[Study of the natural killer cell activity in lung cancer patients]

A total of 50 lung CA patients and 20 normal persons as control were included in our study. We obtained lymphocytes from heparinized blood by Ficoll-Hypaque gradient method and after incubation with Cr51 labelled K562 cells at concentrations of 100: 1, 50:1, 12.5:1 for four hours, we calculated the cytotoxicity activity of NK cells. Significant impairment was noted in the comparison of NK cytotoxicity between stage III-M1 lung CA patients (n = 28) and the control group (n = 20) (E/T; 50:1, 29.55 +/- 24.20% vs 49.83 +/- 14.46%, p less than 0.001; E/T: 25:1, 10.23 +/- 7.19% vs 27.66 +/- 6.06%, p less than 0.001). 4 cases in stage I underwent surgery, the NK cytotoxicity before the operation was noted to be low, E/T: 25:1, 9%, 11%, 14% and 19% respectively. After the operation, the NK cytotoxicity was increased to 33%, 35%, 42% and 44% respectively. 3 stage I lung CA patients has continuously followed up, 2 relapsed cases had decreased NK cytotoxicity to 22% and 25%. These results indicated that the NK cytotoxicity assay was impaired in stage III-M1 lung CA and also suggested that it may act as a therapeutic guide for the results of the operation.