Thymic stromal lymphopoietin and atopic dermatitis: A systematic review and meta-analysis with trial sequential analysis

Objective To comprehensively evaluate the association between Thymic Stromal Lymphopoietin (TSLP) and atopic dermatitis (AD). Methods Six databases were searched for relevant studies. For studies on TSLP levels, the standardized mean difference (SMD) was used. For studies involving gene polymorphisms, evaluation was performed using odds ratios (ORs) and 95% confidence intervals (95% CIs). Based on the between-study heterogeneity, a fixed- or random-effects model was chosen. Analyses were performed using RevMan 5.3 software and R 4.3.0 software. Trial sequential analysis was conducted to evaluate whether the number of cases was sufficient. Results A significant relationship between TSLP rs1898671 polymorphism and AD was found under homozygous (DD vs dd), and dominant contrasts (DD + Dd vs dd), with OR = 0.47 (95% CI: 0.24, 0.92) and 0.46 (95% CI: 0.24, 0.88), respectively ( p < 0.05). Whereas under allele (D vs d), heterozygous (Dd vs dd) and recessive contrasts (DD vs Dd + dd), no significant relationship was found. No significant relationship was found for rs1837253 or rs11466749. Serum TSLP levels were significantly higher in patients with AD, with the SMD = 1.45 (95% CI: 0.65, 2.25) ( p < 0.05). Conclusions TSLP gene rs1898671 polymorphism was associated with AD, and TSLP levels were elevated in patients with AD.