Persistent Low-Level Viremia is an Independent Risk Factor for Virologic Failure: A Retrospective Cohort Study in China

Characteristics of drug resistance mutations in ART-experienced HIV-1 patients with low-level viremia in Zhengzhou City, China

Although most people living with HIV (PLWH) receiving antiretroviral therapy (ART) achieve continuous viral suppression, some show detectable HIV RNA as low-level viremia (LLV) (50-999 copies/mL). Drug resistance mutations (DRMs) in PLWH with LLV is of particular concern as which may lead to treatment failure. In this study, we investigated the prevalence of LLV and LLV-associated DRMs in PLWH in Zhengzhou City, China. Of 3616 ART-experienced PLWH in a long-term follow-up cohort from Jan 2022 to Aug 2023, 120 were identified as having LLV. Of these PLWH with LLV, we obtained partial pol and integrase sequences from 104 (70 from HIV-1 RNA and 34 from proviral DNA) individuals. DRMs were identified in 44 individuals. Subtyping analysis indicated that the top three subtypes were B (48.08%, 50/104), CRF07_BC (31.73%, 33/104), and CRF01_AE (15.38%, 16/104). The proportions of nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and integrase strand transfer inhibitors (INSTIs) associated DRMs were 23.83% (24/104), 35.58% (37/104), 5.77% (6/104), and 3.85% (4/104), respectively, which contributed to an overall prevalence of 42.31% (44/104). When analyzed by individual DRMs, the most common mutation(s) were V184 (18.27%, 19/104), followed by V179 (11.54%, 12/104), K103 (9.62%, 10/104), Y181 (9.62%, 10/104), M41 (7.69%, 8/104), and K65R (7.69%, 8/104). The prevalence of DRMs in ART-experienced PLWH with LLV is high in Zhengzhou City and continuous surveillance can facilitate early intervention and provision of effective treatment.

Factors Associated with Low-Level Viremia in People Living with HIV in the Italian Antiviral Response Cohort Analysis Cohort: A Case-Control Study

Despite effective antiretroviral therapies (ARTs), a subset of people living with HIV (PLWH) still experience low-level viremia (LLV, i.e., 50-1,000 copies/mL). The present study compared PLWH experiencing LLV with those maintaining virological suppression (VS) and explored the potential impact of preexisting drug resistance and other factors on LLV. We conducted a retrospective, 1:1 matched case-control study within a cohort of drug-experienced VS subjects from the Italian Antiviral Response Cohort Analysis database, followed in the period 2009-2019. Cases were individuals experiencing LLV, while controls were those who maintained VS. Matching was for calendar year of first ART regimen. Preexisting drug resistance was calculated as cumulative genotypic susceptibility score (GSS) according to regimen administered at the observational period start. To explore the effect of cumulative GSS, treated as a binary variable (≥2 and <2) and other factors on LLV, we performed a logistic regression analysis. Within a main population of 3,455 PLWH, 337 cases were selected. Cases were comparable to the controls for both gender and age. However, cases showed that they had experienced a longer time since HIV diagnosis, a higher number of drugs previously administered, lower baseline CD4+ T cell count and a higher zenith viral load (VL). By multivariate analysis, we found that higher zenith VL [adjusted odds ratio (aOR) (95% confidence interval [CI]) 1.30 (1.14-1.48)], a cumulative usage of both PI [aOR (95% CI): 2.03 (1.19-3.48)] and InSTI [aOR (95% CI): 2.23 (1.47-3.38)] and a cumulative GSS <2 [aOR (95% CI) 0.67 (0.46-0.98)], were associated with a higher risk in developing LLV. In current high-efficacy ART era, in drug-experienced PLWH, the predictors of increased risk of LLV were the presence of preexisting drug resistance, higher zenith VL, and previous PI, and InSTI exposure.

Incidence of low-level viremia and its impact on virologic failure among people living with HIV who started an integrase strand transfer inhibitors: a longitudinal cohort study

BACKGROUND

Low-level viremia (LLV) has been identified as a potential precursor to virologic failure (VF), yet its clinical implications, particularly within the context of Integrase Strand Transfer Inhibitors (INSTIs)-based regimens, remain insufficiently explored. The study aimed to investigate the relationship between LLV and VF within ART-naïve patients on INSTIs-based regimens in China.

