Lung Transplantation Research Articles

An underrecognized phenotype of pulmonary emphysema with marked pulmonary gas exchange but with mild or moderate airway obstruction

In patients with pulmonary emphysema and mild to moderate airflow limitation, one does not expect the features marked exertional dyspnea and hypoxemia as well as a profound decrease in diffusing capacity of the lung for carbon monoxide (DLCO). Here we describe this phenotype and its prognosis. From our database, we retrospectively selected cases associating emphysema, exertional breathlessness, O2 requirement at least upon exercise, forced expiratory volume in 1 sec (FEV1) ≥ 50% predicted, and DLCO ≤ 50% predicted, without associated combined pulmonary fibrosis and emphysema, right-to-left shunt, or severe pulmonary hypertension. Over a 12-year period, we identified 16 patients with emphysema and the above presentation. At the initial evaluation, the median age was 62 years (interquartile range 53.8–68.9). The median FEV1 and DLCO% predicted and mean pulmonary artery pressure were 86 (65–95)%, 38 (31–41)%, and 20 (17–25) mm Hg, respectively. On room air, the median arterial partial pressure of oxygen and partial pressure of carbon dioxide in arterial blood were 63.5 (55.8–69) mm Hg and 34.5 (31–36) mm Hg with increased median alveolar-arterial oxygen difference (46 [39–51] mm Hg). After the initial evaluation, the respiratory condition worsened in 13 of 14 (92.8%) patients with one or more re-evaluations (median follow-up 2.6 [0.9–5.8] years). In 12, lung transplantation was considered. Four patients died after 5.8, 5.7, 7.1, and 0.8 years of follow-up, respectively. We describe an underrecognized phenotype of pulmonary emphysema featuring a particular profile characterized by marked exertional dyspnea, impaired pulmonary gas exchange with low DLCO and marked oxygen desaturation at least on exercise but with mild or moderate airway obstruction.

Lessons Learned From Extracorporeal Life Support Practice and Outcomes During the COVID-19 Pandemic.

Extracorporeal membrane oxygenation is increasingly being used to support patients with hypoxemic respiratory failure and cardiogenic shock. During the COVID-19 pandemic, consensus guidance recommended extracorporeal life support for patients with COVID-19-related cardiopulmonary disease refractory to optimal conventional therapy, prompting a substantial expansion in the use of this support modality. Extracorporeal membrane oxygenation was particularly integral to the bridging of COVID-19 patients to heart or lung transplantation. Limited human and physical resources precluded widespread utilization of mechanical support during the COVID-19 pandemic, necessitating careful patient selection and optimal management by expert healthcare teams for judicious extracorporeal membrane oxygenation use. This review outlines the evidence supporting the use of extracorporeal life support in COVID-19, describes the practice and outcomes of extracorporeal membrane oxygenation for COVID-19-related respiratory failure and cardiogenic shock, and proposes lessons learned for the implementation of extracorporeal membrane oxygenation as a bridge to transplantation in future public health emergencies.

Postoperative conditions of rehabilitative interest in lung transplantation: a systematic review.

Lung transplantation is an elective treatment option for end-stage respiratory diseases in which all medical therapy options have been exhausted. The current study aimed to identify updated information on the postoperative conditions that may impair rehabilitation after lung transplantation and to provide specific considerations of their clinical relevance during the recovery process. The present study is a systematic review conducted by searching three primary databases: the United States National Library of Medicine PubMed system, Scopus, and the Cochrane Library. The databases were searched for articles published from database inception until May 2024; at the end of the selection process, 27 documents were included in the final analysis. The retrieved material identified 19 conditions of rehabilitative interest that potentially affect the postoperative course: graft dysfunction, dysphagia, postsurgical pain, cognitive impairment, chronic lung allograft dysfunction-bronchiolitis obliterans syndrome, phrenic nerve injury, delayed extracorporeal membrane oxygenation weaning, airway clearance, refractory hypoxemia, mediastinitis, reduced oxidative capacity, sternal dehiscence, coronavirus disease 2019 (COVID-19), gastroparesis, ossification of the elbow, Takotsubo cardiomyopathy, airway dehiscence, recurrent pleural effusion, and scapular prolapse. Although some patients are not amenable to rehabilitation techniques, others can significantly improve with rehabilitation.

Prognosis and Risks for Probable Chronic Lung Allograft Dysfunction: A Prospective Multicenter Study.

