Trichohyalin Is a Potential Major Autoantigen in Human Alopecia Areata

The study identified trichohyalin as a potential major autoantigen in alopecia areata (AA), an autoimmune hair loss disorder. Researchers used serum antibodies from 10 AA patients to isolate hair follicle-specific antigens, revealing strong reactivity to trichohyalin, a structural protein specific to the hair growth phase. Keratin 16 (K16) was also identified as a potential target antigen. Immunofluorescence studies showed that AA sera contained immunoreactivity that colocalized with trichohyalin in the inner root sheath of hair follicles, and partially with K16 in the outer root sheath. The findings suggested that immune responses to these anagen-specific hair follicle antigens might play a role in AA pathogenesis.