Circulating Interleukin-18 Level in Systemic Lupus Erythematosus

ABSTRACT

OBJECTIVE@#This study aimed to evaluate the relationship between circulating interleukin (IL)-18 levels and systemic lupus erythematosus (SLE) and establish a correlation between plasma/serum IL-18 levels and SLE activity.@*METHODS@#We performed a meta-analysis comparing plasma/serum IL-18 levels in patients with SLE to controls by using fixed or random effects model based on the heterogeneity.@*RESULTS@#Sixteen studies with 659 SLE patients and 502 controls were included in this meta-analysis. Meta-analysis showed that IL-18 levels were significantly higher in the SLE group (standardized mean difference=1.556, 95% confidence interval=1.087~2.024, p<0.001). Stratifying by ethnicity showed that IL-18 levels were significantly elevated in the SLE groups of European, Asian, and Arab populations. Stratification by adjustment for age and/or sex revealed a significantly higher IL-18 level in the SLE group, independently of the adjustment. Subgroup analysis by sample size showed significantly higher IL-18 levels in the SLE group for both large sample (n≥50) and small sample (n<50) subgroups. Subgroup analysis by data type showed significantly higher IL-18 levels in the SLE group for both original and calculated data populations.@*CONCLUSION@#This meta-analysis demonstrated that circulating IL-18 levels are higher in patients with SLE.