Immune Regulation in Hair Follicle Protection and Hair Regeneration: Insights from the Collapse of Immune Privilege in Alopecia Areata and Targeted Immunotherapy

This review explores the role of immune regulation in protecting hair follicles and facilitating hair regeneration, particularly focusing on the collapse of immune privilege in alopecia areata. Under normal conditions, hair follicles are protected by immune privilege, which involves spatial isolation, immune regulators, and regulatory T cells. Immune cells also aid in hair regeneration through various pathways and mechanisms. In alopecia areata, stress can lead to the breakdown of this immune privilege, triggering an inflammatory response. The review, which includes approximately 120 studies, highlights recent advances in understanding these processes and discusses current therapies like corticosteroids and Janus Kinase inhibitors, which offer symptomatic relief but not long-term prevention. Emerging targeted immunotherapies show promise for more effective treatment by inhibiting inflammatory pathways and modulating regulatory T cells.