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

Background: Tumor necrosis factor alpha (TNF-alpha) is deeply related to pathogenesis of neurodevelopmental disorders, especially depression. The aim of this study was to explore potential relationships between sera TNF-alpha 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-alpha 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-alpha 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-alpha levels (r = 0.22; p = 0.003) was observed. TNF-alpha levels were significantly increased in patients with active disease (p = 0.012). In addition, we observed a correlation between sera TNF-alpha levels and disease activity (r = 0.28; p = 0.008). In the multivariate analysis, sera TNF-alpha levels were independently associated with depressive symptoms (t = 3.28; 95 % CI 1.08-2.2; p = 0.002). Conclusions: Sera TNF-alpha levels are increased in SLE patients with mood and anxiety disorders. In SLE, sera TNF-alpha 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.