Patricia Macedo

Inflammatory biomarkers in airways of patients with severe asthma compared with non‐severe asthma

Background About 5–10% of patients with asthma suffer from poorly‐controlled disease despite corticosteroid (CS) therapy.

Expression of transforming growth factor-β (TGF-β) in chronic idiopathic cough

In patients with chronic idiopathic cough, there is a chronic inflammatory response together with evidence of airway wall remodelling and an increase in airway epithelial nerves expressing TRPV-1. We hypothesised that these changes could result from an increase in growth factors such as TGFβ and neurotrophins.We recruited 13 patients with persistent non-asthmatic cough despite specific treatment of associated primary cause(s), or without associated primary cause, and 19 normal non-coughing volunteers without cough as controls, who underwent fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsies.There was a significant increase in the levels of TGFβ in BAL fluid, but not of nerve growth factor(NGF) and brain-derived nerve growth factor(BDNF) compared to normal volunteers. Levels of TFGβ gene and protein expression were assessed in bronchial biopsies. mRNA expression for TGFβ was observed in laser-captured airway smooth muscle and epithelial cells, and protein expression by immunohistochemistry was increased in ASM cells in chronic cough patients, associated with an increase in nuclear expression of the transcription factor, smad 2/3. Subbasement membrane thickness was significantly higher in cough patients compared to normal subjects and there was a positive correlation between TGF-β levels in BAL and basement membrane thickening.TGFβ in the airways may be important in the airway remodelling changes observed in chronic idiopathic cough patients, that could in turn lead to activation of the cough reflex.

Sputum hydrogen sulfide as a novel biomarker of obstructive neutrophilic asthma

clinical risk management of food allergy, false-positive results are probably preferable to false-negative results. We must note some limitations to the present study: the small sample size used for analysis and the infrequency (n 5 1) of positive challenges with egg. Although it could be suggested that the tool might not be suitable for patients without prior reactions to the food (ie, high specific IgE levels/skin prick test responses and no known prior ingestion of the specific food), this sample type is currently under investigation in an ongoing study. We have also shown its applicability with data generated a priori from a different clinic setting and patient groups and that it can accommodate different preparations of the index foods (raw or baked egg as with pasteurized egg). We intend to further validate the calculator in real time in diverse partner clinics worldwide and to explore its applicability in secondary and possibly primary care settings. This calculator is intended as a further aide to clinical decision making. The aim of the model is to support decision making by clinicians and not to replace it. Audrey DunnGalvin, PhD L. M. Segal, MD Ann Clarke, MD, MSc, FRCP Reza Alizadehfar, MD Jonathan O’B. Hourihane, PhD Med, MB, MRCPI, FRCPCH

Capsaicin cough sensitivity in smokers with and without airflow obstruction

BACKGROUND Cough is a frequent symptom of cigarette smokers that often precedes the development of airflow obstruction. We determined whether chronic cigarette smoking is associated with an increase in capsaicin cough response in the absence of cough. METHODS We examined this in asymptomatic smokers with normal lung function (n=68, FEV(1) 99.3+/-2.1% predicted) and in patients with established COPD without cough symptoms (n=42; FEV(1) 57.0+/-2.6% predicted), using healthy non-smoking volunteers as control (n=92; FEV(1) 100.6+/-1.7% predicted). Using an incremental capsaicin concentration challenge protocol, we recorded the concentrations that induced 2 (C2) and 5 or more coughs (C5). RESULTS Because females have a lower C2 and C5 than males in the control group, we analysed the data in each group according to gender. Log C5 was decreased both in asymptomatic smokers (1.56+/-0.11 micromol/L, p<0.05) and in COPD patients (1.44+/-0.14 micromol/L, p<0.01) when compared to non-smokers (1.90+/-0.09 micromol/L). Log C2 did not differ between groups. Log C2 and log C5 were decreased in women (0.772+/-0.071 micromol/L and 1.481+/-0.094 micromol/L, respectively) when compared to men (1.045+/-0.088 micromol/L and 1.923+/-0.087 micromol/L, respectively) (p<0.05 for log C2; p<0.001 for log C5). CONCLUSION We conclude that chronic cigarette smoking increases capsaicin cough reflex and that this remains so with the development of COPD.

EMMPRIN (CD147) regulation of MMP-9 in bronchial epithelial cells in COPD.

Background and objective:  Extracellular matrix metalloproteinase inducer (EMMPRIN or CD147) induces the production of matrix metalloproteinases (MMP) such as MMP‐9, which plays an important role in COPD. We determined its cellular origin and role in MMP‐9 production in COPD.

