Breath analysis using electronic nose and gas chromatography-mass spectrometry: A pilot study on bronchial infections in bronchiectasis

Background and aims: In this work, breath samples from clinically stable bronchiectasis patients with and without bronchial infections by Pseudomonas Aeruginosa- PA) were collected and chemically analysed to determine if they have clinical value in the monitoring of these patients. Materials and methods: A cohort was recruited inviting bronchiectasis patients (25) and controls (9). Among the former group, 12 members were suffering PA infection. Breath samples were collected in Tedlar bags and analyzed by e-nose and Gas Chromatography-Mass Spectrometry (GC-MS). The obtained data were analyzed by chemometric methods to determine their discriminant power in regards to their health condition. Results were evaluated with blind samples. Results: Breath analysis by electronic nose successfully separated the three groups with an overall classification rate of 84% for the three-class classification problem. The best discrimination was obtained between control and bronchiectasis with PA infection samples 100% (CI95%: 84-100%) on external validation and the results were confirmed by permutation tests. The discrimination analysis by GC-MS provided good results but did not reach proper statistical significance after a permutation test. Conclusions: Breath sample analysis by electronic nose followed by proper predictive models successfully differentiated between control, Bronchiectasis and Bronchiectasis PA samples

SARS-CoV-2 T-cell response in COVID-19 convalescent patients with and without lung sequelae

A specific T-cell response persists in the majority of COVID-19 patients 6 months after hospital discharge. This response is more prominent in those who required critical care during the acute COVID-19 episode but is reduced in patients with lung sequelae

Influence of Malignant Pleural Fluid from Lung Adenocarcinoma Patients on Neutrophil Response

Malignant pleural effusion (MPE) is a common severe complication of advanced lung adenocarcinoma (LAC). Neutrophils, an essential component of tumor infiltrates, contribute to tumor progression and their counts in MPE have been associated with worse outcome in LAC. This study aimed to evaluate phenotypical and functional changes of neutrophils induced by MPE to determine the influence of MPE immunomodulatory factors in neutrophil response and to find a possible association between neutrophil functions and clinical outcomes. Pleural fluid samples were collected from 47 LAC and 25 heart failure (HF) patients. We measured neutrophil degranulation products by ELISA, oxidative burst capacity and apoptosis by flow cytometry, and NETosis by fluorescence. The concentration of degranulation products was higher in MPE-LAC than in PE-HF. Functionally, neutrophils cultured with MPE-LAC had enhanced survival and neutrophil extracellular trap (NET) formation but had reduced oxidative burst capacity. In MPE, NETosis was positively associated with MMP-9, P-selectin, and sPD-L1 and clinically related to a worse outcome. This is the first study associating NETs with a worse outcome in MPE. Neutrophils likely contribute to tumor progression through the release of NETs, suggesting that they are a potential therapeutic target in LAC

Influence of Malignant Pleural Fluid from Lung Adenocarcinoma Patients on Neutrophil Response

Altres ajuts: Merck KGaA, Darmstadt, Germany; Fondo de Investigaciones Sanitarias (FIS).Malignant pleural effusion (MPE) is a common severe complication of advanced lung ad-enocarcinoma (LAC). Neutrophils, an essential component of tumor infiltrates, contribute to tumor progression and their counts in MPE have been associated with worse outcome in LAC. This study aimed to evaluate phenotypical and functional changes of neutrophils induced by MPE to determine the influence of MPE immunomodulatory factors in neutrophil response and to find a possible association between neutrophil functions and clinical outcomes. Pleural fluid samples were col-lected from 47 LAC and 25 heart failure (HF) patients. We measured neutrophil degranulation products by ELISA, oxidative burst capacity and apoptosis by flow cytometry, and NETosis by fluores-cence. The concentration of degranulation products was higher in MPE-LAC than in PE-HF. Func-tionally, neutrophils cultured with MPE-LAC had enhanced survival and neutrophil extracellular trap (NET) formation but had reduced oxidative burst capacity. In MPE, NETosis was positively associated with MMP-9, P-selectin, and sPD-L1 and clinically related to a worse outcome. This is the first study associating NETs with a worse outcome in MPE. Neutrophils likely contribute to tumor progression through the release of NETs, suggesting that they are a potential therapeutic target in LAC

Elevated plasma levels of epithelial and endothelial cell markers in COVID-19 survivors with reduced lung diffusing capacity six months after hospital discharge

