The Rate of Serious Bacterial Infections Among HIV-Infected Children With Immune Reconstitution Who Have Discontinued Opportunistic Infection Prophylaxis

Use of highly active antiretroviral (ARV) therapy in HIV-infected adults is associated with a decrease in the incidence of opportunistic infections (OIs). In the current study, the authors sought to "evaluate prospectively the incidence of serious bacterial infections (SBIs) and other OIs after discontinuation of OI and/or Pneumocystis jiroveci pneumonia (PCP) prophylaxis among HIV-infected pediatric subjects who experienced immune reconstitution while receiving stable antiretroviral therapy."

Researchers enrolled HIV-infected children and adolescents ranging from age two to 21 who had received OI and/or PCP prophylaxis for up to six months and had sustained responses (>16 weeks prior to study start) to ARV therapy, with CD4 cell percentages of ¡Ý20 percent for children over age six or ¡Ý25 percent for two- to six-year-olds. Prophylaxis was discontinued at entry. Subjects were vaccinated against hepatitis A to determine whether any correlation existed between functional immune reconstitution and protection from OIs. The researchers evaluated the association between the humoral response and the likelihood of developing an OI.

"A total of 235 HIV-infected subjects from 43 participating sites had a median follow-up period of 132 weeks, yielding 547 person-years of observation," the authors said. "Twenty SBIs were observed among 19 subjects, resulting in an incidence rate of 3.66 SBIs per 100 person-years (95% confidence interval: 2.24-5.66 SBIs per 100 person-years). Sixteen of the events were presumed bacterial pneumonia episodes, with 4 proven SBIs. One participant experienced 2 separate pneumonia episodes," they reported.

Baseline CD4 cell counts of ¡Ý750 cells per mm3 were detected in 10 subjects who developed SBIs, and 15 had CD4 cell percentages of ¡Ý25 percent at time of their SBIs. Two participants died from non-SBI-related causes. The researchers reported no statistically significant differences in changes in CD4 cell counts or percentages over time between subjects who experienced primary end points and those who did not. No evidence was found that baseline protease inhibitor use, gender, race/ethnicity, age or CD4 cell count or percentage affected time to SBI development.

"OI or PCP prophylaxis can be withdrawn safely for HIV-infected pediatric patients who experience CD4 cell recovery while receiving stable antiretroviral therapy," concluded the researchers, who added that more studies are needed to determine the association between antibody responses to neoantigens and the development of SBIs.

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