Sfrp1 inhibits lung fibroblast invasion during transition to injury-induced myofibroblasts.

BACKGROUND: Fibroblast-to-myofibroblast conversion is a major driver of tissue remodelling in organ fibrosis. Distinct lineages of fibroblasts support homeostatic tissue niche functions, yet their specific activation states and phenotypic trajectories during injury and repair have remained unclear. METHODS: We combined spatial transcriptomics, multiplexed immunostainings, longitudinal single-cell RNA-sequencing and genetic lineage tracing to study fibroblast fates during mouse lung regeneration. Our findings were validated in idiopathic pulmonary fibrosis patient tissues in situ as well as in cell differentiation and invasion assays using patient lung fibroblasts. Cell differentiation and invasion assays established a function of SFRP1 in regulating human lung fibroblast invasion in response to transforming growth factor (TGF)ß1. MEASUREMENTS AND MAIN RESULTS: We discovered a transitional fibroblast state characterised by high Sfrp1 expression, derived from both Tcf21-Cre lineage positive and negative cells. Sfrp1 + cells appeared early after injury in peribronchiolar, adventitial and alveolar locations and preceded the emergence of myofibroblasts. We identified lineage-specific paracrine signals and inferred converging transcriptional trajectories towards Sfrp1 + transitional fibroblasts and Cthrc1 + myofibroblasts. TGFß1 downregulated SFRP1 in noninvasive transitional cells and induced their switch to an invasive CTHRC1+ myofibroblast identity. Finally, using loss-of-function studies we showed that SFRP1 modulates TGFß1-induced fibroblast invasion and RHOA pathway activity. CONCLUSIONS: Our study reveals the convergence of spatially and transcriptionally distinct fibroblast lineages into transcriptionally uniform myofibroblasts and identifies SFRP1 as a modulator of TGFß1-driven fibroblast phenotypes in fibrogenesis. These findings are relevant in the context of therapeutic interventions that aim at limiting or reversing fibroblast foci formation.

Ex vivo tissue perturbations coupled to single-cell RNA-seq reveal multilineage cell circuit dynamics in human lung fibrogenesis.

Pulmonary fibrosis develops as a consequence of failed regeneration after injury. Analyzing mechanisms of regeneration and fibrogenesis directly in human tissue has been hampered by the lack of organotypic models and analytical techniques. In this work, we coupled ex vivo cytokine and drug perturbations of human precision-cut lung slices (hPCLS) with single-cell RNA sequencing and induced a multilineage circuit of fibrogenic cell states in hPCLS. We showed that these cell states were highly similar to the in vivo cell circuit in a multicohort lung cell atlas from patients with pulmonary fibrosis. Using micro-CT-staged patient tissues, we characterized the appearance and interaction of myofibroblasts, an ectopic endothelial cell state, and basaloid epithelial cells in the thickened alveolar septum of early-stage lung fibrosis. Induction of these states in the hPCLS model provided evidence that the basaloid cell state was derived from alveolar type 2 cells, whereas the ectopic endothelial cell state emerged from capillary cell plasticity. Cell-cell communication routes in patients were largely conserved in hPCLS, and antifibrotic drug treatments showed highly cell type-specific effects. Our work provides an experimental framework for perturbational single-cell genomics directly in human lung tissue that enables analysis of tissue homeostasis, regeneration, and pathology. We further demonstrate that hPCLS offer an avenue for scalable, high-resolution drug testing to accelerate antifibrotic drug development and translation.

Domestic Parasitic Infections in Patients with Asthma and Eosinophilia in Germany - Three Cases with Learnings in the Era of Anti- IL5 Treatments.

