Free Serum IgE In Patients With Severe Allergic Asthma Treated With Omalizumab

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%…

THE RECOVERY-ELISA—A NOVEL ASSAY TECHNIQUE TO MONITOR THERAPY WITH HUMANIZED ANTIBODIES: THE EXAMPLE OF OMALIZUMAB

The therapeutic use of antibodies has grown exponentially, providing new treatment options for various diseases. Monitoring treatment with therapeutic antibodies is a particular challenge because often the target antigen is no longer measurable or the results are unreliable. To overcome this problem, a recovery-ELISA was developed to quantify therapeutic antibody and antigen by a modification of the traditional sandwich immunoassay using omalizumab as an example. Standard serum samples were spiked with IgE and omalizumab in a certain concentration range to create standard curves. After incubation and washout procedures, the reaction was stopped and the plate read with bichromatic absorbance…