Serum Soluble Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Levels in Older Subjects with Dementia and Mild Cognitive Impairment

Background: The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been involved in both physiological and pathological conditions, including vascular pathologies and pathologies of the central nervous system. Nonetheless, the knowledge about the role of systemic TRAIL in patients affected by different types of dementia and mild cognitive impairment (MCI) is still limited. Objective: We assessed serum TRAIL levels in a large cohort of older individuals (n = 644) including patients with late-onset Alzheimer's disease (LOAD), vascular dementia (VAD), ‘mixed' dementia (MIX), MCI, and healthy controls. Methods: Circulating TRAIL was measured by ELISA. Results: At univariate analysis, TRAIL levels were higher in VAD, MIX, and MCI patients compared with LOAD patients and controls. Using the multiple linear regression model, we found that TRAIL levels were associated with VAD and MCI, but not MIX, independent of potential confounding factors. Conclusion: The finding of high levels of circulating TRAIL in VAD and MCI seems to suggest that both of these conditions are characterized by a significant vascular damage with respect to LOAD.