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

OBJECTIVE: The aim of this study was to explore potential relationships between serum BDNF levels and depression in systemic lupus erythematosus (SLE) patients.

METHODS: We 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.

RESULTS: The 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).

CONCLUSION: Serum 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.