Varicella‐Zoster Virus‐Specific Cell‐Mediated Immunity in Facial Palsy: Comparison between Hunt Syndrome and Bell's Palsy

Abstract

Objectives: 1) Compare Varicella-zoster virus (VZV)-specific cell-mediated immunity (CMI) in Hunt syndrome to Bell’s palsy using IFN enzyme-linked immunospot (ELISPOT). 2) Examine the role of VZV-specific CMI for VZV reactivation in the facial nerve in Hunt syndrome. Methods: This prospective study was conducted in our tertiary referral hospital between 2010 and 2012. Six Hunt syndrome and 28 Bell’s palsy patients were enrolled. Mononuclear cells were isolated from whole blood and incubated with VZV antigen in culture plates for 40 h. Anti IFN antibody was added and the ELISPOT system counted immunostained spots indicating VZV-specific CMI. Numbers of spots and the relationship between the spots and days from the onset of palsy were compared between Hunt syndrome and Bell’s palsy patients. Results: No difference in the number of spots was observed between Hunt syndrome and Bell’s palsy. However, Hunt syndrome showed a strong positive relationship between numbers of spots and days from the onset of palsy (r = 0.87). In the early days, spot numbers in Hunt syndrome were much lower, indicating low VZV-specific CMI. In contrast, Bell’s palsy showed no such relationship (r = -0.24). Conclusions: This study indicates that low CMI to VZV may play a role in VZV reactivation in the facial nerve. VZV vaccination may promote VZV-specific CMI, leading to prevention of Hunt syndrome.