Chronic lung allograft dysfunction (CLAD) hinders lung transplant success. A 2019 consensus refined CLAD diagnosis, introducing probable or definite CLAD based on persistence of lung function decline. Outcomes and risks for probable CLAD remain uncertain. Determine the prognosis and clinical risks for probable CLAD in a prospective multicenter cohort. Clinical Trials in Organ Transplantation-20 included 745 CLAD-eligible adult lung recipients at 5 centers and applied rigorous methods to prospectively adjudicate probable CLAD. The impact of probable CLAD on graft loss was determined using a Cox model that considered CLAD as a time-dependent covariate. Regularized Cox modeling with LASSO penalty was used to evaluate donor or recipient characteristics and the occurrence and timing of posttransplant events as probable CLAD risks. Similar analyses were performed for definite CLAD. Probable CLAD occurred in 29.7% of patients at 3 years posttransplant and conferred a marked increase in risk for graft loss (unadjusted HR 4.38, p<0.001). Most patients (80%) with probable CLAD progressed to definite CLAD. Cytomegalovirus infection and specifically late presence (>90 days posttransplant) of donor-specific alloantibodies, acute rejection, acute lung injury, or organizing pneumonia contributed the greatest independent information about probable CLAD risk. Definite CLAD risks were similar. Probable CLAD identifies patients at high risk for graft loss, supporting prospective identification of this condition for early initiation of CLAD-directed interventions. More effective strategies to prevent posttransplant cytomegalovirus, inhibit allospecific immunity, and reduce tissue injury are needed to reduce probable CLAD and improve lung recipient survival.

Efficacy and severity of side-effects of rosuvastatin compared to other statins post-heart-transplantation

Abstract Introduction The International Society of Heart and Lung Transplantation (ISHLT) 2022 guideline recommends statin therapy in heart transplantation (HTx) patients, with the therapeutic low-density lipoprotein (LDL) target being &amp;lt;2.5 mmol/L. Particularly pravastatin is recommended, given proven beneficial effects on long-term clinical outcome and the low prevalence of side effects. Yet, in the general population, rosuvastatin has been shown to be even more potent. Purpose We investigated the lipid-lowering effect and severity of side-effects of rosuvastatin compared to less potent statins in HTx patients. Methods In this before-after study, we included all HTx patients whom were prescribed a change from the statin they were using to rosuvastatin, for better cardiovascular risk management and/or because of side-effects, between February 2018 and February 2023. We evaluated the weight, lipid profile and side-effects (including myalgia, cramps, stiffness and weakness) of these patients up to one year prior to and after the statin change. At the same time, side-effects were measured in a visual analogue scale (VAS) ranging from 0-10, with the average score of side-effects utilized for analysis. We compared the differences using a Wilcoxon signed rank test. Results Out of 299 HTx patients, we included 114 patients, with a median age of 58 [IQR 50-67] years at switch of whom 31 (27%) were females. Median time since HTx was 9 [IQR 5-15] years. The distribution and dosage of prescribed statins before and after switch can be found in Table 1. Compared to statins used prior to therapy change, rosuvastatin was associated with lower total cholesterol, LDL- and triglyceride levels, with high density lipoprotein (HDL) levels remaining the same (Table 2). No difference in bodyweight was found (Table 2). Before switch, 41 (36%) patients achieved the target of LDL-levels below 2.5 mmol/L. After switch, 86 (75%) patients achieved the target of LDL levels below 2.5 mmol/L. Rosuvastatin shows a trend towards a lower prevalence of side-effects (Table 2). Conclusion In HTx patients that were prescribed a change of statin due to better cardiovascular risk management and/or complaints of side-effects, rosuvastatin is related to a more favorable lipid profile, without additional side-effects, compared to other statins. Furthermore, many more patients achieve the guideline recommended LDL-target. Ongoing research should determine whether this translates to a better clinical outcome.

