Correlation between circulating interleukin-18 level and systemic lupus erythematosus: a meta-analysis.

Area of Science:

• Immunology
• Rheumatology
• Biomarkers

Background:

• Systemic lupus erythematosus (SLE) is a complex autoimmune disease.
• Interleukin-18 (IL-18) is a pro-inflammatory cytokine implicated in autoimmune conditions.

Purpose of the Study:

• To conduct a meta-analysis to clarify the association between circulating interleukin-18 (IL-18) levels and systemic lupus erythematosus (SLE).
• To pool data from multiple studies to determine the overall effect size and confidence interval for IL-18 levels in SLE patients.

Main Methods:

• Systematic literature search of major databases (Medline/PubMed, Embase, Scopus, Cochrane Library, Web of Science) up to July 15th, 2020.
• Meta-analysis using standardized mean difference (SMD) and 95% confidence intervals, with heterogeneity assessed by I² statistic.
• Publication bias evaluated using funnel plots and Egger's regression test; meta-regression and subgroup analyses performed.

Main Results:

• Thirty eligible studies from eighteen regions were included in the meta-analysis.
• SLE patients exhibited significantly higher circulating IL-18 levels compared to healthy controls (SMD = 1.56, 95% CI [1.20-1.93]).
• Elevated IL-18 levels were observed in subgroups based on sample type, age, disease duration, testing method, SLEDAI score >5, and Asian, White, Arab, or mixed ethnicity.

Conclusions:

• Circulating IL-18 levels are considerably higher in patients with SLE compared to healthy individuals.
• The findings suggest a significant role for IL-18 in the pathogenesis of systemic lupus erythematosus.
• IL-18 may serve as a potential biomarker for SLE activity and progression.