Profibrotic monocyte-derived alveolar macrophages are expanded in patients with persistent respiratory symptoms and radiographic abnormalities after COVID-19.

Monocyte-derived alveolar macrophages drive lung injury and fibrosis in murine models and are associated with pulmonary fibrosis in humans. Monocyte-derived alveolar macrophages have been suggested to develop a phenotype that promotes lung repair as injury resolves. We compared single-cell and cytokine profiling of the alveolar space in a cohort of 35 patients with post-acute sequelae of COVID-19 who had persistent respiratory symptoms and abnormalities on a computed tomography scan of the chest that subsequently improved or progressed. The abundance of monocyte-derived alveolar macrophages, their gene expression programs, and the level of the monocyte chemokine CCL2 in bronchoalveolar lavage fluid positively associated with the severity of radiographic fibrosis. Monocyte-derived alveolar macrophages from patients with resolving or progressive fibrosis expressed the same set of profibrotic genes. Our findings argue against a distinct reparative phenotype in monocyte-derived alveolar macrophages, highlighting their utility as a biomarker of failed lung repair and a potential target for therapy.

Circuits between infected macrophages and T cells in SARS-CoV-2 pneumonia.

Some patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develop severe pneumonia and acute respiratory distress syndrome1 (ARDS). Distinct clinical features in these patients have led to speculation that the immune response to virus in the SARS-CoV-2-infected alveolus differs from that in other types of pneumonia2. Here we investigate SARS-CoV-2 pathobiology by characterizing the immune response in the alveoli of patients infected with the virus. We collected bronchoalveolar lavage fluid samples from 88 patients with SARS-CoV-2-induced respiratory failure and 211 patients with known or suspected pneumonia from other pathogens, and analysed them using flow cytometry and bulk transcriptomic profiling. We performed single-cell RNA sequencing on 10 bronchoalveolar lavage fluid samples collected from patients with severe coronavirus disease 2019 (COVID-19) within 48 h of intubation. In the majority of patients with SARS-CoV-2 infection, the alveolar space was persistently enriched in T cells and monocytes. Bulk and single-cell transcriptomic profiling suggested that SARS-CoV-2 infects alveolar macrophages, which in turn respond by producing T cell chemoattractants. These T cells produce interferon-γ to induce inflammatory cytokine release from alveolar macrophages and further promote T cell activation. Collectively, our results suggest that SARS-CoV-2 causes a slowly unfolding, spatially limited alveolitis in which alveolar macrophages containing SARS-CoV-2 and T cells form a positive feedback loop that drives persistent alveolar inflammation.

Necroptosis triggers spatially restricted neutrophil-mediated vascular damage during lung ischemia reperfusion injury.

Ischemia reperfusion injury represents a common pathological condition that is triggered by the release of endogenous ligands. While neutrophils are known to play a critical role in its pathogenesis, the tissue-specific spatiotemporal regulation of ischemia-reperfusion injury is not understood. Here, using oxidative lipidomics and intravital imaging of transplanted mouse lungs that are subjected to severe ischemia reperfusion injury, we discovered that necroptosis, a nonapoptotic form of cell death, triggers the recruitment of neutrophils. During the initial stages of inflammation, neutrophils traffic predominantly to subpleural vessels, where their aggregation is directed by chemoattractants produced by nonclassical monocytes that are spatially restricted in this vascular compartment. Subsequent neutrophilic disruption of capillaries resulting in vascular leakage is associated with impaired graft function. We found that TLR4 signaling in vascular endothelial cells and downstream NADPH oxidase 4 expression mediate the arrest of neutrophils, a step upstream of their extravasation. Neutrophil extracellular traps formed in injured lungs and their disruption with DNase prevented vascular leakage and ameliorated primary graft dysfunction. Thus, we have uncovered mechanisms that regulate the initial recruitment of neutrophils to injured lungs, which result in selective damage to subpleural pulmonary vessels and primary graft dysfunction. Our findings could lead to the development of new therapeutics that protect lungs from ischemia reperfusion injury.

Multiorgan transplant for therapy-associated lung and liver failure in a patient with stage III lung cancer.

