Cerebrospinal fluid biomarkers for disease stage and intensity in cognitively impaired patients.

Biomarkers to monitor the degenerative process in Alzheimer's disease would be of great value. We examined the relation between cerebrospinal fluid (CSF) total tau (T-tau), phospho-tau (P-tau) and Abeta42 and magnetic resonance imaging (MRI) measures of brain atrophy. CSF was taken at baseline and MRI at baseline and at 16 months follow-up. At baseline, statistically significantly lower Abeta42 were found with lower brain volume (r=0.55; P<0.0001) and larger ventricular volume (r=-0.53; P<0.001). In contrast, statistically significantly higher T-tau (r=0.47; P<0.001) and P-tau (r=0.41; P=0.005) were found with more marked ventricular widening during the follow-up period. These results suggest that Abeta42 in CSF reflects the stage of the disease, with lower CSF levels as the disease progresses, while T-tau and P-tau reflect the intensity of the disease process, with higher CSF-levels with a more rapid progression.