Inclusion Criteria:  Male or female age (18-65 years) Diagnosis of severe asthma according to the European Respiratory Society (ERS) and American Thoracic Society (ATS) definition, with and without nasal symptoms normal pulmonary function post-therapy (FEV1 post-bronchodilation: greater than 80% of the predicted value, with FEV1/ vital capacity (VC) > 88-89% - for males and females, respectively - of the predicted value) non reversible chronic airflow limitation (FEV1 post-bronchodilation: lower than 70% of the predicted value, with FEV1/VC < 88-89% of the predicted value) Signing of the informed consent  Exclusion Criteria:  Referred Pregnancy Use of therapy with beta-blockers Smoking (current or within the previous 3 months) Negation to participate to the study Current upper and lower airways infectious diseases Current systemic infectious diseases