Uncertainty over when to start antiretroviral treatment in children infected with HIV from their mothers revolves around balancing the benefits of preventing disease progression and the risks and costs of life-long therapy begun within months of birth. Policies on when to start ART vary across Europe. Up to this point, the effect of age on clinical outcome has been difficult to assess because CD4 cell counts--an immunological indicator of HIV progression--experience considerable age-related variation.
However, Marie-Louise Newell, MD, and her colleagues in the European Collaborative Study developed a way to standardize CD4 cell counts in relation to age, and thus better evaluate immune status. They call this age-adjusted CD4 cell count the "z-score." Based on data collected over the past 20 years on infected children born to HIV-1 infected women, the investigators concluded that "children who started their most potent ART between 5 months and 5 years of age were almost 60 percent less likely to attain a 20 percent increase in their CD4 cell count z-score at any time, compared to children who started treatment before 5 months."
However, the authors did not find an association between early age at initiation and an increased likelihood of sustaining CD4 cell level recovery. They found that the risk of subsequent deterioration was similar for children initiating treatment in all age groups.
Still, because initiating effective antiretroviral therapy before 5 months of age was strongly associated with more rapid improvement in CD4 cell count, the authors conclude it should be strongly considered in the management of infants infected with HIV.