Investigation of circulating endothelial progenitor cells and angiogenic and inflammatory cytokines during recovery from an episode of major depression

Abstract

Epidemiological studies strongly suggest a bidirectional positive relationship between mood and cardiovascular disorders (CVD). Reduced numbers of circulating endothelial progenitor cells (cEPCs) are associated with elevated risks of CVD. Previously we demonstrated that patients with a current episode of major depression (MDE) have a decreased number of cEPCs. The role of vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF) has been demonstrated in the etiopathogenesis of depression. In addition these cytokines are also involved in regulation of the vascular system. This suggests that VEGF and/or TNF may also mediate the elevated risk of CVD associated with mood disorders. In the current investigation, which has a self-controlled study design, we examined changes in VEGF and TNF levels and--for the first time--changes in cEPC number during recovery from MDE. Twenty-four patients with MDE were enrolled. The severity of their depressive symptoms improved significantly during the one-month treatment period (~50% decrease in MADRS score; P≤0.001). We did not find significant differences between baseline and end-point levels of VEGF, TNF and the number of cEPCs. Our negative result for alteration in the number of cEPCs in the course of recovery from MDE raises several questions. Before discarding the number of cEPCs as a possible marker of depression--and/or elevated CV risk associated with it--our results would require confirmation in larger samples. Our results for TNF and VEGF do not contradict the findings of prior studies, since these were controversial.