Primary Cicatricial Alopecias Are Characterized by Dysregulation of Shared Gene Expression Pathways

The study investigated primary cicatricial alopecias (PCAs), including lichen planopilaris (LPP), frontal fibrosing alopecia (FFA), and central centrifugal cicatricial alopecia (CCCA), using RNA-sequencing on scalp biopsies from 75 patients. It identified a common gene expression signature across these conditions, characterized by an over-representation of mast cell (MC) genes, downregulation of cholesterogenic pathways, and upregulation of fibrosis and immune signaling genes. Despite clinical differences, the gene expression profiles were highly similar, suggesting shared pathogenic pathways. The study highlighted the potential for unified treatment strategies targeting these pathways, particularly focusing on reducing fibrosis and modulating MC activity, with JAK inhibitors showing promise in reducing LPP activity in 8 out of 10 patients. Environmental factors, such as allergens in facial products and sunscreens, were also suggested to play a role in PCA pathogenesis.