Serum IL‐22 binding protein as a marker for atopic dermatitis activity and response to dupilumab treatment

Abstract

We investigated here the interleukin- 22 (IL- 22)/IL- 22 Binding Protein (IL- 22BP) axis in Atopic Dermatitis (AD) and its modulation upon treatment with Dupilumab, and our findings support its relevance in the clinical management of severe AD. IL- 22 has been emerging as an important player in AD, and its serum levels were shown to be increased in moderate- to- severe AD. 1 IL- 22 assumes major cross- talk functions between immune and epithelial cells, promoting epithelia homeostasis and skin barrier integrity. 2,3 However, it should be tightly regulated, as IL- 22 constitutes one of the cytokines which leads to local inflammation, induction of keratinocyte proliferation and inhibition of its terminal differentiation. 3,4 Part of these effects are likely associated with the role of IL- 22 in the regulation of molecules critically involved in skin barrier. 5 Interestingly, recent data showed that targeting IL- 22 may positively impact on severe AD in the subgroup of patients expressing high level of IL- 22 at baseline. 4 This preliminary study evaluating the clinical outcomes of a small cohort of moderate-to- severe AD with the anti- IL- 22 antibody, Fezakinumab, 4 further supports the relevance of the IL- 22 pathway in AD, given the significant improvement of SCORAD at week 20 ( p = .049). Another player in this axis is the IL- 22BP that inhibits the IL- 22 binding to its membrane bound receptor, IL- 22R. 3,6,7 IL- 22BP was shown to bind IL- 22 with a considerable higher affinity, up to 2000fold, than