Azvudine is a nucleoside analog that inhibits HIV-1 RNA-dependent RNA polymerase and is also an agent against SARS-CoV-2 [1]. It was first approved in China in July 2022 as the treatment for COVID-19 [2] and then approved in Russia in February 2023. The reverse transcriptase M184 V/I mutation has historically been common in regimens that contain lamivudine (3TC) or emtricitabine (FTC) [3]. An in-vitro study demonstrated that M184I is the key mutation in azvudine treatment [4]. Here, we report M184I mutation in five HIV-1 individuals who take azvudine before initiating antiretroviral therapy (ART) in Shanghai Public Health Clinical Center (SPHCC), China, as summarized in Table 1. Genotypic resistance testing (GRT) was performed in these individuals according to our previously established protocols [5].
Table 1.
Clinical characteristics; genotypes; drug resistance mutations of the five patients.
| Patient | Age (years) | Sex | CD4+ T cell count (cells/μl) | Viral load (copies/ml) | Duration of taking azvudine (days) | ART regimen | HIV-1 subtype | RT mutations |
| 1 | 39 | Male | 4.39 | 675 000 | 6 | B/F/TAF | CRF01_AE | NRTI mutations: M184I NNRTI mutations: none RT other mutations: G141X;I142E;R143N;Y144I;Q145S;Y146V;E305X |
| 2 | 26 | Male | 20.25 | 923 000 | 14 | Switched from 3TC/DTG to 3TC/DTG+TDF | CRF01_AE | NRTI mutations: M184I NNRTI mutations: none RT other mutations: I142G;Y144L;Q145L;Y146V;E305X |
| 3 | 40 | Male | 70.46 | 2 200 000 | 4 | B/F/TAF | CRF07_BC | NRTI mutations: M184I NNRTI mutations: none RT other mutations: R143M;Y144E;Q145S;Y146V;E305X |
| 4 | 25 | Male | 16.43 | 127 000 | 5 | B/F/TAF | CRF01_AE | NRTI mutations: M184I NNRTI mutations: none RT other mutations: K238X;S251K;Q258H;V261R;N265R;A267GS268R;I270F |
| 5 | 53 | Male | 14.63 | 2 740 000 | 3 | B/F/TAF | CRF01_AE | NRTI mutations: M184I NNRTI mutations: none RT other mutations: L289∗;T290Q;E2911;V292∗;I293S;L295S |
3TC, lamivudine; ART, antiretroviral therapy; B, bictegravir; DTG, dolutegravir; F, emtricitabine; GRT, genotypic resistance testing; NNRTI, nonnucleoside reverse transcriptase inhibitor; NRTI, nucleoside reverse transcriptase inhibitor; RT, reverse transcriptase; TAF, tenofovir alafenamide; TDF, tenofovir disoproxil.
Patient 1 is a 39-year-old man diagnosed of COVID-19 on 4 January 2023, and received azvudine 5 mg per day for 6 days. He was diagnosed with HIV-1 infection and pneumocystis pneumonia (PCP) on 9 January 2023, before transferring to SPHCC. Upon admission, his baseline CD4+ cell count was 4 cells/μl with HIV viral load of 675 000 copies/ml. The M184I together with other mutations in HIV reverse transcriptase conferred high-level resistance to 3TC and FTC. He then received bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) for ART.
Patient 2 is a 26-year-old man. The patient was diagnosed with COVID-19 on 28 December 2022, and administered azvudine 5 mg per day for 14 days. He was diagnosed with HIV-1 infection on 11 January 2023, with a CD4+ cell count of 20 cells/μl and viral load of 923 000 copies/ml. Then, he received ART of 3TC/dolutegravir on 14 February 2023, before the result of HIV drug-resistance testing was available. After a week, he was readmitted for bradykinesia. Upon readmission, the CD4+ cell count had increased to 108 cells/μl and the viral load had dropped to 76 copies/ml. Due to high levels of resistance to 3TC and FTC identified by the GRT, his ART regimen was switched to tenofovir disoproxil and 3TC/ dolutegravir.
Patient 3 is a 40-year-old man who was diagnosed with COVID-19 on 3 December 2022. Azvudine 5 mg per day was administered for 4 days. The patient was diagnosed with HIV-1 and PCP on 9 February 2023, and transferred to SPHCC. His baseline CD4+ cell count was 70 cells/μl with a HIV viral load of 2 200 000 copies/ml. The patient started B/F/TAF 5 days later because the GRT results showed the M184I with other reverse transcriptase mutations.
Patient 4 is a 25-year-old man who was diagnosed with COVID-19 on 7 February 2023. Azvudine 5 mg per day was administered at COVID-19 diagnosis for 5 days. He presented at SPHCC with fever, cough, and swollen lymph nodes. The patient was diagnosed with HIV-1 on 21 February 2023, and his baseline CD4+ cell count was 16 cells/μl with a HIV viral load of 127 000 copies/ml. The patient then initiated B/F/TAF.
Patient 5 is a 53-year-old man who was diagnosed with COVID-19 on 3 January 2023. The symptoms of COVID-19 were relieved after taking cefoperazone, azvudine 5 mg per day, and dexamethasone for 3 days. He then presented at SPHCC with persistent fever and diagnosed with HIV-1 and PCP on 21 February 2023. His baseline CD4+ cell count was 14 cells/μl with a HIV viral load of 2 740 000 copies/ml. He also initiated B/F/TAF.
All the patients were discharged after clinical improvement.
Our previous study showed that the prevalence of pretreatment M184I mutation is only 0.63% among 317 people with HIV (PWH) naive to ART [5]. Similarly, there is low prevalence of M184I mutation in other regions of China [6,7]. Moreover, the M184I mutation frequency induced by azvudine was 66.67% on day 36, whereas there is no detection of M184 V mutation in-vitro study [4]. It is reasonable to speculate that the RT M184I mutation was induced by azvudine, although GRT was not performed in these individuals before taking azvudine. Pharmacokinetic studies indicated that azvudine triphosphate had longer intracellular retention in peripheral blood mononuclear cells and longer half-life than 3TC triphosphate in PWH [8–10]. This may partially explain why M184I mutation emerged in these individuals as short as only 4 days of exposure to azvudine. Nevertheless, more evidence and further research are still needed to confirm our findings.
In summary, our cases showed that short-term exposure to azvudine may induce M184I mutation in HIV-1 RT. Hence, azvudine should be used with caution before HIV screening, and it should be avoided without ART in PWH.
Acknowledgements
R.J. and J.C. contributed to the study design and the manuscript preparation. R.J., J.S., B.Z., R.Z., and L.L. contributed to the collection of clinical information. All authors read and approved the final manuscript.
This study has been approved by Shanghai Public Health Clinical Center in China and informed consent was obtained from the patient involved. The approval number is 2021-S051-01.
Written informed consent was obtained from the patient for this publication.
Conflicts of interest
Jun Chen is currently receiving a grant (#21Y11901200) from the Science and Technology Commission of Shanghai Municipality and a grant (#SHDC2020RC6025) from the Shanghai Shenkang Hospital Development Center. All the other authors declare no conflicts of interest.
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