Cumulative viral load and virologic decay patterns after antiretroviral therapy in HIV-infected subjects influence CD4 recovery and AIDS

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.

Viral rebound occurrence immediately after drug discontinuation involving neither drug resistance nor latent reservoir

Some viruses exhibit "rebound" when the administration of antiviral drugs is discontinued. Viral rebound caused by resistance mutations or latent reservoirs has been studied mathematically. In this study, we investigated the viral rebound due to other causes. Since immunity is weaker during antiviral treatment than without the treatment, drug discontinuation may lead to an increase in the viral load. We analyzed the dynamics of the number of virus-infected cells, cytotoxic T lymphocytes, and memory cells and identified the conditions under which the viral load increased upon drug discontinuation. If drug is administered for an extended period, a viral rebound occurs when the ratio of viral growth rate in the absence to that in the presence of the antiviral drug exceeds the "rebound threshold." We analyzed how the rebound threshold depended on the patient's conditions and the type of treatment. Mathematical and numerical analyses revealed that rebound after discontinuation was more likely to occur when the drug effectively reduced viral proliferation, drug discontinuation was delayed, and the processes activating immune responses directly were stronger than those occurring indirectly through immune memory formation. We discussed additional reasons for drugs to cause viral rebound more likely.

Determinants of Immunovirological Response among Children and Adolescents Living with HIV-1 in the Central Region of Cameroon

About 90% of new HIV-1 infections in children occur in sub-Saharan Africa, where treatment monitoring remains suboptimal. We sought to ascertain factors associated with immunovirological responses among an ART-experienced paediatric population in Cameroon. A laboratory-based and analytical study was conducted from January 2017 throughout December 2020 wherein plasma viral load (PVL) analyses and CD4 cell counts were performed. Viral suppression (VS) was defined as PVL < 1000 copies/mL and immunological failure (IF) as CD4 < 500 cells/µL for participants ≤5 years and CD4 < 250 cells/µL for those >5 years; p < 0.05 was considered statistically significant. Overall, 272 participants were enrolled (median age: 13 [9-15.5] years; 54% males); median ART duration 7 [3-10] years. Globally, VS was achieved in 54.41%. VS was 56.96% in urban versus 40.48% in rural areas (p = 0.04). IF was 22.43%, with 15.79% among participants ≤5 years and 22.92% among those >5 years (p = 0.66). IF was 20.43% in urban versus 33.33% in rural areas (p = 0.10). Following ART, IF was 25.82% on first-line (non-nucleoside reverse transcriptase inhibitors; NNRTI-based) versus 10.17% on second-line (protease inhibitor-based) regimens (p = 0.01). Interestingly, IF was 7.43% among virally suppressed versus 40.32% among virally unsuppressed participants (p < 0.0001). A low VS indicates major challenges in achieving AIDS' elimination in this paediatric population, especially in rural settings and poor immune statuses. Scaling up NNRTI-sparing regimens alongside close monitoring would ensure optimal therapeutic outcomes.

Temporal Pattern of the Emergence of a Mutant Virus Escaping Cross-Immunity and Stochastic Extinction Within a Host

A high mutation rate of the RNA virus results in the emergence of novel mutants that may escape the immunity activated by the original (wild-type) strain. However, many of them go extinct because of the stochasticity due to the small initial number of infected cells. In a previous paper, we studied the probability of escaping stochastic extinction when the novel mutant has a faster rate of infection and when it is resistant to a drug that suppresses the wild-type virus. In this study, we examine the effect of escaping the immune reaction of the host. Based on a continuous-time branching process with time-dependent rates, we conclude the chance for a mutant strain to be established [Formula: see text] decreases with time [Formula: see text] since the wild-type infection when the mutant is produced. The number of novel mutants that can escape extinction risk has a peak soon after the wild-type infection. The number of novel escape mutations produced per patient in the early phase of host infection is small both for very strong and very weak immune responses, and it attains its maximum value when immune activity is of an intermediate strength.

