Serum concentrations of interleukin-18 in early and advanced cancer patients: enhanced secretion in metastatic disease.

Abstract

The recent availability of adequate methods for cytokine measurement could contribute to better understanding the immunophysiopathology of neoplastic disease. Unfortunately, very little data is available about cytokine secretion in cancer patients. At present, IL-2, IL-12 and IL-15 represent the major antitumor cytokines in humans. Preliminary clinical studies have shown a progressive decline in IL-2 levels with cancer progression, whereas IL-12 seems to increase in the advanced disease. IL-18 is the latest cytokine discovered by potential anticancer and anti-angiogenetic activity, and it has effects similar to those of IL-12. This preliminary study was carried out to analyze IL-18 secretion in early or advanced cancer patients. The study included 40 cancer patients (lung cancer, 21; gastrointestinal tumors, 19), 17 of whom had metastatic disease, and 50 healthy controls. Serum levels of IL-18 were measured by ELISA. No significant difference in IL-18 mean levels was seen between controls and non-metastatic patients. In contrast, metastatic patients showed significantly higher IL-18 mean values with respect to both healthy controls and non-metastatic patients. This preliminary study seems to suggest that metastatic disease may be characterized by enhanced IL-18 secretion the biological and prognostic significance to be established by successive clinical investigation.