Immunotherapy can significantly improve efficacy of cancer treatments. For locally advanced stage III lung cancers, chemoimmunotherapy in the neoadjuvant setting can achieve complete pathological response in about 40% of cases. However, optimal cancer response in patients receiving immunotherapy is sometimes associated with potentially fatal bystander injury to lung and liver. We report a successful combined double lung and liver transplantation for immunotherapy-associated respiratory failure and cirrhosis in a patient with advanced lung cancer. A 68-year-old man with stage IIIA squamous cell lung cancer encountered severe interstitial pneumonitis and nodular regenerative hyperplasia of the liver following systemic anticancer therapy that included immunotherapy and platinum-based chemotherapy. These adverse events culminated into fulminant end-stage pulmonary fibrosis and cirrhosis, which were treated with simultaneous lung and liver transplantation, complete resection of lung cancer, and mediastinal lymphadenectomy. The patient demonstrated promising early outcomes without recurrence of cancer at 12 months. Given that oncologic treatments can induce irreversible solid organ failure despite cancer control, our report suggests that in carefully selected patients without systemic metastasis and in whom complete resection of residual cancer can be performed, organ transplantation can be life-saving.

Temporal correlation between postreperfusion complement deposition and severe primary graft dysfunction in lung allografts.

Growing evidence implicates complement in the pathogenesis of primary graft dysfunction (PGD). We hypothesized that early complement activation postreperfusion could predispose to severe PGD grade 3 (PGD-3) at 72 hours, which is associated with worst posttransplant outcomes. Consecutive lung transplant patients (n = 253) from January 2018 through June 2023 underwent timed open allograft biopsies at the end of cold ischemia (internal control) and 30 minutes postreperfusion. PGD-3 at 72 hours occurred in 14% (35/253) of patients; 17% (44/253) revealed positive C4d staining on postreperfusion allograft biopsy, and no biopsy-related complications were encountered. Significantly more patients with PGD-3 at 72 hours had positive C4d staining at 30 minutes postreperfusion compared with those without (51% vs 12%, P < .001). Conversely, patients with positive C4d staining were significantly more likely to develop PGD-3 at 72 hours (41% vs 8%, P < .001) and experienced worse long-term outcomes. In multivariate logistic regression, positive C4d staining remained highly predictive of PGD-3 (odds ratio 7.92, 95% confidence interval 2.97-21.1, P < .001). Hence, early complement deposition in allografts is highly predictive of PGD-3 at 72 hours. Our data support future studies to evaluate the role of complement inhibition in patients with early postreperfusion complement activation to mitigate PGD and improve transplant outcomes.

Smoking exposure-induced bronchus-associated lymphoid tissue in donor lungs does not prevent tolerance induction after transplantation.

The presence of bronchus-associated lymphoid tissue (BALT) in donor lungs has been suggested to accelerate graft rejection after lung transplantation. Although chronic smoke exposure can induce BALT formation, the impact of donor cigarette use on alloimmune responses after lung transplantation is not well understood. Here, we show that smoking-induced BALT in mouse donor lungs contains Foxp3+ T cells and undergoes dynamic restructuring after transplantation, including recruitment of recipient-derived leukocytes to areas of pre-existing lymphoid follicles and replacement of graft-resident donor cells. Our findings from mouse and human lung transplant data support the notion that a donor's smoking history does not predispose to acute cellular rejection or prevent the establishment of allograft acceptance with comparable outcomes to nonsmoking donors. Thus, our work indicates that BALT in donor lungs is plastic in nature and may have important implications for modulating proinflammatory or tolerogenic immune responses following transplantation.

NCCN Guidelines® Insights: Mesothelioma: Pleural, Version 1.2024.

Mesothelioma is a rare cancer that originates from the mesothelial surfaces of the pleura and other sites, and is estimated to occur in approximately 3,500 people in the United States annually. Pleural mesothelioma is the most common type and represents approximately 85% of these cases. The NCCN Guidelines for Mesothelioma: Pleural provide recommendations for the diagnosis, evaluation, treatment, and follow-up for patients with pleural mesothelioma. These NCCN Guidelines Insights highlight significant updates to the NCCN Guidelines for Mesothelioma: Pleural, including revised guidance on disease classification and systemic therapy options.

