Clinical significance of serum high-mobility group box 1 level in alopecia areata.

BACKGROUND: Alopecia areata (AA), a chronic, relapsing hair-loss disorder, is considered to be a T-cell-mediated autoimmune disease. High-mobility group box 1 (HMGB1), released by necrotic cells and in response to various inflammatory stimuli, is currently considered to be a significant target antigen in diverse autoimmune diseases. OBJECTIVE: We sought to investigate the clinical significance of serum HMGB1 levels in AA. METHODS: We compared levels of HMGB1 in scalp specimens from 7 patients with AA and 8 healthy control subjects and in blood samples from 45 patients with AA and 10 healthy control subjects. Moreover, we evaluated the correlation between HMGB1 level and clinical severity. RESULTS: Immunohistochemical staining of scalp tissues from patients with AA revealed higher HMGB1 levels than in healthy control subjects. In addition, serum HMGB1 levels in the AA group were generally higher, and showed concordance with the patients' clinical characteristics, including onset, hair-pull test results, and treatment response. LIMITATIONS: The number of patients and healthy control subjects evaluated was small. CONCLUSION: These results suggest that HMGB1 plays a significant role in the pathogenesis of AA, and that it is a promising predictor of prognosis and treatment response. Moreover, this study identifies a new potential therapeutic target for the treatment of AA.