Iscador is the tradename for an extract of mistletoe produced by the Hiscia Institute in Switzerland. In test-tube studies it has been shown to improve the ability of phagocytes to engulf foreign organisms and to increase natural killer (NK) cell activity and CD8 cell activity against foreign organisms or infected cells that have been `tagged' by antibodies. Studies in humans also show that mistletoe extracts may increase production of a range of cytokines, some of which are potentially harmful in HIV-infected people.

Current use

Two forms of iscador are currently in use. Only one, the unfermented form, is now being tested in clinical trials, because it is thought that this is a more effective immune-modulator in HIV-infected people.

Iscador is an unlicensed, experimental drug. It has also been used experimentally for the treatment of cancer. A phase I /II study in people with HIV suggested that it may have immune modulating and/or anti-viral effects which merit further study. No further data on its use in HIV infected people has been reported since 1993.

Iscador is given by injection. Some people have reported painful swelling at the injection site and slight fever.

Key research

Gorter enrolled 40 people with HIV with CD4 counts above 200 in a phase I/II dose-escalating study of Iscador (0.01 - 10 mg injected subcutaneously twice a week for 18 weeks). The only side-effects were reddening at the site of injection and a slight increase in body temperature on the day of injection. 28/36 had a CD4 count increase of at least 20% after week 12, average levels of beta₂-microglobulin fell and 2/8 p24 antigenaemic participants became antigen negative.

References

Gorter R et al. Immune modulating and anti-HIV activities of Viscum album (Iscador). 9th Intl Conf AIDS, Berlin, abstract B28-2167, 1993.