Eosinophilic inflammation is a hallmark of asthma, and blood eosinophilia has been established as a biomarker for phenotyping asthma and predicting the response to anti-IL5 treatments. Although parasitic infections are rare in European adults, they remain an important differential diagnosis for blood eosinophilia. We present three patients with both domestic parasitic infections and asthma to raise awareness of the potential challenge of eosinophilia and to provide experience in the management of parasitic infections in the setting of planned or ongoing anti-IL5 treatment. One, a patient from Croatia with moderate asthma but severe blood eosinophilia had an underlying Strongyloides stercoralis infection, with positive stool cultures. Second, a patient with severe allergic asthma and gastrointestinal symptoms had a positive S. stercoralis titer in serology with a clinical response to treatment with ivermectin. Third, a patient with severe nonallergic eosinophilic asthma and eosinophilic granulomatosis with polyangiitis (EGPA) showed an increasing hepatic tumour under anti-IL5-receptor therapy. Positive serology confirmed the diagnosis of Echinococcus multilocularis, and albendazole therapy was initiated. Anti-IL5 therapies were safely started (Patient 2) or resumed (Patient 3) after the initiation of antiparasitic treatment. Screening for parasitic infections is useful in cases of hypereosinophilia, extrapulmonary symptoms or stay in endemic regions.

Posterior reversible encephalopathy syndrome after lung transplantation: Risk factors and management.

INTRODUCTION: Posterior reversible encephalopathy syndrome is a rare neurologic complication that can occur under immunosuppressive therapy with CNI after organ transplantation. METHODS: We retrospectively reviewed medical records of 545 patients who underwent lung transplantation between 2012 and 2019. Within this group, we identified 30 patients with neurological symptoms typical of PRES and compared the characteristics of patients who were diagnosed with PRES (n = 11) to those who were not (n = 19). RESULTS: The incidence of PRES after lung transplantation was 2%. Notably, 73% of the patients with PRES were female and the mean age was 39.2. Seizure (82% vs. 21%, p = .002) was the most common neurological presentation. The risk of developing PRES was significantly associated with age (OR = .92, p < .0001) and having cystic fibrosis (CF) (OP = 10.1, p < .0001). Creatinine level (1.9 vs. 1.1 mg/dl, p = .047) and tacrolimus trough level (19.4 vs. 16.5 ng/ml, p = .048) within 1 week prior to neurological symptoms were significantly higher in patients with PRES. CONCLUSION: Renal insufficiency and high tacrolimus levels are associated with PRES. A change of immunosuppressive drug should be done after confirmed PRES diagnosis or immediately in case of severe neurological dysfunction to improve neurological outcomes and minimize the risk of early allograft rejection.

Outcome of lung transplant recipients infected with SARS-CoV-2/Omicron/B.1.1.529: a Nationwide German study.

PURPOSE: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is currently the major threat for immunocompromised individuals. The course of COVID-19 in lung transplant recipients in the Omicron era remains unknown. The aim of the study was to assess outcome and associated factors in lung transplant recipients in a German-wide multicenter approach. METHODS: All affected individuals from January 1st to March 20th, 2022 from 8 German centers during the Omicron wave were collected. Baseline characteristics and antiviral measures were associated with outcome. RESULTS: Of 218 patients with PCR-proven SARS-CoV-2 infection 166 patients (76%) received any early (< 7 days) antiviral therapy median 2 (interquartile range 1-4) days after symptom onset. Most patients received sotrovimab (57%), followed by remdesivir (21%) and molnupiravir (21%). An early combination therapy was applied in 45 patients (21%). Thirty-four patients (16%) developed a severe or critical disease severity according to the WHO scale. In total, 14 patients (6.4%) died subsequently associated with COVID-19. Neither vaccination and antibody status, nor applied treatments were associated with outcome. Only age and glomerular filtration rate < 30 ml/min/1.73m2 were independent risk factors for a severe or critical COVID-19. CONCLUSION: COVID-19 due to Omicron remains an important threat for lung transplant recipients. In particular, elderly patients and patients with impaired kidney function are at risk for worse outcome. Prophylaxis and therapy in highly immunocompromised individuals need further improvement.

[Use of antifibrotic drugs in interstitial lung disease]. / Einsatz antifibrotischer Medikamente bei interstitiellen Lungenerkrankungen.