METHODS

A longitudinal cohort study was conducted with ART-naïve patients aged ≥ 18 years at Beijing Ditan Hospital, under the Chinese National Free Antiretroviral Treatment Program (NFATP). The LLV was defined as a viral load (VL) ranging from 50 to 199 copies/mL after six months of ART initiation, and VF as a VL ≥ 200 copies/mL. Sensitive analyses were also performed, defining LLV as 50-999 copies/mL and VF as exceeding 1000 copies/mL. Multivariate logistic regression, Kaplan-Meier (KM) curve, and Generalized Estimating Equation (GEE) models were used to evaluate the risk factors associated with LLV and VF events.

RESULTS

The study involved 830 ART-naïve patients, comprising 600 in the INSTIs group and 230 in the protease inhibitors (PIs) group. LLV events were observed in 10.4% of patients on PIs-based regimens and and 3.2% on INSTIs-based regimens (P < 0.001). INSTIs-based regimens demonstrated a protective effect against LLV events (aHR = 0.27, 95% CI 0.137-0.532). VF events occurred in 10.9% of patients on PIs-based regimens and 2.0% on INSTIs-based regimens, respectively (P < 0.001). The occurrence of LLV events significantly increased the risk of VF by 123.5% (95% CI 7.5%-364.4%), while the integrase inhibitors were associated with a 76.9% (95% CI 59.1%-86.9%) reduction in VF risk.

CONCLUSION

Our findings indicate that INSTIs-based regimens are critical protective factors against LLV and subsequent VF. These results underscore the importance of HIV viral load monitoring to ensuring effective treatment outcomes, highlighting the necessity for prompt and precise monitoring to refine HIV treatment methodologies.

Drug Resistance Profile Among HIV-1 Infections Experiencing ART with Low-Level Viral Load in Guangdong China During 2011-2022: A Retrospective Study

Background

Antiretroviral therapy (ART) efficiently reduces the morbidities and mortalities caused by HIV-1 infection and prevents the HIV epidemic. However, virologic failure (VF) occurs in some patients receiving ART experience, especially increases in those patients with intermittent or persistent low-level viremia (LLV). The presence of drug resistance mutations (DRMs) in LLV was a strong predictor of subsequent VF. The data on drug resistance (DR) or DRMs for HIV-1 infections at low-level viral load (LLVL) are limited in China.

Objective

To monitor the prevalence of HIV-1 drug resistance and to evaluate the risk factors associated with drug resistance in LLVL HIV-1 infections during ART in Guangdong, China.

Methods

Plasma samples with LLVL during ART in Guangdong Province between Jan 2011 and Dec 2022 were subjected to a modified reverse-transcription PCR with a pre-step of virus concentration by ultracentrifugation before extraction and the Sanger sequencing. Then, the genotypic resistance test was performed and DR was analyzed by the Stanford HIVDB program. Finally, DR-associated factors were identified by logistic regression analysis.

Results

We found that CRF01_AE (53.57%) and CRF07_BC (25.07%) were the dominant HIV-1 genotypes in LLVL in Guangdong between 2011 and 2022 but that the percentage of CRF01_AE showed a trend of decrease over time. M46 (1.49%), M184 (30.91%), and K103 (21.46%) were the dominant PI-, NRTI-, and NNRTI-associated mutations, respectively. The total DR rate was 47.06%. Specifically, PI (3.71%) showed a significantly lower DR rate than NNRTI (40.74%) and NRTI (34.14%). Duration of ART, initial ART regimen, ethnicity, and WHO clinical stages were associated with DR.

Conclusion

The drug resistance rate among the LLVL during ART in Guangdong, China is high. The risk factors associated with HIV drug resistance should be seriously considered for better control.

Influencing factors and adverse outcomes of different virologic rebound states in antiretroviral treated HIV/AIDS patients

Antiretroviral therapy (ART) aims to inhibit HIV replication, decrease CD4 T cell loss, and immune function recovery in order to reduce the morbidity and mortality associated with the infection. Treatment should also, improve quality of life and control HIV spread. However, incomplete viral suppression still occurs during ART. Viral suppression and virological failure (VF) thresholds vary between studies in terms of virological rebound (VR) states using different detection thresholds. Further understanding of influencing factors and adverse outcomes in various VR states should provide important guidance for HIV treatment.

HIV-1 tropism in low-level viral load HIV-1 infections during HAART in Guangdong, China

Background

Since only a few studies have been conducted on the factors associated with different HIV-1 tropisms in low-level viral load HIV-1 infections in China, we investigated the sequences of HIV-1 V3 loop in prevalent HIV-1 subtypes and factors related to HIV-1 tropism and immune recovery in HIV-1 infections after 6 months of highly active antiretroviral therapy (HAART) in Guangdong, China.

