Search Results (904)

Acute Respiratory Distress Syndrome (ARDS) is a complex and devastating form of respiratory failure, with high mortality rates, for which there is no pharmacological treatment. The acute exudative phase of ARDS is characterized by severe damage to the alveolar–capillary barrier, infiltration of protein-rich fluid into the lungs, neutrophil recruitment, and high levels of inflammatory mediators. Rapid resolution of this reversible acute phase, with efficient restoration of alveolar functional integrity, is essential before the establishment of irreversible fibrosis and respiratory failure. Several lines of in vitro and in vivo evidence support the involvement of potassium (K⁺) channels—particularly KvLQT1, expressed in alveolar cells—in key cellular mechanisms for ARDS resolution, by promoting alveolar fluid clearance and epithelial repair processes. The aim of our study was to investigate whether pharmacological activation of KvLQT1 channels could elicit beneficial effects on ARDS parameters in an animal model of acute lung injury. We used the well-established bleomycin model, which mimics (at day 7) the key features of the exudative phase of ARDS. Our data demonstrate that treatments with the KvLQT1 activator R-L3, delivered to the lungs, failed to improve endothelial permeability and lung edema in bleomycin mice. However, KvLQT1 activation significantly reduced neutrophil recruitment and tended to decrease levels of pro-inflammatory cytokines/chemokines in bronchoalveolar lavages after bleomycin administration. Importantly, R-L3 treatment was associated with significantly lower injury scores, higher levels of alveolar type I (HTI-56, AQP5) and II (pro-SPC) cell markers, and improved alveolar epithelial repair capacity in the presence of bleomycin. Together, these results suggest that the KvLQT1 K⁺ channel may be a potential target for the resolution of the acute phase of ARDS. Full article

Background/Objectives: The quality of clinical studies is largely determined by the bioanalytical methods used for testing study samples. Rigorous assay validation following defined criteria, for example, the European Medicines Agency guideline for bioanalytical method validation, is a prerequisite for such assays. Alpha1-antitrypsin (AAT) measurement, i.e., the specific measurement of AAT protein and its associated elastase-inhibitory activity, is an integral part of assay panels for clinical studies addressing AAT deficiency. Specifically, AAT must be measured in the matrix of citrated human plasma as well as in diluted solutions with high salt concentrations obtained through bronchoalveolar lavage (BAL). Sensitive and selective measurement methods are required, as BAL has a low level of AAT. Methods: We present the validation data obtained for three AAT measurement methods. Two of them, nephelometry and the enzyme-linked immunosorbent assay, which clearly differ in their sensitivity, provide AAT protein concentrations. The third is the highly sensitive, newly developed elastase complex formation immunosorbent assay that specifically measures the inhibitory activity of AAT against its pivotal target, protease neutrophil elastase. Using samples with relevant AAT concentrations, we addressed the assays’ characteristics: accuracy, precision, linearity, selectivity, specificity, limit of quantification and short-term analyte stability Results: Overall, the three methods demonstrated low total errors, a combined measure reflecting accuracy and precision, even at low analyte concentrations of less than 0.5 µg/mL; adequate linearity over the required assay range; and acceptable selectivity and specificity. Furthermore, the short-time stability of the analyte was also demonstrated. Conclusions: All three AAT measurement methods met the acceptance criteria defined by the guidelines on bioanalytical assay validation, qualifying these methods for clinical sample analysis. Full article

