Objective: Since the advent in 2004 of highly active antiretroviral therapy (HAART) in Liaoning, a dramatic improvement had been seen in the number of patients attaining undetectable viral loads (92/104), but the extent of mutation diversity on human immunodeficiency virus 1 (HIV-1) and the prevalence of drug resistance had remained elusive. This study aimed to analyze both HIV-1 mutation profiles and prevalence related to antiretroviral resistance following therapeutic failure.
Methods: A total of 104 blood samples circling Liaoning from HAART-treated between 2004 and 2008 were studied. Patients' CD(4)(+) T-cell count and viral load were determined. HIV-1 pol (PR and part of RT) gene fragments were amplified from patients' plasma by reverse transcriptase polymerase chain reaction (RT-PCR) and nest-PCR, subsequently sequenced and analyzed.
Results: CD(4)(+) T cell numbers and viral replication capacity were assessed. 88.4% (92/104) of the patients were successful after initial non-suppressive NRTI & NNRTI-based HAART regimens. Subjects on non-nucleoside reverse transcriptase inhibitor (NNRTI) regimens developed more (6/104) drug-resistance mutations than those on nucleoside reverse transcriptase inhibitor (NRTI) regimens did (5/104). No protease-inhibitor (PI) drug resistance mutations developed. The whole rate of drug resistance mutations was about 6.73%. Subjects developing NNRTI-resistance (NNRTI-R) seemed more likely to develop drug-resistant viremia than with NRTI-based HAART.
Conclusion: This finding might have implications in which that the prevalence of drug-resistance mutations was low but remained risk of transmission in HIV-infected therapeutic failure. Meanwhile, data from the present study showed that there was a high frequency of primary mutations, which offered resistance to nrti and nnrti. Monitoring patients with treatment failure seems an important tool in helping the physicians to improve their treatment schedule and to carry out epidemiological surveillance programs.