Cerebrospinal fluid tau, Aβ1-42 and inflammatory cytokines in patients with Alzheimer's disease and vascular dementia

In this study we aimed to evaluate the possibility of using cerebrospinal fluid (CSF) tau, Aβ1-42 and inflammatory cytokines for diagnosis of Alzheimer's disease (AD) and vascular dementia (VD). We measured levels of total tau (T-tau), phospho-tau (P-tau), Aβ1-42, IL-6, and TNFα in CSF in groups of AD, VD, and controls using enzyme-linked immunosorbent assay (ELISA). T-tau level was found significantly higher in groups of AD (t = 3.015, P < 0.01) and VD (t = 2.872, P < 0.01) than in controls. IL-6 level as also higher in AD (t = 2.883, P < 0.01) and VD (t = 3.032, P < 0.01) than in controls. Both T-tau and IL-6 were not significantly different between AD and VD (P > 0.05). The group of AD had remarkably higher P-tau (t = 4.261 and 3.883, respectively, P < 0.01) and lower Aβ1-42 (t = 3.883 and 4.129, respectively, P < 0.01), as compared with those in VD and controls. TNFα level in AD was significantly higher than that in controls (t = 2.745, P < 0.01), but lower than in VD (t = 3.032, P < 0.01). Our data suggested that increment of T-tau and IL-6 levels in CSF was useful for screening AD and VD in certain population, while descending Aβ1-42 and ascending TNFα in CSF are preferable to diagnose AD. In addition, a higher level of CSF P-tau might support AD diagnosis.