Hair Follicle Immune Privilege and Its Collapse in Alopecia Areata

The document discussed the collapse of hair follicle immune privilege (HF IP) in alopecia areata (AA) and its critical role in the disease's pathogenesis. HF IP normally protects hair follicles from immune attacks, but its breakdown leads to an autoimmune response involving CD8+ T cells, NK cells, and pro-inflammatory mast cells. Key molecules like IFNγ and Substance P were identified as inducers of HF IP collapse. The document emphasized the complexity of HF IP and the need for therapies that restore HF IP to manage AA effectively, highlighting potential treatments such as gene therapy, cell therapy, and immunoregulatory cell types like Tregs and NK cells.