Abstract

Inhaled steroids in chronic obstructive pulmonary disease

This issue of the Canadian Respiratory Journal contains an interesting paper by Gauvreau et al (pages 26 to 32) concerning inhaled steroids and allergic bronchoprovocation in patients with asthma. They looked at data from previous studies that showed that steroids attenuate both early and late airway responses to allergens, and that this was associated with a reduction in sputum eosinophilia. The new finding is that the presence of neutrophils in the sputum blunted the increase in sputum eosinophils seen with allergen challenge. Gauvreau et al postulated that neutrophils and, presumably, neutrophilic inflammation may reduce the response to steroids in asthma. This is a little tricky, because the level of sputum neutrophils did not influence the degree of bronchoconstriction produced by allergen inhalation. Nevertheless, it seems reasonable to suppose that neutrophilic inflammation is less sensitive to steroids than that due, in large part, to eosinophils, and the hypothesis gives me the opportunity to consider the effects of inhaled steroids in chronic obstructive pulmonary disease (COPD), a disease characterized by neutrophilic inflammation.