Background: Coronavirus disease 2019 (COVID-19) has led to the expansion of the spectrum of invasive fungal infections beyond traditional immunocompromised populations. Although COVID-19-associated pulmonary aspergillosis is increasingly being recognised, COVID-19-associated mucormycosis remains rare, particularly in non-endemic regions. Concurrent COVID-19-associated invasive tracheobronchial aspergillosis and pulmonary mucormycosis with histopathological confirmation is exceedingly uncommon and poses significant diagnostic and therapeutic challenges. Case presentation: We report the case of a 57-year-old female with myelodysplastic syndrome who underwent haploidentical allogeneic haematopoietic stem cell transplantation. During post-transplant recovery, she developed COVID-19 pneumonia, complicated by respiratory deterioration and radiological findings, including a reverse halo sign. Bronchoscopy revealed multiple whitish plaques in the right main bronchus. Despite negative serum and bronchoalveolar lavage fluid galactomannan assay results, cytopathological examination revealed septate hyphae and Aspergillus fumigatus was subsequently identified. Given the patient’s risk factors and clinical features, liposomal amphotericin B therapy was initiated. Subsequent surgical resection and histopathological analysis confirmed the presence of Rhizopus microsporus. Following antifungal therapy and surgical intervention, the patient recovered and was discharged in stable condition. Conclusions: This case highlights the critical need for heightened clinical suspicion of combined invasive fungal infections in severely immunocompromised patients with COVID-19, even in non-endemic regions for mucormycosis. Early tissue-based diagnostic interventions and prompt initiation of optimal antifungal therapy are essential for obtaining ideal outcomes when co-infection is suspected. Full article

Background: Polymerase chain reaction (PCR) is highly sensitive and specific for the rapid diagnosis of invasive fungal disease (IFD) but is not yet widely implemented due to concerns regarding limited standardisation between assays, the lack of commercial options and the absence of clear guidance on interpreting results. Objectives and Methods: This review provides an update on technical and clinical aspects of PCR for the diagnosis of the most pertinent fungal pathogens, including Aspergillus, Candida, Pneumocystis jirovecii, Mucorales spp., and endemic mycoses. Summary: Recent meta-analyses have demonstrated that quantitative PCR (qPCR) offers high sensitivity for diagnosing IFD, surpassing conventional microscopy, culture and most serological tests. The reported specificity of qPCR is likely underestimated due to comparison with imperfect reference standards with variable sensitivity. Although the very low limit of detection of qPCR can generate false positive results due to procedural contamination or patient colonisation (particularly in pulmonary specimens), the rates are comparable to those observed for biomarker testing. When interpreting qPCR results, it is essential to consider the pre-test probability, determined by the patient population, host factors, clinical presentation and risk factors. For patients with low to moderate pre-test probability, the use of sensitive molecular tests, often in conjunction with serological testing or biomarkers, can effectively exclude IFD when all tests return negative results, reducing the need for empirical antifungal therapy. Conversely, for patients with high pre-test probability and clinical features of IFD, qPCR testing on invasive specimens from the site of infection (such as tissue or bronchoalveolar lavage fluid) can confidently rule in the disease. The development of next-generation sequencing methods to detect fungal infection has the potential to enhance the diagnosis of IFD, but standardisation and optimisation are essential, with improved accessibility underpinning clinical utility. Full article

Background: The study evaluates the immunomodulatory potential of secukinumab (SECU) and honokiol (HONK) in a murine model of allergic asthma complicated by acute lung injury (ALI), with an emphasis on modulating key inflammatory pathways. The rationale is driven by the necessity to attenuate Th17-mediated cytokine cascades, wherein IL-17 plays a critical role, as well as to explore the adjunctive anti-inflammatory effects of HONK on Th1 cytokine production, including IL-6, TNF-α, and Th2 cytokines. Methods: Mice were sensitized and challenged with ovalbumin (OVA) and lipopolysaccharide (LPS) was administrated to exacerbate pulmonary pathology, followed by administration of SECU, HONK (98% purity, C₁₈H₁₈O₂), or their combination. Quantitative analyses incorporated OVA-specific IgE measurements, differential cell counts in bronchoalveolar lavage fluid (BALF), and extensive cytokine profiling in both BALF and lung tissue homogenates, utilizing precise immunoassays and histopathological scoring systems. Results: Both SECU and HONK, when used alone or in combination, display significant immunomodulatory effects in a murine model of allergic asthma concomitant with ALI. The combined therapy synergistically reduced pro-inflammatory mediators, notably Th1 cytokines, such as TNF-α and IL-6, as measured in both BALF and lung tissue homogenates. Conclusions: The combined therapy showed a synergistic attenuation of pro-inflammatory mediators, a reduction in goblet cell hyperplasia, and an overall improvement in lung histoarchitecture. While the data robustly support the merit of a combinatorial approach targeting multiple inflammatory mediators, the study acknowledges limitations in cytokine diffusion and the murine model’s translational fidelity, thereby underscoring the need for further research to optimize clinical protocols for severe respiratory inflammatory disorders. Full article