Immune resilience despite inflammatory stress promotes longevity and favorable health outcomes including resistance to infection

Some people remain healthier throughout life than others but the underlying reasons are poorly understood. Here we hypothesize this advantage is attributable in part to optimal immune resilience (IR), defined as the capacity to preserve and/or rapidly restore immune functions that promote disease resistance (immunocompetence) and control inflammation in infectious diseases as well as other causes of inflammatory stress. We gauge IR levels with two distinct peripheral blood metrics that quantify the balance between (i) CD8+ and CD4+ T-cell levels and (ii) gene expression signatures tracking longevity-associated immunocompetence and mortality-associated inflammation. Profiles of IR metrics in ~48,500 individuals collectively indicate that some persons resist degradation of IR both during aging and when challenged with varied inflammatory stressors. With this resistance, preservation of optimal IR tracked (i) a lower risk of HIV acquisition, AIDS development, symptomatic influenza infection, and recurrent skin cancer; (ii) survival during COVID-19 and sepsis; and (iii) longevity. IR degradation is potentially reversible by decreasing inflammatory stress. Overall, we show that optimal IR is a trait observed across the age spectrum, more common in females, and aligned with a specific immunocompetence-inflammation balance linked to favorable immunity-dependent health outcomes. IR metrics and mechanisms have utility both as biomarkers for measuring immune health and for improving health outcomes.

Evaluation of Clinical Biomarkers Related to CD4 Recovery in HIV-Infected Patients—5-Year Observation

Human Immunodeficiency Virus infection leads to the impairment of immune system function. Even long-term antiretroviral therapy uncommonly leads to the normalization of CD4 count and CD4:CD8 ratio. The aim of this study was to evaluate possible clinical biomarkers which may be related to CD4 and CD4:CD8 ratio recovery among HIV-infected patients with long-term antiretroviral therapy. The study included 68 HIV-infected patients undergoing sustained antiretroviral treatment for a minimum of 5 years. Clinical biomarkers such as age, gender, advancement of HIV infection, coinfections, comorbidities and applied ART regimens were analyzed in relation to the rates of CD4 and CD4:CD8 increase and normalization rates. The results showed that higher rates of CD4 normalization are associated with younger age (p = 0.034), higher CD4 count (p = 0.034) and starting the therapy during acute HIV infection (p = 0.012). Higher rates of CD4:CD8 ratio normalization are correlated with higher CD4 cell count (p = 0.022), high HIV viral load (p = 0.006) and acute HIV infection (p = 0.013). We did not observe statistically significant differences in CD4 recovery depending on gender, HCV/HBV coinfections, comorbidities and opportunistic infections. The obtained results advocate for current recommendations of introducing antiretroviral therapy as soon as possible, preferably during acute HIV infection, since it increases the chances of sufficient immune reconstruction.

Viraemic-time predicts mortality among people living with HIV on second-line antiretroviral treatment in Myanmar: A retrospective cohort study

INTRODUCTION

Despite HIV viral load (VL) monitoring being serial, most studies use a cross-sectional design to evaluate the virological status of a cohort. The objective of our study was to use a simplified approach to calculate viraemic-time: the proportion of follow-up time with unsuppressed VL above the limit of detection. We estimated risk factors for higher viraemic-time and whether viraemic-time predicted mortality in a second-line antiretroviral treatment (ART) cohort in Myanmar.

METHODS

We conducted a retrospective cohort analysis of people living with HIV (PLHIV) who received second-line ART for a period >6 months and who had at least two HIV VL test results between 01 January 2014 and 30 April 2018. Fractional logistic regression assessed risk factors for having higher viraemic-time and Cox proportional hazards regression assessed the association between viraemic-time and mortality. Kaplan-Meier curves were plotted to illustrate survival probability for different viraemic-time categories.

RESULTS

Among 1,352 participants, 815 (60.3%) never experienced viraemia, and 172 (12.7%), 214 (15.8%), and 80 (5.9%) participants were viraemic <20%, 20-49%, and 50-79% of their total follow-up time, respectively. Few (71; 5.3%) participants were ≥80% of their total follow-up time viraemic. The odds for having higher viraemic-time were higher among people with a history of injecting drug use (aOR 2.01, 95% CI 1.30-3.10, p = 0.002), sex workers (aOR 2.10, 95% CI 1.11-4.00, p = 0.02) and patients treated with lopinavir/ritonavir (vs. atazanavir; aOR 1.53, 95% CI 1.12-2.10, p = 0.008). Viraemic-time was strongly associated with mortality hazard among those with 50-79% and ≥80% viraemic-time (aHR 2.92, 95% CI 1.21-7.10, p = 0.02 and aHR 2.71, 95% CI 1.22-6.01, p = 0.01). This association was not observed in those with viraemic-time <50%.

