Basophil phenotypes in chronic idiopathic urticaria in relation to disease activity and autoantibodies.

Potentially pathogenic IgG autoantibodies to IgE or its receptor, FceRIα, have been detected in ~40% of chronic idiopathic urticaria (CIU) patients. CIU patients' basophils display distinct altered FceRIα-mediated degranulation. CIU patients with basophil histamine release in response to polyclonal goat anti-human IgE ≥10% are classified as CIU responders (CIU-R) and n =35), 55% of CIU-NR ( n =29), and 57% of non-CIU subjects ( n =23), whereas IgG anti-IgE was present in 43% of CIU-R, 45% of CIU-NR, and 30% of non-CIU subjects. Both the autoantibody levels and the functional basophil phenotype remained stable in subjects with active disease ( n =16), whereas there was an enhancement in basophil function as subjects evolved into a state of remission ( n =6), which appears independent of the presence of autoantibody. IEMAs detected a similar frequency of autoantibodies in CIU-R, CIU-NR, and non-CIU subjects. Basophil function may be independent of IEMA-detected autoantibodies.