Methods

Plasma samples with HIV-1 RNA of 400-999 copies/mL were collected. We analyzed the amino acid sequence of the V3 loop by in silico prediction algorithms. Mann-Whitney and Chi-square tests were used for statistical comparison. Furthermore, logistic regression and multiple linear regression were used, respectively, for factors associated with 351 HIV-1 tropism and immune recovery of 67 cases with continued CD4⁺ T cell count during HAART.

Results

There was a lower percentage of HIV-1 R5-tropic virus in CRF01_AE (66.3%) (p < 0.0001) and CRF55_01B (52.6%) (p < 0.0001) compared with both CRF07_BC (96.1%) and CRF08_BC (97.4%), respectively. Compared with the R5-tropic virus, higher proportions of IIe8/Val8, Arg11/Lys11, and Arg18/His18/Lys18 were observed in the X4-tropic virus of CRF01_AE and CRF07_BC (p < 0.0001). The baseline CD4⁺ T cell count (p < 0.0001) and baseline CD4⁺ T/CD8⁺ T ratio (p = 0.0006) of all R5-tropic infections were higher than those in the X4-tropic infection. The baseline CD4⁺ T cell count (odds ratio [OR] 0.9963, p = 0.0097), CRF07_BC (OR 0.1283, p = 0.0002), and CRF08_BC (OR 0.1124, p = 0.0381) were associated with less HIV-1 X4-tropism. The baseline CD4⁺ T cell count was a positive factor (p < 0.0001) in the recovery of CD4⁺ T cell count during HAART.

Conclusion

R5-tropism represented the majority in low-level viral load HIV-1 infections receiving HAART for more than 6 months in Guangdong, China. The baseline immune level in the HIV-1 R5-tropic infections was higher than that in the X4-tropic infections. The amino acids of the 8th, 11th, and 18th of the HIV-1 V3 loop were more variable in the X4-tropic HIV-1. CRF01_AE, CRF55_01B, and lower baseline CD4⁺ T cell count were associated with more HIV-1 X4-tropism. The immune recovery during HAART was positively related to baseline CD4⁺ T cell count.

A Concentration Method for HIV Drug Resistance Testing in Low-Level Viremia Samples

BACKGROUND

Drug resistance testing in HIV-1 low-level viremia (LLV) samples is challenging yet critical. Our study is aimed at assessing the performance of lentivirus concentration reagent (LCR) in combination with a validated Sanger sequencing (SS) for monitoring drug resistance mutations (DRMs) in LLV samples.

METHODS

A series of clinical samples were diluted and amplified for genotypic resistance testing (GRT) to prove the performance of the LCR. The Stanford HIV-1 drug resistance database (HIVdb version 8.9) was used to analyze the mutations. HIV-1 subtypes and CRFs were determined using the COMET online tool. The overall success rate of genotyping was compared with ultracentrifugation combined with SS. Furthermore, the success rates at varied VL of the two concentration methods were evaluated, and the DRMs of diluted samples were compared with those undiluted samples.

RESULTS

When LCR was used, the overall success rate was 90% (72/80) in the PR and RT regions and 60% (48/80) in the IN region. In addition, when HIV RNA was 1000 copies/ml, 400 copies/ml, 200 copies/ml, and 100 copies/ml, the success rates of PR and RT regions were 100%, 100%, 95%, and 65%, respectively, while the success rates of IN region were 85%, 60%, 45%, and 50%, respectively. We found that the sample DR-387A2 missed the E138A mutation, and mutations in other samples were consistent with undiluted samples using LCR.

CONCLUSIONS

LCR will support monitoring DRMs in HIV-1 patients with LLV and can be an effective alternative for small- and medium-sized laboratories that cannot afford an ultracentrifuge.

HIV-1 Genotypic Resistance Testing Using Sanger and Next-Generation Sequencing in Adults with Low-Level Viremia in China

OBJECTIVE

In this study, we aimed to determine drug-resistance mutations (DRMs) in HIV-1 patients with low-level viremia (LLV) and explored the performance of next-generation sequencing (NGS) in detecting HIV DRMs by using LLV samples.

METHODS

Overall, 80 samples with LLV were amplified and sequenced using a commercial Sanger sequencing (SS) genotyping kit. Furthermore, 51 samples successfully sequenced using SS were simultaneously subjected to NGS. Genotyping success rates of various viremia categories by two sequencing methods were calculated. Stanford HIV-1 drug-resistance database (HIVdb version 8.9) was used to analyze the DRMs. In the NGS assay, a threshold of 5% was considered for reporting low-frequency variants, and the DRMs detected using SS and NGS were compared.

