Blood levels of brain-derived neurotrophic factor (BDNF) in systemic lupus erythematous (SLE): a systematic review and meta-analysis

BDNF has been implicated in the pathophysiology of systemic lupus erythematosus (SLE), especially its neuropsychiatric symptoms. The purpose of this study was to investigate the profile of blood BDNF levels in patients with SLE.We searched PubMed, EMBASE, and the Cochrane Library for papers that compared BDNF levels in SLE patients and healthy controls (HCs). The Newcastle-Ottawa scale was used to assess the quality of the included publications, and statistical analyses were carried out using R 4.0.4.The final analysis included eight studies totaling 323 healthy controls and 658 SLE patients. Meta-analysis did not show statistically significant differences in blood BDNF concentrations in SLE patients compared to HCs (SMD 0.08, 95% CI [ - 1.15; 1.32], P value = 0.89). After removing outliers, there was no significant change in the results: SMD -0.3868 (95% CI [ - 1.17; 0.39], P value = 0.33. Univariate meta-regression analysis revealed that sample size, number of males, NOS score, and mean age of the SLE participants accounted for the heterogeneity of the studies (R2 were 26.89%, 16.53%, 18.8%, and 49.96%, respectively).In conclusion, our meta-analysis found no significant association between blood BDNF levels and SLE. The potential role and relevance of BDNF in SLE need to be further examined in higher quality studies.