Serum levels of IL-12 and the production of IFN-gamma, IL-2 and IL-4 by peripheral blood mononuclear cells (PBMC) in cancer patients treated with Viscum album extract.

A dysregulation between cellular immunity (Th1 cells) and humoral immunity (Th2 cells) is a characteristic of cancerous diseases. Viscum album (VA) extract has an immunomodulatory effect and can be used in the treatment of cancer patients, either following or in combination with chemo- /radiotherapy. In this pilot study, we investigated the effect of VA extract on the serum levels and production of cytokines in a group of cancer patients undergoing treatment (N = 16) in comparison with healthy untreated controls (N = 11). The serum levels of interleukin-12 (IL-12) (p40 and p70), and the production of gamma interferon (IFN-gamma), interleukin 2 (IL-2), and interleukin-4 (IL-4) in peripheral blood mononuclear cells (PBMC) were measured in patients before treatment and on days 3, 5, 8, 15, and 21-29 during therapy, and in the control group at the same time intervals over a two-week period. Cytokine levels were determined by ELISA. In cancer patients, the serum levels of IL-12 (p40 and p70) before therapy were about 3-fold higher than in controls. They increased during therapy, with a borderline significance (Wilcoxon paired signed-rank test, P = 0.06). In PBMC the production of IFN-gamma and IL-2 (before therapy respectively 3-fold and 9-fold lower than in controls) increased significantly (Wilcoxon paired signed-rank test and Mann-Whitney U-test, P < 0.05) during treatment. In PBMC, IL-4 production was in the same range as in controls, and remained unaltered during therapy. In conclusion, the results of this study show that treatment with VA extract leads an increase in Th1 cytokine levels (IFN-gamma and IL-2), which suggests that cell-mediated immunity could be positively affected.