RESULTS

The overall success rate of PR/RT regions was 88.1% (67/80) using SS and 86.3% (44/51) using NGS. Furthermore, a significant linear trend was noted between viral load and the genotyping success rate. A total of 38.8% (26/67) participants harbored at least one mutation, as revealed through SS. Moreover, the prevalence of DRMs in persistent LLV was significantly higher than that in intermittent LLV (62.1% vs. 21.1%; P < 0.05). A total of 69 DRMs were detected using the two sequencing methods at the threshold of 5%. Moreover, 10 DRMs missed by SS were detected using NGS, whereas 8 DRMs missed by NGS were detected by SS.

CONCLUSION

Our data suggested that the genotyping resistance testing is necessary to guide antiretroviral therapy optimization in LLV patients.

The Impact of Low-Level Viraemia on Virological Failure—Results From a Multicenter HIV Antiretroviral Therapy Cohort Study in Yunnan, China

Background

HIV viral load (VL) is an important indicator to monitor treatment response in antiretroviral therapy (ART). Patients on ART may experience viral blips, with low-level elevations of VL between 50 and 999 copies/mL known as low-level viraemia (LLV), but not reaching the threshold for virological failure (≥1,000 copies/mL) defined by WHO guidelines. The objective was to investigate the long-term impact of LLV on virological failure.

Methods

We analyzed adults who were ART naïve at baseline. LLV was defined as having an VL of 51–999 copies/mL at least once. The subjects with LLV were grouped into three categories: 51–199, 200–399, and 400–999 copies/mL. Patients with multiple episodes of LLV were classified based on the highest VL result. The subjects with LLV were also grouped by the frequency of LLV, i.e., a single episode, two consecutive episodes, two intermittent episodes, more than two consecutive episodes, and more than two intermittent episodes. Multivariable Cox models were used to predict the association of LLV with virological failure.

Results

A total of 93,944 subjects were included. The median number of VL tests performed was 3. There were 21,203 LLV cases, with an overall incidence of 22.6%. Most of the LLV cases were found in subjects with LVs of 50–199 copies/mL, followed by 400–999 and 200–399 copies/mL. Most of the LLV cases experienced single episodes, and the numbers of LLV with two consecutive episodes, two intermittent episodes, more than two consecutive episodes and more than two intermittent episodes were decreased successively. The risk factors associated with virological failure include: intermediate-level (200–399 copies/mL) and high-level (400–999 copies/mL) LLV, single episodes of LLV and two or more than two consecutive episodes of LLV, which may put the subjects at a 1.28–2.26-fold higher risk for virological failure.

Conclusion

Strengthened immediate medical attention should be placed on patients with VL of 200–999 copies/mL. The patients having experienced LLV once should be targeted for case management and repeat VL testing within 24 weeks to determine persistent LLV and monitor virological failure.

More HIV-1 RNA detected and quantified with the Cobas 6800 system in patients on antiretroviral therapy

BACKGROUND

Target-detected (TD) results or low-level viraemia (LLV) can be observed in HIV-1 patients on ART, which regularly raises questions.

OBJECTIVES

We describe here the impact on HIV-1 RNA quantification of switching from the COBAS AmpliPrep/COBAS TaqMan (CAP/CTM) to the Cobas 6800 system (C6800), based on analyses of viraemia close to the lower limit of quantification (LLoQ).

PATIENTS AND METHODS

We retrospectively selected two groups of patients: 200 individuals whose viral loads (VLs) were consistently <50 copies/mL with CAP/CTM for at least 3 years before switching to C6800 (group 1), and 35 other patients with confirmed LLV when C6800 was in use (group 2). In both groups, we compared several consecutive VL results performed before and after the change of quantification assay. Analyses were performed with McNemar's paired tests or Fisher's exact tests.

RESULTS

In group 1, the frequency of TD results (below or above the LLoQ) increased significantly after the switch to C6800 for patients with <25% of results being TD for VLs performed with CAP/CTM (P < 0.0001). Significantly more patients had at least one VL ≥20 or ≥50 copies/mL with C6800, in both group 1 (37.0% versus 18.5%; P < 0.0001 and 6.5% versus 0%; P = 0.0009, respectively) and group 2 (100% versus 66%; P = 0.0015 and 97% versus 40%; P < 0.0001, respectively).

CONCLUSIONS

C6800 revealed residual or low-level HIV-1 RNA that was not detected with CAP/CTM, resulting in twice as many patients being found to have a VL ≥20 copies/mL. Physicians and patients should be aware of possible differences in results between assays, and it is crucial to specify the quantitative assay used in studies.