Association between immune activation and early depressive symptoms in cancer patients treated with interleukin-2-based therapy

The relationship between immune activation and the development of early dep ressive symptoms were studied in 33 cancer patients undergoing cytokine the rapy. Patients were treated either with subcutaneous IL-2 administered alon e (n=13) or in association with IFN-alpha (n=5), or with IFN-alpha alone ad ministered subcutaneously at low doses (n=5) or intravenously at high doses (n=10). The intensity of depressive symptoms was assessed during a clinica l interview carried out before the start of cytokine therapy and five days later using the Montgomery and Asberg Depression Rating Scale (MADRS). On t he same days, blood samples were collected for each patient to measure seru m concentrations of cytokines (IL-6, IL-10, IL-1ra) and cytokine-receptors (sIL-2R, LIF-R). Results showed that patients treated with IL-2 or IL-2+IFN -alpha displayed concomitant mood symptoms and increased serum cytokine lev els during treatment. In these patients, the intensity of depressive sympto ms at endpoint was positively correlated with the increases measured in ser um levels of IL-10 between baseline and endpoint. IL-10 is an anti-inflamma tory cytokine that is produced in response to the production of proinflamma tory cytokines, and thereby reflects an inflammatory response. These result s support the hypothesis of close relationship between depressive symptoms and the activation of the cytokine network. (C) 2001 Elsevier Science Ltd. All rights reserved.