Incidence of acute cellular and antibody mediated rejection in heart transplantation from a tertiary care center

Abstract Background Heart transplant greatly increases the survival in patients with end stage heart failure. However, cardiologists and cardiothoracic surgeons face difficulty in detecting rejection at times. Post-cardiac transplant surveillance biopsy remains the gold standard for diagnosing rejection and therapeutic intervention. Purpose The objective is to report our experience of monitoring rejection by endomyocardial biopsy (EMB). Methods The index study is an ambispective one where we evaluated all the patients who underwent heart transplant at our center from 1994 to 2021. Results Heart transplant were carried out in 72 patients within a period of 28 years, with majority being done after 2016. The patients mean age was 31.6 years (10-59 years). The commonest indication was dilated cardiomyopathy (67%) followed by ischemic cardiomyopathy (2.5%), congenital heart disease (7%) and other miscellaneous causes (5%). The mean age of donors was 31.8 years (14-55 years). Eight of the 72 patients died without any post cardiac transplant endomyocardial biopsy. The remaining 64 patients underwent cumulatively a total of 271 endomyocardial biopsy procedures. Majority of endomyocaridal biopsies contained three cores (range 1-7). First EMB procedure was performed in 17 (26.6%) patients within first seven days, 35(53.1%) within the second week and 12(20.3%) after 14 days. Histologically rejection was identified in 42 (66%) patients. Thirty-nine (61%) had only acute cellular rejection (ACR), one (1.6%) had only antibody mediated rejection (AMR) and two (3.1%) had mixed ACR and AMR. These 42 patients with rejection had a total of 90 (33.2%) episodes of ACR detected in 271 endomyocardial biopsies. Out of 90 ACR, 44 (48.9%) occurred in less than six months; seventeen (18.9% of 90 ACR) episodes occurred between six and 12 months and 29 (32.2%) after one year. The mean of presentation of first ACR episode was 36 weeks (range 5 days to 3.6 years). There were 172 endomyocardial procedures within one year of transplantation of which 61 (35%) showed rejection. Ninety-nine endomyocardial procedures were performed one year of transplantation of which 29 (29%) showed rejection. Most common grade in both the time period was ACR grade 1R (International Society for Heart and Lung Transplantation (ISHLT) 2004) (72.1% in ≤1 year and 65.5% in &amp;gt;1 year) followed by 2R and 3R. Thirty-eight (90.4%) of 42 patients expired in less than five years since transplantation. Two (4.8%) patients survived between five to ten years post transplantation and two (4.8%) survived more than ten years. The longest cardiac transplant recipient had completed 23 years since cardiac transplant and is alive till date. Conclusions EMB being the gold standard for cardiac allograft rejection, the cardiac pathologists need to be aware of the various grades of rejection including mixed rejection.Acute cellular rejection (ISHLT 2004)

Afterload mismatch is associated with gender mismatch and negatively affect long-term outcome after heart transplant

Abstract Background Cardiac physiology changes after heart transplant (HT), resulting in a restrictive physiology with an increase in both arterial elastance (Ea) and ventricular elastance (Ees). This leads to a higher susceptibility to develop afterload mismatch, although the early identification of this phenomenon has not yet been explored. The aim of this study is to identify the presence of afterload mismatch after HT, its determinants, and its impact on cardiac mortality. Methods We conducted an observational, single-centre study based on the historical cohort of patients who underwent HT from 1985 to 2015 at our institution. We included patients who had survived the first year after HT with left ventricular ejection fraction (LVEF) ≥ 50%, International Society of Heart and Lung Transplantation (ISHLT) cardiac allograft vasculopathy of grade 0-1, and ISHLT acute cellular rejection of grade 0-1R at 1 year after HT. Ea and Ees were calculated using a non-invasive method based on blood pressure and end-systolic volume and end-diastolic volume measured at transthoracic echocardiography. Patients were grouped in 3 categories according to the presence of increased afterload and afterload mismatch as follows: low afterload (LA - Ea lower the median), matched high afterload (MHA - Ea higher of equal than the median, Ees higher or equal than the median), afterload mismatch (AM - Ea higher or equal than the median, Ees lower than the median). The impact of AM on long-term outcome, defined as cardiac mortality, was investigated, as well as predictors of AM. Results The study cohort consisted of 345 HT patients. The median of Ea and Ees were 4.0mmHg/mL and 6.75mmHg/mL, respectively. 49 patients (13%) developed AM, while LA and MHA groups accounted for 49% and 36% of the cohort, respectively. Patients with AM were mostly male (91%), with ischemic heart disease (45%) and a higher percentage of left ventricular assisted device prior to HT (8%). LVEF was lower in AM (57% vs 63% and 64% for LA and MHA respectively, p &amp;lt; 0.0001), while stroke volume was lower than LA and similar to MHA (27ml vs 35mL and 26mL for LA and MHA respectively, p = 0.0001). Predictors of AM were male recipient from male donor (Mr/Md) (β 015, p = 0.0067) and Mr from female donor (Mr/Fd) (β 0.6, p = 0.0078). After a median of 11.3-year follow-up, 59 (17%) HT recipients died. Cardiac mortality was higher in AM than in the other groups (AM median survival 17.2y vs 27.8y and 24.1y for LA and MHA respectively, log-rank p = 0.005). After adjusting for confounding variables, AM was a predictor of cardiac mortality (HR: 2.26; 95%CI 1.18 – 4.35), such as Mr/Fd (HR 2.94; 95%CI 1.18 – 4.35, p = 0.0358). Conclusion AM, in the context of a normal LVEF, is associated with male donor and sex mismatch, and negatively affects long-term outcome after HT.KM curvesCox proportional hazard model

