Katrin Esther Hostettler

Introduction: In-hospital cardiac arrest is associated with poor outcomes, yet peri-procedural code status discussions before bronchoscopy may be inconsistent, particularly in patients with elevated procedural risk. Methods: We conducted an anonymous online survey of a convenience sample of hospital-based pulmonologists in Germany and Switzerland between April and July 2025. The survey assessed routine practices and attitudes regarding peri-procedural code status discussions, risk stratification, and management of patients with pre-existing No-CPR status. Owing to distribution through multiple channels and secondary forwarding, a precise response rate could not be calculated. Results: A total of 148 pulmonologists participated (mean age 47.8 years; 94.6% board-certified). Discussions regarding CPR preferences were conducted almost always or most of the time before high-risk bronchoscopies by 67.6% of respondents, but were rarely or almost never performed before low-risk procedures by 72.0%. Respondents more frequently reported procedural risk than patient-related factors as a trigger for these discussions. Peri-procedural No-CPR status was considered controversial by 44.9%, and responsibility for these discussions varied among respondents. Only 25% reported formal institutional training. Conclusions: Substantial variability exists in peri-procedural code status practices before bronchoscopy. Clearer responsibilities and structured guidance are needed to better align care with patient preferences.

We report on a 38-year-old patient who presented with rapidly progressive interstitial lung disease (ILD), without any signs of muscular involvement. Antinuclear antibody testing by indirect immunofluorescence revealed a nuclear titer of 1:320 with a fine speckled and a cytoplasmic titer of 1:1’280 with a fine speckled pattern. Subsequent myositis-specific and myositis-associated antibody tests with commercial multiplex dot-immunoassays showed a strong positive result for anti-Ha antibodies, also confirmed by protein immunoprecipitation, establishing the diagnosis of anti-synthetase syndrome with associated ILD. Despite initial improvement after treatment with intravenous cyclophosphamide and high dose steroids, he relapsed shortly after, with additional muscular symptoms. Subsequent escalation of therapy with rituximab resulted in sustained remission. Considering the scarcity of data about the clinical presentation and prognosis of patients with anti-Ha antibodies, our report provides additional information on diagnostic challenges and therapeutic response in these patients.

Background: Severe chronic lung diseases are frequently associated with a high symptom burden, dependence on caregivers, poor quality of life and a high risk of early mortality. Medical, psychological and social situations can become increasingly complex despite established disease-modifying treatment. In patients with lung cancer, palliative care (PC) is well established; however, PC is typically underused in chronic lung diseases including chronic obstructive pulmonary disease, interstitial lung disease and pulmonary hypertension. With this position paper the multidisciplinary and interprofessional expert group aims to guide health care professionals on how to assess and address PC needs and when to refer patients for specialized PC. Furthermore, to increase awareness and encourage interprofessional education and research on PC in patients with chronic lung diseases. Summary: PC is a holistic, multidisciplinary, person-centred approach to control symptoms, and improve quality of life in patients with severe chronic respiratory diseases and to support their caregivers. PC and symptom-oriented treatment should be delivered early alongside with disease-modifying treatment and adapted to individual values and needs of patients and caregivers. General PC can be provided by non-specialists whereas a specialized PC team is needed when symptoms become challenging to treat and care situations become increasingly complex. Key Messages: Patients with severe chronic lung diseases and their caregivers benefit tremendously from PC, which ranges from simple symptom control to complex interventions delivered by multidisciplinary and interprofessional teams. There is still a clear need to improve availability, awareness, education, and research on PC for patients with severe chronic lung diseases.

Rationale: Basal cells (BC) appear ectopically within the lung parenchyma of interstitial lung disease (ILD) patients, potentially through migration of airway BC or though trans-differentiation of alveolar epithelial type 2 (AT2) cells. The exact origin and function of these ectopic alveolar BC remains elusive. By comparing ectopic alveolar to “classical” airway BC, we aimed to get a better understanding of the origin and characteristics of alveolar BC in ILD. Methods: Alveolar and airway BC were isolated from transbronchial and airway mucosal biopsies, respectively, from the same ILD patients and expanded in culture. Samples were analysed by single-cell RNA sequencing (scRNA-seq), TaqMan real-time PCR and immunochemistry. Results: scRNA-seq analysis revealed several differences in gene expression that suggested a shift to a more mesenchymal-like phenotype and a decrease in keratinisation genes in alveolar compared to airway BC. Specific AT2 cell marker genes were not expressed in either BC type. While the morphology, wound repair and proliferation capacities of BC from both origins were not significantly different, alveolar BC formed significantly fewer organoids, expressing more MUC5B. After instillation into bleomycin-injured mice, alveolar and airway BC showed similar engraftment, differentiation capacity and effects on fibrosis. Conclusion: Despite similar overall functionality in vitro and after instillation into bleomycin-injured mice, alveolar and airway BC differed in their transcriptomes and in their capacities to form and to differentiate in organoids. Our data provide no evidence to support their potential derivation from AT2 cells.

