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 (TI) guided by CD4+ count in HIV-infected patients followed-up prospectively. METHODS Patients on HAART with a CD4+ cell count >500 cells/mm3 discontinued therapy with instructions to start therapy again before their CD4+ count dropped below 200 cells/mm3. RESULTS We report data on 112 HIV-infected patients. The median follow-up after starting the first TI was 34.7 months (IQR: 23.1-43.8). The median duration of the first TI was 12 months (IQR: 5.2-25). In the multivariate analysis the factor which most strongly correlated with the duration of the first TI was the CD4+ cell count at the end of the TI. Among the 34 patients who had completed a second TI, the duration of the two periods of interruption was similar if the treatment was recommenced at the end of the first TI at a CD4+ count higher than the nadir count. CONCLUSIONS The strategy of TI is safe if the criteria for restarting therapy are applied correctly. The factor with the greatest influence on the duration of the first TI is the number of CD4+ cells at the end of the TI.