Serum Neopterin and Angiotensin-converting Enzyme In Cancer Patients

Abstract

An elevation of serum angiotensin-converting enzyme (ACE) has been reported in some disorders associated with immune activation, e.g. sarcoidosis, HIV infection or ulcerative colitis. Both endothelial cells and macrophages are thought to be the possible source of increased ACE levels. We have investigated serum ACE and neopterin, an indicator of macrophage activation, in 23 patients with solid tumors as well as in 8 controls. Similar ACE levels have been observed in the cancer patients and the controls (2.6 ± 2.1 vs 3.4 ± 1.1 μkat/1, while neopterin has been significantly higher in the cancer patients (15.4 ± 12.6 vs 7.2 ± 2.2 nmol/I, P<O.02). No correlation has been observed between serum ACE and neopterin. We conclude that an elevation of ACE is not present in cancer patients. Macrophage activation in cancer is not accompanied by increased ACE release.

Keywords

• angiotensin-converting enzyme
• cancer
• neopterin