Viremia copy-years as a predictive marker of all-cause mortality in HIV-1-infected patients initiating a protease inhibitor-containing antiretroviral treatment

Systematic review on cumulative HIV viraemia among people living with HIV receiving antiretroviral treatment and its association with mortality and morbidity

BACKGROUND

We performed a systematic review to generate evidence on the association between cumulative human immunodeficiency virus (HIV) viraemia and health outcomes.

METHODS

Quantitative studies reporting on HIV cumulative viraemia (CV) and its association with health outcomes among people living with HIV (PLHIV) on antiretroviral treatment (ART) were included. We searched MEDLINE via PubMed, Embase, Scopus and Web of Science and conference abstracts from 1 January 2008 to 1 August 2022.

RESULTS

The systematic review included 26 studies. The association between CV and mortality depended on the study population, methods used to calculate CV and its level. Higher CV was not consistently associated with greater risk of acquire immunodeficiency syndrome-defining clinical conditions. However, four studies present a strong relationship between CV and cardiovascular disease. The risk was not confirmed in relation of increased hazards of stroke. Studies that assessed the effect of CV on the risk of cancer reported a positive association between CV and malignancy, although the effect may differ for different types of cancer.

CONCLUSIONS

CV is associated with adverse health outcomes in PLHIV on ART, especially at higher levels. However, its role in clinical and programmatic monitoring and management of PLHIV on ART is yet to be established.

Comparison of Stage I Non-Small-Cell Lung Cancer Treatments for Patients Living With HIV: A Simulation Study

INTRODUCTION

Non-small-cell lung cancer (NSCLC) is a leading cause of death for people living with HIV (PWH). Nevertheless, there are no clinical trial data regarding the management of early-stage lung cancer in PWH. Using data from large HIV and cancer cohorts we parameterized a simulation model to compare treatments for stage I NSCLC according to patient characteristics.

MATERIALS AND METHODS

To parameterize the model we analyzed PWH and NSCLC patient outcomes and quality of life data from several large cohort studies. Comparative effectiveness of 4 stage I NSCLC treatments (lobectomy, segmentectomy, wedge resection, and stereotactic body radiotherapy) was estimated using evidence synthesis methods. We then simulated trials comparing treatments according to quality adjusted life year (QALY) gains by age, tumor size and histology, HIV disease characteristics and major comorbidities.

RESULTS

Lobectomy and segmentectomy yielded the greatest QALY gains among all simulated age, tumor size and comorbidity groups. Optimal treatment strategies differed by patient sex, age, and HIV disease status; wedge resection was among the optimal strategies for women aged 80 to 84 years with tumors 0 to 2 cm in size. Stereotactic body radiotherapy was included in some optimal strategies for patients aged 80 to 84 years with multimorbidity and in sensitivity analyses was a non-inferior option for many older patients or those with poor HIV disease control.

CONCLUSION

In simulated comparative trials of treatments for stage I NSCLC in PWH, extensive surgical resection was often associated with the greatest projected QALY gains although less aggressive strategies were predicted to be non-inferior in some older, comorbid patient groups.

Cumulative Human Immunodeficiency Virus (HIV)-1 Viremia Is Associated With Increased Risk of Multimorbidity Among US Women With HIV, 1997-2019

Background

To evaluate the effect of cumulative human immunodeficiency virus (HIV)-1 viremia on aging-related multimorbidity among women with HIV (WWH), we analyzed data collected prospectively among women who achieved viral suppression after antiretroviral therapy (ART) initiation (1997-2019).

Methods

We included WWH with ≥2 plasma HIV-1 viral loads (VL) <200 copies/mL within a 2-year period (baseline) following self-reported ART use. Primary outcome was multimorbidity (≥2 nonacquired immune deficiency syndrome comorbidities [NACM] of 5 total assessed). The trapezoidal rule calculated viremia copy-years (VCY) as area-under-the-VL-curve. Cox proportional hazard models estimated the association of time-updated cumulative VCY with incident multimorbidity and with incidence of each NACM, adjusting for important covariates (eg, age, CD4 count, etc).