Characteristic disease defects in circulating endothelial cells isolated from patients with pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by elevated pulmonary arterial pressures that can lead to right heart failure and death. No cure exists for this disease, but therapeutic advancements have extended its median survival from 2 to 7 years. Mechanistic research in PAH has been limited by factors including that a) animal models do not fully recapitulate the disease or provide insights into its pathogenesis, and b) cellular material from PAH patients is primarily obtained from donor lungs during autopsy or transplantation, which reflect end-stage disease. Therefore, there is a need to identify tools that can elucidate the specific mechanisms of human disease in individual patients, a critical step to guide treatment decisions based on specific pathway abnormalities. Here we demonstrate a simple method to isolate and culture circulating endothelial cells (CECs) obtained at the time of right heart catheterization in PAH patients. We tested these CECs using transcriptomics and found that they have typical traits of PAH, including those involving key treatment pathways, i.e. nitric oxide, endothelin, prostacyclin and BMP/activin pathways. CECs show important gene expression changes in other central PAH disease pathways. In summary, we present a new cellular model for the ex-vivo mechanistic evaluation of critical PAH pathways that participate in the pathogenesis of the disease and may help personalized therapeutic decisions.

Continuous heart monitoring to evaluate treatment effects in pulmonary hypertension

Abstract Background The treatment of pulmonary hypertension (PH) has improved rapidly in recent years, and there is increasing evidence to support the role of early intervention. However, studies demonstrate that timely intervention is often still lagging which affects clinical outcomes in patients with PH. Purpose To assess treatment effects after escalation of specific PH treatments using continuous heart monitoring via a Reveal LINQ loop recorder. Methods The patients change in heart rate variability (HRV), heart rate (HR), and physical activity were assessed before and after treatment escalation. Treatment escalation was defined as an additional PAH drug, pulmonary endarterectomy (PEA), percutaneous balloon angioplasty (PBA), or bilateral lung transplantation (BLTX). Results In this prospective study, 41 patients (27 with PAH and 14 with chronic thromboembolic pulmonary hypertension) were enrolled. Among them, 15 patients (36.6%) underwent PH treatment escalation. Prior to escalation, patients were monitored for a median of 100 (range: 68–100) days and after therapy escalation for a median duration of 165 (range: 89–308) days. In the escalation group, a significant increase in HRV (Figure), physical activity indexed by daytime HR was observed, while a significant decrease was seen in nighttime HR assessed at baseline and after treatment escalation. These changes were found both in the PAH and CTEPH group. In parallel a significant improvement in WHO functional class, 6-minute walking distance, and N-terminal pro-b-type natriuretic peptide (NT-proBNP) was observed. Conclusions This is the first study to demonstrate a direct association between specific PH therapies and changes in HRV, HR nighttime and physical activity in patients with PAH and CTEPH. Continuous monitoring allows for an early intervention with supplementary treatment for PH. This is especially relevant considering the increasing availability of wearables that allow for a convenient measurement of relevant prognostic parameters in PH.

