Aim of the study was to investigate the expression of members of the interleukin 13 pathway in in atopic dermatitis (AD). IL13 is an emerging target in the treatment of AD. It exerts its effects by binding to the signaling receptor IL13Ra1, through the IL4Ra/IL13Ra1 receptor system and can also bind to the decoy receptor IL13Ra2. Knowledge on the role of IL13 and its receptors in itch signaling in AD including different clinical phenotypes is missing, but is important for a better understanding of itch response to an anti-IL13 therapy. For that, patients with either chronic AD (AD-C) or prurigo nodularis in AD (AD-PN) were recruited, as well as sex and age matched healthy controls (HC). Patients were given clinical questionnaires and punch biopsies on the arms were used to analyze the gene expression in the skin of IL13, IL4, IL31, IL4R, and IL13Rα1, IL13Rα2, and IL31R (qPCR). Expression on protein level of IL13Rα1 and IL13Rα2 was analyzed by immunofluorescence staining on cryosections of the biopsies. The results showed increased expression of IL4 and IL13 and their receptors IL4R and IL13Rα1 in AD-C and AD-PN compared to HC. Interestingly, the expression of IL13Ra2 was only increased in AD-C (vs. HC and AD-PN). No differences in gene expression of IL31RA could be seen across the cohorts. Analysis of the expression of IL13Rα1 and IL13Rα2 at the protein level showed no significant difference between the groups. Both, AD-C and AD-PN, showed a positive correlation between the gene expression levels of IL13 and IL13Rα2. In sum, we mapped the expression of relevant markers for chronic pruritus in AD-C and AD-PN. The upregulation of IL4, IL13 and their receptors IL4R and IL13Ra1 could support the chronification in both of them. The lack of overexpression of the decoy receptor IL13Ra2 in AD-PN, which is upregulated in AD-C and can block IL13 signaling in a negative-feedback mechanism, may worsen the disease in AD-PN and lead to prolonged scratching behavior and multiple pruriginous lesions.

Aim of the study was to investigate the expression of members of the interleukin 13 pathway in in atopic dermatitis (AD). IL13 is an emerging target in the treatment of AD. It exerts its effects by binding to the signaling receptor IL13Ra1, through the IL4Ra/IL13Ra1 receptor system and can also bind to the decoy receptor IL13Ra2. Knowledge on the role of IL13 and its receptors in itch signaling in AD including different clinical phenotypes is missing, but is important for a better understanding of itch response to an anti-IL13 therapy. For that, patients with either chronic AD (AD-C) or prurigo nodularis in AD (AD-PN) were recruited, as well as sex and age matched healthy controls (HC). Patients were given clinical questionnaires and punch biopsies on the arms were used to analyze the gene expression in the skin of IL13, IL4, IL31, IL4R, and IL13Rα1, IL13Rα2, and IL31R (qPCR). The results showed increased expression of IL4 and IL13 and their receptors IL4R and IL13Rα1 in AD-C and AD-PN compared to HC. Interestingly, the expression of IL13Ra2 was only increased in AD-C (vs. HC and AD-PN). No differences in gene expression of IL31RA could be seen across the cohorts.  Both, AD-C and AD-PN, showed a positive correlation between the gene expression levels of IL13 and IL13Rα2. In sum, we mapped the expression of relevant markers for chronic pruritus in AD-C and AD-PN. The upregulation of IL4, IL13 and their receptors IL4R and IL13Ra1 could support the chronification in both of them. The lack of overexpression of the decoy receptor IL13Ra2 in AD-PN, which is upregulated in AD-C and can block IL13 signaling in a negative-feedback mechanism, may worsen the disease in AD-PN and lead to prolonged scratching behavior and multiple pruriginous lesions.

LB016 - IL13 pathway expression in chronic AD and atopic prurigo nodularis

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.