Small airway inflammation in asthma

Asthma was originally described as an inflammatory disease that predominant ly involves the central airways. Pathological and physiological evidence re ported during the past few years suggests that the inflammatory process ext ends beyond the central airways to the peripheral airways and the lung pare nchyma. The small airways are capable of producing T-helper-2 cytokines, as well as chemokines, and they have recently been recognized as a predominan t site of airflow obstruction in asthmatic persons. The inflammation at thi s distal site has been described as more severe than large airway inflammat ion. These findings are of great clinical significance, and highlight the n eed to consider the peripheral airways as a target in any therapeutic strat egy for treatment of asthma.