treatment responses in HIV-infected South African children.

Six-month gain in weight, height, and CD4 predict subsequent antiretroviral treatment responses in HIV-infected South African children.

The aim of the study was to construct percentile curves for 6-month gain in weight, height, CD4 cell count, and CD4 percentage (CD4%) in children initiating antiretroviral therapy, and to assess the association between lower percentiles and subsequent antiretroviral therapy responses. A cohort of 1394 HIV-infected children initiating antiretroviral therapy between April 2004 and March 2008, Johannesburg, South Africa were enrolled. The generalized additive model for location, scale, and shape was used to construct percentile curves for 6-month gain in weight, height, CD4 cell count, and CD4%. Cox proportional models were used to assess the association between lower percentiles of each distribution and death, virological suppression, and treatment failure between 6 to 36 months post-antiretroviral therapy initiation. Lower percentiles for gain in weight, CD4, and CD4% count after 6 months of antiretroviral therapy, but not height, were associated with poor subsequent treatment outcomes independent of baseline characteristics, with increasing strength of association as percentiles decreased. Age-specific 6-month post-antiretroviral therapy weight gain in this cohort was substantially higher compared with 6-month weight gain in non-HIV-infected American children of the Fels Institute cohort and the attained weight-for-age at 6 months post- antiretroviral therapy plotted on WHO weight-for-age growth charts were not associated with subsequent treatment outcomes. Gain in CD4% in the first 6 months of antiretroviral therapy was the best predictor of poor subsequent antiretroviral therapy outcomes. In areas with limited access to CD4%, weight gain post- antiretroviral therapy using these newly developed reference distributions for HIV-infected children on antiretroviral therapy is a good alternative to CD4%, and clearly superior to the commonly used 'Road-to-Health' weight-for-age charts.

A third of children vertically infected do not survive to their first birthday and more than half die before age 2. When children start antiretroviral treatment, it is important to monitor their clinical improvement to assess whether they are benefitting. This innovative study developed HIV-specific weight gain reference curves that can be used by health workers in settings without CD4 percentage laboratory tests to identify which children on treatment are likely to be virologically suppressed and which ones are at higher risk for treatment failure and subsequent death. These reference curves should be tested in other settings and adjusted as necessary to develop international weight gain reference curves for children starting antiretroviral treatment.