Modulation by interferon alpha of the decreased natural killer activity in patients with glioblastoma.

It is known that natural killer (NK) cells are involved in immunosurveillance against tumours. This study examines the NK activity of mononuclear cells (MNC) from the peripheral blood of patients with glioblastoma. The cytotoxic inducer effect of interferon-alpha (IFN-alpha) upon these MNC has also been studied. A marked decrease in NK activity mediated by MNC from these patients was found. This functional defected in MNC is not due to a decrease in phenotypically defined NK cells. After long-term (5-day) incubation with IFN-alpha, MNC from 5 out of 14 patients showed strong lytic activity against NK-sensitive target cells. In this system, IFN-alpha failed to induce cytotoxic activity against NK-resistant target cells in MNC from all the patients studied. This in vitro induction of cytotoxic activity in MNC from some patients with glioblastoma by IFN-alpha suggests a potential immunotherapeutic use of the lymphokine in these subjects.