Mast Cells, Cytokines and Asthma

The appreciation that asthma is a chronic inflammatorydisorder of the airways has led to a reappraisal of theimportance of different cell populations within the bronchialmucosa with respect to their role in the regulation ofthe cellular events in this disease. While mast cell degranulationhas been implicated in the acute allergic bronchoconstrictorresponse, activation of this cell population has notbeen considered relevant to either the late phase inflammatorycell influx within the airways following allergen bronchoprovocationor to the mucosa! eosinophilia in chronicclinical disease. As such, attention has focused on the Tlymphocyte as an orchestrator of these cellular events onaccount of its ability to synthesize and release cytokinesrelevant to the allergic process. It is now, however, realizedthat many cell populations within the airways are able togenerate cytokines comparable with and complimentary tothose produced by T lymphocytes and that asthma cannot beconsidered an inflammatory airway disorder dependentupon activation of one single cell population. This reviewdetails the current evidence that airway mast cells synthesize,store and release cytokines relevant to allergic inflammationand considers their potential involvement not onlyin the cellular influx within the airways but also in thefibrotic structural changes which are evident in chronicdisease