Varicella virus-mononuclear cell interaction.

Varicella zoster virus (VZV) causes varicella (chickenpox), becomes latent in cranial nerve, dorsal root, and autonomic ganglia; and reactivates decades later to produce zoster (shingles). The main complication of zoster is postherpetic neuralgia (PHN), pain that persists for months and often years after zoster. VZV also causes chronic radicular pain without rash (zoster sine herpete). Viremia is associated with each stage of VZV infection. Viral DNA has been found in peripheral blood mononuclear cells (MNCs) of patients with varicella, zoster, PHN, and zoster sine herpete. In varicella, viremia contributes to the widespread distribution of skin lesions and infection of multiple organs. Although the role of viremia in other VZV-associated diseases is not as clear, the detection of VZV DNA (and sometimes VZV RNA and proteins) helps diagnose neurological diseases produced by VZV, has indicated that PHN may reflect a chronic VZV ganglionitis, and has established that VZV reactivates subclinically, especially in immunocompromised humans. In vitro studies have established that VZV can productively infect MNCs for a short time and have identified the subpopulations of MNCs that are infected. Finally, simian varicella virus (SVV) infection of nonhuman primates shares clinical, pathological, and virologic features with VZV in humans. Like VZV, SV viremia in nonhuman primates during acute infection plays an important role in the pathogenesis of SVV. Infectious virus can be isolated from MNCs, and SVV DNA can be detected in MNCs during varicella. Further, SVV DNA can be detected for months in MNCs of monkeys after experimental infection with SVV. Herein, we review the current literature related to VZV infection of MNCs during naturally occurring varicella, PHN, and zoster sine herpete in humans, including studies of experimental infection of human MNCs with VZV. We also review SVV MNC interaction during naturally occurring simian varicella and after experimental infection of primates with SVV.