium and alveolar walls. Patients with ARAD showed significantly lower Activin-A serum concentrations compared to Stable-LTX and BOS patients. Further, increased serum concentrations of Lipocalin-2 and Activin-A were predictors of worse freedom-from-CLAD in Stable-LTX patients. These biomarkers serve as promising serum biomarkers for CLAD prediction and seem suitable for implementation in clinical practice.