Concentrations of neopterin, which is produced by human monocytesl macrophages when stimulated by interferon- γ, were measured in serum specimens from 109 patients with renal cell carcinoma (RCC). Results showed that neopterin levels were significantly higher in the patients with grade 3 RCC compared to the control subjects and patients with grade 1 or grade 2 RCC. When the patients were divided according to serum C-reactive protein (CRP), neopterin levels were significantly higher in the CRP-positive patients compared to the control subjects and CRP-negative patients. A significant correlation was shown between serum neopterin levels and CRP. Our study suggests that serum neopterin levels may supplement laboratory examinations for patients wilh RCC, providing useful information in evaluating the tumor stage and follow-up of the disease.
