Anthropometric and immunological success of antiretroviral therapy and prediction of virological success in west African adults
Eugène Messou, Delphine Gabillard, Raoul Moh, André Inwoley, Souleymane Sorho, Serge Eholié, François Rouet, Catherine Seyler, Christine Danel, Xavier Anglaret
The 6 month assessment of the response to antiretroviral therapy (ART) is a critical step. In sub-Saharan Africa, few people have access to plasma viral-load measurement. We assessed the gain or loss in body mass index (BMI), alone or in combination with the gain or loss in CD4+ T-cell count (CD4), as a tool for predicting the response to ART.
In a cohort of 622 adults in Abidjan, Côte d’Ivoire, we calculated the sensitivity, specificity and predictive values of BMI and CD4 for treatment success defined as viral-load undetectability (< 300 copies/ml) as gold standard.
After 6 months of ART, the median change in BMI was an increase of 1.0 kg/m² (interquartile range, IQR: 0.0–2.1), the median change in CD4 an increase of 148/μl (IQR: 54–230) and 84% of patients reached viral-load undetectability. The distribution of change in BMI was similar among patients who reached undetectability and those who did not (increases of 1.06 kg/m² versus 0.99 kg/m², P = 0.51). With larger changes in BMI, the specificity for treatment success increased but its sensitivity decreased and its positive predictive value was stable around 85%. All results remained similar when combining changes in BMI with those in CD4 and when stratifying by groups of baseline BMI or CD4.
In settings where viral-load measurement is not available, a high BMI gain does not reflect virological success, even when combined with a high CD4 gain. In our population, most patients with detectable viral-load had probably adhered to the drug regimen sufficiently to reach significant gains in body mass and CD4 count but had adhered insufficiently to reach viral suppression.