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Background: We investigated whether a relationship between small airways dysfunction and bronchodilator responsiveness exists in patients with chronic obstructive pulmonary disease (COPD)., Methods: We studied 100 (20 female; mean age: 68±10 years) patients with COPD (forced expiratory volume in 1 second [FEV1]: 55% pred ±21%; FEV1/forced vital capacity [FVC]: 53%±10%) by impulse oscillometry system. Resistance at 5 Hz and 20 Hz (R5 and R20, in kPa·s·L(-1)) and the fall in resistance from 5 Hz to 20 Hz (R5 - R20) were used as indices of total, proximal, and peripheral airway resistance; reactance at 5 Hz (X5, in kPa·s·L(-1)) was also measured. Significant response to bronchodilator (salbutamol 400 μg) was expressed as absolute (≥0.2 L) and percentage (≥12%) change relative to the prebronchodilator value of FEV1 (flow responders, FRs) and FVC (volume responders, VRs)., Results: Eighty out of 100 participants had R5 - R20 >0.03 kPa·s·L(-1) (> upper normal limit) and, compared to patients with R5 - R20 ≤0.030 kPa·s·L(-1), showed a poorer health status, lower values of FEV1, FVC, FEV1/FVC, and X5, along with higher values of residual volume/total lung capacity and R5 (P<0.05 for all comparisons). Compared to the 69 nonresponders and the 8 FRs, the 16 VRs had significantly higher R5 and R5 - R20 values (P<0.05), lower X5 values (P<0.05), and greater airflow obstruction and lung hyperinflation., Conclusion: This study shows that peripheral airway resistance is increased in the vast majority of patients with COPD, who showed worse respiratory reactance, worse spirometry results, more severe lung hyperinflation, and poorer health status. Small airway dysfunction was also associated with the bronchodilator responsiveness in terms of FVC, but not in terms of FEV1.

Exhaled nitric oxide (NO) is a noninvasive marker of airway inflammation. Beclomethasone dipropionate (BDP) is the only inhaled corticosteroid (ICS) available as both extrafine and nonextrafine hydrofluoroalkane (HFA) pressurized metered-dose inhaler (pMDI) formulation. The present study was designed to evaluate whether the different patterns of lung deposition of two HFA BDP formulations are associated with a different effect on bronchial and alveolar NO. This was a prospective double-blind, randomized, controlled, crossover study. After a 2-week placebo run-in period without ICSs, asthmatic patients were randomized to extrafine BDP, 100 μg, b.i.d. or nonextrafine BDP, 250 μg, b.i.d. for two 2-week periods separated by a 2-week washout period. Fourteen patients (5 men) with a mean age 37 years and mean baseline forced expiratory volume in 1 second (FEV₁) of 83% of predicted were analyzed. Exhaled bronchial NO was significantly (p < 0.001) reduced in both treatment groups when compared with the last week of run-in period, whereas alveolar NO was significantly (p < 0.001) reduced only with extrafine BDP. Moreover, extrafine BDP was superior to nonextrafine BDP in both parameters (p < 0.05). Extrafine but not nonextrafine BDP HFA formulation lowers both bronchial and alveolar exhaled NO in asthmatic patients. ICS distribution throughout the whole bronchial tree could be important in patients who do not gain optimal control of inflammation with conventional nonextrafine ICS.

Abstract: Interleukin-17A (IL-17A), cigarette smoke and oxidative/nitrosative stress are involved in inflammatory airway diseases, and the mechanisms behind these processes are still poorly understood. We investigated whether recombinant human IL-17A (rhIL-17A), in combination with cigarette smoke extracts (CSE), increases the levels of inducibile nitric oxide synthase (iNOS), reactive oxygen species, nitrotyrosine (NT) and the activation of signal transducer and activator of transcription 1 (STAT-1) in normal human bronchial epithelial cells (16HBE). The effect of beclomethasone dipropionate (BDP), formoterol and their combination was also evaluated. We demonstrated that rhIL-17A or CSE alone increases iNOS expression, reactive oxygen species and NT production and STAT-1 downstream signalling activation in terms of STAT-1ser727 and STAT-1tyr701 phosphorylation. The combination of both stimuli further increased iNOS, ROS, NT and STAT-1ser727 phosphorylation. The silencing of STAT-1 expression partially reduced the levels of iNOS, reactive oxygen species and NT generated by rhIL-17A and inhibited the effect of CSE alone in 16HBE cells. The treatment of the cells with the MEK1/2 inhibitor U0126 (1,4-diamino-2,3-dicyano-1,4-bis (o-aminophenylmercapto butadiene) abolished the expression of iNOS and STAT-1ser727 phosphorylation generated by rhIL-17A. 16HBE treated with BDP or formoterol alone partially suppressed the effect of IL-17A or CSE on ROS, NT, and STAT-1 activation. Furthermore the use of the drugs in combination showed an additive effect in 16HBE. Our findings demonstrate that IL-17A increases oxidative/nitrosative markers, likely via ERK1/2 downstream signalling and STAT-1 pathway activation in human bronchial epithelial cells. BDP and formoterol treatment reduces this effect showing an additive effect used in combination. [Copyright &y& Elsevier]