Antiretroviral treatment response of HIV-infected children after prevention of mother-to-child transmission in West Africa

Introduction: We assessed the rate of treatment failure of HIV-infected children after 12 months on antiretroviral treatment (ART) in the Paediatric IeDEA West African Collaboration according to their perinatal exposure to antiretroviral drugs for preventing mother-to-child transmission (PMTCT).

Methods: A retrospective cohort study in children younger than five years at ART initiation between 2004 and 2009 was nested within the pWADA cohort, in Bamako-Mali and Abidjan-Côte d'Ivoire. Data on PMTCT exposure were collected through a direct review of children's medical records. The 12-month Kaplan-Meier survival without treatment failure (clinical or immunological) was estimated and their baseline factors studied using a Cox model analysis. Clinical failure was defined as the appearance or reappearance of WHO clinical stage 3 or 4 events or any death occurring within the first 12 months of ART. Immunological failure was defined according to the 2006 World Health Organization age-related immunological thresholds for severe immunodeficiency.

Results: Among the 1035 eligible children, PMTCT exposure was only documented for 353 children (34.1%) and remained unknown for 682 (65.9%). Among children with a documented PMTCT exposure, 73 (20.7%) were PMTCT exposed, of whom 61.0% were initiated on a protease inhibitor-based regimen, and 280 (79.3%) were PMTCT unexposed. At 12 months on ART, the survival without treatment failure was 40.6% in the PMTCT-exposed group, 25.2% in the unexposed group and 18.5% in the children with unknown exposure status (p=0.002). In univariate analysis, treatment failure was significantly higher in children unexposed (HR 1.4; 95% CI: 1.0-1.9) and with unknown PMTCT exposure (HR 1.5; 95% CI: 1.2-2.1) rather than children PMTCT-exposed (p=0.01). In the adjusted analysis, treatment failure was not significantly associated with PMTCT exposure (p=0.15) but was associated with immunodeficiency (aHR 1.6; 95% CI: 1.4-1.9; p=0.001), AIDS clinical events (aHR 1.4; 95% CI: 1.0-1.9; p=0.02) at ART initiation and receiving care in Mali compared to Côte d'Ivoire (aHR 1.2; 95% CI: 1.0-1.4; p=0.04).

Conclusions: Despite a low data quality, PMTCT-exposed West African children did not have a poorer 12-month response to ART than others. Immunodeficiency and AIDS events at ART initiation remain the main predictors associated with treatment failure in this operational context.