Serum levels of brain-derived neurotrophic factor are associated with depressive symptoms in patients with systemic lupus erythematosus

Abstract

ObjectiveThe aim of this study was to explore potential relationships between serum BDNF levels and depression in systemic lupus erythematosus (SLE) patients. MethodsWe included 208 consecutive SLE patients and 100 age-and sex-matched healthy controls. The presence of depressive symptoms was determined through the Beck Depression Inventory-II (BDI-II) score. ResultsThe serum BDNF levels were significantly (P<0.0001) higher in SLE patients as compared to normal controls. There was a negative correlation between levels of BDNF and the SLE disease activity index 2000 (SLEDAI–2K) (r=−0.349, P<0.0001). Depression (defined as BDI-II score≥18) was identified in 54 SLE patients (26.0%, 95%CI: 20%–31.9%). The serum BDNF levels were significantly lower in depression patients at the time of admission as compared with patients without depression [27.6(IQR, 23.2–30.4)ng/ml vs. 36.2(IQR, 31.7–42.3)ng/ml; P<0.0001]. Compared with the first quartile of serum BDNF levels, the second quartile OR for depression was 0.72 (95% CI, 0.61–0.80, P=0.033). For the third and fourth quartiles, it was 0.42 (95% CI, 0.33–0.52, P=0.002) and 0.16 (95% CI, 0.09–0.24; P<0.001). ConclusionSerum BDNF levels are decreased in SLE patients with depressive symptoms. In SLE, serum BNDF levels are independently associated with depressive disorders, suggesting the role of neurotrophic factors in depression.