Persistent Low-level Viremia Predicts Subsequent Virologic Failure: Is It Time to Change the Third 90?

Impact of low-level viraemia on virological failure among Asian children with perinatally acquired HIV on first-line combination antiretroviral treatment: a multicentre, retrospective cohort study

INTRODUCTION

The clinical relevance of low-level viraemia (LLV) and virological outcomes among children living with HIV (CLHIV) remains controversial. This study aimed to determine the impact of LLV on virological failure (VF) among Asian CLHIV on first-line combination antiretroviral therapy (cART).

METHODS

CLHIV aged <18 years, who were on first-line cART for ≥12 months, and had virological suppression (two consecutive plasma viral load [pVL] <50 copies/mL) were included. Those who started treatment with mono/dual antiretroviral therapy, had a history of treatment interruption >14 days, or received treatment and care at sites with a pVL lower limit of detection >50 copies/mL were excluded. LLV was defined as a pVL 50 to 1000 copies/mL, and VF as a single pVL >1000 copies/mL. Baseline was the time of the second pVL < 50 copies/mL. Cox proportional hazards models were performed to assess the association between LLV and VF.

RESULTS

From January 2008 to September 2016, 508 CLHIV (55% female) were eligible for the study. At baseline, the median age was 9.6 (IQR: 7.0 to 12.3) years, cART duration was 1.4 (IQR: 1.3 to 1.8) years, 97% of CLHIV were on non-nucleoside reverse transcriptase inhibitor-based regimens, and the median CD4 was 25% (IQR: 20% to 30%). Over a median follow-up time of 6.0 (IQR: 3.1 to 8.9) years from baseline, 86 CLHIV (17%) had ever experienced LLV, of whom 32 (37%) had multiple LLV episodes. Female sex, living in Malaysia (compared to Cambodia), having family members other than biological parents/grandparents as a primary caregiver, and baseline CD4 < 25% increased risk of LLV. Overall, 115 children (23%) developed VF, corresponding to a rate of 4.0 (95%CI: 3.4 to 4.9) per 100 person-years of follow-up (PYFU). VF was greater among children who had ever experienced LLV compared with those who maintained virological suppression throughout the study period (8.9 vs. 3.3 per 100 PYFU; p < 0.001). In multivariable analyses, ever experiencing LLV was associated with increased risk of subsequent VF (adjusted hazard ratio: 3.01; 95%CI: 1.97 to 4.60).

CONCLUSIONS

LLV increased the risk of subsequent VF among Asian CLHIV who had previously been suppressed on first-line cART. Adherence interventions and additional targeted pVL monitoring may be warranted among children with LLV to facilitate early detection of VF.

Factors associated with high-risk low-level viremia leading to virologic failure: 16-year retrospective study of a Chinese antiretroviral therapy cohort

BACKGROUND

Low level viremia (LLV) often occurs during antiretroviral therapy (ART) against HIV-1. However, whether LLV increases the risk of virologic failure (VF) is controversial because of the non-uniform definitions of LLV and VF.

METHODS

A long-term first line regimen ART cohort from 2002 to 2018 from Shenyang, northeast China, was retrospectively studied. All participants were followed up every 3 to 6 months to evaluate the treatment effect. The high-risk LLV subgroups leading to VF (with strict standards) were explored with Cox proportional hazards model and linear mixed-effect model. The association factors of high-risk LLV were further explored using multivariate logistic regression analyses.

RESULTS

A total of 2155 HIV-1 infected participants were included; of these, 38.7% showed LLV. Both high level LLV (HLLV) and any other level LLV coupled with high level blip (HLB) showed higher risk of VF (hazards ratios, HR_HLLV = 5.93, and HR_HLB = 2.84, p <  0.05 respectively). Moreover, HR increased with prolonged duration of LLV. Independent factors associated with high-risk LLV included the zenith baseline viral load (VL) above 6 log copies/ml (aOR = 3.49, p = 0.002), nadir baseline CD4 + T cell counts below 200 cells/mm³ (aOR = 1.78, p = 0.011), Manchu (aOR = 2.03, p = 0.003), ART over 60 months (aOR = 1.81, p = 0.004), AZT + 3TC + NVP (aOR = 2.26, p <  0.001) or DDI-based regimen (aOR = 9.96, p = 0.002), and subtype B' infection (aOR = 8.22, p = 0.001).

