No evidence of IFN-gamma increase in the serum of HIV-positive and healthysubjects after subcutaneous injection of a non-fermented Viscum album L-extract

Iscador(R), an aqueous extract of Viscum album L., has been used for more t han 80 years as an anticancer drug. Due to its immunomodulatory potential, since the onset of the AIDS epidemic it has also been applied in the treatm ent of HIV-positive and AIDS patients in the form of the preparation V. alb um QuFrF (VaQuFrF; Labor Hiscia, Arlesheim, Switzerland). In in vitro inves tigations, incubation of peripheral blood mononuclear cells with V. album L , extracts resulted in stimulation of lymphocyte activity with increased ge ne expression and release of various cytokines and also of interferon gamma (IFN-gamma). In the latent phase, HIV positives exhibit only slightly elev ated IFN-gamma concentrations in serum in comparison with HIV negatives, bu t in the acute phase of AIDS, there is an increase in levels of IFN-gamma. As the assay of cytokine levels in serum is a simple method of measuring im mune system reactions, the aim of this trial was to determine whether incre ases in serum IFN-gamma levels in HIV positives and HIV negatives can be de tected using this method after repeated injections of VaQuFrF. Five healthy subjects and 13 HIV-positive patients were investigated. IFN-gamma concent rations in serum were assayed using an ELISA test kit (ELISA test; ENDOGEN, Cambridge, Mass., USA). No drug-related elevation of serum IFN-gamma was o bserved at any time point during the trial. It can thus be concluded that t his method is not suitable for direct investigation of the immunomodulatory effects of VaQuFrF in vivo.