Background: Some COVID-19 survivors present lung function abnormalities during follow-up, particularly reduced carbon monoxide lung diffusing capacity (DLCO). To investigate risk factors and underlying pathophysiology, we compared the clinical characteristics and levels of circulating pulmonary epithelial and endothelial markers in COVID-19 survivors with normal or reduced DLCO 6 months after discharge. Methods: Prospective, observational study. Clinical characteristics during hospitalization, and spirometry, DLCO and plasma levels of epithelial (surfactant protein (SP) A (SP-A), SP-D, Club cell secretory protein-16 (CC16) and secretory leukocyte protease inhibitor (SLPI)), and endothelial (soluble intercellular adhesion molecule 1 (sICAM-1), soluble E-selectin and Angiopoietin-2) 6 months after hospital discharge were determined in 215 COVID-19 survivors. Results: DLCO was < 80% ref. in 125 (58%) of patients, who were older, more frequently smokers, had hypertension, suffered more severe COVID-19 during hospitalization and refer persistent dyspnoea 6 months after discharge. Multivariate regression analysis showed that age ≥ 60 years and severity score of the acute episode ≥ 6 were independent risk factors of reduced DLCO 6 months after discharge. Levels of epithelial (SP-A, SP-D and SLPI) and endothelial (sICAM-1 and angiopoietin-2) markers were higher in patients with reduced DLCO, particularly in those with DLCO ≤ 50% ref. Circulating SP-A levels were associated with the occurrence of acute respiratory distress syndrome (ARDS), organizing pneumonia and pulmonary embolisms during hospitalization. Conclusions: Reduced DLCO is common in COVID-19 survivors 6 months after hospital discharge, especially in those older than 60 years with very severe acute disease. In these individuals, elevated levels of epithelial and endothelial markers suggest persistent lung damage

Antimicrobial peptides, disease severity and exacerbations in bronchiectasis

Rationale: Recently a frequent exacerbator phenotype has been described in bronchiectasis, but the underlying biological mechanisms are unknown. Antimicrobial peptides (AMPs) are important in host defence against microbes but can be proinflammatory in chronic lung disease. Objectives: To determine pulmonary and systemic levels of AMP and their relationship with disease severity and future risk of exacerbations in bronchiectasis. Methods: A total of 135 adults with bronchiectasis were prospectively enrolled at three European centres. Levels of cathelicidin LL-37, lactoferrin, lysozyme and secretory leucocyte protease inhibitor (SLPI) in serum and sputum were determined at baseline by ELISA. Patients were followed up for 12 months. We examined the ability of sputum AMP to predict future exacerbation risk. Measurements and main results: AMP levels were higher in sputum than in serum, suggesting local AMP release. Patients with more severe disease at baseline had dysregulation of airway AMP. Higher LL-37 and lower SLPI levels were associated with Bronchiectasis Severity Index, lower FEV1 (forced expiratory volume in 1 s) and Pseudomonas aeruginosa infection. Low SLPI levels were also associated with the exacerbation frequency at baseline. During follow-up, higher LL-37 and lower SLPI levels were associated with a shorter time to the next exacerbation, whereas LL-37 alone predicted exacerbation frequency over the next 12 months. Conclusions: Patients with bronchiectasis showed dysregulated sputum AMP levels, characterised by elevated LL-37 and reduced SLPI levels in the frequent exacerbator phenotype. Elevated LL-37 and reduced SLPI levels are associated with Pseudomonas aeruginosa infection and can predict future risk of exacerbations in bronchiectasis

Lung Function sequelae in COVID-19 Patients 3 Months After Hospital Discharge

About 20% of patients infected by the SARS-CoV-2 virus develop Coronavirus Disease 2019 (COVID-19) pneumonia and require hospitalization.1 Some recent reports have shown that some of them may present lung function abnormalities at discharge, or soon afterwards.Here, we: (1) describe the presence and characteristics of lung function abnormalities 3 months after hospital discharge in a large prospective cohort of well characterized patients hospitalized because of COVID-19 in our institution; and, (2) explore potential clinical predictors these short-term lung function sequelae

Associació d'elements de la resposta immune innata a les infeccions bacterianes en malalties respiratòries cròniques

