The role of cytokines and chemokines in the T-cell-mediated autoimmune process in alopecia areata

The aetiology of alopecia areata (AA) is still not fully understood. However, recent clinical and experimental studies have provided insights into the pathomechanisms of AA and revealed that it is an organ-specific and cell-mediated autoimmune disease. Some triggers, such as viral infections, trauma, hormones and emotional/physical stressors, may cause activation of autoreactive T cells that target hair follicle (HF) autoantigens. In these immunological responses, cytokines and chemokines are regarded as key players that mediate the autoimmune inflammation. This results in the collapse of HF immune privilege, which is central to the pathogenesis of AA. This essay will focus on how cytokines and chemokines contribute to the immunological aspects of AA. The management of AA often remains difficult in a number of cases. Our review suggests that novel therapies for AA may involve targeting cytokines and chemokines.