Decreased Lymphocyte Reactivity and Autoimmunity in Alopecia Areata

In this study from 1981, researchers examined T lymphocyte numbers and functions in 46 patients with alopecia areata compared to 30 healthy controls. They found that lymphocyte reactivity to scalp and hair follicle extracts was undetectable in patients, and lymphocyte responses to PPD, Varidase, and C. albicans were significantly reduced, correlating with hair loss extent and antithyroid antibodies. The study showed that decreased lymphocyte responses were not due to suppressor monocytes, except for C. albicans, where monocyte removal increased reactivity. Patients with alopecia areata had significantly lower T cell numbers, especially those with auto-antibodies, suggesting a link between reduced T cell function, auto-immunity, and alopecia areata.