Early highly active antiretroviral therapy enhances B-cell longevity: a 5 year follow up.

BACKGROUND We have previously reported that an early initiation of highly active antiretroviral therapy (HAART) in HIV-1 vertically infected children enhanced the function of memory B-cells gained during childhood routine vaccinations. On the other hand, a significant waning of immunity was observed for patients with a late treatment. In this follow-up study, we report data from a sample of patients in our cohort including late-treated patients being revaccinated with routine childhood vaccines. METHODS The levels of serum antibodies and cellular immunity were measured by antigen-specific enzyme-linked immunosorbent assay and B-cell ELISpot. Moreover, flow cytometry on the frequencies of mature-activated (CD10-CD21-) and double-negative (CD27-IgD-) B-cells as hallmarks of immune activation and immune senescence, respectively, was performed for all patients. RESULTS Reduced protective humoral immunity and cellular immunity to routine childhood vaccines was observed in late-treated patients. Moreover, we found that timing of HAART related with the frequencies of mature activated and double negative. CONCLUSIONS Altogether the data presented in this follow-up study reenforce the importance for an early start of HAART in HIV-1 vertically infected individuals and suggest that timing of HAART is a fundamental factor to take into account for vaccination design in this population.