Evaluation of long-term immunological and virological response to highly active antiretroviral therapy in a cohort of HIV infected children

Abstract

Background CD4 T cells and HIV-1 RNA count are important markers of HIV progression and help clinical decision-making on how to conduct antiretroviral therapy. Methods We studied the long-term outcomes of viral and immune response of naïve children starting HAART from 1998 to 2006. Immune response was defined by CD4% > 25% and viral response as undetectable viral load on week 24. Regression models investigated predictors of response on week 24 and 144. Results 196 children were evaluated. CD4 > 25% was achieved by 54.7% of patients and undetectable viral load by 44.7% on week 24. Children with baseline CD4 15–24% had a 4 times higher chance to reach CD4 > 25% when compared to those with baseline CD4 < 15% ( P < 0.001). Female patients also experienced higher CD4% on week 24 ( P: 012) and on week 144 ( P: 0.014). Viral response on week 24 and 144 was not associated to any baseline characteristic. Improvements on CD4% was achieved mainly by patients with viral suppression. Growth parameters were similar between patients in viral failure/immune success and viral success/immune success groups ( P < 0.001). Conclusions HAART resulted in substantial increases in CD4% but viral response rates in children are highly variable. A significant proportion of treated individuals who fail to suppress virus experience CD4 T cell reconstitution. The initiation of HAART in children before severe immunessupression occurs should be considered to approach normal values of CD4 by week 24. Patients with immune response despite viral rebound have clinical disease progression rates that are similar than those with viral suppression.