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide, primarily driven by chronic airway inflammation due to cigarette smoke exposure. Despite its burden, however, current anti-inflammatory therapies offer limited efficacy in preventing disease progression. Plasminogen activator inhibitor-1 (PAI-1), as a key regulator of fibrinolysis, has recently been implicated in structural airway changes and persistent inflammation in patients with COPD. This study aimed to investigate the ability of the PAI-1 inhibitor TM5441 to attenuate airway inflammation and structural lung damage induced by a cigarette smoke extract (CSE) in a mouse model. Mice received intratracheal CSE or vehicle on days 1, 8, and 15, and were sacrificed on day 22. TM5441 (20 mg/kg) was administered orally from days 1 to 22. The CSE significantly increased the mean linear intercept, destructive index, airway resistance, and reductions in dynamic compliance. The CSE also increased the numbers of neutrophils and macrophages in the bronchoalveolar lavage fluid, systemic PAI-1 activity, and neutrophil elastase mRNA and protein expression in the lungs. TM5441 treatment significantly suppressed these changes without affecting coagulation time. These findings suggest that TM5441 may be a novel therapeutic agent for COPD by targeting PAI-1-mediated airway inflammation and emphysema. Full article

Background/Objectives: The ongoing evolution of SARS-CoV-2 has highlighted the limitations of parenteral vaccines in preventing viral transmission, largely due to their failure to elicit robust mucosal immunity. Methods: Here, we evaluated an intranasal (IN) vaccine formulation consisting of recombinant receptor-binding domain (RBD) adsorbed onto human probiotic Bacillus subtilis DG101 spores. Results: In BALB/c mice, IN spore-RBD immunization induced strong systemic and mucosal humoral responses, including elevated specific IgG, IgM, and IgA levels in serum, bronchoalveolar lavage fluid (BALF), nasal-associated lymphoid tissue (NALT), and saliva. It further promoted mucosal B cell and T cell memory, along with a Th1/Tc1-skewed T cell response, characterized by increased IFN-γ-expressing CD4⁺ and CD8⁺ T cells in the lungs. Conclusions: All in all, these findings highlight the potential of intranasal vaccines adjuvanted with probiotic B. subtilis spores in inducing sterilizing immunity and limiting SARS-CoV-2 transmission. Full article

Background/Objectives: The correlation between drugs and interstitial lung disease (ILD) is reported, but the presence of the substances of abuse in the lung as a cause of disease has never been proved. In this observational study, our aim was to evaluate a possible correlation between ILD radiological findings and cannabinoids presence in broncho-alveolar lavage (BAL) or in resected lung tissue in patients with a history of cannabis smoke. Methods: Data of patients with ILD chest CT scan findings and history of drug use, submitted to BAL (Group 1), or to lung apex removal for pneumothorax (Group 2), were retrospectively collected. In both groups, drug presence was investigated. A subgroup of Group 1 was checked for the concomitant presence in blood. Fisher’s test was used to study the association between the detection of the drug and ILD. Results: In Group 1, cannabinoids were present in 12/26 (46.2%) BAL samples. ILD emerged on chest CT in 75% of the cannabinoid-positive and in 20% of the cannabinoid-negative BAL samples (p = 0.0299). In the subgroup, the patients who tested positive for cannabinoids/cocaine on BAL were 55.6%; 0% were positive only on blood (p = 0.0294). In Group 2, cannabinoids were present in 10/15 (66.7%) specimens. ILD was evident, respectively, in 40% and in 0% of the patients with cannabinoid-positive and cannabinoid-negative surgical specimens (p = 0.2308). Conclusions: The prevalence of ILD in patients with cannabinoid-positive BAL and in those with cannabinoid-positive surgical specimens suggests that ILD could be caused by cannabis smoke. The non-concomitant presence of substances in BAL and in blood advocates the diagnostic usefulness of searching for the drug in the target organ. Full article

