Tau protein in cerebrospinal fluid (CSF): a blood-CSF barrier related evaluation in patients with various neurological diseases

Tau protein (tau) is primarily localised in neurons, and after brain parenc hymal damage its release into cerebrospinal fluid (CSF) is increased. The p articular influences of blood-CSF barrier function and of disease topograph y on CSF tau levels have not been studied yet. CSF tau concentrations deter mined by enzyme-immunoassay in various neurological diseases (n = 61) were not dependent upon blood-CSF barrier dysfunction. Significant elevation of tau levels in patients with meningoencephalitis and cerebral hemorrhage ind icates brain parenchymal damage. In contrast, tau levels remained normal in patients with bacterial meningitis if encephalitic complications did not o ccur. In patients with Guillain-Barre syndrome tau levels were low. Increas ed tau levels in active multiple sclerosis compared to clinically nonactive states indicate axonal pathology in active disease. (C) 2001 Elsevier Scie nce Ireland Ltd. All rights reserved.