Correlation between serum β2-microglobulin level and systemic lupus erythematosus disease activity: A PRISMA-compliant meta-analysis

Numerous studies have explored whether serum beta 2-microglobulin (β2-MG) can be used as a biomarker for monitoring systemic lupus erythematosus (SLE) disease activity, but the results are conflicting. Therefore, we performed a systematic meta-analysis to further investigate the correlation between serum β2-MG level and SLE disease activity. METHODS: PubMed, Web of Science, Embase, and CNKI databases were thoroughly searched for eligible studies through April 2022. Standardized mean differences with 95% confidence intervals (95% CIs) were used to depict the differences in serum β2-MG levels between groups compared in the studies. The correlation between serum β2-MG level and SLE disease activity was assessed using Fisher z-values. RESULTS: Sixteen articles with combined 1368 SLE patients were included in this meta-analysis. Serum β2-MG levels were significantly higher in SLE patients than in healthy controls (pooled standardized mean difference: 3.98, 95% CI: 2.50–5.46, P < .01). In addition, patients with active SLE had an increased serum β2-MG concentration compared to their inactive SLE counterparts. Furthermore, a positive correlation was observed between serum β2-MG levels and SLE disease activity (pooled Fisher z = 0.78, 95% CI: 0.61–0.96, P < .01). CONCLUSIONS: This study suggests that patients with SLE have higher serum β2-MG levels than healthy controls and that serum β2-MG levels are positively correlated with SLE disease activity. Thus, serum β2-MG level may be a promising biomarker for monitoring SLE disease activity.