Monitoring free serum IgE in severe asthma patients treated with omalizumab

SummaryBackgroundBenefit of treatment with the monoclonal anti-IgE-antibody omalizumab in severe IgE-dependent asthma requires a significant reduction of serum free IgE concentrations. It is unclear if monitoring free serum IgE is clinically meaningful once omalizumab treatment is initiated.MethodsFree IgE and omalizumab serum concentrations were quantified in 22 patients with severe asthma (68% female, 47 ± 11 yrs, mean (±SD) pre-bronchodilator FEV1 62 ± 13%, baseline mean (±SEM) free serum IgE 652 ± 136 ng/ml) treated with omalizumab for 4 months using a Recovery-ELISA.ResultsOmalizumab treatment reduced free serum IgE prior to the second omalizumab injection by 73%, after 16 weeks by 81%…