RANTES in exhaled breath condensate of patients with severe persistent allergic asthma during omalizumab therapy.

Background: Omalizumab is a humanized monoclonal anti-IgE antibody developed for the treatment of IgE-mediated diseases, including asthma. The aim of the study was to determine the effect of omalizumab treatment on changes in RANTES in exhaled breath condensate and other inflammatory markers in patients with persistent severe asthma.

Methods: The study was conducted on a group of 19 patients with severe persistent allergic asthma treated with conventional therapy (according to GINA 2006) and with or without omalizumab (9 vs. 10 patients). Changes in inflammatory parameters [RANTES in exhaled breath condensate, exhaled nitric oxide, blood eosinophil count and serum eosinophil cationic protein (ECP)] were measured before and after 16 weeks of therapy.

Results: Omalizumab-treated patients showed a statistically significant decrease in the concentrations of RANTES in exhaled breath condensate, exhaled nitric oxide (F(ENO)), serum ECP, and blood eosinophil count compared with patients with conventional therapy after 16 weeks of treatment. In this group of patients, statistically significant correlations were revealed between the decrease in RANTES and a decrease in F(ENO) and between the decrease in F(ENO) and a decrease in ECP or blood eosinophil count after omalizumab therapy.

Conclusions: Our results confirmed that during anti-immunoglobulin E therapy with omalizumab in patients with severe persistent allergic asthma, RANTES expression is decreased. This process in turn could lead to a limitation of airway inflammation and could be essential for the beneficial effect of anti-IgE therapy with omalizumab.