Isolated fungal sphenoid sinusitis with unilateral lateral rectus palsy six years post lung transplant

Rhino-orbital-cerebral mucormycosis (ROCM) infections are rare and usually occur in patients with diabetes, malignancy, or organ transplantation. The most common presenting symptoms include facial pain and swelling, fever, and rhinorrhea. Mortality rates reach nearly 50%. Those with previous organ transplants typically present with sinus symptoms a few weeks to months after transplantation. A 75-year-old man presented with headache. His history was significant for bilateral lung transplantation in 2017. On his fourth presentation, he was admitted to the hospital for work up. Imaging showed small fluid levels within the right maxillary and sphenoid sinuses. Infectious work-up revealed no meningitis. On day three, the patient complained of diplopia on the right. His examination was significant for right lateral rectus palsy. Repeat imaging was performed and showed increasing fluid levels of the right maxillary and sphenoid sinuses, and the otolaryngology consultation service was consulted. Nasal endoscopy was significant for pink, vascularised mucosa with no obvious regions of pallor or necrosis. Endoscopic sinus surgery was performed. There were no findings suggestive of fungus but purulence of the right sphenoid grew Rhizopus. The patient’s nerve palsy did not resolve and progressed to the contralateral orbit. Repeat nasal endoscopy continued to show healthy mucosa while MRI showed enhancement worrisome for meningitis. To our knowledge, this is the only reported case of fungal sphenoid sinusitis resulting in meningitis and death six years after transplant. Current literature documents fungal infection in post-transplant patients up to four years after surgery, with most occurring within the first year. Suspicion for fungal infection should remain high in this patient population. Keywords: mucormycosis, lung transplant, sinusitis, lateral rectus palsy

Assessment of the Therapeutic Potential of Enhancer of Zeste Homolog 2 Inhibition in a Murine Model of Bronchiolitis Obliterans Syndrome

Bronchiolitis obliterans syndrome (BOS) is a chronic complication following lung transplantation that limits the long-term survival. Although the enhancer of zeste homolog 2 (EZH2) is involved in post-transplantation rejection, its involvement in BOS pathogenesis remains unclear. We aimed to investigate the therapeutic potential of EZH2 inhibition in BOS. 3-deazaneplanocin A (DZNep) was administered intraperitoneally to heterotopic tracheal transplant recipient model mice. Tracheal allografts were obtained on days 7, 14, 21, and 28 after transplantation. The obstruction ratios of the DZNep and control groups on days 7, 14, 21, and 28 were 15.1% ± 0.8% vs. 20.4% ± 3.6% (p = 0.996), 16.9% ± 2.1% vs. 67.7% ± 11.5% (p &amp;lt; 0.001), 47.8% ± 7.8% vs. 92.2% ± 5.4% (p &amp;lt; 0.001), and 60.0% ± 9.6% vs. 95.0% ± 2.3% (p &amp;lt; 0.001), respectively. The levels of interleukin (IL)-6 and interferon-γ on day 7 and those of IL-2, tumor necrosis factor, and IL-17A on days 14, 21, and 28 were significantly reduced following DZNep treatment. DZNep significantly decreased the number of infiltrating T-cells on day 14. In conclusion, DZNep-mediated EZH2 inhibition suppressed the inflammatory reactions driven by pro-inflammatory cytokines and T cell infiltration, thereby alleviating BOS symptoms.

Post-Transplant Vitamin D Deficiency in Lung Transplant Recipients: Impact on Outcomes and Prognosis

Despite the recognized clinical significance of vitamin D deficiency in other solid organ transplant recipients, its specific relevance in lung transplantation remains to be fully understood. In this study, we performed a retrospective observational study on the impact of vitamin D deficiency on clinical outcomes and prognosis in 125 lung transplant recipients (LTRs) from October 2014 to March 2020 at a university hospital in Seoul, South Korea. Among 125 LTRs, 51 patients (40.8%) were vitamin D deficient. LTRs in the vitamin D-deficient group exhibited a higher incidence of post-transplant pneumonia and overall mortality than those with normal vitamin D levels during the follow-up period. This trend persisted when subjects were stratified into vitamin D tertiles. Furthermore, post-transplant vitamin D levels and C-reactive protein (CRP) significantly impacted pneumonia incidence and survival outcomes. Prognosis also varied based on cumulative vitamin D supplementation after transplantation, with patients receiving higher cumulative supplementation demonstrating improved prognosis. Our findings underscore the importance of assessing and maintaining optimal vitamin D levels post-transplantation, suggesting a potential avenue for improving outcomes in lung transplant recipients, especially in mitigating infection risk and enhancing long-term survival. Further research into optimal vitamin D levels and supplementation strategies in this population is warranted.

FSP1 Acts in Parallel with GPX4 to Inhibit Ferroptosis in COPD.