Diagnosing and prognosing immune-mediated airway diseases, like hypersensitivity pneumonitis (HP) and sarcoidosis, is complicated due to their overlapping symptoms and the lack of definitive biomarkers. Hence, we wanted to compare bronchoalveolar lavage (BAL) cytokine and chemokine profiles from 92 patients with different immune-mediated and inflammatory airway diseases, namely, HP, sarcoidosis, non-allergic asthma, amiodarone lung, and EGPA. We also compared pulmonary function parameters, BAL’s cellularity, and lymphocyte immunophenotypes. We found significant differences across all measured lung functions (VC, VC%, FEV1, FEV1%, and Tiff%) and in the number of macrophages, lymphocytes, neutrophils, and eosinophils. Furthermore, we showed significant differences in CD4, CD8, and CD4/8 across all included ILDs and OLDs; however, no significant differences were found in CD3, CD19, NK, or NKT. We identified nine biomarkers (IL-1β, IL-6, IL-8, IL-13, VEGF, angiogenin, C4a, RANTES, and MCP-1) that significantly differ in the BAL of patients with HP and sarcoidosis and showed that RANTES and IL-6 are associated with fibrotic outcome. We have demonstrated that interstitial and obstructive lung diseases differ in cytokine and cellular lung imprint, which may, in the future, enable the determination of the disease subtype and thus the identification of targets for the treatment of individuals or subgroups within diseases. Full article

IgG antibodies, signaling via the inhibitory receptor, FcγRIIb, are potent inhibitors of IgE-mediated mast cell activation. We have previously reported that in addition to blocking mast cell degranulation, inhibitory IgG signals shut down a proinflammatory transcriptional program in which mast cells produce cytokines and chemokines known to drive type 2 tissue inflammation. To determine whether such effects of allergen-specific IgG can modulate allergic inflammation in vivo, we examined the airways of mice sensitized to ovalbumin (OVA) by intraperitoneal injection and then challenged with intranasal OVA. Pretreatment with allergen-specific IgG significantly reduced the recruitment of inflammatory cells, including macrophages and eosinophils, into the lungs of OVA-sensitized mice. The bronchoalveolar lavage fluid of OVA-challenged mice contained elevated levels of chemokine ligands (CCL2 and CCL24) and interleukin-5, a response that was markedly blunted in animals receiving allergen-specific IgG. IgG-treated animals exhibited attenuated allergen-induced production of IgE, IL-4, and IL-13, along with impaired OVA-induced goblet cell hyperplasia and Muc5ac expression and suppressed airway hyperresponsiveness, consistent with a shift away from a Th2 response. Using mice with a lineage-specific deletion of FcγRIIb, we demonstrated that each of these protective effects of IgG was dependent upon the expression of this receptor on mast cells. Overall, our findings establish that allergen-specific IgG can reduce allergen-driven airway inflammation and airway hyperresponsiveness and point to a mechanistic basis for the therapeutic benefit of aeroallergen-specific IgG therapy. Full article

