Primary cicatricial alopecias are characterized by dysregulation of shared gene expression pathways

To investigate the molecular signatures of the different sub-types of Primary cicatricial alopecia (PCA). We performed high-throughput RNA-sequencing on scalp biopsies of PCA patient. We developed gene expression-based signatures, trained into machine-learning based predictive models and pathways associated with dysregulated gene expression. We performed morphological and cytokine analysis to define the immune cell populations found in PCA sub types. Using bulk RNA sequencing, we identified a common PCA gene signature that was shared between LPP, FFA, and CCCA which revealed a significant over-representation of mast cell signature genes, as well as down regulation of cholesterogenic pathways and up regulation of fibrosis and immune cell signaling genes. Thw Immunohistological analyses revealed an increased presence of mast cells in PCAs lesions. Overall design: high-throughput RNA-sequencing on scalp biopsies of PCA patients to develop gene expression-based signatures