Citations

Background: Telomeres are repetitive sequences at the end of linear chromosomes that preserve genetic information. Patients with telomere biology disorders (TBDs) are subject to multiorgan manifestations, which include the liver. However, due to the rare nature of the disorder, these manifestations are not fully characterized. Methods: Here, we describe the hepatic manifestations of patients with TBD at a large tertiary center within a specialized TBD clinic; 121 consecutive patients with TBD seen from 2017 to 2024 were included. The median age of the TBD diagnosis was 43 years old, with 60% male. The most common pathogenic/likely pathogenic variant was TERT (25%), followed by RTEL1 (10%) and TERC (7%). Results: Evidence of hepatic involvement in TBD was observed in 60% of patients (73 of 121), as determined by imaging studies or abnormal liver chemistries. Hepatic steatosis was the most prevalent imaging finding (56%), while a cholestatic pattern of liver injury was the predominant laboratory abnormality (73%). Biopsy-proven portosinusoidal vascular disorder was present in 4 patients. Findings of portal hypertension were observed in 25 patients (34%), with decompensation observed in 12 patients (16%). Traditional liver imaging modalities (computer tomography, ultrasound, and MRI) were compared with magnetic resonance elastography in 41 patients. Of these, 7 patients had abnormal magnetic resonance elastography with normal traditional imaging (17%), indicating higher sensitivity of magnetic resonance elastography to detect liver involvement. Conclusions: This study describes the liver manifestations within a cohort of patients with TBD with findings of portosinusoidal vascular disorder and hepatopulmonary syndrome similar to other cohorts and a noted higher prevalence of hepatic steatosis as compared with the general population. Liver stiffness measurements, integrated with imaging and laboratory testing, further improve characterization of hepatic manifestations in TBD.

Abstract Rationale Idiopathic Pulmonary Fibrosis (IPF) is characterized by chronic progressive pulmonary fibrosis and high mortality. Genetic markers, summarized into a polygenic risk score (PRS), associate with IPF in well-phenotyped research cohorts. Objectives To evaluate the performance of the PRS using real-world data from routinely captured electronic healthcare records. Methods We conducted an observational study evaluating the association of a PRS for IPF with electronic healthcare record diagnosis of IPF as well as lung transplant-free survival in four independent cohorts; the Mass General Brigham Biobank (MGBB), Mayo Clinic Biobank (MCBB), Mayo Clinic Tapestry Cohort (Tapestry), and U.K. Biobank (UKBB). We used multivariable logistic regression and multivariable Cox proportional hazards models adjusting for age, gender, and principal components of ancestry. The cohorts then underwent fixed and random effects meta-analysis. Measurements and Main Results Of 37,709; 44,195; 43,202; and 447,422 participants from MGBB, MCBB, Tapestry and UKBB respectively, 1,015 (2.7%) 2,879 (6.5%), 1,310 (3.0%), and 2,742 (0.6%) participants had an IPF diagnosis. Meta-analysis demonstrated a high-risk PRS associated with IPF diagnosis, OR 2.88 (95%CI 2.41-3.44) compared to all other individuals. A high-risk PRS also associated with the composite endpoint of mortality or lung transplant among those with an IPF diagnosis, HR 1.23(95%CI 1.11-1.35) compared to all other individuals. Conclusions A PRS can identify those at risk for an IPF diagnosis and mortality in biobank-scale data, which may have implications for clinical decisions. Further work is necessary to evaluate the utility of adding genetics in clinical settings.

