The role of osteopontin in severe refractory asthma and in smoking asthma

BACKGROUNDSevere refractory asthma (SRA) is characterised by an intense inflammatory and remodelling process. Smoking may modify the inflammatory pattern of the asthmatic airways. Osteopontin (OPN) is a glycoprotein that has been associated with inflammation and fibrosis. ΟΡΝ levels have been found elevated in sputums, BAL and biopsies of patients with asthma and have been correlated with fibrotic changes.AIMThe aim of this study was to investigate the levels of OPN in sputum supernatants of patients with SRA, to compare them with milder forms of the disease, to evaluate the levels of OPN in sputum supernatants of smoking asthmatic patients in comparison to non-smoking asthmatics and healthy controls, and to investigate their possible association with mediators and cells involved in the inflammatory and remodeling process.METHODS33 patients with SRA, 29 with moderate asthma, 21 with steroid-naıve asthma and 20 healthy subjects were studied. All subjects underwent lung function tests, bronchial hyper-responsiveness assessment and sputum induction for cell count identification and measurement of OPN, vascular endothelial growth factor, transforming growth factor β1 (TGF-β1), cysteinyl leukotrienes, interleukin 13 (IL-13), eosinophilic cationic protein (ECP) and IL-8 in sputum supernatants. We studied 103 asthma patients (49 smokers) and 40 healthy subjects (20 smokers) who underwent lung function tests, bronchial hyperresponsiveness to methacholine, and sputum induction for cell count identification and measurement of OPN, TGF-β1, IL-8, IL-13 and ECP in sputum supernatants. The concentrations of all mediators were measured using enzyme immunoassays.RESULTSMedian (IQR) OPN levels (pg/ml) were significantly higher in patients with SRA than in those with moderate asthma, steroid-naive asthma and healthy control subjects (1840 (1125e11000) vs 130 (100e210) vs 100 (67e130) vs 50 (42e70), respectively, p<0.001). Regression analysis showed a significant association between log OPN and sputum eosinophils, cysteinyl leukotrienes, IL-13, TGF-β1 and ECP. TGF-β1 represented the strongest association with OPN. The above associations were not observed in milder forms of the disease or in healthy subjects. OPN levels (pg/ml) were significantly higher in smoking asthmatics compared to non-smoking asthmatics, and both non-smoking and smoking controls [median (interquartile ranges) 1120 (651, 1817) vs. 197 (118, 341) vs. 50 (42, 70) vs. 102 (77, 110) pg/ml, respectively; p < 0.001]. Regression analysis provided significant associations between OPN and sputum neutrophils, IL-8 and TGF-β1, the most significant being the one with TGF-β1. These associations were present only in smoking asthmatics.CONCUSIONSThe results indicate that OPN levels are higher in SRA than in less severe forms of the disease. Moreover, OPN is associated with mediators involved in both the inflammatory and remodelling process such as TGF-β1, IL-13 and cysteinyl leukotrienes only in SRA. Smoking habit significantly affects sputum OPN levels in asthma. The associations of OPN with sputum neutrophils, TGF-β1 and IL-8 in smoking asthmatics suggest a possible role for OPN in the neutrophilic inflammation and remodeling process in this phenotype of asthma.Εισαγωγή: Το σοβαρό ανθιστάμενο στη θεραπεία χαρακτηρίζεται από εμμένουσα φλεγμονή και αναδιαμόρφωση των αεραγωγών. Οι ασθματικοί καπνιστές έχουν βαρύτερα συμπτώματα άσθματος ενώ η φλεγμονή των αεραγωγών των καπνιστών ασθματικών φαίνεται να διαφέρει από αυτή των μη καπνιστών ασθματικών. Η οστεοποντίνη (OPN) είναι μία γλυκοπρωτείνη που λειτουργεί τόσο ως μόριο της εξωκυττάριας θεμέλιας ουσίας όσο και ως κυτταροκίνη και έχει συσχετιστεί με την αναδιαμόρφωση των ιστών. Η ΟΡΝ έχει βρεθεί αυξημένη στα πτύελα, στο BAL και σε βρογχικές βιοψίες ασθματικών ασθενών.