Glutathione peroxidase 4 (GPX4) has recently been reported to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Ferroptosis suppressor protein-1 (FSP1) is a protein that defends against ferroptosis in parallel with GPX4, but its role in the pathogenesis of COPD remains unexplored, and further research is needed. Normal and COPD lung tissues were obtained from lobectomy and lung transplant specimens, respectively. FSP1-overexpressing mice were established by monthly transfection with AAV9-FSP1 through modified intranasal administration. The expression of FSP1, GPX4, and prostaglandin-endoperoxide synthase 2 (PTGS2) was measured by Western blotting, immunohistochemistry and other methods. The correlation between FSP1 and ferroptosis and the role of FSP1 in COPD were explored by screening the expression of ferroptosis-related genes in a COPD cell model after the inhibition and overexpression of FSP1. We then explored the underlying mechanism of low FSP1 expression in patients with COPD in vitro by methylated RNA immunoprecipitation (MeRIP)-qPCR. We found that cigarette smoke exposure can lead to an increase in lipid peroxide production and ultimately ferroptosis, which is negatively regulated by FSP1 activity. FSP1 overexpression can prevent ferroptosis and alleviate emphysema. Next, we found that decreased FSP1 expression was caused by increased m6A modification of FSP1 mRNA. Moreover, the level of FSP1 decreased in a YTHDF2-dependent manner. These results indicate that METTL3-induced FSP1 mRNA methylation leading to low FSP1 expression is a potential therapeutic target for COPD. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Impact of Long-Term Atorvastatin Therapy on the Development of Chronic Lung Allograft Dysfunction in Patients with Azithromycin Prophylaxis after Lung Transplantation

ObjectiveTo assess the impact of long-term atorvastatin (ATO) therapy on reducing recipient inflammation and immune response, thus lowering the risk of chronic lung allograft dysfunction (CLAD) in lung transplant recipients. This study aimed to investigate the effects of ATO on overall survival, lung function recovery, and its influence on inflammatory factors alongside azithromycin (AZI) prophylaxis. MethodsThis retrospective single-center study included lung transplant recipients from January 2017 to December 2022. Patients who survival >1 year after lung transplantation and who were receiving AZI prophylaxis for >6 months were selected. Outcome measures involved pulmonary function assessments at various time points after AZI treatment, complete blood cell analysis, and inflammatory factor evaluations. ResultsThe incidence of CLAD was significantly lower in the long-term ATO group compared with those not on ATO (P = .011). Long-term ATO treatment significantly delayed CLAD onset after lung transplantation (850 days vs. 630 days; P = .041), with patients showing notably enhanced lung function recovery within 6 months of AZI therapy compared with the non-ATO group. Neutrophil levels decreased in patients with CLAD, and interleukin-6 concentrations significantly decreased in the AZI + ATO group compared with the AZI group. Overall patient survival was significantly better in the AZI+ATO group than in the AZI group (P = .02). ConclusionIn cases where CLAD develops despite AZI prophylaxis, long-term ATO treatment may lead to short-term improvements in lung function. It could also decrease inflammation levels in lung transplant recipients and enhance overall survival. The combination of AZI and long-term ATO therapy may be beneficial for CLAD prevention.

Remote kidney and liver injury after transplantation of lung allografts in an allogeneic mouse model

Background: Remote organ dysfunction is common after lung transplantation and might negatively affect outcome. The local anesthetic ropivacaine was previously demonstrated to attenuate acute rejection after allogeneic lung transplantation in mice. We hypothesized that lung transplantation might result in detectable molecular signs of injury in kidneys and liver and that ropivacaine might attenuate this damage. Methods: Organs from C57BL/6 mice undergoing allogeneic orthotopic single-lung transplantation were procured at postoperative day five and analyzed using western blot and real-time quantitative polymerase chain reaction probing for Src protein tyrosine kinase, STAT3 and bax/bcl-2. During cold ischemia, the allograft had either been flushed with normal saline only or in combination with ropivacaine (1 µM). A non-transplanted group of animals served as baseline controls. Results: The allogeneic stimulus induced by transplantation lead to an increase in Src-phosphorylation and STAT3-expression in kidneys and livers of lung-transplanted mice compared to non-transplanted animals. Bax/bcl-2 as a marker of cellular apoptosis was not affected by the transplantation. In contrast to the findings in the transplanted lungs, the addition of ropivacaine did not have an effect on the examined markers of inflammation in the remote organs. Conclusions: The observed increase in the inflammatory signaling provides first insight into a possible mechanism, by which remote organ dysfunction after lung transplantation might occur.

