Lichen Planopilaris (LPP) is a lymphatic disease affecting the scalp and it is characterized by chronic inflammation leading to cicatricial alopecia. Perturbation in host immune response as well as the alteration of the scalp microbiota observed in our previous study on another model of scalp auto-immune disease suggests a disequilibrium within the scalp microbiota in LPP patients and a role in its physiopathology. Scalp and biopsy layers have never been investigated in LPP for microbial communities. We examined the significant taxa of this chronic relapsing inflammatory skin disease together with the connections with metabolic pathways featuring this microbial community. We used a multilevel analysis based on 16S rRNA marker sequencing in order to detect taxa abundances in pathologic/healthy samples, real time PCR for measuring the levels of IL-23 interleukin expression and urinary metabolomics to find out volatile organic metabolites (VOMs). By using a linear regression model, we described those peculiar taxa that significantly differentiated LPP and healthy sample sub-groups. By correlating taxa abundances and interleukin mRNA levels we found that the Microbacteriaceae family resulted negatively correlated with the IL-23 expression. Moreover, starting from 16S taxa abundances, we predicted the metabolic pathways featuring this microbial community. Thanks to a systematic and multi-level analysis we described the differential abundance of various taxa in the swab and dermis of LPP patients together with their related biochemical pathways. Metagenomics and other multi-omics approaches will allow a deep identification of genomic bacterial profiles. At the same time the transcript expression levels of those species contributing to biochemical pathways modification linked to LPP immune-related functions will be inspected.

ESDR339 - Lichen Planopilaris: The First Biopsy Layer Microbiota Inspection

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