Les infeccions bacterianes respiratòries en pacients amb Malaltia Pulmonar Obstructiva Crònica (MPOC) i amb bronquièctasis són una de les principals causes d’empitjorament del pronòstic d’aquestes malalties. Sovint aquestes infeccions causen episodis d’agudització durant les quals la simptomatologia dels pacients s’agreuja, arribant a requerir ingrés hospitalari per controlar la infecció. Es coneix que aquests pacients pateixen una inflamació pulmonar i sistèmica que apareix durant l’estabilitat clínica i s’accentua durant les aguditzacions. A més, es creu que el microambient inflamatori pulmonar d’aquestes malalties afavoreix la infecció per determinats bacteris, com la Pseudomona aeruginosa i l’Hemophilus influenzae, associats amb major severitat. Tot i així, encara es desconeixen els mecanismes immunològics pels quals hi ha pacients que aguditzen freqüentment, anomenats aguditzadors freqüents (AF) i altres pacients que no aguditzen o ho fan de manera poc freqüent (NF). Per aquestes raons, aquesta tesi pretén estudiar els diferents elements de la resposta immune innata local implicats en la defensa de les infeccions bacterianes, en dues malalties respiratòries d’elevat impacte en la salut pública com són la MPOC i les bronquièctasis. El primer objectiu ha estat associar els nivells pulmonars de Fatty-acid binding protein 4 (FABP4) en pacients amb MPOC amb la presència d’infecció respiratòria, severitat de la malaltia i poblacions cel·lulars. El segon objectiu s’ha centrat en estudiar els nivells pulmonars dels pèptids antimicrobians (PAMs) Lactoferrina, Lisozima, LL-37 i Secretory Leukocyte Protease Inhibitor (SLPI) com a possibles marcadors pronòstic de futures aguditzacions en pacients amb bronquièctasis. Per últim, el tercer objectiu ha estat caracteritzar diferents perfils immunològics d’inflamació pulmonar en pacients amb bronquièctasis i associar aquests als paràmetres clínics.Las infecciones bacterianas respiratorias en pacientes con Enfermedad Pulmonar Obstructiva Crónica (EPOC) y con bronquiectasias son una de las principales causas de empeoramiento del pronóstico de estas enfermedades. A menudo estas infecciones causan episodios de agudización durante las cuales la sintomatología de los pacientes se agravia, llegando a requerir ingreso hospitalario para controlar la infección. Se conoce que estos pacientes sufren una inflamación pulmonar y sistémica que aparece durante la estabilidad clínica y se acentúa durante las agudizaciones. Además, se cree que el microambient inlamatorio pulmonar de estas enfermedades favorece la infección por determinados bacterias, como la Pseudomona aeruginosa y la Hemophilus influenzae, asociados con mayor severidad. Aun así, todavía se desconocen los mecanismos inmunológicos por los cuales hay pacientes que agudizan frecuentemente, denominados aguditzadors frecuentes (AF) y otros pacientes que no agudizan o lo hacen de manera poco frecuente (NF). Por estas razones, esta tesis pretende estudiar los diferentes elementos de la respuesta inmune innata local implicados en la defensa de las infecciones bacterianas, en dos enfermedades respiratorias de elevado impacto en la salud pública como son la MPOC y las bronquiectasias. El primer objetivo ha estado asociar los niveles pulmonares de Fatty-acid binding protein 4 (FABP4) en pacientes con MPOC con la presencia de infección respiratoria, severidad de la enfermedad y poblaciones celulares. El segundo objetivo se ha centrado en estudiar los niveles pulmonares de los péptidos antimicrobianos (Palmos) Lactoferrina, Lisozima, LL-37 y Secretory Leukocyte Protease Inhibitor (SLPI) como posibles marcadores pronóstico de futuras agudizaciones en pacientes con bronquiectasias. Por último, el tercer objetivo ha estado caracterizar diferentes perfiles inmunológicos de inflamación pulmonar en pacientes con bronquiectasias y asociar estos a los parámetros clínicos.Respiratory bacterial infections in patients with Chronic Obstructive Pulmonary Disease (COPD) and patients with bronchiectasis are one of the main causes of worsening the prognosis. These infections can cause exacerbations, known as episodes of acute worsening of disease symptoms which sometimes require hospitalization to stabilize the infection. These patients suffer from systemic and pulmonary inflammation during clinical stability and are elevated during exacerbations. In addition, the pulmonary inflammatory microenvironment of these diseases is thought to promote infection by certain bacteria, such as Pseudomona aeruginosa and Hemophilus influenzae, which are associated with greater severity. However, the immunological mechanisms by which patients frequently exacerbate, called frequent exacerbators (AF), and other patients who do not exacerbate or infrequently (NF) are still unknown. For these reasons, this thesis aims to study the different elements of the local innate immune response involved in the defense of bacterial infections, in two respiratory diseases with high public health impact such as COPD and bronchiectasis. The first objective was to associate the pulmonary and systemic levels of Fatty-acid binding protein 4 (FABP4) in COPD patients with the presence of respiratory infection, disease severity, and cell populations. The second objective was to study the pulmonary and systemic levels of antimicrobial peptides (AMPs) Lactoferrin, Lysozyme, LL-37 and Secretory Leukocyte Protease Inhibitor (SLPI) as an outcome marker of future exacerbations in patients with bronchiectasis. Finally, the third objective was to characterize different profiles of pulmonary inflammation in patients with bronchiectasis.Universitat Autònoma de Barcelona. Programa de Doctorat en Immunologia Avançad