T-helper and natural killer cells’ disturbance in active alopecia areata

Background and aim Alopecia areata (AA) is a common nonscarring hair disease targeting the hair follicles during the anagen phase, leading to hair loss. The etiology of AA is still unclear; however, evidence revealed the association of this disease with immune disturbance. Therefore, we aimed in this study to evaluate the level of natural killer (NK) and T-helper 1 (Th1) cells in the peripheral circulation of patients with different subtypes of AA during the active stage in comparison with the controls. Patients and methods Venous blood samples from 50 female patients and 50 healthy-controls were collected to evaluate the level of Th1 and NK cells using flow cytometry. Results Patients with active patchy AA, alopecia totalis, and alopecia universalis were associated with a lower level of circulating Th1 and NK cells when compared with the controls. Conclusion The observed reduction in the circulating Th1 and NK cells indicates the autoimmune nature of the disease. Also, we highlight the cellular shift from the peripheral circulation to the lesion site during the active stage; however, more research is required to reveal the exact mechanism for this phenomenon.