The interstitial lung diseases ILDs are a heterogeneous group of diseases that often lead to progressive fibrosis of the lungs with corresponding functional impairment. With nintedanib, a tyrosinkinase inhibitor and angiokinase inhibitor, as well as pirfenidone, which unfolds its effect among other things by inhibiting the transforming growth factor ß, there are currently 2 approved antifibrotic drugs. In the rapidly progressing idiopathic pulmonary fibrosis IPF, the antifibrotic drugs nintedanib and pirfenidone have been established and approved in therapy for several years. The initiation of antifibrotic therapy should be carried out early after diagnosis by multidisciplinary discussion (MDD). In systemic scleroderma with lung involvement nintedanib should be used in the case of relevant fibrosis in addition to immunosuppressive therapy. Recently, nintedanib has also become a new option for the treatment of progressive fibrosing ILDs (PF-ILDs). This describes the course of various disease entities such as connective tissue disease associated ILDs (CTD-ILDs), fibrosing hypersensitivity pneumonitis or fibrosing courses of non-IPF idiopathic interstitial pneumonitis (non-IPF IIPs) that have a corresponding fibrose-related worsening of respiratory symptoms, a deterioration of lung-functioning parameters or a disease progression in CT. Although pirfenidone also shows positive signals for this group of patients in some selected studies, its use in PF-ILD is not yet recommended. In particular, gastrointestinal side effects can occur under therapy with antifibrotic drugs and require a long-term close interdisciplinary connection of patients.

Response to high-altitude triggers in seasonal asthmatics on and off inhaled corticosteroid treatment.

Background: Due to the effects of climate change, winter sport enthusiasts will be increasingly forced to stay at higher altitudes. High altitude (HA) environmental factors such as cold temperature, physical exertion, and hypoxia with subsequent hypocapnia due to hyperventilation have been shown to induce bronchoconstriction. With bronchial asthma being highly prevalent, asthmatics also will be increasingly exposed to HA environment and might experience increasing symptoms. Methods: We analysed the effects of HA factors at around 2600 m a.s.l. (metres above sea level) on lung function in mild seasonal asthmatics while they were routinely off (January) and on (March, after start of lowland pollen season) low-dose inhaled corticosteroid (ICS) treatment (n = 10), and matched healthy controls (n = 11). Results: Without inhaled corticosteroid (ICS) treatment mean FEV1 in asthmatics was 230 ml lower after exercise at HA compared to low altitude (LA, p < 0.05), while in healthy controls there was no significant difference. This decrease was mainly induced by cold and exercise at HA. During ICS treatment, this decrease was prevented. Methacholine response was reduced at HA compared to LA. Conclusions: The decrease of FEV1 in response to a combination of hypoxia, cold, and exercise is prevented by ICS treatment in mild, seasonal asthmatics. However, the FEV1 response to high altitude factors was overall small.

Spray drying siRNA-lipid nanoparticles for dry powder pulmonary delivery.

While all the siRNA drugs on the market target the liver, the lungs offer a variety of currently undruggable targets which could potentially be treated with RNA therapeutics. Hence, local, pulmonary delivery of RNA nanoparticles could finally enable delivery beyond the liver. The administration of RNA drugs via dry powder inhalers offers many advantages related to physical, chemical and microbial stability of RNA and nanosuspensions. The present study was therefore designed to test the feasibility of engineering spray dried lipid nanoparticle (LNP) powders. Spray drying was performed using 5% lactose solution (m/V), and the targets were set to obtain nanoparticle sizes after redispersion of spray-dried powders around 150 nm, a residual moisture level below 5%, and RNA loss below 15% at maintained RNA bioactivity. The LNPs consisted of an ionizable cationic lipid which is a sulfur-containing analog of DLin-MC3-DMA, a helper lipid, cholesterol, and PEG-DMG encapsulating siRNA. Prior to the spray drying, the latter process was simulated with a novel dual emission fluorescence spectroscopy method to preselect the highest possible drying temperature and excipient solution maintaining LNP integrity and stability. Through characterization of physicochemical and aerodynamic properties of the spray dried powders, administration criteria for delivery to the lower respiratory tract were fulfilled. Spray dried LNPs penetrated the lung mucus layer and maintained bioactivity for >90% protein downregulation with a confirmed safety profile in a lung adenocarcinoma cell line. Additionally, the spray dried LNPs successfully achieved up to 50% gene silencing of the house keeping gene GAPDH in ex vivo human precision-cut lung slices at without increasing cytokine levels. This study verifies the successful spray drying procedure of LNP-siRNA systems maintaining their integrity and mediating strong gene silencing efficiency on mRNA and protein levels both in vitro and ex vivo. The successful spray drying procedure of LNP-siRNA formulations in 5% lactose solution creates a novel siRNA-based therapy option to target respiratory diseases such as lung cancer, asthma, COPD, cystic fibrosis and viral infections.

