A STUDY OF INTERACTIONS AMONG MARKERS OF MACROPHAGE FUNCTIONS IN METASTATIC SOLID TUMORS - NEOPTERIN LEVELS IN RELATION TO THOSE OF TUMOR-NECROSIS-FACTOR-ALPHA AND OF SOLUBLE INTERLEUKIN-2 RECEPTORS

High levels of the macrophage activation marker neopterin have been de scribed in metastatic cancer patients. Since macrophages may either co unteract or stimulate tumor development, it is important to establish which macrophage activity is mainly related to neopterin release. The present study was carried out to evaluate neopterin levels in metastat ic solid tumor patients in respect with the antitumor macrophage cytok ine TNF and with soluble IL-2 receptor(SIL-2R), whose secretion is sti mulated by macrophages and it is associated with the immunosuppessive status of cancer patients. The study included 35 patients with metasta tic solid neoplasms. Serum levels of neopterin, TNF and SIL-2R were me asured in blood samples collected during the morning. Abnormally high concentrations of neopterin were seen in 18/35 (51%) patients. Patient s with high levels of neopterin showed significantly higher concentrat ions of SIL-2R than those with normal neopterin values, whereas no dif ference was found in TNF levels. This study would suggest that the inc reased secretion of neopterin may reflect macrophage-mediated immunosu ppression in metastatic solid neoplasms, rather than to be associated with the antitumor activity of macrophages.