Depressive symptoms are associated with tumor necrosis factor alpha in systemic lupus erythematosus.

Background: Tumor necrosis factor alpha (TNF-α) is deeply related to pathogenesis of neurodevelopmental disorders, especially depression. The aim of this study was to explore potential relationships between sera TNF-α levels and mood and anxiety disorders in systemic lupus erythematosus (SLE) patients.

Methods: We included 153 consecutive SLE patients (women 148; median age 30; range 10-62) and 40 (women 37; mean age 28.5; range 12-59) age- and sex-matched healthy controls. Mood and anxiety disorders were determined through Beck Depression and Beck Anxiety Inventory. SLE patients were further assessed for clinical and laboratory SLE manifestations. TNF-α levels were measured by enzyme-linked immunosorbent assay using commercial kits.

Results: Depressive symptoms were identified in 70 (45.7 %) SLE patients and in 10 (25 %) healthy controls (p < 0.001). Anxiety symptoms were identified in 93 (60.7 %) SLE patients and in 16 controls (40 %) (p < 0.001). Sera TNF-α levels were increased in SLE patients with depressive symptoms (p < 0.001) and with anxiety symptoms (p = 0.014). A direct correlation between the severity of depressive symptoms and sera TNF-α levels (r = 0.22; p = 0.003) was observed. TNF-α levels were significantly increased in patients with active disease (p = 0.012). In addition, we observed a correlation between sera TNF-α levels and disease activity (r = 0.28; p = 0.008). In the multivariate analysis, sera TNF-α levels were independently associated with depressive symptoms (t = 3.28; 95 % CI 1.08-2.2; p = 0.002).

Conclusions: Sera TNF-α levels are increased in SLE patients with mood and anxiety disorders. In SLE, sera TNF-α levels are independently associated with mood disorders. The etiology of mood disorders is still debated in SLE, but our findings suggest the presence of immunological basis for depression in SLE.