Long-term suppression of HIV with antiretroviral therapy in children is associated with a sustained increase in CD4 percentage, according to a Spanish study published in the January edition of BMC Infectious Diseases. However, the investigators also established that even if a child did not achieve an undetectable viral load in the long-term, there was still an immunological benefit from HIV therapy.
Researchers wished to see if longer-term changes in CD4 cell count were associated with persistent control of HIV. “The overall effectiveness of long-term HAART on HIV infected children has been scarcely studied”, they noted. Accordingly, they conducted a retrospective study involving 160 vertically infected children aged over six months who received potent anti-HIV therapy between 1996 and 2004. They compared CD4 cell percentages at twelve, 24, 36 and 48 months in the 33 children who had a constant viral load below 400 copies/ml with the 127 children who had a persistently detectable viral load, even though they changed their anti-HIV therapy. Information was also gathered on new AIDS-defining illnesses, deaths and adherence to antiretroviral treatment.
At baseline, children who maintained virologic control and those who did not had comparable age, CD4 cell percentage (median 12% vs. 18%), CD8 cell percentage and viral load. Both groups of children experienced a similar and significant increase in CD4 cell percentage after a year of potent HIV treatment (median 28% vs. 26%). However, after two years of treatment, CD4 cell percentage was significantly higher in children with virological control (30% vs. 27%, p = 0.01). This difference was also present after three years of treatment (31% vs. 28%, p = 0.005) and four years (32% vs. 28%, p = 0.004).
However, the investigators emphasised that even though the children with controlled viral load had larger increases in CD4 cell percentage, children with a detectable viral load nevertheless had significant and sustained increases in their immune function from baseline. “This indicates that viral load suppression was not indispensable to the recovery of the immune system in vertically infected children”, they comment. In addition, they note that only one child who did not control viral load died and another progressed to AIDS. What’s more, there were no differences in growth, weight or the number of opportunistic infections between those children who maintained an undetectable viral load and those who did not.
Further analysis of their data indicated that children with detectable HIV were much more likely to have been previously treated with suboptimal HIV therapy (87% vs. 61%) and that a significantly smaller proportion of children who always had detectable HIV had good adherence to their potent HIV therapy (48% vs. 91%).
Resino S et al. Impact of long-term viral suppression in CD4+ recovery of HIV-positive children on highly active antiretroviral therapy. BMC Infectious Diseases 6: 10, 2006.