Lobar graft evaluation in cadaveric lobar lung redo transplantation after living-donor lobar lung transplantation: a case report

BackgroundLung transplantation is a vital option for patients with end-stage lung disease. However, it faces a significant challenge due to the shortage of compatible donors, which particularly affects individuals with small chest cavities and pediatric patients. The novel approach of cadaveric lobar lung transplantation is a promising solution to alleviate the donor shortage crisis. Both the mid-term and long-term outcomes of lobar lung transplantation are comparable to those of standard lung transplantation. However, patients undergoing lobar lung transplantation reported a significantly higher rate of primary graft dysfunction compared to patients undergoing standard lung transplantation. Therefore, careful donor selection is critical to improve outcomes after lobar transplantation. However, no established method exists to evaluate each lung lobar graft of deceased donors. This case report describes a case of cadaveric lobar lung transplantation to overcome size mismatch and donor shortage, with particular emphasis on lobar graft evaluation.Case presentationA 39-year-old woman with scleroderma-related respiratory failure was listed for deceased donor lung transplantation due to a rapidly progressing disease. Faced with a long waiting list and impending mortality, she underwent bilateral living-donor lobar lung transplantation donated by her relatives. Post-transplant complications included progressive pulmonary vein obstruction and pleural effusion, which ultimately required retransplantation. An oversized donor with pneumonia in the bilateral lower lobes was allocated. Lung ultrasound was used to evaluate each lung lobar graft during procurement. The right upper and middle lobes and left upper lobe were confirmed to be transplantable, and lobar lung redo transplantation was performed. The patient’s post-transplant course was uneventful, and she was discharged home and returned to her daily activities.ConclusionsThis case highlights the clinical impact of cadaveric lobar lung transplantation as a feasible and effective strategy to overcome the shortage of donor lungs, especially in patients with small thoracic cavities. By establishing donor lung evaluation techniques and overcoming anatomical and logistical challenges, cadaveric lobar lung transplantation can significantly expand the donor pool and offer hope to those previously considered ineligible for transplantation.

Deep learning-based approach for acquisition time reduction in ventilation SPECT in patients after lung transplantation.

We aimed to evaluate the image quality and diagnostic performance of chronic lung allograft dysfunction (CLAD) with lung ventilation single-photon emission computed tomography (SPECT) images acquired briefly using a convolutional neural network (CNN) in patients after lung transplantation and to explore the feasibility of short acquisition times. We retrospectively identified 93 consecutive lung-transplant recipients who underwent ventilation SPECT/computed tomography (CT). We employed a CNN to distinguish the images acquired in full time from those acquired in a short time. The image quality was evaluated using the structural similarity index (SSIM) loss and normalized mean square error (NMSE). The correlation between functional volume/morphological volume (F/M) ratios of full-time SPECT images and predicted SPECT images was evaluated. Differences in the F/M ratio were evaluated using Bland-Altman plots, and the diagnostic performance was compared using the area under the curve (AUC). The learning curve, obtained using MSE, converged within 100 epochs. The NMSE was significantly lower (P < 0.001) and the SSIM was significantly higher (P < 0.001) for the CNN-predicted SPECT images compared to the short-time SPECT images. The F/M ratio of full-time SPECT images and predicted SPECT images showed a significant correlation (r = 0.955, P < 0.0001). The Bland-Altman plot revealed a bias of -7.90% in the F/M ratio. The AUC values were 0.942 for full-time SPECT images, 0.934 for predicted SPECT images and 0.872 for short-time SPECT images. Our findings suggest that a deep-learning-based approach can significantly curtail the acquisition time of ventilation SPECT, while preserving the image quality and diagnostic accuracy for CLAD.

The Future of Lung Transplantation in Cystic Fibrosis

AN INSIGHTFUL session on the future of lung transplantation presented at this year’s European Respiratory Society (ERS) Congress explored the insights shared by experts during sessions on lung transplantation, the role of machine learning in cystic fibrosis care, and the future challenges ahead.

