Cognitive dysfunction, brain-derived neurotrophic factor and IL-6 levels in cancer patients with depression

Abstract

8632 Background: Increased proinflammatory cytokines (IL-6) and decreased brain-derived neurotrophic factor (BDNF) levels have been implicated in the pathophysiology of depression. Depression has been shown to be associated with cognitive dysfunction. The objective of this study was to assess the correlations between cognitive dysfunction, IL-6 and BDNF in cancer patients (pts) with depression. Methods: Depression was assessed in 55 patients with metastatic cancer by the Hospital Anxiety and Depression Scale (HADS) and diagnosis was established according to DSM-IV criteria. Cognitive function was assessed by the Auditory Verbal Learning Test (AVLT). Plasma concentrations of Interleukin-6 and BDNF were measured at 8 AM the same day. In the statistical analysis the Mann-Whitney test and the Pearson correlation were applied. Results: Pts characteristics (n=55): median age 60 y (25–85); 76.9% Females, 23.1% males. 52% of pts had depression. There were no significant differences in mean age or Karnofsky-index between pts with and without depression. Depression was associated with a significant higher median IL-6 level (14.8 vs. 3.7 pg/ml; p<0,001). For Cognitive function only the longterm memory was significantly reduced in depression (p=0.01). However, there was no difference in BDNF levels between both groups (p=0.164). There were correlations between HADS-D score and IL6 (r=4.11; p=0.002), IL-6 and BDNF (r= −0.42; p=0.001), BDNF and longterm memory (r=0.48; p=0.02). No correlations were found for level of depression (HADS-D score) and BDNF levels (r= −0.20; P=0.14). Conclusions: Depression and increased plasma IL-6 concentrations are strongly associated in pts with cancer. There seems to be no association between BDNF and depression in cancer pts. However there is a positive correlation between the cognitive function, at least for longterm memory, with BDNF. No significant financial relationships to disclose.