FK506-Binding Protein 11 Is a Novel Plasma Cell-Specific Antibody Folding Catalyst with Increased Expression in Idiopathic Pulmonary Fibrosis.

Antibodies are central effectors of the adaptive immune response, widespread used therapeutics, but also potentially disease-causing biomolecules. Antibody folding catalysts in the plasma cell are incompletely defined. Idiopathic pulmonary fibrosis (IPF) is a fatal chronic lung disease with increasingly recognized autoimmune features. We found elevated expression of FK506-binding protein 11 (FKBP11) in IPF lungs where FKBP11 specifically localized to antibody-producing plasma cells. Suggesting a general role in plasma cells, plasma cell-specific FKBP11 expression was equally observed in lymphatic tissues, and in vitro B cell to plasma cell differentiation was accompanied by induction of FKBP11 expression. Recombinant human FKBP11 was able to refold IgG antibody in vitro and inhibited by FK506, strongly supporting a function as antibody peptidyl-prolyl cis-trans isomerase. Induction of ER stress in cell lines demonstrated induction of FKBP11 in the context of the unfolded protein response in an X-box-binding protein 1 (XBP1)-dependent manner. While deficiency of FKBP11 increased susceptibility to ER stress-mediated cell death in an alveolar epithelial cell line, FKBP11 knockdown in an antibody-producing hybridoma cell line neither induced cell death nor decreased expression or secretion of IgG antibody. Similarly, antibody secretion by the same hybridoma cell line was not affected by knockdown of the established antibody peptidyl-prolyl isomerase cyclophilin B. The results are consistent with FKBP11 as a novel XBP1-regulated antibody peptidyl-prolyl cis-trans isomerase and indicate significant redundancy in the ER-resident folding machinery of antibody-producing hybridoma cells.

Inhibition of SARS-CoV-2 replication in the lung with siRNA/VIPER polyplexes.

SARS-CoV-2 has been the cause of a global pandemic since 2019 and remains a medical urgency. siRNA-based therapies are a promising strategy to fight viral infections. By targeting a specific region of the viral genome, siRNAs can efficiently downregulate viral replication and suppress viral infection. However, to achieve the desired therapeutic activity, siRNA requires a suitable delivery system. The VIPER (virus-inspired polymer for endosomal release) block copolymer has been reported as promising delivery system for both plasmid DNA and siRNA in the past years. It is composed of a hydrophilic block for condensation of nucleic acids as well as a hydrophobic, pH-sensitive block that, at acidic pH, exposes the membrane lytic peptide melittin, which enhances endosomal escape. In this study, we aimed at developing a formulation for pulmonary administration of siRNA to suppress SARS-CoV-2 replication in lung epithelial cells. After characterizing siRNA/VIPER polyplexes, the activity and safety profile were confirmed in a lung epithelial cell line. To further investigate the activity of the polyplexes in a more sophisticated cell culture system, an air-liquid interface (ALI) culture was established. siRNA/VIPER polyplexes reached the cell monolayer and penetrated through the mucus layer secreted by the cells. Additionally, the activity against wild-type SARS-CoV-2 in the ALI model was confirmed by qRT-PCR. To investigate translatability of our findings, the activity against SARS-CoV-2 was tested ex vivo in human lung explants. Here, siRNA/VIPER polyplexes efficiently inhibited SARS-CoV-2 replication. Finally, we verified the delivery of siRNA/VIPER polyplexes to lung epithelial cells in vivo, which represent the main cellular target of viral infection in the lung. In conclusion, siRNA/VIPER polyplexes efficiently delivered siRNA to lung epithelial cells and mediated robust downregulation of viral replication both in vitro and ex vivo without toxic or immunogenic side effects in vivo, demonstrating the potential of local siRNA delivery as a promising antiviral therapy in the lung.