Results

Eight hundred six WWH contributed 6368 women-years, with median 12 (Q1-Q3, 7-23) VL per participant. At baseline, median age was 39 years, 56% were Black, and median CD4 was 534 cells/mm3. Median time-updated cumulative VCY was 5.4 (Q1-Q3, 4.7-6.9) log10 copy-years/mL. Of 211 (26%) WWH who developed multimorbidity, 162 (77%) had incident hypertension, 133 (63%) had dyslipidemia, 60 (28%) had diabetes, 52 (25%) had cardiovascular disease, and 32 (15%) had kidney disease. Compared with WWH who had time-updated cumulative VCY <5 log10, the adjusted hazard ratio of multimorbidity was 1.99 (95% confidence interval [CI], 1.29-3.08) and 3.78 (95% CI, 2.17-6.58) for those with VCY 5-6.9 and ≥7 log10 copy-years/mL, respectively (P < .0001). Higher time-updated cumulative VCY increased the risk of each NACM.

Conclusions

Among ART-treated WWH, greater cumulative viremia increased the risk of multimorbidity and of developing each NACM, and hence this may be a prognostically useful biomarker for NACM risk assessment in this population.

Analyzing Longitudinally Collected Viral Load Measurements in Youth With Perinatally Acquired HIV Infection: Problems and Possible Remedies

Human immunodeficiency virus (HIV) viral load (VL) is an important quantitative marker of disease progression and treatment response in people living with HIV infection, including children with perinatally acquired HIV. Measures of VL are often used to predict different outcomes of interest in this population, such as HIV-associated neurocognitive disorder. One popular approach to summarizing historical viral burden is the area under a time-VL curve (AUC). However, alternative historical VL summaries (HVS) may better answer the research question of interest. In this article, we discuss and contrast the AUC with alternative HVS, including the time-averaged AUC, duration of viremia, percentage of time with suppressed VL, peak VL, and age at peak VL. Using data on youth with perinatally acquired HIV infection from the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol, we show that HVS and their associations with full-scale intelligence quotient depend on when the VLs were measured. When VL measurements are incomplete, as can be the case in observational studies, analysis results may be subject to selection bias. To alleviate bias, we detail an imputation strategy, and we present a simulation study demonstrating that unbiased estimation of a historical VL summary is possible with a correctly specified imputation model.

Cumulative HIV Viremia Copy-Years and Hypertension in People Living with HIV

BACKGROUND

Evidence regarding the association between HIV viral load (VL) and hypertension is inconsistent. In this study, we investigated the relationship using viremia copy-years (VCY), a cumulative measure of HIV plasma viral burden.

METHODS

Data were analyzed for 686 PLWH in the Florida Cohort Study, who had at least five years of VL data before the baseline. VL data were extracted from Enhanced HIV/AIDS Reporting System (eHARS) and used to define peak VL (pVL), recent VL (rVL), and undetectable VL (uVL: rVL<50copies/mL). A five-year VCY (log10 copy × years/mL) before the baseline investigation, was calculated and divided into 5 groups (≤2.7, 2.8-3.7, 3.8-4.7, 4.8-5.7 and >5.7) for analysis. Hypertension was determined based on hypertension diagnosis from medical records. Multivariable logistic regression was used for association analysis.

RESULTS

Of the total sample, 277 (40.4%) participants were hypertensive. Compared to the participants with lowest VCY (≤2.7 log10 copy × years/mL), the odds ratios (OR) and 95% confidence interval [95% CI] for hypertension of the remaining four groups, in order, were 1.91 [1.11, 3.29], 1.91 [1.03, 3.53], 2.27 [1.29, 3.99], and 1.25 [0.65, 2.42], respectively, controlling for confounders. The association was independent of pVL, rVL, and uVL, each of which was not significantly associated with hypertension.

CONCLUSION

Persistent HIV infection is a risk factor for hypertension among PLWH. Information provided by VCY is more effective than single time-point VL measures in investigating HIV infection- hypertension relationship. The findings of this study support the significance of continuous viral suppression in hypertension prevention among PLWH.

HIV viral exposure and mortality in a multicenter ambulatory HIV adult cohort, United States, 1995-2016

The aim of this study was to identify viral exposure (VE) measures and their relationship to mortality risk among persons with HIV.Prospective multicenter observational study to compare VE formulae.Eligible participants initiated first combination antiretroviral therapy (cART) between March 1, 1995 and June 30, 2015. We included 1645 participants followed for ≥6 months after starting first cART, with cART prescribed ≥75% of time, who underwent ≥2 plasma viral load (VL) and ≥1 CD4+ T-lymphocyte cell (CD4) measurement during observation. We evaluated all-cause mortality from 6 months after cART initiation until June 30, 2016. VE was quantified using 2 time-updated variables: viremia copy-years and percent of person-years (%PY) spent >200 or 50 copies/mL. Cox models were fit to estimate associations between VE and mortality.Participants contributed 10,453 person years [py], with median 14 VLs per patient. Median %PY >200 or >50 were 10% (interquartile range: 1%-47%) and 26% (interquartile range: 6%-72%), respectively. There were 115 deaths, for an overall mortality rate of 1.19 per 100 person years. In univariate models, each measure of VE was significantly associated with mortality risk, as were older age, public insurance, injection drug use HIV risk history, and lower pre-cART CD4. Based on model fit, most recent viral load and %PY >200 copies/mL provided the best combination of VE factors to predict mortality, although all VE combinations evaluated performed well.The combination of most recent VL and %PY >200 copies/mL best predicted mortality, although all evaluated VE measures performed well.