Σκοπός: Ο σκοπός της παρούσας μελέτης είναι να αξιολογήσει τα επίπεδα οστεοποντίνης στο υπερκείμενο των προκλητών πτυέλων ασθενών με σοβαρό άσθμα και να τα συγκρίνει με τα επίπεδα ΟΡΝ των ασθενών με ηπιότερες μορφές της νόσου, να αξιολογήσει τα επίπεδα ΟΡΝ στο υπερκείμενο των πτυέλων ασθματικών ασθενών που καπνίζουν σε σύγκριση με αυτά των μη καπνιστών ασθματικών και να διερευνήσει πιθανές συσχετίσεις των επιπέδων ΟΡΝ με μεσολαβητές και κύτταρα που εμπλέκονται και συμμετέχουν στη φλεγμονώδη διεργασία των αεραγωγών και στην αναδιαμόρφωση.Μέθοδοι: Τριάντα τρεις ασθενείς με σοβαρό, ανθιστάμενο στη θεραπεία άσθμα, είκοσι εννέα ασθενείς με μέτριας βαρύτητας άσθμα, είκοσι ένα ασθενείς με ήπιο διαλείπον άσθμα (που δεν λάμβαναν θεραπεία με κορτικοστεροειδή), σύμφωνα με τη ταξινόμηση κατά GINA 2005, και είκοσι υγιή, μη ατοπικά άτομα συμμετείχαν στη μελέτη Α. Στη μελέτη Β μελετήθηκαν συνολικά 103 ασθενείς, 54 εκ των οποίων ήταν μη καπνιστές ασθματικοί και 49 ασθματικοί που ήταν ενεργοί καπνιστές. Όλοι οι συμμετέχοντες υποβλήθηκαν σε λειτουργικό έλεγχο της αναπνοής, έλεγχο βρογχικής υπεραντιδραστικότητας και πρόκληση πτυέλων προκειμένου να υπολογιστεί η επί της εκατό αναλογία φλεγμονωδών κυττάρων και να προσδιοριστούν τα επίπεδα OPN, VEGF, TGF-β1, Cyst-Lts, IL-13, ECP, IL-8 στο υπερκείμενο των προκλητών πτυέλων.Αποτελέσματα: Τα επίπεδα OPN [pg/ml] βρέθηκαν στατιστικά σημαντικά υψηλότερα στους ασθενείς με σοβαρό, ανθιστάμενο στη θεραπεία άσθμα σε σύγκριση με τους ασθενείς με μέτριο, ήπιο άσθμα ή με την ομάδα των υγιών ατόμων [1840 (1125-11000) vs 130 (100-210) vs 100 (67-130) vs 50 (42-70), p<0.001]. Η ανάλυση γραμμικής παλινδρόμησης έδειξε ότι η OPN είχε μία στατιστικά σημαντική θετική συσχέτιση με τα ηωσινόφιλα των προκλητών πυέλων και στατιστικά σημαντικές θετικές συσχετίσεις βρέθηκαν επίσης μεταξύ των επιπέδων ΟΡΝ με τα επίπεδα των Cyst-Lts, της IL-13, της ECP, και του TGF-β1 στους ασθενείς με σοβαρό, ανθιστάμενο στη θεραπεία άσθμα. Η ισχυρότερη συσχέτιση της OPN με τους φλεγμονώδεις μεσολαβητές ήταν αυτή με τον TGF-β1. Τα επίπεδα ΟΡΝ (pg/ml) βρέθηκαν επίσης στατιστικά σημαντικά υψηλότερα στους καπνιστές ασθματικούς σε σύγκριση με τους μη καπνιστές ασθματικούς καθώς και με ομάδες ελέγχου (μη καπνιστές και καπνιστές) [1120 (651, 1817) vs. 197 (118, 341) vs. 50 (42, 70) vs. 102 (77, 110) pg/ml, p < 0.001]. Η ανάλυση γραμμικής παλινδρόμησης έδειξε στατιστικά σημαντική συσχέτιση μεταξύ της ΟΡΝ και των ουδετεροφίλων των προκλητών πτυέλων, της IL-8 και του TGF-β1. Η ισχυρότερη συσχέτιση ήταν αυτή της ΟΡΝ με τον TGF-β1. Συμπεράσματα: Στη συγκεκριμένη μελέτη φάνηκε ότι τα επίπεδα ΟΡΝ είναι σημαντικά υψηλότερα στα προκλητά πτύελα των ασθενών σε σοβαρό, ανθιστάμενο στη θεραπεία άσθμα σε σύγκριση με τους ασθενείς με μέτριο και ήπιο άσθμα και με τους υγιείς. Επιπλέον, η ΟΡΝ συσχετίστηκε με μεσολαβητές και κύτταρα που συμμετέχουν και εμπλέκονται στη φλεγμονώδη διεργασία και στην αναδιαμόρφωση των αεραγωγών, όπως ο TGF-β1, η IL-13 και τα κυστεινικά λευκοτριένια μόνο στην ομάδα του σοβαρού άσθματος. Φάνηκε επίσης ότι η καπνιστική συνήθεια επηρεάζει τα επίπεδα ΟΡΝ στα προκλητά πτύελα των ασθενών με άσθμα. Τα υψηλά επίπεδα ΟΡΝ στους καπνιστές ασθματικούς και οι συσχετίσεις της ΟΡΝ με τα ουδετερόφιλα των προκλητών πτυέλων, τον TGF-β1 και την IL-8 προτείνουν ένα πιθανό ρόλο της ΟΡΝ στην επικράτηση του ουδετεροφιλικού φλεγμονώδους προτύπου και στην διαδικασία αναδιαμόρφωσης των αεραγωγών σε αυτό το φαινότυπο του άσθματος

