Comparisons in the changes of clinical characteristics and cerebrospinal fluid cytokine profiles between varicella-zoster virus meningitis/encephalitis and other central nervous system infections.

OBJECTIVES:Varicella-zoster virus (VZV) is one of the most common etiologies of viral meningitis/encephalitis. The early clinical manifestations and cerebrospinal fluid (CSF) changes of VZV meningitis/encephalitis lack specificity, and it is easy to be misdiagnosed as other viral encephalitides or tuberculous meningitis. This study aims to investigate whether the clinical characteristics, CSF analysis findings, and CSF cytokine levels could distinguish VZV meningitis/encephalitis from central nervous system (CNS) herpes simplex virus (HSV) and Mycobacterium tuberculosis (MTB) infections. METHODS:The medical records from 157 CNS infections, including 49 HSV (45 HSV-1, 4 HSV-2), 55 VZV, and 53 MTB infections between January 2018 and June 2021 in the Cytology Laboratory, Department of Neurology, Third Xiangya Hospital of Central South University were retrospectively reviewed. The data of 3 groups included demographic characteristics, laboratory results, radiographic findings, and outcomes. The levels of 12 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, IFN-γ, IFN-α, and TNF-α) in the CSF of 68 patients (13 HSV, 22 VZV, and 33 MTB infection cases) were quantified. Clinical and laboratory data were compared among the 3 groups. RESULTS:The most common clinical manifestations in the 3 groups were fever, headache, vomiting, and neck stiffness. The clinical manifestations of HSV and VZV CNS disease were similar, although fever and altered consciousness were less common in the VZV group than those in the HSV and MTB groups (63.6% vs 87.8% vs 96.2%, P<0.001, and 14.5% vs 26.5% vs 47.2%, P=0.004, respectively). Seven patients (7/55, 12.7%) presented cutaneous zoster in the VZV group. CSF leukocyte count was significantly higher in the VZV group (230×106 cells/mL) and MTB groups (276×106 cells/mL) than that in the HSV group (87×106 cells/mL, P=0.002). CSF protein level was significantly higher in the VZV than that in the HSV group (1 034 mg/L vs 694 mg/L, P=0.011) but lower than that in the MTB group (1 744 mg/L, P<0.001). IL-6 (VZV vs HSV vs MTB: 2 855.93 pg/mL vs 2 128.26 pg/mL vs 354.77 pg/mL, P=0.029) and IL-8 (VZV vs HSV vs MTB: 4 001.46 pg/mL vs 1 578.11 pg/mL vs 1 023.25 pg/mL, P=0.046) levels were significantly different among the 3 groups and were elevated in the VZV group.Post hoc analysis revealed that IL-6 and IL-8 were significantly higher in the VZV group than those in the MTB group (P=0.002 and P=0.035, respectively), but not in the HSV group (P>0.05). CONCLUSIONS:VZV meningitis/encephalitis presents with CSF hypercellularity and proteinemia, challenging the classical view of CSF profiles in viral encephalitis. CSF IL-6 and IL-8 levels are elevated in patients with VZV meningitis/encephalitis, indicating a more intense inflammatory response in these patients.