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Background: In acute HIV-1 infection, STI may induce immunologic control of HIV-1 replication. Several prospective trials of STI in chronic HIV-1 infection have been less encouraging. A previously presented retrospective analysis of our patients showed that in those with a significant CD4 increase (>200 cells) on antiretroviral therapy (ART), 2 or more interruptions may significantly lower viral set point. This prospective study describes STI in a cohort of patients.

Methods: 10 patients with either a positive response to therapy interruption retrospectively or those expressing interest in the strategy who met inclusion criteria (VL BLQ on ART, good adherence, robust CD4 response) were selected. Interruptions analyzed were prospective and supervised. Timing of STI cycles was based on CD4 and Viral Load (VL) responses not a predetermined schedule. Data collected included demographics, ART, VL, CD4, and illnesses during STI.

Results: Of 7/10 patients with data at 4 weeks off ART, the mean VL was 1.78 log10 copies/ml below baseline (BL). In 10 patients > 8 weeks off ART, the mean VL was 1.38 log10 below BL. 7/10 maintained VL 8 weeks off ART (mean 27 weeks, 1 > 2 years). 4/7 with data during more than one STI showed an increase in time to reach 5000 copies/ml. None developed resistance-conferring mutations nor HIV-related illnesses during interruption. ART regimen or Hepatitis C seropositivity were not statistically significant factors affecting response to STI (durationΔVL; p>0.05).

Conclusions: Although no consensus exists concerning the effectiveness of STI in chronic HIV infection, a majority of our subjects were able to stop ART and maintain viral control for a period of time. Closely monitored STI was associated with lowered viral set point during the interruption in most cases. A larger prospective study is warranted but we recommend future trials measure additional parameters and avoid using the same STI schedule for all subjects.


Diseases | Infectious Disease | Medical Sciences | Medical Specialties | Medicine and Health Sciences


Department of Medicine

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