Copy-Years Viremia and Risk of Virological Failure in Long-Term-Treated HIV Patients

BACKGROUND

Viremia copy-years (VCY) is associated with mortality and disease outcome prediction. This study evaluated the association of VCY with virological failure (VF), defined as a plasma viral load (pVL) >400 copies/mL, and with single levels of viremia.

METHODS

Eight hundred and fifty antiretroviral therapy (ART)-treated patients with pVL < 37 copies/mL [target not detected or target detected (TD)] or >37, but less than 200 copies/mL (low-level viremia), and at least 6-pVL measures during 54 months of follow-up were selected. VCY was calculated individually over the follow-up as the area under pVL curve. Pearson's χ test was used to analyze differences in VCY quartiles distribution between groups.

RESULTS

Higher VCY values were detected in patients with low-level viremia {294 copy-years [interquartile range (IQR): 99-1870]} than in TD [52 copy-years (IQR: 53-153)] and target not detected groups [19 copy-years (IQR: 8-54)]. VCY was also significantly different between patients with undetectable viremia and patients with basal pVL TD (P < 0.001). Pearson's χ test revealed a significant association between VCY and basal levels of viremia (P < 0.0001). In addition, the risk of VF rose with increasing VCY (Hazard ratio 1.01, 95% confidence interval: 1.01 to 1.02).

CONCLUSIONS

This study revealed the association of VCY with VF and with single levels of viremia suggesting that, despite the success of ART, minimal residual viremia may cause the cumulative viral burden to rise. Full viral load suppression during ART is crucial to limit the increase in VCY.

Bias in the estimation of cumulative viremia in cohort studies of HIV-infected individuals

PURPOSE

The use of cumulative measures of exposure to raised HIV viral load (viremia copy-years) is increasingly common in HIV prevention and treatment epidemiology due to the association of long-term elevated viral load with more rapid progression to disease. We sought to estimate the magnitude and direction of bias in a cumulative measure of viremia caused by different frequency of sampling and duration of follow-up.

METHODS

We simulated longitudinal viral load measures and reanalyzed cohort study data sets with longitudinal viral load measurements under different sampling strategies to estimate cumulative viremia.

RESULTS

In both simulated and observed data, estimates of cumulative viremia by the trapezoidal rule show systematic upward bias when there are fewer sampling time points and/or increased duration between sampling time points, compared with estimation of full time series. Absolute values of cumulative viremia vary appreciably by the patterns of viral load over time, even after adjustment for total duration of follow-up.

CONCLUSIONS

Sampling bias due to differential frequency of sampling appears extensive and of meaningful magnitude in measures of cumulative viremia. Cumulative measures of viremia should be used only in studies with sufficient frequency of viral load measures and always as relative measures.

Cumulative Human Immunodeficiency Viremia, Antiretroviral Therapy, and Incident Myocardial Infarction

BACKGROUND

People living with HIV are at risk of increased myocardial infarction (MI). Cumulative HIV viral load (VL) has been proposed as a better measure of HIV inflammation than other measures of VL, like baseline VL, but its associations with MI are not known.

METHODS

The multisite Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort includes clinical data and centrally adjudicated MI with distinction between atheroembolic MI (type 1) and MI related to supply-demand mismatch (type 2). We examined CNICS participants who were not on antiretroviral therapy (ART) at enrollment. Cumulative VL (copy-days of virus) from 6 months after enrollment was estimated with a time-weighted sum using the trapezoidal rule. We modeled associations of cumulative and baseline VL with MI by type using marginal structural Cox models. We contrasted the 75% percentile of the VL distribution with the 25% percentile.

