Single-Nucleus and Bulk RNA Sequencing Reveals the Involvement of Natural Killer and CD8+ T Cells in the Progression of Androgenetic Alopecia

This study examines the involvement of immune cells, specifically natural killer (NK) cells and CD8+ T cells, in the progression of androgenetic alopecia (AGA) by analyzing hair follicle samples from 9 patients. The research finds that inflammation increases with AGA progression, particularly in grade 5 patients, with 14 immune-related pathways identified. NK and CD8+ T cells are significantly present in balding follicles, associated with increased cytotoxicity and cell killing, suggesting their crucial role in disrupting normal hair follicle cycling and contributing to hair loss. The study also notes reduced angiogenic factors in blood endothelial cells and compositional differences in keratinocytes and fibroblasts. These findings highlight the potential of targeting immune-mediated mechanisms for therapeutic intervention in AGA, although the study's small sample size and variability in inflammatory infiltration emphasize the need for further research.