Non-Small Cell Lung Cancer, Version 4.2024, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Non-Small Cell Lung Cancer (NSCLC) provide recommendations for the treatment of patients with NSCLC, including diagnosis, primary disease management, surveillance for relapse, and subsequent treatment. The panel has updated the list of recommended targeted therapies based on recent FDA approvals and clinical data. This selection from the NCCN Guidelines for NSCLC focuses on treatment recommendations for advanced or metastatic NSCLC with actionable molecular biomarkers.

Chemical Localization With Robotic Bronchoscopy: Can It Aid Resection of Subsolid Lung Nodules?

INTRODUCTION: Subsolid nodules or those located deep in lung parenchyma are difficult to localize using minimally invasive thoracic surgery. While image-guided percutaneous needle localization has been performed, it is inconvenient and has potential complications. In this study, the role of chemical localization using robotic bronchoscopy to facilitate resection was evaluated. METHODS: Consecutive patients undergoing surgical resection for lung nodules between 8/2019-3/2022 were included. Patients with subsolid lung nodules, or small nodules deep in lung parenchyma that were deemed difficult to localize, were chemically localized (CL) using robotic bronchoscopy before resection. Clinico-demographic data were obtained retrospectively using a prospectively maintained database. RESULTS: Localization of lung nodules before resection was performed in 139 patients while 110 patients were not localized. Daily activity score was higher for localized patients. Nodules in the localized group were smaller (P < 0.001) and had similar solid:ground glass ratio. In the localized group, larger margins were observed, and no re-resection of the parenchymal margin was required. Twenty patients in the non-localized group required re-resection intraoperatively due to close pathological margins or inability to locate the nodule in the resected specimen. Operative time was a median of 10-15 min longer for localized patients, P < 0.001. Length of stay was shorter in the localized group (P < 0.05). CONCLUSIONS: Chemical localization of lung nodules using robotic bronchoscopy appears to be a safe and effective method of identifying the location of nodules with small size and less density and aids increased tumor margins intraoperatively.

Predictors of Cytomegalovirus Recurrence Following Cessation of Posttransplant Prophylaxis.

INTRODUCTION: Cytomegalovirus (CMV) infection is associated with a poor prognosis after lung transplantation, and donor and recipient CMV serostatus is a risk factor for reactivation. CMV prophylaxis is commonly administered in the first year following transplantation to reduce CMV infection; however, the risk factors for long-term reactivation remain unclear. We investigated the timing and risk factors of CMV infection after prophylactic administration. METHODS: This study was a retrospective review of the institutional lung transplantation database from June 2014 to June 2022. Data on patient characteristics, pretransplantation laboratory values, postoperative outcomes, and CMV infection were collected. Donor CMV-IgG-positive and recipient CMV-IgG-negative groups were defined as the CMV mismatch group. RESULTS: During the study period, 257 patients underwent lung transplantation and received a prophylactic dose of valganciclovir hydrochloride for up to 1 y. CMV infection was detected in 69 patients (26.8%): 40 of 203 (19.7%) in the non-CMV mismatch group and 29 of 54 (53.7%) in the CMV mismatch group (P < 0.001). CMV infection after prophylaxis occurred at a median of 425 and 455 d in the CMV mismatch and non-CMV mismatch groups, respectively (P = 0.07). Multivariate logistic regression analysis revealed that preoperative albumin level (odds ratio [OR] = 0.39, P = 0.04), CMV mismatch (OR = 15.7, P < 0.001), and donor age (OR = 1.05, P = 0.009) were significantly associated with CMV infection. CONCLUSIONS: CMV mismatch may have increased the risk of CMV infection after lung transplantation, which decreased after prophylaxis. In addition to CMV mismatch, low preoperative albumin level and donor age were independent predictors of CMV infection.

Automated, multiparametric monitoring of respiratory biomarkers and vital signs in clinical and home settings for COVID-19 patients.