RESULTS

Among 11,324 participants, 218 MIs occurred between 1996 and 2016. Higher cumulative VL was associated with risk of all MI (hazard ratio [HR] = 1.72; 95% confidence interval [CI] = 1.26, 2.36), type 1 MI (HR = 1.23; 95% CI = 0.78, 1.96), and type 2 MI (HR = 2.52; 95% CI = 1.74, 3.66). While off ART, cumulative VL had a stronger association with type 1 MI (HR = 2.13; 95% CI = 1.15, 3.94) than type 2 MI (HR = 1.25; 95% CI = 0.70, 2.25). Baseline VL was associated with all MI (HR = 1.60; 95% CI = 1.28, 2.01), type 1 MI (HR = 1.73; 95% CI = 1.26, 2.38), and type 2 MI (HR = 1.51; 95% CI = 1.10, 2.08).

CONCLUSIONS

Higher cumulative and baseline VL is associated with all MI, with a particularly strong association between cumulative VL and type 2 MI.

Viremia copy-years and mortality among combination antiretroviral therapy-initiating HIV-positive individuals: how much viral load history is enough?

OBJECTIVE

Ongoing HIV replication while receiving combination antiretroviral therapy (cART) may reduce survival. Viremia copy-years (VCY) has shown improved mortality risk prediction over single time-point viral load measures. However, the timing of a patient's viral load history most associated with later mortality has not been studied. Here we determined the optimal duration and temporality of viral load history for predicting mortality.

DESIGN

Survival analysis among HIV-positive men who initiated cART in the Multicenter AIDS Cohort Study (1995-2015).

METHODS

VCY measures were derived from area-under-the-viral load-curve. The overall VCY based upon the complete post-cART viral load history was compared with 20 VCYs derived from viral loads assessed during different shorter time periods (the most recent 1-10 years and initial 1-10 years following cART initiation) for associations with mortality.

RESULTS

Each 10-fold increase in VCYs based on the most recent 3-8 years was significantly associated with 23-26% decrease in survival times, a magnitude of effect greater than that of the most recent viral load (16%). These associations were independent of CD4 cell count and single time-point viral loads. In addition, the degree of pre-cART immunodeficiency did not affect the mortality prognostic value of VCY based on viral loads in the most recent 3 years. Conversely, the overall VCY and VCYs based on viral loads immediately following cART initiation were not independent predictors of mortality.

CONCLUSION

Among cART-treated men, VCY based upon viral loads in the recent 3 years (six viral loads) has a mortality prognostic value greater than that of the overall VCY and single time-point viral loads, making the former a more feasible measure for use.

Marginal Structural Models to Assess Delays in Second-Line HIV Treatment Initiation in South Africa

Background

South African HIV treatment guidelines call for patients who fail first-line antiretroviral therapy (ART) to be switched to second-line ART, yet logistical issues, clinician decisions and patient preferences make delay in switching to second-line likely. We explore the impact of delaying second-line ART after first-line treatment failure on rates of death and virologic failure.

Methods

We include patients with documented virologic failure on first-line ART from an observational cohort of 9 South African clinics. We explored predictors of delayed second-line switch and used marginal structural models to analyze rates of death following first-line failure by categorical time to switch to second-line. Cox proportional hazards models were used to examine virologic failure on second-line ART among patients who switched to second-line.

Results

5895 patients failed first-line ART, and 63% switched to second-line. Among patients who switched, median time to switch was 3.4 months (IQR: 1.1–8.7 months). Longer time to switch was associated with higher CD4 counts, lower viral loads and more missed visits prior to first-line failure. Worse outcomes were associated with delay in second-line switch among patients with a peak CD4 count on first-line treatment ≤100 cells/mm³. Among these patients, marginal structural models showed increased risk of death (adjusted HR for switch in 6–12 months vs. 0–1.5 months = 1.47 (95% CI: 0.94–2.29), and Cox models showed increased rates of second-line virologic failure despite the presence of survivor bias (adjusted HR for switch in 3–6 months vs. 0–1.5 months = 2.13 (95% CI: 1.01–4.47)).

Conclusions

Even small delays in switch to second-line ART were associated with increased death and second-line failure among patients with low CD4 counts on first-line. There is opportunity for healthcare providers to switch patients to second-line more quickly.

Low-level viraemia, measured as viraemia copy-years, as a prognostic factor for medium-long-term all-cause mortality: a MASTER cohort study

OBJECTIVES

We investigated the association between persistent low-level viraemia, measured as viraemia copy-years (VCY), and all-cause mortality.

