Expression of varicella-zoster virus in blood mononuclear cells of patients with postherpetic neuralgia.

Postherpetic neuralgia (PHN), the most frequent complication of varicella-zoster virus (VZV) reactivation, is characterized by pain that persists for greater than 1 mo and often for years after zoster rash. To examine whether PHN might be related to reactivation of VZV, blood mononuclear cells of patients with PHN were tested for the presence of VZV DNA and proteins. VZV DNA was detected in the mononuclear cells of one PHN patient. VZV-specific proteins were detected in mononuclear cells of two acute-varicella patients, one acute zoster patient, and six elderly patients with PHN, but these VZV-specific proteins were not detected in three elderly zoster patients without PHN. Furthermore, pulse-chase experiments revealed further processing or degradation of VZV-specific proteins in the mononuclear cells. These findings strongly suggest that persistence, reactivation, and expression of VZV may result in PHN.