Influence of interferon gamma secretory activity of natural killer cells and psychological stress on herpes zoster

Abstract

Background: Herpes zoster (HZ) results from reactivation of varicella-zoster virus (VZV) which is latent in dorsal root ganglia. Several risk factors of VZV reactivation has been identified such as older age, female gender, psychological stress and decreased cellular immunity. The pathogenesis of HZ is closely linked to reduced varicella-zoster virus-specific cell-mediated immunity. However, little is known about the role of natural killer (NK) cells in the pathogenesis of HZ. Psychological stress is known to be associated with reduced cell mediated immunity and might impair the function of NK cells in HZ. This study aimed to investigate possible associations among NK cells, T cells and psychological stress in HZ. <br/> Materials and methods: Case-control study was done in order to investigate the association between psychological stress and the function of NK cells in HZ. Forty-four case subjects with recent history of HZ were matched to 44 control subjects without history of HZ at the ratio of 1:1 for age and gender. The function of NK cells was measured by the levels of interferon-gamma secretion from NK cells in 1ml of whole blood with a stimulant. Interferon-gamma secretion from NK cells, psychological stress events, stress cognition scale scores and cytomegalovirus-specific cell-mediated immunity were compared. <br/> Results: A significantly lower median level of interferon-gamma secreted by NK cells was observed in patients with a recent diagnosis of HZ than in control subjects (582.7 pg/ml vs. 1783 pg/ml