Relationships of varicella zoster virus (VZV)-specific cell-mediated immunity and persistence of VZV DNA in saliva and the development of postherpetic neuralgia in patients with herpes zoster

There are no surrogate markers for the development of postherpetic neuralgia (PHN) in patients with herpes zoster (HZ). All patients with HZ were prospectively enrolled to evaluate the associations of saliva varicella zoster virus (VZV) DNA persistence and VZV-specific cell-mediated immunity (CMI) with the development of PHN. Slow clearers were defined if salivary VZV DNA persisted after day 15. Salivary VZV was detected in 60 (85.7%) of a total of 70 patients with HZ on initial presentation. Of 38 patients for whom follow-up saliva samples were available, 26 (68.4%) were classified as rapid clearers and 12 (31.6%) as slow cleares. Initial VZV-specific CMI was lower in slow clearers than rapid clearers (median 45 vs 158 spot forming cells/10 ⁶ cells, P = .02). Of the 70 patients with HZ, 22 (31.4%) eventually developed PHN. Multivariate analysis showed that slow clearers (OR, 15.7, P = .01) and lower initial VZV-specific CMI (OR, 13.8, P = .04) were independent predictors of the development of PHN, after adjustment for age and immunocompromised status. Initial low VZV CMI response and persistence of VZV DNA in saliva may be associated with the development of PHN.