IgE and High Affinity IgE Receptor in Chronic Inducible Urticaria,
pathogenic and management relevance
Abstract
BACKGROUND: IgE and High-affinity IgE receptor (FcεRI) expression on
basophils has been scarcely explored in patients with chronic inducible
urticaria (CIndU). OBJECTIVES: To investigate baseline serum IgE and
FcεRI expression on blood basophils in a large cohort of CIndU patients
and its relationship to treatment response. METHODS: Baseline total
serum IgE and basophil FcεRI expression measured by flow cytometry in
165 patients with CIndU was studied. The relationship of both parameters
with the response to antihistamine and anti-IgE (omalizumab) treatment
was considered in a subsample of CIndU patients. FcεRI expression in
basophils was assessed by mean fluorescence intensity (MFI) and basophil
FcεRI standardized density (receptors/cell). RESULTS: The median FcεRI
expression standardized per density in blood basophils was found
significantly higher in patients with CIndU compared to HCs. A positive
correlation was found between IgE serum levels and basophil FcεRI
expression. Basal FcεRI expression was not related to antihistamine
treatment response. However, it was related to omalizumab, and patients
responding to omalizumab showed higher basal basophil expression of
FcεRI levels. Non-responders to the antihistamine showed significantly
higher IgE serum levels. CONCLUSIONS: FcεRI receptor overexpression in
patients with CIndU shows almost the same pattern than Chronic
Spontaneous Urticaria. It seems to be independent of CIndU subtypes.
Although additional studies would be welcome, our work highlights the
relevance of FcεRI receptor regulation in CIndU supporting the
autoimmune pathogenesis and suggest that CIndU patients benefit from
anti-IgE therapy.