Objective To undersatnd the initiation time specific antiviral effect on risk for virological failure and treatment prognosis of HIV/AIDS patients with low-level viremia (LLV) and provide evidence for the improvement treatment effect in HIV/AIDS patients with LLV.

Methods A retrospective cohort study was conducted for 4 007 HIV/AIDS patients who had received antiretroviral therapy (ART) for ≥2 years in Henan province since 2011, and those with two consecutive HIV RNA levels between 50 and 1 000 copies/mL were included. The follow-up was conducted until December 31, 2024. Based on the time from HIV infection diagnosis to the initiation of ART, the study participants were divided into three groups: <1-year group, 1～<5-year group, and ≥5-year group. The risk for virological failure in the three groups was analyzed by using χ² test. Joinpoint 5.1.0.0 analysis was used to assess the trends in CD4⁺T lymphocyte counts and CD4⁺T/CD8⁺T lymphocyte ratio at different follow-up times, and the intergroup comparisons were made by using F-test and Bonferroni test.

Results A total of 131 study participants were included in the study, in whom 45 (34.35%) were in the <1-year group, 31 (23.67%) were in the 1～<5-year group, and 55 (41.98%) were in the ≥5-year group. By the end of the follow-up, 18 cases (13.74%) experienced virological failure. Among them, the incidence of virological failure was highest in the ≥5-year group (23.64%), followed by the 1～<5-year group (12.90%), and <1-year group (2.22%). The differences were significant（χ²=9.600, P=0.008）. The CD4⁺ T lymphocyte counts in the 1-year group and the ≥5-year group showed upward trends from 2011 to 2016 annual percent change (APC)=10.10%, 95% CI: 7.98%～12.27%, P=0.002; APC=8.07%, 95% CI: 6.99%～9.16%, P < 0.001 and from 2016 to 2024 (APC=1.43%, 95% CI: 0.67%～2.20%, P=0.015; APC=1.49%, 95% CI: 1.09%～1.90%, P=0.004), while the 1～<5-year group showed an upward trend only from 2011 to 2016 (APC=11.62%, 95% CI: 4.33%～19.42%, P=0.020). Further analysis on the <1-year group revealed that the CD4⁺T lymphocyte count in the 30-day subgroup showed an upward trend (APC=4.12%, 95% CI: 1.38%～6.94%, P=0.011), while the 30-day-<1-year subgroup showed an upward trend only from 2011 to 2016（APC=12.58%, 95% CI: 6.41%～19.11%, P=0.012）. The overall ratio of CD4⁺T/CD8+T lymphocytes in the <1-year group and the ≥5-year group showed upward trend (APC=8.73%, 95% CI: 7.15%～10.33%, P＜0.001; APC=7.76%, 95% CI: 3.87%～11.79%, P=0.003), while in the 1～<5-year group, it only showed an upward trend from 2011 to 2020 (APC=12.41%, 95% CI: 5.29%～20.01%, P=0.016). The trends of the ＜30-day subgroup and the 30-day-<1-year subgroup were consistent with those of the <1-year group（P＜0.001). By the end of the follow-up, the mean CD4⁺T lymphocyte count was ＞600/µL and the CD4⁺T/CD8⁺T lymphocyte ratio was ＞1.0 in the <1-year group. However, in the 1～<5-year group and the ≥5-year group, the mean CD4⁺T lymphocyte count was ＜600/µL, and the CD4⁺T/CD8⁺T lymphocyte count ratio was ＜1.0, but they continued to increase. There was no follow-up specific significant difference in the CD4⁺T lymphocyte count (all P≥0.05), while there was follow-up specific significant difference in the CD4⁺T/CD8⁺T lymphocyte count ratio (all P<0.05), and the <1-year group had the highest value, followed by the 1～<5-year group and the ≥5-year group, the differences were significant (P<0.05). There were no follow-up specific significant differences in the trends between the ＜30-day subgroup and the 30-day-<1-year subgroup (all P>0.05).

Conclusion HIV/AIDS patients in Henan have increased risk for virological failure due to low-level viremia. Early initiation of treatment (within 30 days of diagnosis) can promote immune reconstitution and reduce the risk for virological failure. Clinically, it is necessary to strengthen monitoring and promote early diagnosis and treatment.