Role of regulatory T cells in patients with acute herpes zoster and relationship to postherpetic neuralgia

This study is to analyze distribution of peripheral T cell subsets including regulatory T cells in patients with acute herpes zoster (AHZ) and investigate its relationship to the development of postherpetic neuralgia (PHN). T lymphocyte subsets in peripheral blood from 76 patients with AHZ and 38 normal controls were analyzed using flow cytometry. According to the visual analogue scales in the acuter phase and followed up by PHN for 3 months, patients with herpes zoster (HZ) were divided into different patient groups. The results demonstrated a significant decrease in the percentage of CD4 lymphocytes and CD4/CD8 ratios in each patient group as compared with normal controls, and the CD4+ subsets in the severe group were significantly decreased as compared with mild group and moderate group (p < 0.01). Moreover, there seemed a relationship between severity of acute pain during zoster and PHN. The proportions of regulatory T cells (Treg; CD4+CD25+FoxP3+ T cells) were significantly elevated from AHZ patients as compared with normal controls, and CD4+ T cells were inversely correlated with Treg cells (p < 0.01). Furthermore, FoxP3 expression was significantly increased by CD4+CD25^high T cells in the severe group as compared with mild group, moderate group and normal controls. These results indicated that T cellular immunity in AHZ patients was impaired and suggested increased activation of Treg cells may suppress anti-viral CD4+ T cells immune responses, especially in the severe HZ patients. Treg cells may play an important role in the pathogenesis of AHZ and progression toward PHN.