Capabilities in continuous monitoring of key physiological parameters of disease have never been more important than in the context of the global COVID-19 pandemic. Soft, skin-mounted electronics that incorporate high-bandwidth, miniaturized motion sensors enable digital, wireless measurements of mechanoacoustic (MA) signatures of both core vital signs (heart rate, respiratory rate, and temperature) and underexplored biomarkers (coughing count) with high fidelity and immunity to ambient noises. This paper summarizes an effort that integrates such MA sensors with a cloud data infrastructure and a set of analytics approaches based on digital filtering and convolutional neural networks for monitoring of COVID-19 infections in sick and healthy individuals in the hospital and the home. Unique features are in quantitative measurements of coughing and other vocal events, as indicators of both disease and infectiousness. Systematic imaging studies demonstrate correlations between the time and intensity of coughing, speaking, and laughing and the total droplet production, as an approximate indicator of the probability for disease spread. The sensors, deployed on COVID-19 patients along with healthy controls in both inpatient and home settings, record coughing frequency and intensity continuously, along with a collection of other biometrics. The results indicate a decaying trend of coughing frequency and intensity through the course of disease recovery, but with wide variations across patient populations. The methodology creates opportunities to study patterns in biometrics across individuals and among different demographic groups.

Downregulation of a tumor suppressor gene LKB1 in lung transplantation as a biomarker for chronic murine lung allograft rejection.

BACKGROUND: We recently demonstrated decreased tumor suppressor gene liver kinase B1 (LKB1) level in lung transplant recipients diagnosed with bronchiolitis obliterans syndrome. STE20-related adaptor alpha (STRADα) functions as a pseudokinase that binds and regulates LKB1 activity. METHODS: A murine model of chronic lung allograft rejection in which a single lung from a B6D2F1 mouse was orthotopically transplanted into a DBA/2J mouse was employed. We examined the effect of LKB1 knockdown using CRISPR-CAS9 in vitro culture system. RESULTS: Significant downregulation of LKB1 and STRADα expression was found in donor lung compared to recipient lung. STRADα knockdown significantly inhibited LKB1, pAMPK expression but induced phosphorylated mammalian target of rapamycin (mTOR), fibronectin, and Collagen-I, expression in BEAS-2B cells. LKB1 overexpression decreased fibronectin, Collagen-I, and phosphorylated mTOR expression in A549 cells. CONCLUSIONS: We demonstrated that downregulation of LKB1-STRADα pathway accompanied with increased fibrosis, results in development of chronic rejection following murine lung transplantation.

NCCN Guidelines® Insights: Non-Small Cell Lung Cancer, Version 2.2023.

The NCCN Guidelines for Non-Small Cell Lung Cancer (NSCLC) provide recommendations for management of disease in patients with NSCLC. These NCCN Guidelines Insights focus on neoadjuvant and adjuvant (also known as perioperative) systemic therapy options for eligible patients with resectable NSCLC.

Mesothelioma: Peritoneal, Version 2.2023, NCCN Clinical Practice Guidelines in Oncology.

Mesothelioma is a rare cancer originating in mesothelial surfaces of the peritoneum, pleura, and other sites. These NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) focus on peritoneal mesothelioma (PeM). The NCCN Guidelines for PeM provide recommendations for workup, diagnosis, and treatment of primary as well as previously treated PeM. The diagnosis of PeM may be delayed because PeM mimics other diseases and conditions and because the disease is so rare. The pathology section was recently updated to include new information about markers used to identify mesothelioma, which is difficult to diagnose. The term "malignant" is no longer used to classify mesotheliomas, because all mesotheliomas are now defined as malignant.

Rural-Urban Disparities in Receipt of Surgery for Potentially Resectable Non-Small Cell Lung Cancer.

