Increased Levels of Chitotriosidase and YKL-40 in Cerebrospinal Fluid from Patients with Alzheimer's Disease

BACKGROUND: The cerebrospinal fluid (CSF) biomarkers total tau, abnormally phosphorylated tau and amyloid β 1-42 are strongly associated with Alzheimer's disease (AD). Apart from the pathologic hallmarks that these biomarkers represent, other processes such as inflammation and microglial activation are present in the brains of patients with AD. New biomarkers related to these processes could be valuable for the diagnosis and follow-up of AD patients and for the evaluation of inflammation-related pathologies. AIM: The aim of this study was to evaluate the association of inflammatory CSF biomarkers with AD. METHODS: Twenty-five AD patients and 25 controls who had a pathological and normal CSF profile of the core AD biomarkers, respectively, were included in this study. CSF levels of chitotriosidase, YKL-40 (also known as chitinase-3-like protein 1) and monocyte chemoattractant protein-1 (MCP-1) were quantified and the levels compared between the groups. RESULTS: AD patients had increased CSF levels of chitotriosidase and YKL-40 (both approximately twice higher than in controls), while the levels of MCP-1 were similar in the AD and control groups. CONCLUSION: The results indicate that chitotriosidase and YKL-40 may be helpful for the evaluation of cerebral inflammatory activity in AD patients.