Safety and factors predicting the duration of first and second treatment interruptions guided by CD4+ cell counts in patients with chronic HIV infection

Objectives: To evaluate the safety of treatment interruption (Tl) guided by CD4+ count in HIV-infected patients followed-up prospectively. Methods: Patients on HAART with a CD4+ cell count >500 cells/mm 3 discontinued therapy with instructions to start therapy again before their CD4+ count dropped below 200 cells/mm 3 . Results: We report data on 112 HIV-infected patients. The median follow-up after starting the first Tl was 34.7 months (IQR: 23.1-43.8). The median duration of the first Tl was 12 months (IQR: 5.2-25). In the multivariate analysis the factor which most strongly correlated with the duration of the first Tl was the CD4+ cell count at the end of the Tl. Among the 34 patients who had completed a second Tl, the duration of the two periods of interruption was similar if the treatment was recommenced at the end of the first Tl at a CD4+ count higher than the nadir count. Conclusions: The strategy of Tl is safe if the criteria for restarting therapy are applied correctly. The factor with the greatest influence on the duration of the first Tl is the number of CD4+ cells at the end of the Tl.