Tracheal stenosis in prolonged mechanically ventilated patients: prevalence, risk factors, and bronchoscopic management.

BACKGROUND: Various complications may arise from prolonged mechanical ventilation, but the risk of tracheal stenosis occurring late after translaryngeal intubation or tracheostomy is less common. This study aimed to determine the prevalence, type, risk factors, and management of tracheal stenoses in mechanically ventilated tracheotomized patients deemed ready for decannulation following prolonged weaning. METHODS: A retrospective observational study on 357 prolonged mechanically ventilated, tracheotomized patients admitted to a specialized weaning center over seven years. Flexible bronchoscopy was used to discern the type, level, and severity of tracheal stenosis in each case. We described the management of these stenoses and used a binary logistic regression analysis to determine independent risk factors for stenosis development. RESULTS: On admission, 272 patients (76%) had percutaneous tracheostomies, and 114 patients (32%) presented mild to moderate tracheal stenosis following weaning completion, with a median tracheal cross-section reduction of 40% (IQR 25-50). The majority of stenoses (88%) were located in the upper tracheal region, most commonly resulting from localized granulation tissue formation at the site of the internal stoma (96%). The logistic regression analysis determined that obesity (OR 2.16 [95%CI 1.29-3.63], P < 0.01), presence of a percutaneous tracheostomy (2.02 [1.12-3.66], P = 0.020), and cricothyrotomy status (5.35 [1.96-14.6], P < 0.01) were independently related to stenoses. Interventional bronchoscopy with Nd:YAG photocoagulation was a highly effective first-line treatment, with only three patients (2.6%) ultimately referred to tracheal surgery. CONCLUSIONS: Tracheal stenosis is commonly observed among prolonged ventilated patients with tracheostomies, characterized by localized hypergranulation and mild to moderate airway obstruction, with interventional bronchoscopy providing satisfactory results.

Polyomavirus exerts detrimental effects on renal function in patients after lung transplantation.

INTRODUCTION: Chronic kidney disease (CKD) is associated with significant morbidity and mortality after lung transplantation (LTX). Calcineurin inhibitor (CNI) nephrotoxicity is the leading cause of CKD. After kidney transplantation, polyomavirus-associated nephropathy (PyVAN) is a well-recognized problem. This study aims to evaluate the role of polyomavirus in patients after LTX. METHODS: From January 2017 to January 2020, all lung transplant recipients who performed follow-up visits in our center were included in the study and retrospectively assessed. We measured renal function (creatinine levels before and after transplantation), JCPyV, and BKPyV load by polymerase chain reaction (PCR) in serum and urine samples after transplantation. RESULTS: In total, 104 consecutive patients (59 males, 56.7%) with a mean age of 49.6 ± 11.1 years were identified. JCPyV was found in urine of 36 patients (34.6%) and serum of 3 patients (2.9%). BKPyV was found in urine of 40 patients (38.5%) and serum of 4 patients (3.8%), respectively. Urine evidence for JCPyV (p < 0.001, coefficient: +21.44) and BKPyV (p < 0.001, coefficient: +29.65) correlated highly with further kidney function decline. CONCLUSION: Kidney function deterioration is associated with JCPyV and BKPyV viruria in patients after LTX. This might indicate a role of PyVAN in lung transplant recipients.

Real-life effectiveness of biological therapies on symptoms in severe asthma with comorbid CRSwNP.

