The development of specific anti-inflammatory agents for the treatment of asthma is overdue, but new research provides scope for optimism. Two early reports suggest that therapeutic agents blocking signalling molecules interleukin-5 or supplementing interleukin-12 can lower the number of blood and sputum eosinophils in patients with mild asthma.
Professors Peter Barnes and Stephen Holgate from London and Southampton respectively, joined forces to study the effects of interleukin-5 blocking monoclonal antibody and recombinant human interleukin-12. In the two separate double-blind randomised placebo-controlled trials they found that a single dose of monoclonal antibody to interleukin-5 decreased blood eosinophils for up to 16 weeks and sputum eosinophils at 4 weeks (
However these are only the forward steps of the tango. The major backward step is the finding that the reduction of eosinophils had no significant effects on airway hyper-responsiveness or late asthmatic reaction. This questions the role of eosinophils in these reactions.