Background: Accurate differentiation between Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM) is essential for proper diagnosis and treatment. This study compares the diagnostic performance of two commercial real-time PCR kits, AdvanSure^TM TB/NTM and Kogene PowerChek^TM MTB/NTM, for detecting MTB, NTM, and negative (no growth, NG) clinical specimens. Methods: A total of 390 clinical residual specimens were collected from patients between December 2022 and June 2023. The samples, including sputum, bronchoalveolar lavage, tracheal aspirate and body fluid, were initially tested with MGIT culture and then analyzed using both PCR kits. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were evaluated. Discrepant results between the two PCR assays were further investigated using sequencing to identify the detected mycobacterial species, and final diagnoses were verified by culture results and review of electronic medical records. Results: Of the 390 specimens, both AdvanSure^TM and PowerChek^TM real-time PCR assays demonstrated 100% sensitivity for both MTB and NTM detection. For MTB detection, AdvanSure^TM demonstrated a specificity of 100%, with a PPV, NPV, and overall accuracy all reaching 100%. In comparison, PowerChek^TM showed a specificity of 98.62%, a PPV of 96.15%, an NPV of 100%, and an overall accuracy of 98.97%. For NTM detection, both AdvanSure^TM and PowerChek^TM exhibited identical performance metrics. The specificity was 99.58% for both assays, with a PPV of 99.34%, NPV of 100%, and an overall accuracy of 99.74%. Five discrepant results were finally confirmed as four NTM detection cases and one negative case by culture and clinical diagnosis which showed four cases of PowerChek^TM MTB+NTM detection and one case of NTM detection, respectively. Conclusions: The PowerChek^TM MTB/NTM real-time PCR kit demonstrated excellent diagnostic performance for the detection of MTB and NTM, with high sensitivity, specificity, and accuracy. Minor discrepancies, particularly in detecting MTB+NTM mixed infections, highlight the importance of complementary sequencing analysis for resolving uncertain results. These findings support the clinical utility of both PCR assays as reliable tools for rapid diagnosis of mycobacterial infections. PowerChek^TM showed occasional false positives, suggesting that optimizing the assay’s cutoff threshold or amplification parameters could enhance its specificity and reduce false-positive results in clinically ambiguous cases. Full article

Background/Objectives: The porcine respiratory disease complex (PRDC) is a multifaceted, polymicrobial syndrome resulting from a combination of environmental stressors, primary infections (e.g., PRRSV) and secondary infectious agents (viruses and bacteria). PRDC causes severe lung pathology, leading to reduced performance, increased mortality rates, and higher production costs in the global pig industry. Our goal was to conduct a comprehensive study correlating both the anti-PRRSV immune response and 21 secondary infectious agents with PRDC severity. Methods: To this end, PRRSV-negative weaners were vaccinated with a PRRSV-2 MLV and put into a farm with a history of PRDC. Subsequently, anti-PRRSV cellular and antibody responses were monitored pre-vaccination, at 28 days post vaccination (dpv) and during PRDC outbreak (49 dpv). NanoString was used to quantify 21 pathogens within the bronchoalveolar lavage (BAL) at the time of necropsy (51 dpv). PRRSV-2 was present in 53 out of 55 pigs, and the other five pathogens (PCMV, PPIV, B. bronchiseptica, G. parasuis, and M. hyorhinis) were detected in BAL samples. Results: Although the uncontrolled settings of field trials complicated data interpretation, multivariate correlation analyses highlighted valuable lessons: (i) high weaning weight predicted animal resilience to disease and high weight gains correlated with the control of the PRRSV-2 field strain; (ii) most pigs cleared MLV strain within 7 weeks, and the field PRRSV-2 strain was the most prevalent lung pathogen during PRDC; (iii) all pigs developed a systemic PRRSV IgG antibody response which correlated with IgG and IgA levels in BAL; (iv) the induction of anti-field strain-neutralizing antibodies by MLV PRRSV-2 vaccination was both late and limited; (v) cellular immune responses were variable but included strong systemic IFN-γ production against the PRRSV-2 field strain; (vi) the most detected lung pathogens correlated with PRRSV-2 viremia or lung loads; (vii) within the six detected pathogens, two viruses, PRRSV-2 and PCMV, significantly correlated with the severity of the clinical outcome. Conclusions: While a simple and conclusive answer to the multifaceted nature of PRDC remains elusive, the key lessons derived from this unique study provide a valuable framework for future research on porcine respiratory diseases. Full article