Rationale: Basal cells (BC) appear ectopically within the lung parenchyma of interstitial lung disease (ILD) patients, potentially through migration of airway BC or though trans-differentiation of alveolar epithelial type 2 (AT2) cells. The exact origin and function of these ectopic alveolar BC remains elusive. By comparing ectopic alveolar to “classical” airway BC, we aimed to get a better understanding of the origin and characteristics of alveolar BC in ILD. Methods: Alveolar and airway BC were isolated from transbronchial and airway mucosal biopsies, respectively, from the same ILD patients and expanded in culture. Samples were analyzed by single cell RNA sequencing (scRNA-seq), TaqMan RT-PCR, and immunochemistry. Results: scRNA-seq analysis revealed several differences in gene expression that suggested a shift to a more mesenchymal-like phenotype and a decrease in keratinization genes in alveolar compared to airway BC. Specific AT2 cell marker genes were not expressed in either BC type. While the morphology, wound repair and proliferation capacities of BC from both origins were not significantly different, alveolar BC formed significantly fewer organoids, expressing more MUC5B. After instillation into bleomycin-injured mice, alveolar and airway BC showed similar engraftment, differentiation capacity and effects on fibrosis. Conclusion: Despite similar overall functionality in vitro and after instillation into bleomycin-injured mice, alveolar and airway BC differed in their transcriptomes and in their capacities to form and to differentiate in organoids. Our data provide no evidence to support their potential derivation from AT2 cells. Take home message: Alveolar and airway basal cells differ in their transcriptomes and in their capacities to form and to differentiate in organoids, although with no indication of an AT2 cell origin.

Background: Honeycomb cysts (HC) within the alveolar region are distinct histopathological features in the lungs of idiopathic pulmonary fibrosis (IPF) patients. HC are lined with a single-or stratified layer of basal cells (BC), or with a bronchiolar-like epithelium composed of basal-, ciliated- and secretory epithelial cells. By using cultured IPF patient-derived alveolar BC, we aimed to establish an in vitro- and in vivo model to mimic HC formation in IPF. We (1) optimized conditions to culture and propagate IPF patient-derived alveolar BC, (2) cultured the cells on an air liquid interface (ALI) or in a three dimensional (3D) organoid model, and (3) investigated the cells` behavior after instillation into bleomycin-challenged mice. Methods: Alveolar BC were cultured from peripheral IPF lung tissue and grown on tissue-culture treated plastic, an ALI, or in a 3D organoid model. Furthermore, cells were instilled into bleomycin-challenged NRG mice. Samples were analyzed by TaqMan RT-PCR, immunoblotting, immunocytochemistry/immunofluorescence (ICC/IF), or immunohistochemistry (IHC)/IF. Mann–Whitney tests were performed using GraphPad Prism software. Results: Cultured alveolar BC showed high expression of canonical basal cell markers (TP63, keratin (KRT)5, KRT14, KRT17), robust proliferation, and wound closure capacity. The cells could be cryopreserved and propagated for up to four passages without a significant loss of basal cell markers. When cultured on an ALI or in a 3D organoid model, alveolar BC differentiated to ciliated- and secretory epithelial cells. When instilled into bleomycin-challenged mice, human alveolar BC cells formed HC-like structures composed of human basal-, and secretory epithelial cells within the mouse parenchyma. Conclusion: IPF patient-derived alveolar BC on an ALI, in 3D organoids or after instillation into bleomycin-challenged mice form HC-like structures that closely resemble HC within the IPF lung. These models therefore represent powerful tools to study honeycomb formation, and its potential therapeutic inhibition in IPF.

Summary: Honeycomb cysts (HC) within the alveolar region are distinct histopathological features in the lungs of idiopathic pulmonary fibrosis (IPF) patients. HC are lined with basal cells (BC), or with a bronchiolar-like epithelium composed of basal-, ciliated- and secretory epithelial cells. By using cultured IPF patient-derived alveolar BC, we aimed to establish in vitro - and in vivo models to mimic HC formation in IPF. In order to do so, we cultured the cells (1) on an air liquid interface (ALI) or (2) in a three dimensional (3D) organoid model in vitro , and (3) investigated the cells’ behavior after instillation into bleomycin-challenged mice in vivo . Under the here tested in vitro - and in vivo conditions, alveolar BC differentiate and formed HC-like structures, which closely resemble HC within the IPF lung. These models therefore represent powerful tools to study HC formation, and its potential therapeutic inhibition in IPF.

Introduction: Long-term survival after allogeneic hematopoietic cell transplantation (alloHCT) is limited by chronic pulmonary graft-versus-host disease (cGvHD) which comprise classical bronchiolitis obliterans (BO), but also various forms of restrictive disease. Histological confirmation of BO by transbronchial forceps biopsy has a low sensitivity and surgical lung biopsy is gold standard. The clinical diagnosis of BO syndrome (BOS) is based on lung function and radiological data. However, sensitivity of BOS-criteria for biopsy-proven BO is unsatisfactory. Aim: Retrospective study to investigate the diagnostic value of transbronchial cryobiopsy in alloHCT-patients with suspicion of pulmonary cGvHD not fulfilling BOS-criteria. Histology was integrated into the multidisciplinary discussion (MDD) and diagnostic consensus was sought. Results: 20 patients underwent cryobiopsy. In 13/20 patients (65%) cryobiopsies revealed findings leading to a specific diagnosis: obliterative/lymphocytic bronchiolitis in four (20%), distinct parenchymal abnormalities leading to the diagnosis of interstitial lung disease (ILD) or cGvHD-associated ILD in 9/20 patients (45%). In 7/20 patients (35%), cryobiopsies showed normal lung parenchyma. In 4/7, a consensus diagnosis of BOS was reached after MDD. Complications of cryobiopsy included pneumothorax (25%) and locally controlled bleeding (20%). Conclusion: In alloHCT-patients with suspicion of pulmonary cGvHD not fulfilling BOS-criteria, transbronchial cryobiopsy led to a histology-based diagnosis in two-thirds of patients, and – embedded in an MDD - to a final diagnosis in 90% of patients.