Background: Chronic and heavy alcohol abuse or dependence may result in impaired cognition and dementia. The increased risk of Alzheimer's disease (AD) in older individuals interferes with the differential diagnosis, especially when dealing with elderly patients with a long history of alcohol abuse. The aim of the present study was to evaluate the diagnostic value of the putative cerebrospinal fluid (CSF) biomarkers tau, beta-amyloid 1-42 (Abeta42) and their ratio in differentiating alcohol related cognitive disorder (ARCD) from AD.
Methods: Double-sandwich ELISA (Innotest htau antigen and beta-Amyloid (1-42), Innogenetics) were used to quantify the above markers in a total of 20 patients with ARCD, 33 AD patients with mild to moderate dementia and 50 mentally intact subjects.
Results: Tau protein successfully differentiated AD from normal ageing with 96% specificity and 93.9% sensitivity and from ARCD with 95% specificity, and 87.9% sensitivity. Abeta42 alone had a specificity of 88% and a sensitivity of 69.7% in differentiating AD from normal ageing, while the corresponding values for differentiating AD from ARCD were 80% and 84.8% respectively. The tau/Abeta42 ratio was better than tau alone for differentiating AD from normal ageing (specificity 94%, sensitivity 97%) and better than any of the candidate markers alone, for differentiating AD from ARCD (specificity 100%, sensitivity 97%).
Conclusions: The combined use of CSF tau and Abeta42 may be a useful tool in the differential diagnosis of ARCD from AD, especially in the early stages, where diagnostic uncertainty is greater.
(c) 2005 John Wiley & Sons, Ltd.