Abstract Background Telomere maintenance and surfactant-related genetic mutations are increasingly recognized as contributing factors in familial pulmonary fibrosis (PF). Pathogenic variants in the SFTPA2 gene have been associated with early-onset pulmonary fibrosis and an elevated risk of developing lung cancer. Currently, PF lacks a definitive cure beyond lung transplantation, and treatment options remain limited. Understanding the prevalence and clinical implications of pathogenic SFTPA2 variants is critical. This study aims to assess the prevalence of PF, lung cancer, and other co-morbidities among individuals carrying pathogenic SFTPA2 variants. Ultimately, this study seeks a comprehensive understanding of the natural history and potential screening needs for SFTPA2 variants. Methods Individuals with pathogenic SFTPA2 variants were identified in the Tapestry genomic database at our academic medical center. Electronic medical records (EMR) were reviewed for personal or family histories of PF, lung cancer, and other significant comorbidities. Imaging reports were evaluated for radiographic evidence of PF or lung cancer. Studies were approved by the local IRB. Results Out of 98,109 participants in the Tapestry database, 18 individuals were identified as carriers of SFTPA2 variants. The variants (NM_001098668.4) included c.460G>C - p.(Ala154Pro) in 13 individuals, c.557A>G - p.(Tyr186Cys) in 1 individual, and c.532G>A - p.(Val178Met) in 4 individuals. The mean age was 60.5 years, and 67% were female. No participants had a formal diagnosis of PF; however, five (28%) had prior chest CTs showing ground-glass opacities, fibrosis, or irregular nodularity. EMR review did not confirm clinically significant PF. Notably, 44% reported a family history of primary lung cancer, though no familial PF was documented. Comorbidities included inflammatory bowel disease (22%, with a tapestry cohort prevalence of 9%) and a personal history of cancer in 44%, encompassing nine distinct malignancies such as metastatic colon adenocarcinoma (1), prostate cancer (1), basal cell carcinoma of the skin (1), endometrial cancer (1), breast cancer (2), melanoma (1), and squamous cell carcinoma of the skin (1). Conclusions In this cohort of individuals with SFTPA2 variants, no cases of clinically confirmed PF or lung cancer were identified. However, there was a notable prevalence of abnormal parenchymal chest CT findings, inflammatory bowel disease, personal cancer history, and family history of lung cancer. These findings underscore the variable penetrance of SFTPA2 variants and highlight the need for longitudinal studies to elucidate the genetic, environmental, and immunologic factors that modulate disease expression. Improved understanding may inform screening strategies and therapeutic interventions for at-risk individuals. This abstract is funded by: None

Abstract Rationale Systemic sclerosis (SSc) is a rare, chronic autoimmune disease characterized by vasculopathy and fibrosis of the skin and internal organs. Among its manifestations, interstitial lung disease (ILD) is the leading cause of mortality, yet its clinical course is variable, ranging from stable to progressive pulmonary fibrosis (PPF). The 2022 ATS/ERS/JRS/ALAT guidelines defined progressive PPF as a phenotype of non- Idiopathic Pulmonary Fibrosis (IPF) - ILDs that behave similarly to IPF. Although a subset of SSc-ILD patients develop PPF, biomarkers predicting progression remain lacking. We and others have shown that endothelial dysfunction contributes to the progression of fibrotic lung disease, and that the pulmonary vasculature, continuously exposed to the bloodstream, is influenced by soluble circulating factors, including circulating extracellular vesicles (cEVs), which carry bioactive cargo capable of modulating endothelial behavior. Here, we investigated whether cEVs from SSc patients with distinct fibrotic phenotypes differentially influence human lung endothelial cells (ECs), promoting a pro-fibrotic endothelial phenotype. Methods plasma samples were collected from five groups: 1) Healthy controls (n = 4); 2) SSc-noILD (no high-resolution-CT (HCRT( or functional evidence of ILD at time of enrollment, n = 4); 3) SSc-ILD (HCRT and functional evidence of ILD without meeting the PPF criteria at time of sampling, n = 3); 4) SSc-PPF (meeting the PPF criteria, plasma collected prior to anti-fibrotic therapy, n = 4); 5) IPF (plasma collected prior to anti-fibrotic therapy, n = 3). cEVs were isolated using size-exclusion-chromatography and characterized using Nanoparticle Tracking Analysis (NTA). Human lung ECs were treated with cEVs from the five groups (2x109 particles/ml, 48 hours), followed by qPCR for markers selected for their established involvement in endothelial dysfunction during lung fibrotic progression. Results NTA showed no significant differences in plasma cEV concentrations across the five groups. Human lung ECs exposed to cEVs from SSc or SSc-ILD patients exhibited no significant gene expression changes compared to healthy controls. In contrast, cEVs from SSc-PPF patients markedly downregulated endothelial identity (PECAM1, ERG, TEK), barrier integrity (CDH13, S1PR1), and basement membrane (COL4A1, HSPG2) genes, similarly to changes induced by cEVs from IPF patients. Conclusion cEVs from SSc-PPF patients induce pro-fibrotic transcriptional changes in lung ECs resembling those induced by IPF cEVs and distinct from SSc-ILD cEVs, suggesting that EVs carry cargo that both reflect and influence fibrosis progression. These findings highlight the potential of cEVs as biomarkers for identifying SSC-ILD patients at risk of progression and highlight the clinical relevance of future studies aimed at characterizing their cargo. This abstract is funded by: James Depauw Grant for Pilot Projects

