Biomarkers of Alzheimer Disease Observed in Down Syndrome
Neurological and neuropsychological examinations were performed to assess intellectual disabilities, and biological assays were performed on collected CSF and plasma.
Findings from a recent cross-sectional, single-site study highlight potential diagnostic biomarkers of Alzheimer disease-related neurodegeneration in Down syndrome. The study was published in The Lancet Neurology.
Researchers sought to determine whether biomarker (ie. NfL, Ab1-40, Ab1-42, t-tau, p-tau) concentrations in the cerebrospinal fluid (CSF) and plasma would have diagnostic potential in detecting either prodromal Alzheimer disease (AD) or AD dementia in Down syndrome. The convenience sample (n=469) consisted of adult participants with Down syndrome in 1 of 3 categories: asymptomatic (n=194), prodromal AD (n=39), and AD dementia (n=49). Neurological and neuropsychological examinations were performed to assess intellectual disabilities, and biological assays were performed on collected CSF and plasma.
Data showed that NfL, Ab1-40, and Ab1-42 plasma concentrations were higher in all Down syndrome cohorts in comparison with controls (all P <.0001). Also, t-tau concentrations in the plasma were higher in the AD dementia group in comparison with controls. The researchers showed that NfL (P =.0001), Ab1-40 (P =.02), and t-tau (P =.0003) plasma concentrations were highest in the AD dementia group in comparison with the asymptomatic and prodromal AD groups. Results showed controls had higher levels of CSF concentrations of Ab1-42. NfL, t-tau, and p-tau CSF concentrations were higher in prodromal AD and AD dementia cohorts than in controls.
Study limitations include the cross-sectional collection period for sample analysis and a need for validation of findings on a multicenter level.
These findings suggest that the differing concentration levels of various biomarkers can be determined and utilized in the diagnosis for AD-related neurodegeneration in Down syndrome patients.
Disclosures: Please refer to original reference for a full list of authors' disclosures.
Fortea J, Carmon-Iragui M, Benejam B, et al. Plasma and CSF biomarkers for the diagnosis of Alzheimer's disease in adults with Down syndrome: a cross-sectional study [Published online August 29, 2018]. Lancet Neurol. doi: 10.1016/S1474-4422(18)30285-0