Alopecia Areata Patients Show Deficiency of FOXP3+CD39+ T Regulatory Cells and Clonotypic Restriction of Treg TCRβ-Chain, Highlighting the Immunopathological Aspect of the Disease

The study investigated the role of T regulatory cells (Tregs) in Alopecia Areata (AA) by comparing 20 AA patients with active hair loss to 15 healthy subjects. It found a significant reduction in the Treg suppressor HLA-DR+ subpopulation and CD39+ cells among the CD4+CD25+Foxp3+ Treg subpopulation in AA patients. Specifically, FOXP3+CD39+ Treg cells were reduced by 75% in non-lesional skin and 90% in lesional skin of AA patients. Additionally, the study identified unique Treg clonotypes in healthy individuals that were absent in AA patients, suggesting a protective role. The findings suggest that the deficiency of these Treg cells may contribute to the disease process and that targeting CD39 expression on T-cells could be a potential therapeutic approach. The study also noted a clonotypic restriction in the Treg TCRβ-chain in AA patients, indicating a less diverse TCR repertoire, which could be involved in the pathogenesis of AA.