Anti-IgE treatment, airway inflammation and remodelling in severe allergic asthma: current knowledge and future perspectives

Asthma is a disorder of the airways involving various inflammatory cells and mediators and characterised by bronchial hyperresponsiveness, chronic inflammation and structural alterations in the airways, also known as remodelling. IgE is an important mediator of allergic reactions and has a central role in allergic asthma pathophysiology, as it is implicated in both the early and late phase allergic response. Moreover, clinical and mechanistic evidence has lately emerged, implicating IgE in the development of airway remodelling. The use of monoclonal antibodies targeting IgE, such as omalizumab, has proven very effective in improving respiratory symptoms and quality of life, while reducing asthma exacerbations, emergency room visits and the use of systemic corticosteroids in allergic severe asthma. These effects are believed to be mainly mediated by omalizumab's inhibitory effect on the initiation and further propagation of the allergic inflammation cascade. However, there is evidence to suggest that anti-IgE treatment remains effective long after it has been discontinued. In part, these findings could be attributed to the possible ameliorating effects of anti-IgE treatment on airway remodelling. In this review, we discuss recent findings supporting the notion that anti-IgE treatment modulates the complex immune responses that manifest clinically as asthma and ameliorates airway remodelling changes often observed in allergic severe asthma phenotypes

Exhaled Nitric Oxide and Exhaled Breath Condensate pH in Severe Refractory Asthma

Background: Distinct inflammatory cellular phenotypes of severe refractory asthma (SRA) have been reported. Fractional exhaled nitric oxide (FENO) primarily is related to eosinophilic inflammation. Exhaled breath condensate (EBC) pH has been suggested as a noninvasive tool in the assessment of patients with asthma. We sought to determine whether FENO and EBC pH could identify the presence and type of the underlying cellular inflammation in patients with SRA. Methods: Twenty-nine patients with SRA, 27 patients with moderate asthma, and 17 healthy subjects underwent FENO measurement, EBC collection for pH measurement, and sputum induction for cell count identification. Results: FENO was significantly higher and pH significantly lower in patients with SRA than in the other groups. In SRA, FENO levels of &gt;19 parts per billion were associated with a sensitivity of 0.78 and a specificity of 0.73 for sputum eosinophilia, whereas FEND levels of &lt;19 parts per billion were associated with a sensitivity of 0.63 and a specificity of 0.9 for sputum neutrophilia irrespective of the presence of eosinophils. The pH failed to predict the cellular profile in SRA, but a cutoff value of &lt;7.37 could predict sputum eosinophilia in moderate asthma. Conclusions: In patients with SRA, different FENO threshold values can identify those with predominant eosinophilia as well as those with neutrophilia. FENO levels were reduced in patients with predominant neutrophilia regardless of the concomitant presence of eosinophilia. Although pH could not identify the cellular profile in SRA, it seemed to be a better index for predicting eosinophilia in moderate asthma. CHEST 2010; 138(1):107-11

Increased levels of osteopontin in sputum supernatant in severe refractory asthma

