10-year outcome of temporary structured treatment interruption (STI) among HIV-1-infected patients: An observational study in a single medical center

Background Lifelong antiretroviral therapy (ART) is recommended for HIV-1 infected patients but may lead to intolerance or poor adherence. Structured treatment interruption (STI) is a strategy for drug holiday or to boost HIV-specific immunity. But the long-term outcome of STI was never reported in literature. Methods This is a single-center observational study. We followed the HIV-infected patients who already had a stable viral suppression and voluntarily started temporary STI with a fixed 12-week interval after counseling, evaluation and education. HIV-1-specific T cell response was also measured in some patients. Results Totally 34 HIV-infected patients received temporary STI since July, 2006. 18 patients completed 10-year follow-up. All patients received protease inhibitors (PI)-based ART before and during temporary STI. The patients received temporary STI with a period of 36–85 weeks. All of them reached viral suppression after 12 weeks of restarting continuous ART. No viral rebound or opportunistic disease was recorded during follow-up. No adverse event or comorbidity was attributed to STI. The plasma viral load (PVL) at the end of STI was significantly lower than baseline PVL in patients with a longer duration of STI (≤36 weeks vs. >36 weeks, P = 0.005). The T cell response study revealed that cyclically increased HIV-1-specific T cell response after starting STI in patients with baseline CD4+ count >350/μL. Conclusion Temporary STI may not lead to worse long-term outcome among highly selected patients. The policy may partially control viral replication through reminding the HIV-1 specific T cell immunity.