Abstract
BACKGROUND: Non-scarring hair loss (NSHL) is a global health concern with increasing prevalence due to lifestyle changes and an aging population. It can cause psychological distress and affect quality of life. OBJECTIVE: This study aimed to identify the associations between NSHL and immune cell phenotypes using a two-sample Mendelian randomization (MR) analysis, offering insights for future immune-based therapies for NSHL. METHODS: We obtained immunocyte data from the IEU Open GWAS Project and NSHL data from the same database and used MR analysis to evaluate the causal association between each immunophenotype and NSHL. Three statistical methods were employed: the MR-Egger regression, weighted median estimation, and inverse variance weighting (IVW). RESULTS: The MR resonance imaging identified 31 immunocyte phenotypes associated with NSHL. Among these, 19 immunocyte phenotypes were negatively associated with NSHL, indicating their protective effects. The remaining 12 immunocyte phenotypes were positive association. Sensitivity analyses suggested the robustness of all MR findings. CONCLUSION: These findings highlight a clear correlation between NSHL and immunity, demonstrating the significant role of certain immune cell phenotypes. This study offers a new direction for immune-based therapies in the treatment of NSHL.