Abstract
Th2 cells are well known to play important roles in allergic diseases including allergic rhinitis (AR). Meanwhile, the factors that induce and sustain the pathogenesis of AR remain unclear. The recent development of sublingual Immunotherapy (SLIT) is expected to allow changes to the underlying pathogenesis of AR. However, the phenotype of the pathogenic Th2 cells (Tpath2) cells in house dust mite-induced AR (HDM-AR) and the relation between Tpath2 and SLIT efficacy have not been clarified. Therefore we analyzed the cytokine production and frequency of HDM-reactive T-cell subsets in peripheral blood mononuclear cells (PBMCs) using flow cytometry in 89 HDM-AR patients (placebo; n = 43 and HDM 300 IR; n = 46) who participated in a placebo-controlled study of SLIT with HDM tablets. All patients provided samples both before treatment as a baseline and at the end of the 52-week study. HDM-reactive IL-5+IL-13+CD27-CD161+CD4+ cells and ST2+CD45RO+CD4+ cells were observed in the PBMCs from each patient with HDM-AR; these cells significantly decreased after SLIT in the group treated with active tablets. HDM-reactive ST2+CD45RO+CD4+ cells were significantly lower in active-responders.
In conclusion, HDM-reactive ST2+CD45RO+CD4+ cells or those combined with IL-5+IL-13+CD27-CD161+CD4+ cells may be useful as markers indicating the successful treatment of SLIT. These cells may play a crucial role in the pathogenesis of HDM-AR as Tpath2.
