Antiretroviral Therapy and Extreme Weight (EXTATIC)

Our primary endpoint is the individual trough concentrations of interest at steady state for NNRTI or boosted PI; Principal outcome measure: comparison of the concentrations between patients \<25kg/m2 and patients\<25kg/m2 Secondary endpoints: * Occurrence of virologic failure * Occurrence of clinical/biological adverse events * Percentage of patients with concentration within the therapeutic range * Body composition Secondary outcome measures: comparison of the occurrence of virologic failure, occurrence or adverse event, patients with concentration within the therapeutic range between groups. Correlation between body composition and concentration. Methodology, study design: open-labelled monocentric study. Sample size: It will be a descriptive experimental study involving 120 overweight subjects, 120 normal weight subjects Inclusion criteria : * Patients with HIV+ * Patients aged more than 18 years old. * Patient giving its well-informed and free consent. Study design : Plasma concentration was performed during the usual clinical follow-up. Study duration: 12 months Duration for a patient: 1 day Investigating center and participating units: one center enrolling the patients and the lab performing drug dosages.