Antiretroviral therapy interruption guided by CD4 cell counts and plasma HIV-1 RNA levels in chronically HIV-1-infected patients

OBJECTIVE: We evaluated the safety of CD4 cell count and plasma HIV-1 RNA (pVL)-guided treatment interruptions (GTI) and determined predictors of duration of treatment interruption. METHODS: Chronically HIV-1-infected adults with sustained CD4 cell counts > 500 cells/μl and pVL < 50 copies/ml were randomly assigned to either continue with standard antiretroviral therapy (control group, n = 101) or to interrupt therapy aimed at maintaining CD4 cell counts > 350 cells/μl and pVL < 100 000 copies/ml (GTI group, n = 100). Both groups were followed for 2 years. RESULTS: There were no AIDS-defining illnesses or deaths in either group. Compared to controls, subjects interrupting therapy reduced treatment exposure by 67%, but suffered significantly more adverse events related to the intake of medication or to therapy interruption [relative hazard, 2.71; 95% confidence interval (CI), 1.64-4.49; P < 0.001), mainly due to an excess in mononucleosis-like symptoms. While GTI subjects demonstrated improvements in the psychosocial spheres of quality of life and pain reporting, GTI had no effect on the physical aspects of quality of life. Although both groups had a similar hazard for developing CD4 cell count < 200 cells/μl; at least 10% of subjects on GTI had CD4 cell counts < 350 cells/μl at every time point. Drug resistance mutations were detected in 36% of subjects but were selected de novo only in subjects interrupting non-nucleoside reverse transcriptase inhibitor therapy. Lower CD4 cell count nadir, higher set-point pVL and prior exposure to suboptimal regimens were all independent predictors of the need to reinitiate treatment. CONCLUSIONS: Overall, GTI were not as safe as continuing therapy. Despite achieving some improvements in quality of life, GTI did not reduce the overall rate of management-related adverse events.