Alopecia Areata Is Driven by Cytotoxic T Lymphocytes and Is Reversed by JAK Inhibition

The study concluded that alopecia areata (AA) was driven by cytotoxic CD8+NKG2D+ T cells and could be reversed by inhibiting Janus kinase (JAK) pathways. Experiments demonstrated that JAK inhibitors, such as ruxolitinib and tofacitinib, effectively restored hair growth in both mouse models and human subjects. In a small clinical trial, three patients treated with oral ruxolitinib achieved near-complete hair regrowth within 3-5 months. These findings suggested that JAK inhibitors could be a promising therapeutic approach for treating AA by targeting specific immune pathways.