Cerebrospinal fluid apolipoprotein E concentration and progression of Alzheimer's disease

Apolipoprotein E plays a role in the pathogenesis of Alzheimer's disease (AD). Cerebrospinal fluid (CSF) and plasma level alterations have been reported in AD patients. In search of a potential biomarker, which would be predictive of cognitive, functional, or motor decline, we analyzed CSF apolipoprotein E (ApoE) levels of AD patients in this regard.

Subjects with newly diagnosed AD enrolled into an observational study were followed up longitudinally. Neuropsychological testing and physical examination were performed annually. In a sub-cohort of patients, where baseline CSF ApoE concentration values were available, multiple regression analyses were used to determine possible associations of CSF ApoE concentration and speed of decline on different cognitive, functional, and motor scales (MMSE, iADL, bADL, GDS, UPDRSIII) adjusting for possible confounders.

No association of CSF ApoE levels and speed of decline on the various scales could be established (p = 0.09 to 0.88). Nevertheless, the use of neuroleptic drugs could be linked to higher velocity of global and extrapyramidal deterioration (p = 0.04 and 0.05 for GDS and UPDRSIII, respectively), but not to other outcomes (MMSE, bADL, and iADL).

Herein, CSF ApoE at time of AD diagnosis could not be shown to be a viable biomarker for future cognitive, functional, or motor decline. Expectedly, the use of neuroleptic drugs was associated with detrimental effects.