Predicting the Clinical Response to Omalizumab With Anti-Immunoglobulin E (IgE) Ab Response or Syk Expression in Basophils

This research is being done to test whether differences in blood cells at baseline (start of the study) can be used to predict how well omalizumab will work in a patient. Omalizumab (Xolair) is a drug approved by the U.S. Food and Drug Administration (FDA) to treat asthma. Studies show that omalizumab improves the symptoms of asthma but some people experience better improvement than others.