CIRCULATING SERUM INTERFERON AND ITS EFFECT ON THE ACTIVITY OF HUMAN NATURAL-KILLER-CELLS

The interferon content in the plasma of 6 healthy donors and 10 patients with multiple sclerosis and the effect of an 1-h treatment of mononuclear cells with autologous plasma on their natural killer activity are studied in vitro using H-3-uridine-labeled (3 mu Ci/ml) human erythromyeloleukosis cells K-562. The serum interferon content in healthy donors is 2.3+/-0.82 IU/ml, whereas that in patients is higher: 5.2+/-0.8 IU/ml. Autologous plasma does not affect the activity of natural killer cells in vitro, whereas it increases the cytotoxicity of mononuclear cells obtained from patients with multiple sclerosis by 35-64%.