HIV immunity and infection: a paediatric perspective

The response of the developing immune system to HIV infection is complex and involves many innate and adaptive components. In almost all cases, the immune response is insufficient to eradicate the virus, and infection eventually results in a gradual decline of CD4 cells from both memory and naïve cell compartments. This can be quantitatively reversed by the institution of highly active antiretroviral therapy (HAART). Immune reconstitution of CD4 T cells following HAART in children is characterised by a sustained increase of naïve T cells, a pattern of immune reconstitution that differs from that seen in adults. This, and other differences between HIV infection in children and adults, indicates that it cannot be assumed that the therapeutic approach used in adults will be optimal for HIV-infected children. The future of paediatric HIV infection is dependent on a greater understanding of the kinetics of CD4 depletion and reconstitution.