CONCLUSIONS

Key populations were at risk for having a higher viraemic-time on second-line ART. Viraemic-time predicts clinical outcomes. Differentiated services should target subgroups at risk for a higher viraemic-time to control both HIV transmission and mortality.

Virulence of a virus: How it depends on growth rate, effectors, memory cells, and immune escape

A viral strain may infect a host, proliferate rapidly, become controlled by immune reactions, and eventually be eliminated from the body. The virulence, or the magnitude of harm to the host due to infection, depends on the abundance and duration of the viral strain in the body, and the importance of the damaged tissue of the host. In this study, we investigated how the cumulative viral load (time-integral of the number of infected cells) depends on various factors, such as the viral growth rate, the effectiveness of immune cells to kill infected cells, speed of immune activation, formation of memory cells, and longevity of immune cells. In addition, viruses may produce a mutant with different antigen types, escape the immune reaction targeting the original type, and inflate virulence. We succeeded in deriving simple and explicit formulas of the virulence in four different parameter regions. We found that, in some parameter region, enhancing memory cells is very effective in suppressing virulence, but direct activation of immune effector cells is not effective; while the opposite is the case in other regions. The result could be important in designing drug suppressing virus effectively. Additionally, we discussed the reported correlation between virulence and molecular evolution rate.

Immunologic resilience and COVID-19 survival advantage

BACKGROUND

The risk of severe coronavirus disease 2019 (COVID-19) varies significantly among persons of similar age and is higher in males. Age-independent, sex-biased differences in susceptibility to severe COVID-19 may be ascribable to deficits in a sexually dimorphic protective attribute that we termed immunologic resilience (IR).

OBJECTIVE

We sought to examine whether deficits in IR that antedate or are induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection independently predict COVID-19 mortality.

METHODS

IR levels were quantified with 2 novel metrics: immune health grades (IHG-I [best] to IHG-IV) to gauge CD8+ and CD4+ T-cell count equilibrium, and blood gene expression signatures. IR metrics were examined in a prospective COVID-19 cohort (n = 522); primary outcome was 30-day mortality. Associations of IR metrics with outcomes in non-COVID-19 cohorts (n = 13,461) provided the framework for linking pre-COVID-19 IR status to IR during COVID-19, as well as to COVID-19 outcomes.

RESULTS

IHG-I, tracking high-grade equilibrium between CD8+ and CD4+ T-cell counts, was the most common grade (73%) among healthy adults, particularly in females. SARS-CoV-2 infection was associated with underrepresentation of IHG-I (21%) versus overrepresentation (77%) of IHG-II or IHG-IV, especially in males versus females (P < .01). Presentation with IHG-I was associated with 88% lower mortality, after controlling for age and sex; reduced risk of hospitalization and respiratory failure; lower plasma IL-6 levels; rapid clearance of nasopharyngeal SARS-CoV-2 burden; and gene expression signatures correlating with survival that signify immunocompetence and controlled inflammation. In non-COVID-19 cohorts, IR-preserving metrics were associated with resistance to progressive influenza or HIV infection, as well as lower 9-year mortality in the Framingham Heart Study, especially in females.

CONCLUSIONS

Preservation of immunocompetence with controlled inflammation during antigenic challenges is a hallmark of IR and associates with longevity and AIDS resistance. Independent of age, a male-biased proclivity to degrade IR before and/or during SARS-CoV-2 infection predisposes to severe COVID-19.

Cumulative viral load as a predictor of CD4+ T-cell response to antiretroviral therapy using Bayesian statistical models

INTRODUCTION

There are Challenges in statistically modelling immune responses to longitudinal HIV viral load exposure as a function of covariates. We define Bayesian Markov Chain Monte Carlo mixed effects models to incorporate priors and examine the effect of different distributional assumptions. We prospectively fit these models to an as-yet-unpublished data from the Tshwane District Hospital HIV treatment clinic in South Africa, to determine if cumulative log viral load, an indicator of long-term viral exposure, is a valid predictor of immune response.

METHODS

Models are defined, to express 'slope', i.e. mean annual increase in CD4 counts, and 'asymptote', i.e. the odds of having a CD4 count ≥500 cells/μL during antiretroviral treatment, as a function of covariates and random-effects. We compare the effect of using informative versus non-informative prior distributions on model parameters. Models with cubic splines or Skew-normal distributions are also compared using the conditional Deviance Information Criterion.

