CSF biomarker profiles in CNS infection associated with HSV and VZV mimic pattern in Alzheimer’s disease.
Abstract Background: Central nervous system (CNS) infections have been reported to have a certain etiological relevance to Alzheimer’s disease (AD). In particular, herpes simplex virus (HSV) and varicella zoster virus (VZV) infections has been reported as risk factors for AD. The aim of this study was to determine whether or not AD-related biomarkers were changed in patients with HSV or VZV CNS infections.Methods: Nine patients with HSV infection of the CNS, eight patients with VZV complicated by CNS involvement, and eighteen age-matched controls were enrolled. Amyloid β (Aβ)1-42, Aβ1-40, total-tau (t-tau), tau phosphorylated at threonine 181 (p-tau), neurofilament light chain (NfL), phosphorylated neurofilament heavy chain (p-NfH), glial fibrillary acidic protein (GFAP), and soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in were measured in cerebrospinal fluid (CSF), and NfL in serum.Results: Compared with the control group, CSF Aβ1-42, Aβ1-40, and the Aβ1-42/ Aβ1-40 ratio were significantly decreased, and CSF t-tau, p-tau, sTREM2, and GFAP were significantly increased in the HSV and VZV combined group, in which biomarker changes were similar to those reported in AD. CSF NfL levels measured on admission were significantly correlated with the disease severity and a poor outcome after age adjustment. Serum NfL on admission was also associated with disease severity after age adjustment.Conclusions: The fact that the biomarker profile in patients with CNS HSV and VZV infections mimicked that in AD patients should be paid attention to as a potential confounding factor in CSF biomarker-based diagnosis of AD, and it suggests an etiological similarity between herpetic virus infection and AD. The CSF NfL concentration on admission may be useful as a predictive marker of severity and prognosis in patients with CNS HSV and VZV infections.