[Alterations in NK cell activity in the presence of sera of patients with metastases].

In previous reports it was shown that sera of patients with breast cancer in the early clinical stage enhance the activity of NK cells of healthy persons and patients, and that this effect disappears with the advance of the disease. In this studi the effect of sera of 33 breast cancer patients with metastases on NK cell activity of healthy controls was investigated. All of the sera had an inhibitory effect (5 to 84% compared to control sera), the average inhibition obtained by all of the investigated sera was 44% and in one third it was more than 60%. In 21 of 33 patients an increase in the level of immune complexes was found. Investigation of immunoglobulins showed an increase in 12 parients mostly of IgG, which was well correlated with the findings of immune complexes. These investigations clearly show that sera of patients with metastases have an inhibitory effect on NK cell activity of healthy controls, and this most likely contributes to the lower activity of NK cells of patients in advanced stages of this disease, as well as that these sera most often have increased immune complexes, although this was not always proportional to the observed inhibitory effect.