Effects of an interleukin-5 blocking monoclonal antibody on eosinophils, airway hyper-responsiveness, and the late asthmatic response.

A single dose of monoclonal antibody to IL-5 decreased blood eosinophils for up to 16 weeks and sputum eosinophils at 4 weeks, which has considerable therapeutic potential for asthma and allergy. However, our findings question the role of eosinophils in mediating the late asthmatic response and causing airway hyper-responsiveness.