Absence of Varicella Zoster Virus Reactivation after Infliximab Administration for Plaque Psoriasis

Background: Herpes zoster (HZ) in patients receiving tumor necrosis factor (TNF) antagonists may be more severe and the incidence seems increased. The influence of TNF antagonists on varicella zoster virus (VZV) reactivation is unknown. Objective: To prospectively search in a pilot study for VZV DNA in sequential blood samples before and after infliximab administration. Setting: University medical center. Subjects and Methods: Blood samples of six patients with longstanding and severe plaque psoriasis were taken on day 1 (before infliximab administration) and on days 2, 7, 21 and 42 for the determination of VZV viremia by ORF21 real-time polymerase chain reaction. Patients with varicella, HZ and normal subjects were included as controls. Results: None of the six patients presented VZV viremia at any of the time points. High-load viremia was present during varicella, low-load viremia in some HZ patients and no viremia in the control patients. Limitations: Small number of patients. Conclusions: In this pilot study, infliximab did not reactivate VZV and did not induce subclinical VZV viremia.