The efficacy of omalizumab treatment in chronic spontaneous urticaria is associated with basophil phenotypes.

Background: The mechanisms underlying disease pathogenesis in chronic spontaneous urticaria (CSU) and improvement with omalizumab are incompletely understood.

Objectives: This study sought to examine whether the rate of clinical remission is concordant with baseline basophil features or the rate of change of IgE-dependent functions of basophils and/or plasmacytoid dendritic cells during omalizumab therapy.

Methods: Adults (n = 18) with refractory CSU were treated with omalizumab 300 mg monthly for 90 days.