Type 1 Interferon Signature in the Scalp Lesions of Alopecia Areata

The study examined the presence of type 1 interferon-related proteins in scalp lesions of patients with alopecia areata (AA) and compared them to other scalp conditions. Scalp biopsies from 6 patients with inflammatory AA, 2 with non-inflammatory AA, 2 with discoid lupus erythematosus (DLE), 2 with lichen planopilaris (LPP), and 2 with androgenetic alopecia were analyzed for the expression of myxovirus protein A (MxA), CXCR3, granzyme B (GrB), and T-cell intracytoplasmic antigen 1 (TiA-1). The results showed that MxA was expressed in inflammatory AA similar to cicatricial alopecia but not in non-inflammatory AA or androgenetic alopecia. CXCR3-expressing cells correlated with MxA expression, and AA lesions had fewer GrB+ cells and more TiA-1+ cells compared to cicatricial alopecia. The study concluded that AA features a type 1 interferon signature and differs from cicatricial alopecia in the pattern of interferon signature and cytotoxic proteins, suggesting AA is a cytotoxic assault on the hair follicle. Treatments that induce type 1 IFN were found ineffective for AA, indicating that targeting the IFN-α pathway may be a potential therapeutic approach.