Resistance to common viruses during intralymphatic injections of tumor cell vaccines. Correlation with circulating cytokines.
Patients with advanced malignancies who received intralymphatic injections of irradiated tumor cell suspensions ("vaccines") were unexpectedly found to be resistant to common viral diseases; 17 patients with a documented past history of viral infections who have been observed for 48 to 148 months (median 108 months), were analyzed. The resistance to viruses was found to correlate closely with the presence, in the serum, of certain cytokines. Specifically, the interleukins, -2, -6, -8 and interferon-gamma, at low but sustained levels appeared to be possibly responsible for the nonspecific protection against viral infections obtained by intralymphatic injections of cellular material. These findings suggest that viral infections in normal or immunosuppressed individuals at particular risk might be prevented by treatments aimed at attaining very modest levels of certain cytokines.