Neuropsychological correlates of plasma NfL in adults with Down syndrome. (December 2021)

• Record Type: Journal Article
• Authors: Carmona‐Iragui, Maria; Videla, Laura; Benejam, Bessy; Valldeneu, Sílvia; Barroeta, Isabel; Altuna, Miren; Fernandez, Susana; Garzón, Diana; Padilla, Concepción; Iulita, M. Florencia; Bejanin, Alexandre; Alcolea, Daniel; Blesa, Rafael; Lleó, Alberto; Fortea, Juan
• Is Part Of: Alzheimer's & dementia. Volume 17(2021)Supplement 4
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12
• Subjects: Alzheimer's disease -- Periodicals; Alzheimer Disease -- Periodicals; Dementia -- Periodicals; Démence; Maladie d'Alzheimer; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.83
• DOI: 10.1002/alz.052881
• Languages: English
• ISSNs: 1552-5260

Abstract

Abstract: Background: The diagnosis of symptomatic Alzheimer's disease (AD) in Down syndrome (DS) is challenging, mainly because the variability in cognitive performance associated with the different levels of intellectual disability. Plasma NfL levels are a promising biomarker of axonal damage with good diagnostic and prognostic performance, but its impact on cognitive performance has not been assessed. We aimed to explore this association between NfL levels and both baseline cognitive performance and the longitudinal cognitive decline. Method: Prospective longitudinal cohort study. We included adults with DS from the Down Alzheimer Barcelona Neuroimaging Initiative cohort with mild and moderate levels of intellectual disability (ID) who had available plasma and a neuropsychological evaluation (Cambridge Cognitive Examination for Older Adults with Down's syndrome [CAMCOG‐DS] and/or modified Cued Recall Test [mCRT]). Plasma NfL levels were determined by Simoa SR‐XTM. We performed correlation analysis between baseline NfL levels and cognitive scores and linear mixed models to account for longitudinal cognitive measures. Age, sex and cognitive status (asymptomatic, prodromal AD, AD dementia) were considered as co‐variables in the analysis. The analyses were stratified in mild and moderate ID separately. Result: We selected 378 individuals (mean age: 43.1 [sd 10.9], 46.6% female): 287 had CAMCOG‐DS scores and 224 had mCRT scores. We observed a significant correlation between baseline NfL levels and both CAMCOG‐DS and mCRT (R 2 =0.18 and R 2 =0.30, respectively, both p<0.001) (Figure). This correlation remained significant after stratification by ID (R 2 =0.17 and R 2 =0.19 for mild ID, R 2 =0.19 and R 2 =0.32 for moderate ID, all p<0.001). There was a significant association between longitudinal cognitive scores and baseline NfL levels (β=‐0.0035, p=0.011 for CAMCOG‐DS; β=‐0.015, p<0.001 for mCRT). Conclusion: Cognitive performance is inversely correlated to plasma NfL levels in adults with DS. This study supports the potential role of plasma NfL levels to identify and track AD‐related cognitive decline in DS.