[Natural killer cell activity in patients with nasopharyngeal carcinoma].

In 1984 and 1985, a total of 30 patients with biopsy confirmed nasopharyngeal carcinoma (NPC) were randomly selected for studies on natural killer cell (NK) activity. Control study on 30 normal subjects were also done. Lymphocyte separation was done by centrifuge of heparinized peripheral blood with Ficoll-Hypaque and monocytes were removed by Petri dish adhesion. K562 cells were used as target cells of NK activity. The lymphocyte-target reaction of 4 hours was done and the ratio was 50:1, 25:1 and 12.5:1. The results of 50:1 was taken as the NK activity. The mean value of NK activity in NPC patients was 34.8 +/- 22.7%, this is significantly different (t = 2.90, p less than 0.01) from 51.6 +/- 22.1% of the controls. If NK activity of 20% or more are taken for the normal standard, then the positive rate in NPC patients was 63.3% and that in the controls was 90.0%. The difference is significant, as chi 2 = 4.56, p less than 0.05. The NK activity in NPC patients is not correlated with the sex and age of the patients, the disease extent and the EB virus associated antibody titers.