[Treatment interruption in 30 HIV-infected patients with successful viral suppression under highly active...

To evaluate clinical and laboratory results in HIV-infected patients with complete viral suppression under HAART (highly active antiretroviral treatment) for whom treatment was interrupted and to identify risk factors associated with prolonged (i.e., successful) treatment interruption.

Retrospective study of patients who interrupted therapy while on HAART with a plasma HIV RNA <400 copies/mL. Multivariate regression analysis was performed to identify factors associated with a prolonged interruption (more than 6 months).

36 treatment interruptions in 30 patients were analyzed. Patients' mean age was 42 years, 83% were men, and 60% were infected through homosexual contact. Median CD4 cell count at initiation of HAART was 292/mm3 and median viral load 43,000 copies/mL. Reported reasons for HAART discontinuation included patient or clinician choice (n=21) or drug toxicity (n=15). Median CD4 cell count when treatment interruption began was 606/mm3, and its median duration was 14 months. During treatment interruption, adverse clinical events or laboratory findings occurred in 9 patients (30%), all of whom had a CD4 cell count nadir < 300/mm3. When HAART resumed, median CD4 cell count was 302/mm3, and median viral load 59,800 copies/mL. Plasma HIV RNA dropped to <400 copies/mL in all patients within 4 months of resuming treatment. In multivariate analysis, the factors associated with resuming HAART within 6 month of treatment interruption were: HAART including non-nucleoside analog (adjusted Hazard Ratio [aHR]: 3.6, 95% CI: 1.2-10.6, p = 0.02), a CD4 cell count nadir < 300 (adjusted Hazard Ratio [aHR]: 5.5, 95% CI: 2.0-26, p = 0.0057), undetectable plasma HIV RNA for longer than 21 months at the interruption (aHR: 7.2, 95% CI: 2-26, p = 0.002). This probability was 45.5% in patients with a CD4 cell count nadir < 300 and 14.3% in the others (p 0.10).

Antiretroviral treatment should be interrupted only with caution in patients with a CD4 cell count nadir <300/mm3 because of the risk of adverse clinical events or laboratory findings.