Immune correlates of herpes zoster in HIV-infected children and youth.

To identify immunologic factors that modulate the risk of herpes zoster (HZ), we compared varicella-zoster virus (VZV)-specific and nonspecific T-cell subpopulations of 47 HIV-infected children before they developed HZ with those of 141 VZV-positive HZ-negative matched controls. Compared with controls, HZ cases had lower VZV-specific CD8(+) CD107a(+) cell percentages independently of CD4(+) percentages or HIV loads, suggesting that VZV-specific cytotoxic T cells are protective against HZ. In contrast, high nonspecific regulatory and activated T cells were associated with an increased risk of HZ.