Abstract Pulmonary fibrosis (PF) involves excessive collagen accumulation, yet mechanisms shifting the balance of synthesis and degradation toward net deposition remain unclear. Myeloperoxidase (MPO) inversely correlates with survival in PF. Using the bleomycin model, we found MPO knockout (MPOko) mice were protected from fibrosis, and pharmacological MPO inhibition after peak inflammation (day 7) recapitulated this protection. MPO persisted in lung tissue 21 days post-injury despite neutrophil efflux, linking acute inflammation to sustained remodeling. Mechanistically, we identified that MPO inhibits Cathepsin K (CatK), a potent collagenolytic enzyme involved in fibrosis resolution. Notably, CatK gene expression ( CTSK ) is elevated in PF, suggesting post-translational inhibition of CatK. MPOko and inhibitor-treated mice exhibited elevated CatK activity after bleomycin; exogenous addition of pathophysiologic concentrations of MPO reduced CatK activity in mouse precision-cut lung slices and human fibroblasts. Biochemically, MPO reduced CatK activity to 33% of control. In two distinct cohorts of PF patients, we observed significantly increased MPO protein levels in platelet poor plasma and in lung tissue. In PF patients, 62% had MPO levels in platelet poor plasma exceeding healthy controls, while lung tissue from other PF patients showed significantly elevated MPO staining. Plasma levels were inversely correlated with decreased survival, FVC, and DLCO. These findings establish MPO as a post-translational inhibitor of CatK-mediated collagenolysis, revealing a mechanism linking acute inflammation to sustained fibrosis and suggest a patient subpopulation that may benefit from MPO-targeted therapy. Graphical Abstract Myeloperoxidase persists in lung tissue after injury and inhibits cathepsin K activity, impairing collagen degradation and promoting extracellular matrix accumulation during pulmonary fibrosis.

Abstract Background New insights into community-acquired pleural infection microbiology may enable development of more rapid and accessible diagnostics that can streamline treatment. This study systematically compared molecular approaches for pathogen detection in pleural fluid from patients with such infections. Considering the need for rapid results with minimum hands-on time and test complexity, off-label use of the cassette-based, random-access BIOFIRE Joint Infection Panel (BF-JIP, bioMérieux) with and without supplementary in-house polymerase chain reaction (PCR) assays was evaluated. Methods Pleural fluids from 162 subjects from the Mayo Clinic (Rochester, Minnesota) and Haukeland University Hospital (Bergen, Norway), where molecular tests are routinely used for analyzing pleural fluid, were studied. The performance of the BF-JIP was compared to 16S rRNA gene PCR followed by Sanger and/or next-generation sequencing (16S rRNA gene PCR/sequencing), an in-house PCR panel specifically designed for pleural space infections, and culture. Results The BF-JIP supplemented with 3 in-house PCR assays targeting Fusobacterium nucleatum group, Streptococcus intermedius/constellatus, and Aggregatibacter aphrophilus detected 96.8% of pleural infections, providing complete microbial profiles in 70.1%. In comparison, the detection rate of 16S rRNA gene PCR/sequencing was 92.2%, providing complete microbial profiles in 87.0%. Culture detected bacteria in only 31.9% of pleural fluids, providing complete microbial profiles in 15.3%. Conclusions These results underscore the importance of molecular approaches in diagnosing pleural space infections and demonstrate the feasibility of panel-based PCR-based diagnostics for these sometimes-complex infections. The BF-JIP, designed for testing synovial fluid, could be modified to provide a useful diagnostic for testing pleural fluid.

