Autophagy and alopecia areata: is there a link?

Background Autophagy is essential for the normal growth of hair. Active autophagy is evident through the anagen phase of the hair cycle. Moreover, autophagy has important roles in both innate and adaptive immunity and dysfunctional autophagy had been found in some autoimmune diseases. Objective To assess the possible contribution of dysfunctional autophagy in the pathogenesis of alopecia areata (AA) by evaluation of the serum level of autophagy-related protein 5 (ATG5). Patients and methods Fifty patients with AA who did not receive any medications for at least 3 months before the study or newly diagnosed untreated patients of a minimum 2 months’ duration were selected for this case–control study. The severity of hair loss in the scalp was quantified using the Severity of Alopecia Tool score. Measuring of the serum level of ATG5 was done using enzyme-linked immunosorbent assay technique. Results The mean serum level of ATG5 was significantly lower in the patients, group (1494.52±164.9 ng/l) than control group (1807.47±361.3 ng/l) ( P <0.001). Patients with the very severe disease had significantly lower level of serum ATG5 in comparison to those with severe, moderate, and limited disease. Conclusion Serum level of ATG5 decreases significantly in AA patients. This highlights the underlying role of dysfunctional autophagy in AA pathogenesis. However more in-depth studies are still needed to determine the exact pathogenic role of ATG5 in the development of AA and to evaluate the use of autophagy stimulation as a new therapeutic target in AA.