ELEVATED URINARY NEOPTERIN SUGGESTS IMMUNE ACTIVATION IN ALZHEIMERS-DISEASE AND DOWNS-SYNDROME

Neopterin, an unconjugated pteridine, is secreted in large quantities by activated macrophages and can be used as a clinical marker of activ ated cellular immunity in a patient. Hence, neopterin levels were meas ured in urine samples taken from patients with Down's syndrome (DS), n on-hospitalised and hospitalised Alzheimer's disease (AD) and age and sex matched controls. All subjects and patients were free from infecti ous and malignant disease. A significant effect of age on urinary neop terin levels was found in control subjects, levels being greater in yo unger and older subjects. No significant trends with age were found in AD and DS patients. The mean level of neopterin was significantly inc reased in DS and AD compared with age matched controls suggesting immu ne activation in these patients. In DS, elevated neopterin levels were present in individuals at least 17yrs old suggesting that immune acti vation could be associated with the initial deposition of beta/A4 prot ein in the brain.