House dust mite allergens Der f and Der p induce IL‐31 production by blood‐derived T cells from atopic dermatitis patients

Aero‐allergens, such as house dust mite (HDM), have been suggested to play a role in the initiation of atopic dermatitis (AD)‐related skin inflammation. Here, we analysed the proliferation and the cytokine expression of blood‐derived T cells from AD and healthy individuals upon HDM‐allergen stimulation. The proliferating cells from healthy individuals and AD patients had a significantly different, distinct cytokine profile: in AD blood, we found increased frequencies of HDM‐reactive IL‐31‐producing T cells, as well as a decreased Th1/Th2 and Tc1/Tc2 ratio, suggesting that allergen‐specific T cells in blood of chronic AD patients are subject to pre‐existent Th2‐Tc2 and “Th31‐Tc31” programming.