Case reports of sarcoma patients with optimized lectin-oriented mistletoe extract therapy.

Background: Mistletoe (Viscum album L) extracts (ME) are widespread as immunomodulatory therapeutic agents in alternative tumor treatment. Assessing the often-controversial clinical results is rather difficult since the effects of ME on the immune system cannot be equally reproduced. Mistletoe lectins (ML) are the only mistletoe ingredients also found in vivo that are capable of having a positive effect on the immune balance of patients with tumors. Other components have only been tested in vitro, and the removal of mistletoe lectins ML from the extract can put an end to the immunological efficacy of ME. Preclinical investigations in the tumor models (using nude mice xenotransplanted with human leiomyosarcoma and interleukin-12-deficient C57BL6 mice) show that without immunological reactions, ME induce less antitumor efficacy. ML, functioning as ligands for pattern recognition receptors of the natural immune system, are docked to ganglioside molecules (CD75) of monocytes and granulocytes, thereby stimulating the natural antitumor mechanisms.

Objectives: The aim of this article is to present and discuss several favorable clinical responses of patients who had sarcoma and who were treated with immunologically effective ME preparations. COURSE OF THERAPY AND RESULTS: In accordance with the bell-shaped dose-response relationship of ML, the patients with sarcoma were treated with ME preparations, standardized for the active sugar-binding lectin contents. Thus, an optimal dose of 0.75-1.0 ng/kg ML was given twice a week subcutaneously. In this report, the clinical progress of 6 patients with sarcoma showed remissions of tumor symptoms.

Conclusions: It seems that this disease is beneficially influenced by optimized lectin-oriented ME therapy since patients with sarcoma may react especially well to the improved balance of natural immunological mechanisms. These case reports require further clinical studies with patients with sarcoma.