Induction of antibodies to viscotoxins A1, A2, A3, and B in tumour patients during therapy with an aqueous mistletoe extract.
Mistletoe extracts exert immunomodulatory properties on immunocompetent cells of the innate as well as the specific immune system. These effects have been mainly ascribed to mistletoe lectin 1 (ML-1) present in most of the extracts. However, it became evident that also other components of these extracts may induce immunological reactions, and especially viscotoxins (VT) may be of relevance. Aim of the study was, therefore, to evaluate whether VT like ML-1 could activate B-cells and lead to the production of VT-specific antibodies. Sera from 26 patients with different tumours who were treated with the mistletoe extract ABNOBAviscum Mali (AM) 4 for at least 18 weeks were analysed before therapy and after 3, 6, 9, 12, and 18 weeks. Sera were tested by ELISA against the four viscotoxins A1, A2, A3, B, as well as against ML-1. Within the observation period twenty-four (92%) of the 26 patients developed antibodies to at least one of the four VT and 25 (96%) to ML-1. In most instances, anti-VT antibodies appeared after 6-9 weeks of treatment. The antibodies were predominantly of the IgG type belonging preferentially to the IgG1 and IgG3 subclass. IgE antibodies were found only to VT-B and to ML-1. There was no relation between the development of antibodies to VT and ML-1, and also cross-reactivity could be excluded with high probability. These data indicate that not only ML-1 but also VT induce immunological responses in patients treated with mistletoe extracts. Whether there is any relationship to the postulated anti-tumour effect of mistletoe extracts has, however, still to be evaluated.
Department of Internal Medicine II, University of Tübingen, Germany. reinhild.klein@med.uni-tuebingen.de
Reinhild
R
Klein
K
K
Classen
S
S
Fischer
M
M
Errenst
A
A
Scheffler
G M
GM
Stein
R
R
Scheer
H B
HB
von Laue
D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000032:analysis / Q000097:blood; D001402:B-Lymphocytes / Q000276:immunology; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy / Q000276:immunology; D002292:Carcinoma, Renal Cell / Q000188:drug therapy / Q000276:immunology; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000276:immunology; D008297:Male; D008875:Middle Aged; D014784:Mistletoe; D009369:Neoplasms / Q000188:drug therapy* / Q000276:immunology; D028321:Plant Preparations / Q000276:immunology* / Q000627:therapeutic use*; D010940:Plant Proteins; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000276:immunology; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological / Q000276:immunology* / Q000627:therapeutic use*
D000276:Adjuvants, Immunologic; D000906:Antibodies; D028321:Plant Preparations; D010940:Plant Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological; C009674:ribosome inactivating protein, Viscum; C488038:viscotoxin