Low Regulatory T Cells are Present in Patients with Frontal Fibrosing Alopecia-like Lupus

Alopecia, defined as total or partial hair loss is classified into scarring, non-scarring, and hair shaft disorders. Lupus is an autoimmune disease, characterized by an immune response imbalance, with 30-50% of patients experiencing alopecia and a predominance of T-lymphocytes in histopathological analysis. We aimed to identify scalp T-lymphocyte subpopulations in lupus patients and correlate them with clinical findings. This cross-sectional study (IRB# 69467223.0.0000.5243) evaluated scalp biopsies obtained from patients recruited through the Dermatology Departments of HUAP/EBSERH-UFF. Biopsies were performed by the clinical staff in areas of active lesions using a 6mm punch. The biopsies were fragmented and processed using a tissue dissociation protocol with IV collagenase, followed by cell purification and extracellular and intracellular staining using an 18-antibody flow cytometry panel (CD3, CD45, CD4, CD45RO, CD25, CD8, CD127, TCRγδ, CD103, CD69, CCR6, PD-1, CCR4, CD56, CD19, T-bet, Ki-67, and FOXP3), were then analyzed on a BD FACSymphony A5 cytometer (Fiocruz). Among 15 patients (mean age 55.6 ± 18.1 years; 86.7% women; 66.7% systemic lupus erythematosus), we found no cellular differences between systemic and cutaneous lupus, but significant differences were identified only after stratification based on the presence or absence of frontal hairline involvement, as no differences have yet been observed between those with and without scalp plaques. So, patients with frontal fibrosing alopecia (FFA)-like involvement (n=8) had a lower percentage of CD4+CD25+FOXP3+ Treg cells than non-FFA-like patients (9.52% vs 11.40%; p=0.028). Within the total Treg pool, the FFA-like group had fewer CD69+ cells than the non-FFA-like group (76.75% vs 88.40%; p=0.028). Conclusion: The decrease in CD4+CD25+FOXP3+CD69+ Tregs in FFA-like lupus suggests compromised local immunoregulatory capacity and reduced control of tissue inflammation. Further analyses are currently in progress.