BACKGROUND: We aimed to evaluate the effectiveness of different antibody therapies on nasal polyp symptoms in patients treated for severe asthma. METHODS: We performed a retrospective analysis of patients with severe asthma and comorbid CRSwNP who were treated with anti-IgE, anti-IL-5/R or anti-IL-4R. CRSwNP symptom burden was evaluated before and after 6 months of therapy. RESULTS: Fifty patients were included hereof treated with anti-IgE: 9, anti-IL-5/R: 26 and anti-IL-4R: 15 patients. At baseline median SNOT-20 was similar among groups (anti-IgE: 55, anti-IL-5/R: 52 and anti-IL-4R: 56, p = 0.76), median visual analogue scale (VAS) for nasal symptoms was 4, 7 and 8 (p = 0.14) and VAS for total symptoms was higher in the anti-IL-4R group (4, 5 and 8, p = 0.002). After 6 months SNOT-20 improved significantly in all patient groups with median improvement of anti-IgE: -8 (p < 0.01), anti-IL-5/R: -13 (p < 0.001) and anti-IL-4R: -18 (p < 0.001), with larger improvement in the anti-IL-4R group than in anti-IgE (p < 0.001) and anti-IL-5/R (p < 0.001) groups. VAS nasal symptoms improved by median anti-IgE: 0 (n.s.), anti-IL-5/R: -1 (p < 0.01) and anti-IL-4R: -3 (p < 0.001), VAS total symptoms by anti-IgE: -1 (n.s.), anti-IL-5/R: -2 (p < 0.001) and anti-IL-4R: -2 (p < 0.001). CONCLUSIONS: Treatment by all antibodies showed effectiveness in reducing symptoms of CRSwNP in patients with severe asthma, with the largest reduction observed in anti-IL-4R-treated patients.

Letermovir in lung transplant recipients with cytomegalovirus infection: A retrospective observational study.

Letermovir is a new antiviral drug approved for the prophylaxis of CMV infection in allogeneic stem cell transplants. The aim of the study was to assess the therapeutic efficacy of letermovir in difficult to treat CMV infections in lung transplant recipients. All lung transplant recipients between March 2018 and August 2020, who have been treated with letermovir for ganciclovir-resistant or refractory CMV infection were included in the study and analysed retrospectively. In total, 28 patients were identified. CMV disease was present in 15 patients (53.6%). In 23 patients (82.1%), rapid response was noticed, and CMV-viral load could be significantly decreased (>1 log10 ) after a median of 17 [14-27] days and cleared subsequently in all of these patients. Five patients (17.9%) were classified as non-responder. Thereof, development of a mutation of the CMV UL56 terminase (UL-56-Gen: C325Y) conferring letermovir resistance could be observed in three patients (60%). Common side effects were mild and mostly of gastrointestinal nature. Mild adjustments of the immunosuppressive drugs were mandatory upon treatment initiation with letermovir. In addition to other interventions, letermovir was effective in difficult to treat CMV infections in lung transplant recipients. However, in patients with treatment failure mutation conferring letermovir, resistance should be taken into account.

The diagnostic challenge of coexistent sarcoidosis and thyroid cancer - a retrospective study.

BACKGROUND: Sarcoid lesions may mimic metastatic disease or recurrence in thyroid cancer (TC) patients as both diseases may affect the lungs and lymph nodes. We present the first study to systematically evaluate the clinical course of patients with (TC) after adjuvant radioactive iodine therapy (RIT) and concomitant sarcoidosis of the lung or the lymph nodes. METHODS: We screened 3285 patients and retrospectively identified 16 patients with TC (11 papillary thyroid cancer (PTC), 3 follicular thyroid cancer (FTC), 1 oncocytic PTC, 1 oncocytic FTC) and coexisting sarcoidosis of the lung and/or the lymph nodes treated at our institute. All patients had undergone thyroidectomy and initial adjuvant RIT. Challenges in diagnosing and the management of these patients were evaluated during long term follow-up (median 4.9 years (0.8-15.0 years)). RESULTS: Median age at first diagnosis of TC was 50.1 years (33.0-71.5 years) and of sarcoidosis 39.4 years (18.0-63.9 years). During follow-up, physicians were able to differentiate between SA and persistent or recurrent TC in 10 of 16 patients (63%). Diagnosis was complicated by initial negative thyroglobulin (Tg), positive Tg antibodies and non-specific imaging findings. Histopathology can reliably distinguish between SA and TC in patients with one suspicious lesion. CONCLUSION: Physicians should be aware of the rare coexistence of sarcoidosis and TC. Lymphadenopathy and pulmonary lesions could be metastases, sarcoidosis or even a mix of both. Therefore, this rare patient group should receive a thorough work up including histopathological clarification and, if necessary, separately for each lesion.