Abstract Introduction: We present a case of constrictive bronchiolitis with paraneoplastic autoimmune multi-organ syndrome (PAMS) treated with lung transplantation. To our knowledge, this is the first reported case of PAMS with constrictive bronchiolitis managed with this approach. Presentation: A 45-year-old woman presented with 3 months of dyspnea. PFTs showed severe airflow obstruction with air trapping and no immediate bronchodilator response. [FEV1 0.94L (z: -3.9), FVC 2.98L (z: -0.515), TLC 4.89L (z: 1.0), RV 1.70L (z: 2.4) and DLCO 22 ml/min/mmhg (z: 0.58)] CT chest with expiratory views showed air trapping in the left upper lobe and ground glass opacities, consistent with constrictive bronchiolitis. 6 months prior, she was diagnosed with abdominal grade 1 follicular lymphoma, treated with Bendamustine and Rituximab. One month into treatment, she developed a lichenoid rash involving the oro-gential mucosa and erythematous papular skin eruptions. Her eruptions and constrictive bronchiolitis were consistent with PAMS with pulmonary involvement. The rash improved with oral steroids and topical therapies, but her pulmonary symptoms did not. The likelihood of progression was low, so lymphoma was not a contraindication for lung transplantation. To ensure complete metabolic remission, she was further treated with R-CHOP and maintained on Rituximab. During transplant evaluation, FEV1 was 30% with NYHA class II, Karnofsky score 60 and she required 4L oxygen. She grew mycobacterium abscessus subspecies abscessus on 3 different sets of induced sputum. Secondary to radiographic findings consistent with NTM-PD (bronchial wall thickening and mucoid impaction) and pending lung transplant, she was treated with omadacycline, tedizolid, amikacin and clofazimine until sputum culture negativity (3-months). She underwent lung transplantation and received pre-operative Mycophenolate and Methylprednisolone without induction immunosuppression. Post-operatively she was started on Tacrolimus, Mycophenolate Mofetil and Prednisone. M. Abscessus therapy continued for 2 months post-transplant. At 6 months post-transplant, she is well, and PFTs are improving without evidence of organ rejection, lymphoma recurrence, or M. abscessus infection. Discussion: Pulmonary involvement in PAMS is associated with high mortality and is not reversed by treatment of the neoplasm, due to non-reversible destruction of small airways. The only disease modifying therapy is lung transplant. Her lymphoma recurrence risk was very low after 2 years of remission following initial treatment, and as her lymphoma was not associated with immunosuppression, post-transplant immunosuppression likely does not increase risk of recurrence. Additionally, while mycobacterium abscessus poses significant risks, intensive treatment in the peri-transplant period can help allow for safe transplantation.

ABSTRACT Pneumocystis jirovecii pneumonia (PJP) remains a significant cause of morbidity and mortality during AIDS. In AIDS, the absence of CD4 immunity results in exuberant and often fatal PJP. In addition, organism clearance requires a balanced macrophage response since excessive inflammation promotes lung injury and respiratory failure. Corticosteroids given in addition to antibiotics significantly improve outcomes during PJP. However, concerns exist that corticosteroids further suppress immunity and increase co-infections. New strategies to promote killing and clearance of Pneumocystis while balancing lung inflammation are required. Prior studies have shown that innate immunity to Pneumocystis is mediated by C-type lectin receptors (CLRs) on macrophages and involves downstream CARD9 activation. CARD9 can be targeted by a novel specific small molecule inhibitor (BRD5529) that significantly reduces inflammatory signaling by macrophages. CARD9 serves as the central intracellular molecule through which Dectin-1, Dectin-2, Mincle, and other CLRs signal. Dectin-1 CLR is activated through its own intracytoplasmic domain, whereas other innate CLRs (e.g., Dectin-2 and Mincle) require interactions with a common Fc-gamma receptor (FcγR) accessory chain to mediate responses. We now observe that mice double deficient in both Dectin-1 and Fcer1g (which lack the FcγR gamma chain) exhibit markedly reduced organism clearance compared with Card9 −/− infected animals. These mice also possess deficiencies in immunoglobulin (Ig) Fc receptors directly mediating antibody responses, further implicating altered humoral responses in Pneumocystis killing. We further demonstrate in the Pneumocystis pneumonia (PCP) mouse model that BRD5529 administration successfully suppresses inflammatory cytokines. Our data support that innate immune responses through the CLR-CARD9 axis and humoral response act together to mediate effective responses resulting in optimal organism killing and generation of host inflammatory responses. Furthermore, host lung inflammation during PCP may be successfully reduced with a novel CARD9 small molecule inhibitor. IMPORTANCE Pneumocystis pneumonia (PCP) causes severe respiratory impairment in hosts with suppressed immunity, particularly those with CD4 deficiencies, such as HIV. In addition to lymphocytic immunity, both innate and humoral immunities also participate in host defense against Pneumocystis . In the current studies, we defined the relative roles of CLR receptor-mediated inflammation, as well as FcgR-related inflammation and clearance of Pneumocystis organisms. Our studies reveal important roles for CLR activities for inducing lung inflammation, which can be ameliorated with a novel small molecule inhibitor of the CARD9 adaptor protein that is necessary for CLR signaling. In contrast, FcgR has a dominant role in organism clearance, underscoring an integral role of humoral responses for the elimination of this infection.