INTRODUCTION: Access to cancer care, especially surgery, is limited in rural areas. However, the specific reasons rural patient populations do not receive surgery for non-small cell lung cancer (NSCLC) is unknown. We investigated geographic disparities in reasons for failure to receive guideline-indicated surgical treatment for patients with potentially resectable NSCLC. METHODS: The National Cancer Database was used to identify patients with clinical stage I-IIIA (N0-N1) NSCLC between 2004 and 2018. Patients from rural areas were compared to urban areas, and the reason for nonreceipt of surgery was evaluated. Adjusted odds of (1) primary nonsurgical management, (2) surgery being deemed contraindicated due to risk, (3) surgery being recommended but not performed, and (4) overall failure to receive surgery were determined. RESULTS: The study included 324,785 patients with NSCLC with 42,361 (13.0%) from rural areas. Overall, 62.4% of patients from urban areas and 58.8% of patients from rural areas underwent surgery (P < 0.001). Patients from rural areas had increased odds of (1) being recommended primary nonsurgical management (adjusted odds ratio [aOR]: 1.14, 95% confidence interval [CI]: 1.05-1.23), (2) surgery being deemed contraindicated due to risk (aOR: 1.19, 95% CI: 1.07-1.33), (3) surgery being recommended but not performed (aOR: 1.13, 95% CI: 1.01-1.26), and (4) overall failure to receive surgery (aOR: 1.21, 95% CI: 1.13-1.29; all P < 0.001). CONCLUSIONS: There are geographic disparities in the management of NSCLC. Rural patient populations are more likely to fail to undergo surgery for potentially resectable disease for every reason examined.

A Comprehensive Landscape of De Novo Malignancy After Double Lung Transplantation.

Although the association between post-transplant malignancy (PTM) and immunosuppressive therapy after organ transplantation has been studied, an integrated review of PTM after lung transplantation is lacking. We investigated the incidence and types of de novo PTM and its impact on survival following double lung transplantation (DLT). The incidence and type of PTM as well as the annual and cumulative risks of each malignancy after DLT were analyzed. The overall survival (OS) of recipients with or without PTM was compared by the Kaplan-Meier survival method and landmark analysis. There were 5,629 cases (23.52%) with 27 types of PTMs and incidences and OS varied according to the types of PTMs. The recipients with PTM showed a significantly longer OS than those without PTM (p < 0.001). However, while the recipients with PTM showed significantly better OS at 3, and 5 years (p < 0.001, p = 0.007), it was worse at the 10-year landmark time (p = 0.013). And the single PTM group showed a worse OS rate than the multiple PTM group (p < 0.001). This comprehensive report on PTM following DLT can help understand the risks and timing of PTM to improve the implementation of screening and treatment.

Early initiation of physical and occupational therapy while on extracorporeal life support improves patients' functional activity.

PURPOSE: Managing acute respiratory distress syndrome (ARDS) patients on venovenous extracorporeal membrane oxygenation (V-V ECMO), without sedation/neuromuscular blockade to allow physical and occupational therapy (PT/OT) participation, is untraditional. Here, we investigate the impact of early PT/OT initiation on discharge functional activity for ARDS patients managed on V-V ECMO. METHODS: This is a retrospective review of 67 ARDS patients managed with V-V ECMO at a single academic center from February 2018 to June 2021. Data collected included patient characteristics, days of V-V ECMO support, day of PT/OT initiation, and ambulation distance and Activity Measure for Post-Acute Care (AMPAC) Six-Clicks score on day of discharge. RESULTS: Patients with >7 days of V-V ECMO support had decreased ambulation and AMPAC scores compared to those with <7 days (70.5 vs. 162.1, p < 0.01 and 12.3 vs. 16.4, p = 0.01, respectively). PT/OT initiation within 7 days after starting V-V ECMO significantly improved ambulation and AMPAC scores (163.5 vs. 59.5, p < 0.001, and 16.6 vs. 11.8, p < 0.01, respectively). Additionally, in patients with >7 days of V-V ECMO support, those who began PT/OT within 8 days of V-V ECMO cannulation had significantly improved ambulation and AMPAC scores (151.8 vs. 44.2, p < 0.01, and 16.5 vs. 11.0, p < 0.01, respectively). CONCLUSION: Early PT/OT initiation in severe ARDS patients managed on V-V ECMO is associated with improved patient functional activity on day of discharge. Our study further supports the use of V-V ECMO in treatment of severe ARDS without sedation/neuromuscular blockade and specifically demonstrates PT/OT should be started early following V-V ECMO cannulation.

