Abstract
Cells that express FcεRIα, including mast cells, basophils, and plasmacytoid dendritic cells (pDCs), are regulated by IgE binding to FcεRIα. Omalizumab binds IgE and prevents its engagement with FcεRIα, thereby downregulating its expression and modulating cell function. Because these cells are implicated in the pathobiology of many allergic and immunologic diseases, as well as host defense mechanisms, it is unsurprising that omalizumab studies continue yielding biologic insights and treatment break-throughs for many diseases. Several recent updates in the biology and use of omalizumab will be presented here, and others will be summarized in Table I, highlighting available biomarker-based personalized approaches.