Risk factors associated with increased risk of lymphopenia were: duration since the diagnosis of HIV ≤ 6 months OR 12.3(IC 95% 3.9-38.4; p = 0.000), duration since the initiation of HAART ≤6 months OR 26.07(IC 95% 2.52-269.3; p = 0.006), CD4 count < 200 cells/μl OR 14.5(IC 95% 4.97-42.53), presence of anemia OR 17.5(IC 95% 2.3-132.98; p = 0.000), presence of leucopenia OR 6.23(IC 95% 2.32-16.74; p = 0.000) and presence of opportunistic infection OR 3.58(IC 95% 1.27-10.05; p = 0.021). This evidence concerns the gene CD4 and anemia.