Atopic dermatitis (AD) is a chronic, inflammatory skin disease characterized by significant barrier damage. Since the regulation and maintenance of the antimicrobial and permeability skin barriers are closely connected, and the literature data regarding the expression of AMPs in AD are controversial (mainly suggesting their decreased level), we aimed to comprehensively investigate the expression of different AMPs in lesional (AD L) and non-lesional (AD NL) skin samples both at the mRNA (qRT-PCR) and the protein levels (immunohistochemistry). Therefore skin samples from 9 patients with severe AD, and 9 samples from healthy individuals as controls were gained, and the expression levels of different AMP groups were investigated: AMPs with antimicrobial activity (LL-37/Cathelicidin, hBD 1-4), protease inhibitor/enzyme activity (SLPI, PI3, Rnase5, Rnase7, and LYZ), chemokine activity (S100A7, S100A8, S100A9, CCL20), neuropeptide activity (ADM) and other (LCN2). In AD NL skin, at the gene level we found only some minor and not consequent alterations compared to healthy skin, and we could not strengthen them at the protein level. In AD L samples some AMPs were elevated only at the gene level (PI3, LYZ, S100A7, S100A9), while four of the investigated AMPs, namely hBD2, hBD4, S100A8 and LCN2 showed significant and consequent increase both at the gene and the protein levels. In summary we can conclude that AMPs are not present in AD NL skin, therefore they may not play a role in the primary events of AD pathogenesis. On the other hand, the expressions of hBD2, hBD4, S100A8 and LCN2 are increased both at the gene and the protein levels in AD L skin, therefore previous literature data suggesting that the expression of AMPs are downregulated in AD L skin is misleading, their levels are decreased only when compared to psoriatic skin.

ESDR407 - Investigation of antimicrobial peptides in atopic dermatitis

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.