TO THE EDITOR: Many patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develop a syndrome that fulfills the Berlin definition for the acute respiratory distress syndrome (ARDS) characterized by very high mortality ( 14). The pathogenesis of ARDS is complex and partially dependent on the underlying mechanism; however, polymorphonuclear cell influx into the extravascular compartments of the lungs is considered a defining characteristic of the disease (13).P-selectin (formerly PADGEM and GMP140) is an integral membrane protein that mediates the adhesion of activated platelets (8) and endothelial cells (5) to neutrophils and monocytes. Upon binding to the cognate ligand on leukocytes, P-selectin glycoprotein ligand (PSGL)-1, P-selectin mediates the initial rolling of leukocytes onto the inflamed endothelium, which represents the first step in leukocyte recruitment to sites of inflammation (4). P-selectin also activates monocytes to synthesize tissue factor, an essential cofactor in the initiation of the so-called extrinsic pathway of blood coagulation (3).A possible role for P-selectin-mediated leukocyte recruitment into the lungs during ARDS has been investigated. Infusion of either a monoclonal antibody to P-selectin (9) or of Sialyl-Lewis-X, a component of PSGL-1 (10), dramatically reduced lung injury in a rat model of ARDS. In humans, soluble P-selectin is increased in ARDS patients compared with controls and in nonsurvivors compared with survivors (11). More recently, a genome-wide association study has recognized SELPLG, encoding PSGL-1, as a novel ARDS susceptibility gene. The authors also report data showing a significant attenuation of lung injury in Selplg Ϫ/Ϫ mice exposed to LPS. These observations have prompted the authors to conclude that SELPLG and PSGL-1 are potentially novel therapeutic targets for reducing ARDS pathobiology (2). Although P-selectin expression is considered limited to platelets and endothelial cells (4), Yen et al. (12) surprisingly demonstrated the expression of P-selectin in pneumocytes in autopsy specimens of a patient who died from the 2002 coronavirus (SARS CoV) infection; they expanded on the observation showing that cells of the immortal alveolar epithelial line, A549, express P-selectin (both mRNA and protein) upon exposure to the SARS CoV. As leukocytes do not roll on epithelial cells, the biological relevance of this observation remains speculative and worthy of further investigation; how-

Background. Neutrophilic bronchial inflammation is a main feature of bronchiectasis, but not much is known about its relationship with other disease features. Aim. To compare airway inflammatory markers with clinical and functional findings in subjects with stable noncystic fibrosis bronchiectasis (NCFB). Methods. 152 NFCB patients (62.6 years; females: 57.2%) underwent clinical and functional cross-sectional evaluation, including microbiologic and inflammatory cell profile in sputum, and exhaled breath condensate malondialdehyde (EBC-MDA). NFCB severity was assessed using BSI and FACED criteria. Results. Sputum neutrophil percentages inversely correlated with FEV1 (P < 0.0001; rho = −0.428), weakly with Leicester Cough Questionnaire score (P = 0.068; rho = −0.58), and directly with duration of the disease (P = 0.004; rho = 0.3) and BSI severity score (P = 0.005; rho = 0.37), but not with FACED. Sputum neutrophilia was higher in colonized subjects, P. aeruginosa colonized subjects showing greater sputum neutrophilia and lower FEV1. Patients with ≥3 exacerbations in the last year showed a significantly greater EBC-MDA than the remaining patients. Conclusions. Sputum neutrophilic inflammation and biomarkers of oxidative stress in EBC can be considered good biomarkers of disease severity in NCFB patients, as confirmed by pulmonary function, disease duration, bacterial colonization, BSI score, and exacerbation rate.

Cell-derived microparticles are small (0.1-1 μm) vesicles shed by most eukaryotic cells upon activation or during apoptosis. Microparticles carry on their surface, and enclose within their cytoplasm, molecules derived from the parental cell, including proteins, DNA, RNA, microRNA and phospholipids. Microparticles are now considered functional units that represent a disseminated storage pool of bioactive effectors and participate both in the maintenance of homeostasis and in the pathogenesis of diseases. The mechanisms involved in microparticle generation include intracellular calcium mobilisation, cytoskeleton rearrangement, kinase phosphorylation and activation of the nuclear factor-κB. The role of microparticles in blood coagulation and inflammation, including airway inflammation, is well established in in vitro and animal models. The role of microparticles in human pulmonary diseases, both as pathogenic determinants and biomarkers, is being actively investigated. Microparticles of endothelial origin, suggestive of apoptosis, have been demonstrated in the peripheral blood of patients with emphysema, lending support to the hypothesis that endothelial dysfunction and apoptosis are involved in the pathogenesis of the disease and represent a link with cardiovascular comorbidities. Microparticles also have potential roles in patients with asthma, diffuse parenchymal lung disease, thromboembolism, lung cancer and pulmonary arterial hypertension. @ERSpublications Microparticles are potential biomarkers and targets for therapeutic interventions in respiratory medicine http://ow.ly/ZTCp6