CONCLUSIONS

In case of VF with strict standards, high-risk LLV leading to VF includes VL above 400 copies/ml, occurring at least once. Serious laboratory indicators or advanced stage of infection, long term ART and subtype B' infection might also predict the occurrence of high-risk LLV.

Factors associated with unsuppressed viremia in women living with HIV on lifelong ART in the multi-country US-PEPFAR PROMOTE study: A cross-sectional analysis

BACKGROUND

Despite recent efforts to scale-up lifelong combination antiretroviral therapy (cART) in sub-Saharan Africa, high rates of unsuppressed viremia persist among cART users, and many countries in the region fall short of the UNAIDS 2020 target to have 90% virally suppressed. We sought to determine the factors associated with unsuppressed viremia (defined for the purpose of this study as >200 copies/ml) among sub-Saharan African women on lifelong cART.

METHODS

This cross-sectional analysis was based on baseline data of the PROMOTE longitudinal cohort study at 8 sites in Uganda, Malawi, Zimbabwe and South Africa. The study enrolled 1987 women living with HIV who initiated lifelong cART at least 1-5 years ago. Socio-demographic, clinical, and cART adherence data were collected. We used multivariable Poisson regression with robust variance to identify factors associated with unsuppressed viremia.

RESULTS

At enrolment, 1947/1987 (98%) women reported taking cART. Of these, HIV-1 remained detectable in 293/1934 (15%), while 216/1934 (11.2%) were considered unsuppressed (>200 copies/ml). The following factors were associated with an increased risk of unsuppressed viremia: not having household electricity (adjusted prevalence risk ratio (aPRR) 1.74, 95% confidence interval (CI) 1.28-2.36, p<0.001); not being married (aPRR 1.32, 95% CI 0.99-1.78, p = 0.061), self-reported missed cART doses (aPRR 1.63, 95% CI 1.24-2.13, p<0.001); recent hospitalization (aPRR 2.48, 95% CI 1.28-4.80, p = 0.007) and experiencing abnormal vaginal discharge in the last three months (aPRR 1.88; 95% CI 1.16-3.04, p = 0.010). Longer time on cART (aPRR 0.75, 95% CI 0.64-0.88, p<0.001) and being older (aPRR 0.77, 95% CI 0.76-0.88, p<0.001) were associated with reduced risk of unsuppressed viremia.

CONCLUSION

Socioeconomic barriers such as poverty, and individual barriers like not being married, young age, and self-reported missed doses are key predictors of unsuppressed viremia. Targeted interventions are needed to improve cART adherence among women living with HIV with this risk factor profile.

Reliability of plasma HIV viral load testing beyond 24 hours: Insights gained from a study in a routine diagnostic laboratory

Background

Viral load testing is key to monitoring response to anti-retroviral therapy (ART). However, in lower and middle income countries with large epidemics, pre-analytical challenges threaten the quality of testing. It is unknown how much delayed processing and adverse storage affects the validity of results. The aim of this study was to determine the impact of delayed testing and warmer storage conditions on HIV RNA stability in diagnostic samples.

Methods

1194 samples, collected in EDTA or plasma preparation (PPT) tubes, were studied. Immediately after initial testing, primary tubes were stored for 72, 96 or 168 hours at 4°C, 20°C or 30°C. The viral load was then repeated and the 2 results were compared.

Results

Viral loads were very stable, with <0.5 log copies/ml median difference noted between paired tests for all storage times and temperatures. The viral load in samples stored for up to a week reliably differentiated between ART-suppressed and failing patients in 98.83% of instances. However, re-centrifugation immediately prior to repeat testing was essential to avoid falsely elevated readings, probably due to contamination of plasma with cell-associated viral nucleic acids. Approximately 20% of samples with initially undetectable viral loads were weakly positive (<100 copies/mL) on repeat. This was not exacerbated by duration or temperature of storage.

Conclusion

Viral RNA in diagnostic samples is stable well beyond currently recommended limits. However, when testing stored primary samples, contamination of plasma with cellular material easily occurs. Low viral loads (<100copies/mL) in samples stored in this way should be interpreted with caution.