Lack of association between mean platelet volume and disease activity in systemic lupus erythematosus patients: a systematic review and meta-analysis.

Currently, many studies have focused on the possibility of using mean platelet volume (MPV) as a biomarker for disease activity in patients with systemic lupus erythematosus (SLE). To derive a more accurate estimation, a meta-analysis was conducted. Embase, PubMed, The Cochrane Library database and several Chinese databases (up to Nov 1 2017) were used to acquire published literatures on association of MPV levels with disease activity in SLE patients. Fixed-effects or random-effect model analysis was performed to calculate pooled standard mean difference (SMD) with 95% confidence interval (CI). Heterogeneity test was tested by the Q statistic and quantified using I2. A funnel plot and Egger's linear regression test were used to evaluate the potential publication bias. A total of 618 articles were identified, nine studies with 376 active SLE patients and 270 inactive SLE patients were finally included. No significant difference in MPV level was found between active SLE patients and inactive SLE patients (SMD = - 0.05, 95% CI: - 0.83, 0.73). Subgroup analyses stratified by age or region also demonstrated consistent results. No significant publication bias was observed (P > 0.05). The sensitivity analysis showed no significant change when any one study was excluded. In summary, our meta-analysis does not support the use of MPV as an indicator for monitoring disease activity in SLE patients. Further longitudinal studies with larger sample size are warranted to unveil the possibility of using MPV as a biomarker of disease activity.