Varicella zoster as a manifestation of immune restoration disease in HIV-infected children

Background: Exacerbation of opportunistic infections in HIV-infected patients shortly after initiation of highly active antiretroviral therapy (HAART) has been named immune restoration disease (IRD). Thus far, IRD has not been reported in children. Objective: We describe the clinical and immune characteristics of IRD in HIV-infected children treated with HAART. Methods: A historical cohort study was conducted in a tertiary HIV center in perinatally HIV-infected children who were started on a first stable HAART between January 1996 and July 2002. The incidence of opportunistic infections, newly AIDS-defining events or death after initiation of HAART, and virologic and immunologic information was evaluated at baseline and every 3 months post-HAART. Results: Sixty-one perinatally HIV-infected children were started and maintained on HAART for >6 months. Seven episodes of IRD occurred. All were cutaneous herpes zoster (HZ). Children who developed HZ had significantly lower baseline CD4(+) and CD8(+) T-cell numbers compared with children who did not. HZ occurred only in children (7 of 34 subjects) with virological and immunological success to HAART. In children with a previous history of varicella infection, the risk of developing HZ after HAART was higher in those without a protective level of varicella-specific IgG (50%, or 5 of 10 subjects) compared with those with seroprotection (10%, or 2 of 20). Conclusion: Herpes zoster is a common manifestation of IRD in HIV-infected children after the initiation of HAART. Risks for developing HZ include no protective varicella-specific antibody despite previous varicella infection, severe immunodeficiency at baseline, and vigorous immunologic and virologic responses to HAART.