Research on the treatment effects and drug resistances of long-term second-line antiretroviral therapy among HIV-infected patients from Henan Province in China

Background: HIV/AIDS patients who fail to respond to first-line treatment protocols are switched to second-line ART. Identifying factors that influence effective second-line treatment can improve utilization of limited medical resources. We investigated the efficacy of long-term second-line anti-retroviral therapy (ART) after first-line virologic failure as well as the impact of non-nucleotide reverse transcriptase inhibitor (NNRTI), nucleotide reverse transcriptase inhibitor (NRTI), and protease inhibitor (PI) resistance mutations and medication adherence on ineffective viral suppression. Methods: A total of 120 patients were evaluated at 6, 12, 18, 24, and 48months after initiation of second-line ART; a paper questionnaire was administered via a face-to-face interview and venous blood samples were collected. CD4(+) T cell count, viral load, and drug resistance genotypes were quantified. Results: CD4(+) T cell counts increased from 170 cells/L (IQR 100-272) at baseline to 359 cells/L (IQR 236-501) after 48months of second-line treatment. Viral load (log(10)) decreased from 4.58 copies/mL (IQR 3.96-5.17) to 1.00 copies/mL (IQR 1.00-3.15). After switching to second-line ART, nine patients newly acquired the NRTI drug-resistant mutation, M184V/I. No major PI resistance mutations were detected. Logistical regression analysis indicated that medication adherence <90% in the previous month was associated with ineffective viral suppression; baseline high/low/moderate level resistance to 3TC/TDF was protective towards effective viral suppression. Conclusions: Long-term second line ART was effective in the Henan region of China. Drug resistance mutations to NRTIs were detected in patients receiving second-line ART, suggesting that drug resistance surveillance should be continued to prevent the spread of resistant strains. Patient medication adherence supervision and management should be strengthened to improve the efficacy of antiviral treatment.