Lung transplantation for coronavirus disease 2019 associated severe acute respiratory distress syndrome.

PURPOSE OF REVIEW: The purpose of this review is to analyze the most recent and relevant literature involving lung transplantation for coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS), the pathological mechanisms of lung injury, selection criteria and outcomes. RECENT FINDINGS: Pathological analysis of lungs after COVID-19 ARDS has shown architectural distortion similar to that observed in explanted lungs from patients undergoing lung transplantation for end-stage lung diseases such as emphysema. Short-term outcomes after lung transplantation for COVID-19 associated respiratory failure are comparable to those performed for other indications. SUMMARY: Lung transplantation after COVID-19 ARDS is a potentially life-saving procedure for appropriately selected patients with no evidence of lung function recovery despite maximal treatment. Lung transplantation should be ideally performed in high-volume centers with expertise.

Lung transplantation for coronavirus disease 2019 acute respiratory distress syndrome/fibrosis: silver lining of a global pandemic.

PURPOSE OF REVIEW: The COVID-19 pandemic revolutionized the field of lung transplantation, as lung transplant is now an acceptable life-saving therapy for select patients with COVID-19-associated acute respiratory distress syndrome (ARDS), while prior to the pandemic, few transplants were performed for ARDS. This review article details the establishment of lung transplantation as a viable therapy for COVID-19-related respiratory failure, how to evaluate COVID-19 patients for lung transplant, and specific technical considerations for the operation. RECENT FINDINGS: Lung transplantation is a life-altering treatment for two distinct cohorts of COVID-19 patients: those with irrecoverable COVID-19-associated ARDS and those who recover from the initial COVID-19 insult but are left with chronic, debilitating post-COVID fibrosis. Both cohorts require stringent selection criteria and extensive evaluation to be listed for lung transplantation. As the first COVID-19 lung transplantation was recently performed, long-term outcomes are lacking; however, short-term outcome data of COVID-19-related lung transplants are promising. SUMMARY: Given the challenges and complexities associated with COVID-19-related lung transplantation, strict patient selection and evaluation are required with an experienced multidisciplinary team at a high-volume/resource center. With promising short-term outcome data, ongoing studies are needed to assess long-term outcomes of COVID-19-related lung transplants.

Low-dose IL-2 prevents murine chronic cardiac allograft rejection: Role for IL-2-induced T regulatory cells and exosomes with PD-L1 and CD73.

To determine the effects and immunological mechanisms of low-dose interleukin-2 (IL-2) in a murine model of chronic cardiac allograft rejection (BALB/c to C57BL/6) after costimulatory blockade consisting of MR1 (250 µg/ip day 0) and CTLA4-Ig (200 µg/ip day 2), we administered low-dose IL-2 (2000 IU/day) starting on posttransplant day 14 for 3 weeks. T regulatory (Treg) cell infiltration of the grafts was determined by immunohistochemistry; circulating exosomes by western blot and aldehyde bead flow cytometry; antibodies to donor MHC by immunofluorescent staining of donor cells; and antibodies to cardiac self-antigens (myosin, vimentin) by ELISA. We demonstrated that costimulation blockade after allogeneic heart transplantation induced circulating exosomes containing cardiac self-antigens and antibodies to both donor MHC and self-antigens, leading to chronic rejection by day 45. Treatment with low-dose IL-2 prolonged allograft survival (>100 days), prevented chronic rejection, and induced splenic and graft-infiltrating CD4+ CD25+ Foxp3 Treg cells by day 45 and circulating exosomes (Foxp3+) with PD-L1 and CD73. MicroRNA 142, associated with the TGFß pathway, was significantly downregulated in exosomes from IL-2-treated mice. In conclusion, low-dose IL-2 delays rejection in a murine model of chronic cardiac allograft rejection and also induces graft-infiltrating Tregs and circulating exosomes with immunoregulatory molecules.