To examine whether the high incidence of herpes zoster in patients with systemic lupus erythematosus (SLE) is associated with the frequency of memory T cells specific to varicella zoster virus (VZV).
Whole blood samples from 47 subjects [24 patients with SLE, 11 with rheumatoid arthritis (RA) as a disease control, and 12 healthy negative controls] were stimulated with VZV antigen, stained for surface CD4 and CD8 and intracellularly stained for the cytokines interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin 4 (IL-4), and IL-10, followed by flow cytometry analyses. Correlations of VZV-specific T cell frequencies with the clinical status of patients were analyzed.
Percentage of IFN-gamma-positive CD4 T cells was significantly lower in patients with SLE (0.043 +/- 0.009%) than in RA (0.102 +/- 0.019%) and healthy controls (0.126 +/- 0.025%) upon VZV stimulation. A similar pattern was seen in TNF-alpha-positive CD4 T cell responses. These low frequencies of VZV-specific CD4 T cells in patients with SLE were significantly related with disease activity (r = -0.435, p = 0.043).
These data suggest that the high incidence of herpes zoster in patients with SLE was related to the intrinsic defects in controlling VZV reactivation, and thus VZV-specific CD4 T cell frequency could be another practical risk factor of herpes zoster in patients with SLE.