Objective: To study the incidence of herpes zoster, the relationship between herpes zoster and immunological markers, and the prognostic value of herpes zoster for progression of HIV disease.
Design and methods: A total of 966 homosexual participants in The Amsterdam Cohort Study were studied. Herpes zoster was defined by its characteristic clinical presentation. Incidence was calculated using Poisson regression, cumulative incidence by the Kaplan-Meier product-limit method and the prognostic value was evaluated using Cox proportional hazards model.
Results: The incidence of first episodes of herpes zoster was 3.31 per 1000 person-years (PY) in HIV-seronegatives and 51.51 per 1000 PY in HIV-1-seropositive individuals. Recurrences only occurred in HIV-1-positive patients (25.6%). Cumulative incidences of first episodes increased linearly with the duration of follow-up. In HIV-1-seropositives the incidence was 31.2 per 1000 PY at CD4+ cells > or = 500 x 10(6)/l, 47.2 per 1000 PY [relative risk (RR), 1.51; 95% confidence interval (CI), 0.78-2.94] at CD4+ cells 200-499 x 10(6)/l and 97.5 per 1000 PY (RR, 3.13; 95% CI, 1.54-6.32) at CD4+ cells < 200 x 10(6)/l. Besides CD4+ cell counts, CD3 monoclonal antibodies and phytohaemagglutinin-induced T-cell reactivity were independent predictors for herpes zoster. The hazard ratio for AIDS after herpes zoster was 1.6 (95% CI, 1.1-2.4) and for death 1.7 (95% CI, 1.1-2.5), but these were not independent from CD4+ cell counts.
Conclusion: In HIV-1 infection the incidence of herpes zoster increases with the decrease of CD4+ cell counts and T-cell reactivity, but herpes zoster is not an independent predictor for disease progression.