IgE and Fcε RI are highly expressed on innate cells in psoriasis.

Background Although elevated serum IgE levels have been reported in psoriasis, the role of IgE in psoriasis still needs to be clarified. Objectives To analyse serum total IgE levels in addition to the presence and distribution of IgE and Fcε RI in psoriatic lesions, and to investigate alteration of IgE and Fcε RI after successful systemic treatment. Methods Total serum IgE levels were determined using enzyme-linked immunosorbent assay. The expression and localization of IgE and Fcε RI was investigated using immunohistochemistry and double immunofluorescence. Results Elevated total serum IgE levels were found in 39% of patients with psoriasis. The levels of total serum IgE were significantly higher in male patients compared with female patients. Furthermore, total serum IgE levels decreased after successful systemic treatment. A positive correlation between IgE+ and Fcε RI+ cells and a significant increase of these cells was found in psoriatic lesions when compared with normal skin. Interestingly, IgE+ and Fcε RI+ cells decreased significantly after successful therapy with ustekinumab. IgE and Fcε RI were coexpressed on mast cells, epidermal Langerhans cells, dermal dendritic cells, macrophages and a small number of neutrophils. Conclusions IgE might participate in the development of psoriasis by activating Fcε RI-bearing cells. [ABSTRACT FROM AUTHOR]