Cathepsin B promotes collagen biosynthesis, which drives bronchiolitis obliterans syndrome.

Bronchiolitis obliterans syndrome (BOS) is a major complication after lung transplantation (LTx). BOS is characterised by massive peribronchial fibrosis, leading to air trapping-induced pulmonary dysfunction. Cathepsin B, a lysosomal cysteine protease, has been shown to enforce fibrotic pathways in several diseases. However, the relevance of cathepsin B in BOS progression has not yet been addressed. The aim of the study was to elucidate the function of cathepsin B in BOS pathogenesis.We determined cathepsin B levels in bronchoalveolar lavage fluid (BALF) and lung tissue from healthy donors (HD) and BOS LTx patients. Cathepsin B activity was assessed via a fluorescence resonance energy transfer-based assay and protein expression was determined using Western blotting, ELISA and immunostaining. To investigate the impact of cathepsin B in the pathophysiology of BOS, we used an in vivo orthotopic left LTx mouse model. Mechanistic studies were performed in vitro using macrophage and fibroblast cell lines.We found a significant increase of cathepsin B activity in BALF and lung tissue from BOS patients, as well as in our murine model of lymphocytic bronchiolitis. Moreover, cathepsin B activity was associated with increased biosynthesis of collagen and had a negative effect on lung function. We observed that cathepsin B was mainly expressed in macrophages that infiltrated areas characterised by a massive accumulation of collagen deposition. Mechanistically, macrophage-derived cathepsin B contributed to transforming growth factor-ß1-dependent activation of fibroblasts, and its inhibition reversed the phenotype.Infiltrating macrophages release active cathepsin B, thereby promoting fibroblast activation and subsequent collagen deposition, which drive BOS. Cathepsin B represents a promising therapeutic target to prevent the progression of BOS.

Differential response to biologics in a patient with severe asthma and ABPA: a role for dupilumab?

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a severe hypersensitivity reaction to aspergillus species colonizing the airways of patients with asthma or cystic fibrosis. Biologics including anti-IgE and anti-IL5 antibodies have strongly changed the treatment of severe asthmatics and have partly been reported to be effective in the treatment of ABPA. Recently, dupilumab, an anti-IL4-Rα antibody which inhibits signaling by the Th2-cytokines IL4 and IL13, has been approved for the treatment of severe asthma. CASE PRESENTATION: Here, we report the case of a 49-year-old woman with severe asthma and ABPA, who was uncontrolled despite maximum inhalative therapy, anti-IL5-Rα antibody and continuous oral steroid therapy. Moreover, trials of itraconazole as well as omalizumab showed insufficient efficacy. Lung function revealed peripheral obstruction. FeNO and IgE were increased, eosinophils were suppressed under treatment while marked increases had been documented previously. Switching to dupilumab led to a complete resolution of pulmonary symptoms, resolution of exacerbations and complete withdrawal of oral steroids. A drastic improvement in lung function was noted, with an increase in FEV1 of almost 1 l. FeNO was normalized and IgE strongly reduced. CONCLUSION: Our case highlights that a patient may exhibit differential treatment responses to the currently available asthma biologics and suggests switching treatment if outcome is insufficient. A potential role for dupilumab in the treatment of ABPA warrants future studies.

High prevalence of falsely declaring nicotine abstinence in lung transplant candidates.

