biostudies-literatureConnell SJBLRD VANIAID NIH HHSNIAMS NIH HHS103061https://www.ebi.ac.uk/biostudies/studies/S-EPMC9018517biostudies-literatureUnknown21(5)Alopecia areata (AA) is an autoimmune disease that affects approximately 2% of the general population. Patients with AA most commonly present with one or more patches of hair loss on the scalp in defined circular areas. A fraction of patients progress to more severe forms of the disease, in some cases with involvement of all body surfaces. The healthy anagen stage hair follicle is considered an immune privileged site, described as an environment that suppresses inflammatory immune responses. However, in AA, this immune privileged state collapses and marks the hair follicle as a target for the immune system, resulting in peri- and intrafollicular infiltration by lymphocytes. The complexity of the inflammatory ecosystem of the immune response to the hair follicle, and the relationships betweAutoimmunity reviewsThe current state of knowledge of the immune ecosystem in alopecia areata.PMC9018517R01 AR077194I01 BX004907T32 AI007485K08 AR069111Jabbari AConnell SJfalseThe current state of knowledge of the immune ecosystem in alopecia areata.Alopecia areata (AA) is an autoimmune disease that affects approximately 2% of the general population. Patients with AA most commonly present with one or more patches of hair loss on the scalp in defined circular areas. A fraction of patients progress to more severe forms of the disease, in some cases with involvement of all body surfaces. The healthy anagen stage hair follicle is considered an immune privileged site, described as an environment that suppresses inflammatory immune responses. However, in AA, this immune privileged state collapses and marks the hair follicle as a target for the immune system, resulting in peri- and intrafollicular infiltration by lymphocytes. The complexity of the inflammatory ecosystem of the immune response to the hair follicle, and the relationships betwe2022-01-01T00:00:00Z2022 May2025-04-18T20:36:48.48Z2024-11-07T10:24:52.638ZS-EPMC90185173515188510.1016/j.autrev.2022.103061