METHODS

We included 3271 HIV-infected patients who initiated their first combined ART (cART) during 1998-2012 enrolled in the multicentre Italian MASTER cohort. VCY was defined as the area under the curve of plasma viral load (pVL) and expressed in log₁₀ copies · years/mL. VCY was evaluated from cART initiation until the end of follow-up [VCY-overall (VCY-o)], and stratified into before [VCY-early (VCY-e)] and after [VCY-late (VCY-l)] the eighth month from starting cART, and as the ratio of VCY-l to follow-up duration (VCY-l/FUD).

RESULTS

The risk of death increased of about 40% for higher than the median levels of VCY-o and VCY-e. Compared with subjects with permanently suppressed pVL after the eighth month from starting cART, mortality increased by 70% for those with VCY-l ≥3 log₁₀ copies·years/mL, and by about 20-fold for those with VCY-l/FUD ≥2.3 log₁₀ copies/mL. Patients who maintained low levels of VCY-l (<3 log₁₀ copies · years/mL) or VCY-l/FUD (<2.3 log₁₀ copies/mL) had a risk of death similar to patients with permanently suppressed pVL. CD4 cell count at baseline was predictive of high risk of death only in subjects with VCY-l ≥3 log₁₀ copies · years/mL.

CONCLUSIONS

The risk of death did not increase in HIV-infected patients with low levels of VCY-l compared with patients with permanent virological suppression.

Associations between HIV-RNA-based indicators and virological and clinical outcomes

OBJECTIVES

To evaluate and compare the performance of six HIV-RNA-based quality of care indicators for predicting short-term and long-term outcomes.

DESIGN

Multinational cohort study.

METHODS

We included EuroSIDA patients on antiretroviral therapy (ART) with at least three viral load measurements after baseline (the latest of 01/01/2001 or entry into EuroSIDA). Using multivariate Poisson regression, we modelled the association between short-term (resistance, triple-class failure) and long-term (all-cause mortality, any AIDS/non-AIDS clinical event) outcomes and the indicators: viraemia copy years; consecutive months with viral load ≥ 50 copies/ml; percentage of time on ART spent fully suppressed (%FS); stable on ART; 48 weeks snapshot; and current viral load. Indicators were compared using area under the ROC curve (AUC) and different measures of model fit.

RESULTS

Adjusted incidence rate ratios for all outcomes tended to increase with increasing viraemia copy years, number of consecutive months with viral load ≥ 50 copies/ml, current viral load and with lower %FS, but the gradient of increased risk was weak across strata. None of the indicators reliably identified those at risk of long-term outcomes (AUC 0.54-0.58), but performed consistently better with short-term outcomes [triple class failure (AUC 0.67-0.76) and resistance (AUC 0.64-0.79)]. Goodness of fit varied with the outcome evaluated, but differences between indicators were small.

CONCLUSION

Differences between quality of care indicators were small and no indicator performed consistently better than current viral load. Given the simplicity in assessing and interpreting this indicator, we propose to use current viral load when HIV-RNA-based indicators are used to evaluate the efficacy of ART programs.

Reevaluating Cumulative HIV-1 Viral Load as a Prognostic Predictor: Predicting Opportunistic Infection Incidence and Mortality in a Ugandan Cohort

Recent studies have evaluated cumulative human immunodeficiency virus type 1 (HIV-1) viral load (cVL) for predicting disease outcomes, with discrepant results. We reviewed the disparate methodological approaches taken and evaluated the prognostic utility of cVL in a resource-limited setting. Using data on the Infectious Diseases Institute (Makerere University, Kampala, Uganda) cohort, who initiated antiretroviral therapy in 2004-2005 and were followed up for 9 years, we calculated patients' time-updated cVL by summing the area under their viral load curves on either a linear scale (cVL1) or a logarithmic scale (cVL2). Using Cox proportional hazards models, we evaluated both metrics as predictors of incident opportunistic infections and mortality. Among 489 patients analyzed, neither cVL measure was a statistically significant predictor of opportunistic infection risk. In contrast, cVL2 (but not cVL1) was a statistically significant predictor of mortality, with each log10 increase corresponding to a 1.63-fold (95% confidence interval: 1.02, 2.60) elevation in mortality risk when cVL2 was accumulated from baseline. However, whether cVL is predictive or not hinges on difficult choices surrounding the cVL metric and statistical model employed. Previous studies may have suffered from confounding bias due to their focus on cVL1, which strongly correlates with other variables. Further methodological development is needed to illuminate whether the inconsistent predictive utility of cVL arises from causal relationships or from statistical artifacts.