Cell-Mediated Immune (CMI) Responses and Zoster-associated Pain in Herpes Zoster (HZ) Patients

Learning Objectives for this Presentation:
By end of presentation participants will be able to:
1. Discuss VZV-specific CMI responses.

Background:
Varicella-zoster virus (VZV)-specific CMI responses were compared over time following an episode of HZ and in age-matched controls without HZ.

Objectives:
Discuss VZV-specific CMI responses.

Methods:
Multicenter study evaluated variability & kinetics of VZV-specific CMI responses in adults with acute (<=2 hr after lesion onset) HZ or w/in 4-6 days after lesion onset & in age-, race-, & gender-matched healthy controls (HC) using validated IFN-gamma ELISPOT assay. PCR verified VZV among suspected cases. Blood drawn for immunogenicity in HZ patients at Day 0, 2 wks, 6 wks, & 6 mos. Zoster brief pain inventory (validated questionnaire) assessed zoster-associated pain.

Results:
HZ patients (n=140) had significantly higher IFN-gamma ELISPOT responses to VZV than did HC (n=140).
ELISPOT geometric mean count (GMC) responses (95% CI) <=2-hrs:
HZ Patients >=60 yrs: Day 0, n=49, GMC=110 (60,201); Week 2, n=48, GMC=235 (155,357)
HZ Patients 21-59 yrs: Day 0, n=23, GMC=111 (54,227); Week 2, n=21, GMC=198 (122,322)
HC >=60 yrs: Day 0, n=50, GMC=19 (12,30); Week 2, n=45, GMC=18 (9,34)
HC 21-59 yrs: Day 0, n=28, GMC=59 (31,112); Week 2, n=18, GMC=56 (25,127)
Mean pain score (95% CI) across age groups at 1 wk post-rash (n=106) was 6.0 (5.5, 6.5) & at 2 wks post-rash (n=119) was 3.5 (2.9, 4.0). Percent HZ patients with substantial pain (score>=3) at 6 wks post-rash increased with age from 8% (21-49 yrs), to 16% (50-59 yrs), to 22% (>=60 yrs).

Conclusions:
VZV-specific CMI response substantially boosted by episode of HZ, measured by ELISPOT. Older adults had lower VZV-specific CMI than younger subjects at baseline, but boosting effect of HZ was substantial for all age groups. HZ patients experienced considerable zoster-associated acute (1-2 wks post-rash) pain across age groups, while chronic pain increased with age.ased with age.