Multiplex analysis of cytokines in the serum and cerebrospinal fluid of patients with Alzheimer's disease by color-coded bead technology

Background and purpose: The availability and promise of effective treatments for neurodegenerative disorders are increasing the importance of early diagnosis. Having molecular and biochemical markers of Alzheimer's disease (AD) would complement clinical approaches, and further the goals of early and accurate diagnosis. Combining multiple biomarkers in evaluations significantly increases the sensitivity and specificity of the biochemical tests. Methods: In this study, we used color-coded bead-based Luminex technology to test the potential of using chemokines and cytokines as biochemical markers of AD. We measured the levels of 22 chemokines and cytokines in the serum and cerebrospinal fluid (CSF) of 32 de novo patients (13 controls, 11 AD, and 8 Parkinson's disease [PD]). Results: MCP-1 was the only cytokine detectable in CSF, and its levels did not differ between control and disease groups. However, the serum concentration of eotaxin was significantly higher in AD patients than in the control group. Conclusions: The analysis of multiple inflammatory mediators revealed marginal differences in their CSF and serum concentrations for the differential diagnosis of AD and PD. These results provide evidence that immunological responses are not major contributors to the pathogenesis of AD and PD.