[The important role and interaction of platelet-activating factor and T cell immune function in the pathogenesis of vitiligo].

Objective To investigate the relationship between serum platelet-activating factor (PAF) level, T cell immune function and disease activity in vitiligo patients. Methods A total of 102 patients with vitiligo treated in our hospital from July 18th, 2022 to July 26th, 2023 were enrolled as study subjects. According to VIDA score, the patients were divided into an advanced-stage group (n=54) and a stable stage group (n=49). PAF and T lymphocyte levels were compared between the two groups. Logistic regression analysis was performed to examine the relationship between PAF levels and disease activity, as well as their correlation with T cell subsets. Unconditional logistic regression modeling was employed to analyze the interaction between PAF levels and T cell subsets in disease activity. Results No significant difference was observed in CD3 levels between advanced and stable stage vitiligo patients. PAF and CD8 levels in advanced group were significantly higher than those in stable group, while CD4 levles and CD4/CD8 ratios were significantly lower than those in stable group. When PAF level was 18.24 ng/L, the maximum Youden index reached 0.670, with corresponding sensitivity of 84.22% and specificity of 82.77%. The area under ROC curve AUC was 0.858. The intensity of association between PAF level and disease activity was nonlinear dose-response relationship. Among patients with VIDA score ≥1, significant differences were observed in both CD4 and CD8 levels across different PAF levels, and the CD4/CD8 ratios in vitiligo patients with different VIDA scores was significantly different. Interaction analysis revealed that after adjusting for confounding factors, the effect of PAF levels and T cell subsets on disease activity in vitiligo patients showed significant interaction in both additive model (RERI=4.674, 95%CI: 1.03211.942; AP=0.763, 95%CI: 0.3361.201; S=6.854, 95%CI: 1.90416.520) and multiplicative model (OR=3.461, 95%CI: 1.3658.713). Conclusion Serum PAF, CD4, CD8 and CD4/CD8 of vitiligo patients are closely related to disease activity, and PAF level interacts with T cell subsets (CD4, CD8, CD4/CD8) in the disease activity of vitiligo patients. PAF and T cell immune function may contribute to the occurrence and development of vitiligo, which could serve as clinical indicators of disease activity to guide timely management.