IGHE and asthma: Reductions in IgE levels could with time reduce mast cell responsiveness to allergen triggering [5], while reductions in IgG1 levels would decrease IgG1-allergen immune complex formation, and thereby downstream activation of Fc-gamma RIII- and Fc-gamma RIV-bearing cells such as mast cells, basophils and eosinophils that contribute to the pathogenesis of asthma [4].