Alzheimer's disease (AD) has emerged as a growing threat to human health. It is a multifactorial disorder, in which abnormal
amyloid beta metabolism and
neuroinflammation have been demonstrated to play a key role. Intrathecal
inflammation can be triggered by
infections and precede brain damage for years. We analyzed the influence of
infections of the central nervous system on
biomarkers that are crucially involved in AD pathology. Analyses of the cerebrospinal fluid (CSF) levels of Aβ1-42, Aβ1-40, Tau, and pTau
proteins were performed in 53 children with neuroinfections of viral (n = 26) and bacterial origin (n = 19), and in controls (n = 8). We found no changes in CSF
amyloid Aβ1-42 concentrations, regardless of etiology. We showed an increase in tau and phosphorylated tau concentrations in purulent
CNS infections of the brain, compared to other etiologies. Moreover, the total concentrations of tau in the CSF correlated with the CSF absolute number of neutrophils. These findings and the Aβ 42/40 concentration quotient discrepancies in CFS between
meningitis and
encephalitis suggest that
infections may affect the metabolism of AD
biomarkers.