Investigation of immunosuppressive treatment compliance, dyspnea, anxiety, and depression levels in lung transplant recipients: online interview

IntroductionFollowing lung transplantation (LTx), it is important for recipients to comply with immunosuppressive treatment and cope with related problems. In the post-LTx period, the course of dyspnea and psychological problems it causes in case of progression are not known. Depression and anxiety may develop in recipients after LTx. However, the relationship between this situation and treatment compliance and dyspnea is uncertain.ObjectiveThe aim of this study was to investigate dyspnea, anxiety, and depression levels of recipients following LTx and their immunosuppressive treatment compliance.MethodThe study was planned as a descriptive, correlational, and cross-sectional study. Data were collected on various social media platforms via an online interview, and 65 LTx recipients were included in the sample (n = 65). A Participant Information Form, the Modified Borg Scale, the Beck Anxiety Inventory, the Beck Depression Inventory, and the Immunosuppressive Drug Compliance Scale were employed to collect data. The collected data were analyzed using descriptive statistics, the Mann–Whitney U test, and the Kruskal-Wallis test.ResultsThe mean age of the participants was found to be 52.60 ± 9.44 years, and 56.9% were male. Forty percent of the participants were dependent on oxygen support, and 32.2% had hypertension. Their dyspnea levels were mild, anxiety levels were moderate, depression levels were high, and immunosuppressive treatment compliance levels were slightly above-average. According to the correlation analysis results, dyspnea was associated with anxiety and depression (p &amp;lt; 0.05). As depression increased, immunosuppressive treatment compliance decreased, and the correlation between the two variables was statistically significant (p &amp;lt; 0.05).ConclusionIn this study, as the severity of dyspnea experienced by LTRs increased, the severity of their anxiety and depression also increased. Additionally, there was an inverse correlation between depression and immunosuppressive treatment compliance. LTRs demonstrated insufficient adherence to their immunosuppressive drug regimens, which is very significant in terms of graft survivability. These results suggest that LTRs should be closely monitored at home.

GLP-1R activation attenuates the progression of pulmonary fibrosis via disrupting NLRP3 inflammasome/PFKFB3-driven glycolysis interaction and histone lactylation

BackgroundPulmonary fibrosis is a serious interstitial lung disease with no viable treatment except for lung transplantation. Glucagon-like peptide-1 receptor (GLP-1R), commonly regarded as an antidiabetic target, exerts antifibrotic effects on various types of organ fibrosis. However, whether GLP-1R modulates the development and progression of pulmonary fibrosis remains unclear. In this study, we investigated the antifibrotic effect of GLP-1R using in vitro and in vivo models of pulmonary fibrosis.MethodsA silica-induced pulmonary fibrosis mouse model was established to evaluate the protective effects of activating GLP-1R with liraglutide in vivo. Primary cultured lung fibroblasts treated with TGF-β1 combined with IL-1β (TGF-β1 + IL-1β) were used to explore the specific effects of liraglutide, MCC950, and 3PO on fibroblast activation in vitro. Cell metabolism assay was performed to determine the glycolytic rate and mitochondrial respiration. RNA sequencing was utilized to analyse the underlying molecular mechanisms by which liraglutide affects fibroblast activation. ChIP‒qPCR was used to evaluate histone lactylation at the promoters of profibrotic genes in TGF-β1 + IL-1β- or exogenous lactate-stimulated lung fibroblasts.ResultsActivating GLP-1R with liraglutide attenuated pulmonary inflammation and fibrosis in mice exposed to silica. Pharmacological inhibition of the NLRP3 inflammasome suppressed PFKFB3-driven glycolysis and vice versa, resulting in decreased lactate production in TGF-β1 + IL-1β-stimulated lung fibroblasts. Activating GLP-1R inhibited TGF-β1 + IL-1β-induced fibroblast activation by disrupting the interaction between the NLRP3 inflammasome and PFKFB3-driven glycolysis and subsequently prevented lactate-mediated histone lactylation to reduce pro-fibrotic gene expression. In addition, activating GLP-1R protected mitochondria against the TGF-β1 + IL-1β-induced increase in oxidative phosphorylation in fibroblasts. In exogenous lactate-treated lung fibroblasts, activating GLP-1R not only repressed NLRP3 inflammasome activation but also alleviated p300-mediated histone lactylation. Finally, GLP-1R activation blocked silica-treated macrophage-conditioned media-induced lung fibroblast activation.ConclusionsThe antifibrotic effects of GLP-1R activation on pulmonary fibrosis could be attributed to the inhibition of the interaction between NLRP3 inflammasome and PFKFB3-driven glycolysis, and histone lactylation in lung fibroblasts. Thus, GLP-1R is a specific therapeutic target for the treatment of pulmonary fibrosis.