Macrophage-Derived Chemokine: A Putative Marker of Pharmacological Therapy Response in Major Depression?

INTRODUCTION: Inflammatory processes play an important and complex role in the pathophysiology of major depressive disorder (MDD), but, so far, no specific investigation of chemokines exists. METHODS: In this study, we investigated the changes of plasma chemokine levels (eotaxin-1, eotaxin-3, IP-10, MCP-1, MCP-4, MDC, MIP-1α, MIP-1ß, and TARC) in 47 MDD patients before (PRE) and after 1 and 6 weeks of pharmacological treatment (POST1 and POST6) in relation to the response to antidepressive therapy. We hypothesized that the direction of alterations in levels of chemokines would significantly differ between the 2 groups, responders and nonresponders. RESULTS: Among the investigated chemokines, only the level of macrophage-derived chemokine (MDC) changed significantly in relation to therapy response. MDC levels were significantly elevated in the responder group at POST6. DISCUSSION: MDC is a constitutively expressed chemokine involved in the pathophysiology of infectious and neoplastic diseases. This is the first study providing valuable hints that MDC might serve as a marker of pharmacological therapy response in MDD.