MicroRNAs (miRNAs) are a class of short non-coding RNAs involved in the regulation of gene expression and the control of several cellular processes at physiological and pathological levels. Furthermore, extracellular vesicles (EV), which are small membrane-bound vesicles secreted by cells in the extracellular environment, contain functional miRNAs. The remarkable deregulation of many miRNAs has been demonstrated in respiratory diseases. Among them, miR-206, miR-133a-5p, and miR-133a-3p are striated muscle-specific miRNAs (myo-miRNA), related to skeletal muscle dysfunction, one of the commonest systemic manifestations in patients with chronic obstructive pulmonary disease (COPD). Nevertheless, their circulating expression in COPD patients is not demonstrated. For these reasons, we performed a pilot study to analyze the expression profiles of myo-miRNAs in plasma-derived EV from patients with COPD. We analyzed the expression profiles of selected myo-miRNAs in plasma-derived EV from COPD. Receiver operating characteristic analyses were carried out to evaluate whether selected plasma miRNAs were able to discriminate between different groups of COPD patients. We found EV-embedded myo-miRNAs in the bloodstream of COPD patients. Specifically, miR-206, miR-133a-5p and miR-133a-3p were significantly upregulated in group B patients. Receiver operating characteristic analyses of the combination of these selected miRNAs showed their high capacity to discriminate group B from other COPD patients. Our data provide evidence that myo-miRNA are present in EV in the plasma of COPD patients and their expression (miR-206, miR-133a-5p, and miR-133a-3p) can discriminate group B from group C patients. The future analysis of a larger number of patients should allow us to obtain more refined correlations.

Chronic obstructive pulmonary disease (COPD) is a complex condition in which systemic inflammation plays a role in extrapulmonary manifestations, including cardiovascular diseases: interleukin (IL)-6 has a role in both COPD and atherogenesis. The 2011 GOLD document classified patients according to FEV1, symptoms, and exacerbations history, creating four groups, from A (less symptoms/low risk) to D (more symptoms/high risk). Extracellular vesicles (EV) represent potential markers in COPD: nevertheless, no studies have explored their value in association to both disease severity and inflammation. We conducted a pilot study to analyze circulating endothelial-(E) and monocyte-derived (M) EV levels in 35 COPD patients, who were grouped according to the 2011 GOLD document; the relationship between EV and plasmatic markers of inflammation was analyzed. We found a statistically significant trend for increasing EEV, MEV, IL-6, from group A to D, and a significant correlation between EEV and IL-6. The associations between both EEV and MEV and disease severity, and between EEV and IL-6, suggest a significant interplay between pulmonary disease and inflammation, with non-respiratory cells (endothelial cells and monocytes) involvement, along with the progression of the disease. Thus, EV might help identify a high-risk population for extrapulmonary events, especially in the most severe patients.

Real world data indicate that adherence to GOLD guidelines is only partially met by GPs in their general practice and shows higher prescription appropriateness by pulmonologists.

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Cell-derived extracellular vesicles (EVs) found in the circulation and body fluids contain biomolecules that could be used as biomarkers for lung and other diseases. EVs from bronchoalveolar lavage (BAL) might be more informative of lung abnormalities than EVs from blood, where information might be diluted. To compare EVs’ characteristics in BAL and blood in smokers with and without COPD. Same-day BAL and blood samples were obtained in 9 nonsmokers (NS), 11 smokers w/o COPD (S), and 9 with COPD (SCOPD) (FEV1: 59 ± 3% pred). After differential centrifugation, EVs (200–500 nm diameter) were identified by flow cytometry and labeled with cell-type specific antigens: CD14 for macrophage-derived EVs, CD326 for epithelial-derived EVs, CD146 for endothelial-derived EVs, and CD62E for activated-endothelial-derived EVs. In BAL, CD14-EVs were increased in S compared to NS [384 (56–567) vs. 172 (115–282) events/μL; p = 0.007] and further increased in SCOPD [619 (224–888)] compared to both S (p = 0.04) and NS (p < 0.001). CD326-EVs were increased in S [760 (48–2856) events/μL, p < 0.001] and in SCOPD [1055 (194–11,491), p < 0.001] when compared to NS [15 (0–68)]. CD146-EVs and CD62E-EVs were similar in the three groups. In BAL, significant differences in macrophage and epithelial-derived EVs can be clearly detected between NS, S and SCOPD, while these differences were not found in plasma. This suggests that BAL is a better medium than blood to study EVs in lung diseases.