During recent years there has been a growing interest in using non-invasive biomarkers to understand and monitor the airway inflammation in subjects with respiratory tract disorders and mainly asthma and chronic obstructive pulmonary disease (COPD). Sputum induction is generally a well-tolerated and safe procedure and a European Respiratory Society Task Force has published a comprehensive review on sputum methodology. Induced sputum cell count and, to a lesser extent, mediator measurements have been particularly well validated.

In asthma, the sputum and the cell culture supernatant can be used for the measurement of a variety of soluble mediators, including eosinophil-derived proteins, nitric oxide (NO) derivatives, cytokines and remodelling-associated proteins. Sputum eosinophilia (> 3%) is a classic feature of asthma although half of the patients seems to be non eosinophilic. Measuring the percentage of sputum eosinophils has proved to be useful in the clinical arena in helping to predict short term response to inhaled corticosteroids (ICS) and tailor the dose of ICS in the severe patients but there is scope for the application of other induced sputum markers potentially useful in clinical practice. The widespread application of induced sputum in asthma across the spectrum of disease severity has given insight into the relationship between airway function and airway inflammation, proposed new disease phenotypes and defined which of these phenotypes respond to current therapy, and perhaps most importantly provided an additional tool to guide the clinical management of asthmatic patients.

To date sputum induction is the only non-invasive measure of airway inflammation that has a clearly proven role in asthma management.

Nasal polyps (NP) are common benign degeneration of nasal sinus mucosa with a prevalence around 4% in the adult population. The causes are still uncertain but there is a strong association with allergy, infection, asthma and aspirin sensitivity. Histologically, the presence of a large quantity of extracellular fluid, mast cell degranulation and eosinophilia has been demonstrated.

Typically the patients show nasal obstruction, anosmia and rhinorrhoea. Nasal endoscopic examination and CT imaging allow evaluation of the disease extention. A combined medical and surgical treatment is recommended for symptoms control in preventing symptomatic NP recurrence. We will review the current knowledge in the pathogenesis and treatment of this complex disease entity.

Peripheral muscle strength and endurance are decreased in patients with chronic pulmonary diseases and seem to contribute to patients' exercise intolerance. However, the authors are not aware of any studies evaluating peripheral muscle function in children with asthma. It seems to be implied that children with asthma have lower aerobic fitness, but there are limited studies comparing the aerobic capacity of children with and without asthma.

The present study aimed to evaluate muscle strength and endurance in children with persistent asthma and their association with aerobic capacity and inhaled corticosteroid consumption.

Methods Forty children with mild persistent asthma (MPA) or severe persistent asthma (SPA) (N=20 each) and 20 children without asthma (control group) were evaluated. Upper (pectoralis and latissimus dorsi) and lower (quadriceps) muscle strength and endurance were assessed, and cardiopulmonary exercise testing was performed. Inhaled corticosteroid consumption during the last 6 and 24 months was also quantified.

Results Children with SPA presented a reduction in peak oxygen consumption (VO(2)) (28.2±8.1 vs 34.7±6.9 ml/kg/min; p<0.01) and quadriceps endurance (43.1±6.7 vs 80.9±11.9 repetitions; p<0.05) compared with the control group, but not the MPA group (31.5±6.1 ml/kg/min and 56.7±47.7 repetitions respectively; p>0.05). Maximal upper and lower muscle strength was preserved in children with both mild and severe asthma (p>0.05). Finally, the authors observed that lower muscle endurance weakness was not associated with reductions in either peak VO(2) (r=0.22, p>0.05) or corticosteroid consumption (r=-0.31, p>0.05) in children with asthma.

Conclusion The findings suggest that cardiopulmonary exercise and lower limb muscle endurance should be a priority during physical training programs for children with severe asthma.

Chronic hepatitis C virus (HCV) infection causes intra- and extra-hepatic complications. The elimination of HCV has been reported to be beneficial for asthmatic patients with HCV infection. Therefore, we hypothesized that chronic HCV infection might be associated with the severity of asthma.

Methods: Asthmatic patients were prospectively enrolled from 13 outpatient settings. Hepatitis B surface (HBs) antigen and HCV-RNA were measured at the time of enrollment and evaluated along with the clinical characteristics of the patients including the age, sex, duration of asthma, atopic status, smoking history, and treatment step according to the Global Initiative for Asthma guideline.

Results: Of 1327 asthmatic patients, 1258 patients (94.8%) were treated with inhaled corticosteroids, 18 patients were positive for HBs antigen (1.4%), and 32 patients (2.4%) were positive for HCV-RNA. When compared with HCV-RNA-negative patients, HCV-RNA-positive patients required significantly more drugs for the treatment of asthma. No such relationship was observed in patients with positive HBs antigen. A multivariate logistic regression analysis showed that the male sex, a long duration of asthma, status as a current smoker, and HCV-RNA positivity were independently associated with more severe asthma.

Conclusions: These results suggest that chronic HCV infection is an independent factor that predisposes asthmatic patients to more severe asthma. The evaluation of chronic HCV infection may be helpful for the management of severe asthmatic patients without obvious factors associated with severe asthma.