Background: Transmitted drug resistance (TDR) is a major challenge in the clinical management of acquired immunodeficiency syndrome (AIDS). Therefore, this study aimed to investigate the epidemic characteristics of and risk factors for human immunodeficiency virus (HIV)-1 TDR in Nanjing from 2018 to 2021 to provide support for clinical management.
Methods: The HIV-1 Pol gene was amplified by nested reverse transcription polymerase chain reaction from venous blood of 1190 HIV-infected patients who did not receive antiviral therapy, and the amplified product was sequenced using an in-house sequencing method. The sequencing result was compared with the HIV drug resistance database from Stanford University to elucidate the rates of antiviral drug resistance and distribution of drug-resistant mutation sites. Factors associated with TDR were evaluated using a logistic regression model.
Results: Detection of drug resistance at the gene level was successful in 1138 of 1190 HIV-1-infected patients (95.6%), and the overall 4-year drug resistance rate was 8.2% (93/1138). The drug resistance rate was higher for non-nucleoside reverse transcriptase inhibitors (NNRTIs; 6.7%) than for nucleoside reverse transcriptase inhibitors (NRTIs; 2.5%) or protease inhibitors (PIs; 0.1%) (χ ² = 83.907, P< 0.0001). The most common NNRTI-related mutation was V179D/E followed by K103N. M184V was the dominant NRTI-associated mutation, and M46L/I was the most prevalent PI-associated mutation. A CD4⁺ T cell count of < 50 cells/μL was significantly associated with an increased risk of TDR (OR=3.62, 95% CI: 1.38– 9.51, P=0.009).
Conclusion: The prevalence of TDR in the city of Nanjing from 2018 to 2021 was at a moderate epidemic risk according to World Health Organization standards. Continuous monitoring of TDR can inform clinical diagnosis and treatment. Patients with advanced disease and a low CD4⁺ T lymphocyte count are more likely to have TDR in Nanjing.
Keywords: HIV-1, transmitted drug resistance, mutation sites