The authors present a Czech population based study on CSF biomarkers - total tau protein, phosphorylated tau protein and beta amyloid were examined in the group of patients with Alzheimer's disease (AD), Frontotemporal dementia (FTD) and an age-matched cognitively intact control group. All subjects underwent brain MRI and extended neuropsychological examinations to make it possible to classify the patients according to NINCDS-ADRDA criteria for probable AD and Neary criteria for FTD.
There is no consensus in generally accepted normal values for all the three markers according to the published papers as the results of various studies differ. Due to this fact we assessed the normal values for our laboratory (average 2 standard deviations) and ROC (receiver operating characteristic) curve to measure the best sensitivity and specificity for a given marker: total tau protein 355 pg/ml, phosphorylated tau protein 55 pg/ml and beta amyloid 458 pg/ml.
The highest specificity provides determination of total tau protein and phosphorylated tau protein in AD, lower in FTD. The less reliable is beta amyloid.
The authors have discussed these results with those yielded in other studies including the only study done on the Czech population.