Circulating levels of soluble receptor for advanced glycation end products in Alzheimer disease and vascular dementia.

The receptor for advanced glycation end products (RAGE) is a cell surface receptor that has been implicated in vascular disease and neurodegeneration. Low levels of its secreted isoform, soluble RAGE (sRAGE), have been regarded as a putative risk factor for atherosclerosis. In addition, administration of sRAGE has been shown to reduce development of cerebral beta-amyloidosis in an Alzheimer disease mouse model. To investigate the role of sRAGE as a biological marker for Alzheimer disease and vascular dementia. Cross-sectional study of 152 patients with a clinical diagnosis of Alzheimer disease, 91 with vascular dementia and 161 control subjects. Plasma levels of sRAGE. Levels of sRAGE were significantly reduced in the plasma of patients with Alzheimer disease compared with that for those with either vascular dementia (P<.05) or with controls (P<.001). Patients with Alzheimer disease have reduced levels of sRAGE in plasma compared with patients with vascular dementia and controls. The striking reduction of circulating sRAGE in Alzheimer disease further supports a role for the RAGE axis in this clinical entity and requires further investigation.