[Correlation of NK cell activity against autologous tumour cells and K562 cells with the clinical outcome during therapy with mistletoe extracts].
BACKGROUND
Suppression of NK cell activity is considered to be an unfavourable prognostic factor for tumour progression. There is proof that mistletoe extracts may increase NK cell activity. However, the inverse relation between an increase of NK cell activity and clinical progress of cancer has not been investigated.


OBJECTIVE
The relation of NK cell activity and progress of cancer in patients under therapy with mistletoe extracts was examined in a prospective, monocentric, cohort study. At the same time the in vitro killing of K562 cells and autologous tumour cells was compared.


METHODS
40 patients with operable cancer of the breast or colon were included. The patients did not receive any immunologically relevant therapies except for mistletoe extracts. The absolute NK cell count in peripheral blood as well as the in vitro NK cell activity were monitored for up to 2 years and compared with clinical outcome as well as quality of life.


RESULTS
The absolute NK cell count in peripheral blood increased within the observation period. Patients without progression had a significantly higher mean activity of NK cells against K562 cells than patients with progression. In the latter group, only stage IV patients showed reduced NK cell activity. The killing activity against autologous tumour cells was <5% in about 77.5% of the patients and could not be evaluated further. The NK cell activity against K562 cells was not related to the number of NK cells.


CONCLUSIONS
We found a relation between NK cell activity and the progression of malignant disease. In further studies the causality of this relation has to be clarified. The establishment of NK cell activity against autologous tumour cells as a suitable parameter during follow-up was not successful.
Schink
Michael
M
Forschungsabteilung, Verein Filderklinik e.V., Filderstadt, Deutschland. schink@filderklinik.de
Tröger
Wilfried
W
Goyert
Andreas
A
Scheuerecker
Heinz
H
Selbmann
Hans-Konrad
HK
Glaser
Florian
F
D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy / Q000276:immunology*; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D018450:Disease Progression; D005260:Female; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D014784:Mistletoe / Q000737:chemistry*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D011446:Prospective Studies; D016896:Treatment Outcome
D010936:Plant Extracts