Domiciliary diurnal variation of exhaled nitric oxide fraction for asthma control

A major goal of asthma management is maintaining optimal control. Current assessment is based on symptoms and lung function. We evaluated whether domiciliary daily home exhaled nitric oxide fraction (FeNO) monitoring could be useful as an index of asthma control. 50 asthmatic subjects and 15 healthy volunteers with a range of asthma severity underwent asthma control questionnaire (ACQ), spirometry before and after salbutamol and sputum induction. FeNO and peak expiratory flow (PEF) were measured twice daily for 2 weeks. A record of exacerbations was obtained 3 months later. Diurnal FeNO variation in uncontrolled asthmatics was significantly greater than in controlled asthmatics (p<0.01). PEF variation was not different. The daily variation of FeNO levels was also greater in uncontrolled asthmatics compared with controlled asthmatic and healthy subjects (p<0.01). 80% of uncontrolled asthmatics experienced at least one or more exacerbations over the 3 months after the enrolment. The combination of diurnal FeNO variation ≥16.6% and ACQ scores ≥1.8 was best at predicting uncontrolled asthma (area under curve 0.91, 95% CI 0.86–0.97; p<0.001). Diurnal variation in FeNO can be used as a biomarker of asthma control and as a predictor of the risk of future exacerbation. Prospective studies are warranted. Diurnal variation in FeNO can be used as a biomarker of asthma control and a predictor of the risk of future exacerbation http://ow.ly/r2MCY

Effect of JAK Inhibitors on Release of CXCL9, CXCL10 and CXCL11 from Human Airway Epithelial Cells.

Background CD8+ T-cells are located in the small airways of COPD patients and may contribute to pathophysiology. CD8+ cells express the chemokine receptor, CXCR3 that binds CXCL9, CXCL10 and CXCL11, which are elevated in the airways of COPD patients. These chemokines are released from airway epithelial cells via activation of receptor associated Janus kinases (JAK). This study compared the efficacy of two structurally dissimilar pan-JAK inhibitors, PF956980 and PF1367550, and the glucocorticosteroid dexamethasone, in BEAS-2B and human primary airway epithelial cells from COPD patients and control subjects. Methods Cells were stimulated with either IFNγ alone or with TNFα, and release of CXCL9, CXCL10 and CXCL11 measured by ELISA and expression of CXCL9, CXCL10 and CXCL11 by qPCR. Activation of JAK signalling was assessed by STAT1 phosphorylation and DNA binding. Results There were no differences in the levels of release of CXCL9, CXCL10 and CXCL11 from primary airway epithelial cells from any of the subjects or following stimulation with either IFNγ alone or with TNFα. Dexamethasone did not inhibit CXCR3 chemokine release from stimulated BEAS-2B or primary airway epithelial cells. However, both JAK inhibitors suppressed this response with PF1367550 being ~50-65-fold more potent than PF956980. The response of cells from COPD patients did not differ from controls with similar responses regardless of whether inhibitors were added prophylactically or concomitant with stimuli. These effects were mediated by JAK inhibition as both compounds suppressed STAT1 phosphorylation and DNA-binding of STAT1 and gene transcription. Conclusions These data suggest that the novel JAK inhibitor, PF1367550, is more potent than PF956980 and that JAK pathway inhibition in airway epithelium could provide an alternative anti-inflammatory approach for glucocorticosteroid-resistant diseases including COPD.

Sputum-to-serum hydrogen sulfide ratio in COPD

Objectives Hydrogen sulfide (H2S) is a gas produced by respiratory cells including smooth muscle cells and may play a role as a cellular gasotransmitter. We evaluated whether H2S levels in serum or sputum could represent a new biomarker of COPD in a cross-sectional study. Methods H2S levels in sputum and serum samples were measured using a sulfide-sensitive electrode in 64 patients with stable COPD (S-COPD), 29 COPD subjects during acute exacerbation (AE-COPD), 14 healthy smokers and 21 healthy non-smokers. Results Sputum H2S levels in AE-COPD subjects were higher than those in S-COPD, healthy smoking and non-smoking subjects (p<0.001), but serum H2S levels in AE-COPD were lower than those in S-COPD (p<0.001). Thus, the sputum-to-serum ratio of H2S (H2S ratio) in AE-COPD subjects were higher than those in stable COPD, healthy smoking and non-smoking subjects (p<0.001). In 14 COPD subjects whose H2S ratios were measured during and after an exacerbation, the mean ratio was increased during exacerbation (p<0.05). H2S ratio was positively correlated with St. Georges Respiratory Questionnaire score, sputum neutrophils and IL-6 and IL-8 levels in sputum and serum (p<0.01) but inversely correlated with sputum macrophages (%), FEV1%predicted and FEV1/FVC (p<0.01). The cut-off level of H2S ratio to indicate an exacerbation was ≥0.44 (sensitivity of 93.1% and specificity of 84.5%). Conclusions The ratio of sputum-to-serum levels of H2S may provide a useful marker of COPD indicative of obstructive neutrophilic inflammation and of potential ongoing exacerbation.