Chronic Obstructive Pulmonary Disease (COPD) is defined as a disease characterized by persistent, progressive airflow limitation. Recent studies have underlined that COPD is correlated to many systemic manifestations, probably due to an underlying pattern of systemic inflammation. In COPD fractional exhaled Nitric Oxide (FeNO) levels are related to smoking habits and disease severity, showing a positive relationship with respiratory functional parameters. Moreover FeNO is increased in patients with COPD exacerbation, compared with stable ones. In alpha-1 antitrypsin deficiency, a possible cause of COPD, FeNO levels may be monitored to early detect a disease progression. FeNO measurements may be useful in clinical setting to identify the level of airway inflammation, per se and in relation to comorbidities, such as pulmonary arterial hypertension and cardiovascular diseases, either in basal conditions or during treatment. Finally, some systemic inflammatory diseases, such as psoriasis, have been associated with higher FeNO levels and potentially with an increased risk of developing COPD. In these systemic inflammatory diseases, FeNO monitoring may be a useful biomarker for early diagnosis of COPD development.

In the literature, psoriasis was demonstrated to increase the incidence of a large number of diseases which share an inflammatory origin [2]. While several hypotheses have been proposed, the most currently accepted is the pro-inflammatory cytokine spillover from active psoriatic lesions which may cause large inflammation on distant tissues [1]. This article is protected by copyright. All rights reserved

Background: Forced expiratory flow at 25 and 75% of the pulmonary volume (FEF_25-75%) might be considered as a marker of early airway obstruction. FEF_25-75% impairment might suggest earlier asthma recognition in symptomatic subjects even in the absence of other abnormal spirometry values. Objectives: The study was designed in order to verify whether FEF_25-75% impairment in a cohort of subjects with asthma-like symptoms could be associated with the risk of bronchial hyperresponsiveness (BHR) and with airway inflammation expressed as fractional exhaled nitric oxide (FeNO) and eosinophil counts in induced sputum. Methods: Four hundred adults with a history of asthma-like symptoms (10.5% allergic) underwent spirometry, determination of BHR to methacholine (PD₂₀FEV₁), FeNO analysis and sputum induction. FEF_25-75% <65% of predicted or <-1.64 z-score was considered abnormal. Results: All subjects had normal FVC, FEV₁ and FEV₁/FVC, while FEF_25-75% was abnormal in 27.5% of them. FEF_25-75% (z-score) was associated with PD₂₀FEV₁ (p < 0.001), FeNO (p < 0.001) and sputum eosinophils (p < 0.001). Patients with abnormal FEF_25-75% showed higher levels of FeNO and eosinophils in induced sputum than did patients with normal FEF_25-75% (p < 0.01 and p < 0.01, respectively). Subjects with abnormal FEF_25-75% had an increased probability of being BHR positive (OR = 13.38; 95% CI: 6.7-26.7; p < 0.001). Conclusions: Our data show that abnormal FEF_25-75% might be considered an early marker of airflow limitation associated with eosinophilic inflammation and BHR in subjects with asthma-like symptoms, indicating a role for FEF_25-75% as a predictive marker of newly diagnosed asthma.