Psoriasis may very rarely manifest along the lines of Blaschko. We assessed gene expression in 2 individuals with Blaschko-linear psoriasis (BLP) and compared genes and pathways with their non-lesional skin as well as public repository psoriasis vulgaris (PV) skin data. By undertaking differential expression analysis between lesional and non-lesional BLP skin samples, we identified 763 differentially expressed (DE) genes (adjusted P<0.1). To assess pathway enrichment, we performed gene ontology (GO) and gene set enrichment analysis (GSEA). Top enriched GO terms included cornification, epidermis development, keratinization and skin development. We also noted a plethora of immune pathways reflecting the enhanced inflammatory responses in lesional skin. Next, we compared the BLP transcriptome with the publicly available RNA-Seq data for three PV datasets and observed strong correlations, suggesting that the transcriptomic changes of BLP and PV are highly similar. By focusing on the log-fold changes of the top 14 DE genes, however, we observed that the PV datasets were more similar to each other than to the BLP dataset. Moreover, 150 out of the BLP DE genes showed significant divergent expression between BLP and PV datasets. STRING network constitution and functional enrichment analysis highlighted these differences related to formation of cornified envelope, and inflammatory responses including IL-4, IL-13 and IL-36 signalling pathways. In most regards, however, the BLP and PV transcriptomes are similar, supporting the notion that primary keratinocyte pathology (BLP) can lead the generation of several key signatures of psoriasis.

ESDR128 - Transcriptional profiling of Blaschko-linear psoriasis skin highlights mostly shared but occasionally divergent features with psoriasis vulgaris

50th Annual Meeting of the European Society for Dermatological Research. VIRTUAL MEETING