Impact of HIV drug resistance on virologic and immunologic failure and mortality in a cohort of patients on antiretroviral therapy in China

OBJECTIVES: To study the dynamics of HIV drug resistance (HIVDR) and its association with virologic and immunologic failure as well as mortality among patients on combination antiretroviral therapy (cART) in China. DESIGN: We recruited 365 patients on cART in two rural Chinese counties in 2003-2004 and followed them every 6 months until May 2010. METHODS: Virologic failure, HIVDR, immunologic failure and death were documented. We used Kaplan-Meier and the proportional hazards models to identify the timing of the events, and risk factors for mortality. RESULTS: At the end of study, patients had been followed for 1974.3 person-years, a median of 6.1 years. HIVDR mutations were found in 235 (64.4%) patients and 75 died (20.5%, 3.8/100 person-years). Median time from cART to detection of virologic failure was 17.5 months, to HIVDR 36.6 months and to immunologic failure 55.2 months (≈ 18-month median interval between each adverse milestone). Being male, having a baseline CD4 cell count of less than 50 cells/μl and HIVDR were associated with higher mortality. Patients who developed HIVDR in the first year of treatment had higher mortality than those developing HIVDR later (adjusted hazard ratio 1.90, 95% confidence interval 1.01-3.48). CONCLUSION: HIVDR was common and was associated with higher mortality among Chinese patients on cART, particular when HIVDR was detected early in therapy. Our study reinforces the importance of improving patient adherence to cART in order to delay the emergence of HIVDR and obviate the need to switch to costly second-line drug regimens too early.