Tobacco use after lung transplantation is associated with adverse outcome. Therefore, active smoking is regarded as a contraindication for lung transplantation and should be excluded prior to placement on the waiting list. The aim of the study was to compare self-reporting with a systematic cotinine based screening approach to identify patients with active nicotine abuse. Nicotine use was systematically assessed by interviews and cotinine test in all lung transplant candidates at every visit in our center. Patients were classified according to the stage prior to transplantation and cotinine test results were compared to self-reports and retrospectively analyzed until June 2019. Of 620 lung transplant candidates, 92 patients (14.8%) had at least one positive cotinine test. COPD as underlying disease (OR 2.102, CI 1.110-3.981; p = 0.023), number of pack years (OR 1.014, CI 1.000-1.028; p = 0.047) and a time of cessation less than one year (OR 2.413, CI 1.410-4.128; p = 0.001) were associated with a positive cotinine test in multivariable regression analysis. The majority of non-COPD patients (n = 13, 72.2%) with a positive test had a cessation time of less than one year. 78 patients (84.7%) falsely declared not consuming any nicotine-based products prior to the test. Finally, all never smokers were test negative. In conclusion, our data demonstrate that active nicotine use is prevalent in transplant candidates with a high prevalence of falsely declaring nicotine abstinence. COPD was the main diagnosis in affected patients. Short cessation time and a high number of pack years are risk factors for continued nicotine abuse.

Safety and Efficacy of Steroid Pulse Therapy for Acute Loss of FEV1 in Lung Transplant Recipients After Exclusion of Acute Cellular Rejection.

BACKGROUND: The standard treatment of acute cellular rejection after lung transplantation (LTx) is a high-dose steroid pulse therapy. In our center, this therapy is also the standard of care for LTx recipients with acute loss of forced expiratory volume in 1 second (FEV1), after excluding specific causes such as acute rejection on biopsy. The aim of this retrospective study was to evaluate the safety and efficacy of steroid pulse therapy. METHODS: From 2015 to 2018, 33 consecutive patients (17 male patients, mean age ± SD, 50.5 ± 12.5 years) were included. All patients underwent routine examinations to exclude acute cellular rejection and other specific causes. FEV1 was routinely measured after 5 days, and 1, 3, and 6 months. Positive response to steroid pulse therapy was defined by increase of FEV1 > 10%. RESULTS: The mean decrease ± SD from baseline in FEV1 at the start of steroid pulse therapy was 380 ± 630 mL (P = .02). FEV1 changed after 5 days by 170 ± 180 mL (P = .0007), and after 1 month by 140 ± 230 mL (P = .70), 3 months by -60 ± 240 mL (P = .15), and 6 months by -80 ± 290 mL (P = .73). A positive response was observed in 21% of patients after 3 months and 12% after 6 months. High bronchoalveolar lavage (BAL) eosinophil count correlated with a higher FEV1 after steroid pulse therapy. Serious complications were observed in 4 out of 33 patients (12%) with 1 fatal event (pneumonia). CONCLUSIONS: Only a minority of patients after LTx with loss of FEV1 after exclusion of acute cellular rejection benefit from steroid pulse therapy. Patients with BAL eosinophilia are more likely to respond. However, severe complications were observed.

Feasibility and accuracy of SPECT myocardial perfusion imaging in end-stage lung disease.

BACKGROUND: Coronary artery disease (CAD) is associated with increased mortality in patients with chronic lung disease. However, non-invasive diagnostic of CAD is difficult, especially in patients with more advanced disease. Therefore, we aimed to assess the feasibility and accuracy of SPECT-myocardial perfusion imaging (MPI) stress testing with regadenoson in patients with end-stage lung disease (ELD) undergoing assessment of stable CAD. METHODS: Between January 2012 and May 2018, 102 patients with ELD, who were referred to our institution for lung transplant evaluation, were assessed retrospectively. All patients underwent both stress SPECT-MPI as well as coronary angiography. RESULTS: The mean age in our population was 57±6 years. All patients had severe pulmonary function impairment. During stress SPECT-MPI 14 patients (14%) reported regadenoson-related symptoms, but only 2 patients (2%) required medical treatment. Coronary angiography revealed obstructive CAD in 20 patients (20%). Among those, 5 patients had abnormal SPECT-MPI and PCI was performed in 3 patients accordingly. In 14 patients with obstructive CAD, revascularization was deferred based on normal SPECT-MPI findings. CONCLUSIONS: SPECT-MPI using regadenoson is well tolerated in patients with ELD and can help to make decisions about coronary revascularization before lung transplant.