Background: The efficacy of EA575 in the treatment of respiratory diseases is described in various clinical studies, improving patients’ disease-related symptoms. However, mechanistic in vivo data proving its beneficial effects are limited. Methods: Focusing on the treatment of acute airway inflammation and accompanying cough, this study aimed to elucidate antitussive and mucoactive properties of EA575, applying two animal models. Animals were treated orally twice daily for 7 days, resulting in 43, 215.2, or 430.5 mg/kg bw/d of EA575. Antitussive effects were investigated within an acute lung inflammation model of bleomycin-treated guinea pigs after citric acid exposure. Hereby, the number of coughs, enhanced pause (penH), and bronchoalveolar lavage fluid (BALF) were investigated. Mucoactivity of EA575 was assessed within a murine model, determining phenol red concentration in BALF. Results: EA575 treatment within the acute lung inflammation model reduced cough events up to 56% while reducing inflammatory cell influx in BALF dose-dependently, e.g., reducing neutrophils in BALF up to 70.9%. This suggests a strong connection between anti-inflammatory and antitussive properties of EA575. Furthermore, penH decreased in a dose-dependent manner, suggesting an ease in respiration. Mucoactivity was shown by a dose-dependent increase in phenol red concentration in BALF up to 38.9%. Notably, EA575/salbutamol co-administration resulted in enhanced phenol red secretion compared to respective single administrations. Conclusions: These data highlight the benefits of EA575 in treating cough-related respiratory diseases, particularly when accompanied by sputum, as EA575 has been shown to obtain mucoactivity. Furthermore, the combinatory effect of EA575/salbutamol treatment provides a foundation for future research in the treatment of chronic respiratory diseases. Full article

Respiratory syncytial virus (RSV) represents one of the main respiratory infections found among immunocompromised patients. Objective: The study analyzes the incidence of RSV infection in different populations of immunocompromised patients as organ transplant recipients (lung, other solid organs, hematopoietic stem cells) and oncologic patients (solid organ malignancy and hematological malignancy) compared to a group of non-immunocompromised patients. We also assessed the prevalence of viral, bacterial, and mycotic coinfection. Moreover, we aimed at evaluating the efficacy of ribavirin treatment in terms of mortality reduction. Methods: We conducted a retrospective analysis on a total of 466 transplant patients undergoing bronchoscopy with bronchoalveolar lavage for suspected viral disease or surveillance between 2016 and 2023, compared to 460 controls. Results: The incidence of RSV was significantly higher in immunocompromised patients, particularly in those with lung and bone marrow transplants. Among RSV+ patients, a higher prevalence of viral (influenza virus), bacterial (S. pneumoniae, M. pneumoniae, Nocardia spp.), and fungal (Aspergillus spp.) coinfections were observed. The efficacy of ribavirin in reducing mortality did not show significant differences compared to supportive therapy alone. Conclusions: The results of our exploratory study suggest that immunocompromised patients are particularly vulnerable to RSV infection and coinfections. Our hypothesis-generating data warrant the need for future studies aimed at exploring preventive and therapeutic strategies for RSV infection in these high-risk patient groups. Full article

Ventilator-associated pneumonia (VAP) develops in patients who stay on mechanical ventilation for more than 48 h. In the presence of causative pathogens, the patient develops clinical signs such as purulent tracheal discharge, fever, and respiratory distress. A prospective observational study was carried out in the Intensive Care Unit (ICU) of Max Healthcare Centre, New Delhi, from 2020 to 2023. The study comprised 70 samples from patients diagnosed with VAP. This study thoroughly examined VAP-associated microorganisms and resistance in the hospital ICU. Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa were the most commonly reported pathogens. Significant drug resistance was seen in P. aeruginosa, K. pneumoniae, A. baumannii and Staphylococcus aureus. The heatmap also supported the antibiotic resistance data patterns obtained from conventional and automated systems of determination. Notably, Serratia marcescens, Escherichia coli, Klebsiella pneumoniae, Ralstonia insidiosa, and Ralstonia mannitolilytica, showed 60 to 100% of resistance to a number of antibiotics. Among all VAP patients, 31.42% early-onset and 68.57% late-onset VAP cases were detected. Out of 70 patients, 43 patients died (mortality rate 61.4%); majority of them suffered from late-onset VAP. The study goal was to describe the antibiotic resistance patterns and microbial ecology of the pathogens that were isolated from VAP patients. According to the heatmap analysis, a varied VAP microbiome with high prevalences of MDR in A. baumannii, P. aeruginosa, K. pneumoniae, and S. aureus was identified. To address the increasing prevalence of MDR VAP, the study highlights the critical need for improved VAP monitoring, strong infection control, and appropriate antibiotic usage. Full article