Abstract
Cytotoxic T lymphocyte has been a concern for the etiopathogenesis of alopecia areata (AA), some recent evidence suggests that the regulatory T (T(reg)) cell deficiency is also a contributing factor. In the lesional scalp of AA, T(reg) cells residing in the follicles are impaired, leading to dysregulated local immunity and hair follicle (HF) regeneration disorders. New strategies are emerging to modulate T(reg) cells' number and function for autoimmune diseases. There is much interest to boost T(reg) cells in AA patients to suppress the abnormal autoimmunity of HF and stimulate hair regeneration. With few satisfactory therapeutic regimens available for AA, T(reg) cell-based therapies could be the way forward. Specifically, CAR-T(reg) cells and novel formulations of low-dose IL-2 are the alternatives.