Anthropometric and immunological success of antiretroviral therapy and prediction of virological success in west African adults

Objective 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 (CN), as a tool for predicting the response to ART Methods In a cohort of 622 adults in Abidjan, Cote d'lvoire, 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. Findings After 6 months of ART, the median change in BMI was an increase of 1.0 kg/m(2) (interquartile range, IQR: 0.0-2.1), the median change in CD4 an increase of 148/mu l (IOR: 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/m(2) versus 0.99 kg/m(2), 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 CN. Conclusion 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.