A lower level of Hb (8.4±3.7 vs 9.6±2.8g/dl, p=0.006) was observed in the group of HIV-positive patients treated with ART, along with an higher prevalence of both severe (Hb<7g/dl) and moderate (Hb<10g/dl) anemia. This evidence concerns the gene GSTM1 and anemia (phenotype).