Background Osteopontin (OPN) is a glycoprotein that has been associated with inflammation and fibrosis. Severe refractory asthma (SRA) is characterised by an intense inflammatory and remodelling process. The aim of this study was to investigate the levels of OPN in sputum supernatants of patients with SRA, to compare them with milder forms of the disease and to investigate their possible association with mediators and cells involved in the inflammatory and remodelling process. Methods 33 patients with SRA, 29 with moderate asthma, 21 with steroid-naïve asthma and 20 healthy subjects were studied. All subjects underwent lung function tests, bronchial hyper-responsiveness assessment and sputum induction for cell count identification and measurement of OPN, vascular endothelial growth factor, transforming growth factor β1 (TGF-β1), cysteinyl leukotrienes, interleukin 13 (IL-13), eosinophilic cationic protein (ECP) and IL-8 in sputum supernatants. Results Median (IQR) OPN levels (pg/ml) were significantly higher in patients with SRA than in those with moderate asthma, steroid-naive asthma and healthy control subjects (1840 (1125–11000) vs 130 (100–210) vs 100 (67–130) vs 50 (42–70), respectively, p<0.001). Regression analysis showed a significant association between log OPN and sputum eosinophils, cysteinyl leukotrienes, IL-13, TGF-β1 and ECP. TGF-β1 represented the strongest association with OPN. The above associations were not observed in milder forms of the disease or in healthy subjects. Conclusions The results indicate that OPN levels are higher in SRA than in less severe forms of the disease. Moreover, OPN is associated with mediators involved in both the inflammatory and remodelling process such as TGF-β1, IL-13 and cysteinyl leukotrienes only in SRA

Novel therapies for severe asthma in children and adults.

The heterogeneous nature of asthma requires personalised treatments. Monoclonal antibody treatments showed good efficacy, and should be considered when symptoms are poorly controlled despite good inhaler technique, compliance and controlled comorbidities. http://ow.ly/UWpg30hImQh

Levels of angiopoietins 1 and 2 in induced sputum supernatant in patients with COPD

Pathological features of chronic obstructive pulmonary disease (COPD) include lung vascular remodeling and angiogenesis. Angiopoietin-1 (Ang-1), is an essential mediator of angiogenesis by establishing vascular integrity, whereas angiopoietin-2 (Ang-2) acts as its natural inhibitor. We determined the levels of angiopoietins in sputum supernatants of patients with COPD and investigated their possible association with mediators and cells involved in the inflammatory and remodeling process. Fifty-nine patients with COPD, 25 healthy smokers and 20 healthy non-smokers were studied. All subjects underwent lung function tests, sputum induction for cell count identification and Ang-1, Ang-2, VEGF, TGF-β1, MMP-2, LTB4, IL-8, albumin measurement in sputum supernatants. Airway vascular permeability (AVP) index was also assessed. Ang-2 levels were significantly higher in patients with COPD compared to healthy smokers and healthy non-smokers [median, interquartile ranges pg/ml, 267 (147–367) vs. 112 (67–171) and 98 (95–107), respectively; p < 0.001]. Regression analysis showed a significant association between Ang-2 levels and AVP index, VEGF, IL-8 and MMP-2 levels in COPD, the strongest being with VEGF. Our results indicate that induced sputum Ang-2 levels are higher in COPD compared to healthy smokers and healthy non-smokers. Moreover, Ang-2 is associated with AVP, IL-8, MMP-2, and VEGF, indicating a possible role for Ang-2 in the pathogenesis of the disease

Levels of angiopoietins 1 and 2 in induced sputum supernatant in patients with COPD

Pathological features of chronic obstructive pulmonary disease (COPD) include lung vascular remodeling and angiogenesis. Angiopoietin-1 (Ang-1), is an essential mediator of angiogenesis by establishing vascular integrity, whereas angiopoietin-2 (Ang-2) acts as its natural inhibitor. We determined the levels of angiopoietins in sputum supernatants of patients with COPD and investigated their possible association with mediators and cells involved in the inflammatory and remodeling process. Fifty-nine patients with COPD, 25 healthy smokers and 20 healthy non-smokers were studied. All subjects underwent lung function tests, sputum induction for cell count identification and Ang-1, Ang-2, VEGF, TGF-beta 1, MMP-2, LTB4, IL-8, albumin measurement in sputum supernatants. Airway vascular permeability (AVP) index was also assessed. Ang-2 levels were significantly higher in patients with COPD compared to healthy smokers and healthy non-smokers [median, interquartile ranges pg/ml, 267 (147-367) vs. 112 (67-171) and 98 (95-107), respectively; p &lt; 0.001]. Regression analysis showed a significant association between Ang-2 levels and AVP index, VEGF, IL-8 and MMP-2 levels in COPD, the strongest being with VEGF. Our results indicate that induced sputum Ang-2 levels are higher in COPD compared to healthy smokers and healthy non-smokers. Moreover, Ang-2 is associated with AVP, IL-8, MMP-2, and VEGF, indicating a possible role for Ang-2 in the pathogenesis of the disease. (C) 2012 Elsevier Ltd. All rights reserved