Varicella-zoster virus (VZV) reactivation is common in HIV-infected persons. Although qualitative VZV antibody testing can determine past VZV disease or vaccination, it is unknown whether quantitative VZV antibody levels can predict future zoster development. We evaluated longitudinal quantitative VZV antibody levels in US Military HIV Natural History (NHS) participants with and without a diagnosis of zoster.
NHS participants with a zoster diagnosis ≥5 years after HIV diagnosis (n=100) were included as cases. Control participants (n=200) who did not develop zoster were matched by age, race, gender, and CD4 count at HIV diagnosis. Two repository plasma specimens were evaluated using a quantitative anti-VZV ELISA assay, including a baseline level ≥3 years before and a second level 30-180 days prior to zoster diagnosis. Specimen time-points for controls were matched to corresponding cases. Differences in quantitative VZV levels over time were analyzed by paired samples t-tests and ANOVA with Repeated Measures controlling for time intervals between specimens.
Participants were predominantly male (94%) in both groups with a median age of 29 [IQR 24-34] years at HIV diagnosis. The median CD4 count at HIV diagnosis was similar for cases and controls (535 [IQR 384-666] vs 523 [IQR 377-690] cells/uL; p=0.940), however cases had a significantly lower CD4 count at VZV diagnosis compared to controls (436 [IQR 277-631] vs 527 [IQR 367-744] cells/uL; p=0.007). Antiretroviral therapy (ART) use at zoster diagnosis was also lower for cases (52.0%) compared to controls (64.5%; p=0.025). Cases had similar mean VZV antibody levels prior to zoster diagnosis compared to controls (2.25 ± 0.85 vs 2.44 ± 0.96 index value/optical density ratio (OD); p=0.151) and there was no difference in the change in VZV antibody levels over time (0.08 ± 0.71 vs 0.01 ± 0.94 index value/OD per year; p=0.276).
Quantitative VZV levels are stable during the first several years of HIV infection and do not appear to predict future development of zoster. Similar to previous reports, we observed that lower CD4 counts and lack of ART use is more common in those who develop zoster and these characteristics may better predict VZV reactivation in HIV-infected individuals.
J. White, None
T. S. Sunil, None
R. Deiss, None
A. Ganesan, None
B. Agan, None
J. Okulicz, None