RESULTS

The data of 750 patients are analyzed. Overall, models adjusting for cumulative log viral load provide a significantly better fit than those that do not. An increase in cumulative log viral load is associated with a decrease in CD4 count slope (19.6 cells/μL (95% credible interval: 28.26, 10.93)) and a reduction in the odds of achieving a CD4 counts ≥500 cells/μL (0.42 (95% CI: 0.236, 0.730)) during 5 years of therapy. Using informative priors improves the cumulative log viral load estimate, and a skew-normal distribution for the random-intercept and measurement error results is a better fit compared to using classical Gaussian distributions.

DISCUSSION

We demonstrate in an unpublished South African cohort that cumulative log viral load is a strong and significant predictor of both CD4 count slope and asymptote. We argue that Bayesian methods should be used more frequently for such data, given their flexibility to incorporate prior information and non-Gaussian distributions.

The future of a partially effective HIV vaccine: assessing limitations at the population level

OBJECTIVES

Mathematical models have unanimously predicted that a first-generation HIV vaccine would be useful and cost-effective to roll out, but that its overall impact would be insufficient to reverse the epidemic. Here, we explore what factors contribute most to limiting the impact of such a vaccine.

METHODS

Ranging from a theoretical ideal to a more realistic regimen, mirroring the one used in the currently ongoing trial in South Africa (HVTN 702), we model a nested hierarchy of vaccine attributes such as speed of scale-up, efficacy, durability, and return rates for booster doses.

RESULTS

The predominant reasons leading to a substantial loss of vaccine impact on the HIV epidemic are the time required to scale up mass vaccination, limited durability, and waning of efficacy.

CONCLUSIONS

A first-generation partially effective vaccine would primarily serve as an intermediate milestone, furnishing correlates of immunity and platforms that could serve to accelerate future development of a highly effective, durable, and scalable next-generation vaccine capable of reversing the HIV epidemic.

Bibliometric analysis of global publications in medication adherence (1900-2017)

OBJECTIVES

Medication non-adherence is a worldwide problem. The aim of this study was to assess the global research output, research trends and topics that shaped medication adherence research.

METHODS

A bibliometric methodology was applied. Keywords related to 'medication adherence' were searched in Scopus database for all times up to 31 December 2017. Retrieved data were analyzsd, and bibliometric indicators and maps were presented.

KEY FINDINGS

In total, 16 133 documents were retrieved. Most frequently encountered author keywords, other than adherence/compliance, were HIV, hypertension, diabetes mellitus, schizophrenia, depression, osteoporosis, asthma and quality of life. The number of documents published from 2008 to 2017 represented 62.0% (n = 10 005) of the total retrieved documents. The h-index of the retrieved documents was 223. The USA ranked first (43.1%; n = 6959), followed by the UK (8.6%; n = 1384) and Canada (4.5%; n = 796). The USA dominated the lists of active authors and institutions. Top active journals in publishing research on medication adherence were mainly in the field of AIDS. Top-cited articles in the field focused on adherence to anti-HIV medications, the impact of depression on medication adherence and barriers to adherence.

CONCLUSION

Adherence among HIV patients dominated the field of medication adherence. Research on medication adherence needs to be strengthened in all countries and in different types of chronic diseases. Research collaboration should also be encouraged to increase research activity on medication adherence in developing countries.

Global research output on HIV/AIDS-related medication adherence from 1980 to 2017

BACKGROUND

"Human Immunodeficiency Virus (HIV)" and Acquired Immunodeficiency Syndrome (AIDS) are global health burden. Medication adherence in people living with HIV (PLWH) is a key element in reducing morbidity and mortality. Quantitative and qualitative assessment of research activity helps identify research gaps as well as efforts implemented to improve adherence behaviors in PLWH. The aim of the current study was to assess and analyze literature on HIV/AIDS-related medication adherence using bibliometric methods.

METHODS

SciVerse Scopus was used to accomplish the purpose of the current study. The study period included all times up to 2017. The analysis was restricted to documents published in academic journals.

RESULTS

Search strategy retrieved 3021 documents with an average of 32.5 citations per document, an h-index of 136, and an average of 4.4 authors per documents. The volume of literature on HIV/AIDS-related medication adherence constituted 1.3% of the overall HIV/AIDS literature. There was a significant (p < 0.01; r = 0.9) correlation between the growth of publications in AIDS-related stigma and medication adherence. The regions of America (567.9) had the highest research output per one million infected people (567.9) followed by the European region (314.3), Western Pacific Region (70.7), Eastern Mediterranean region (31.4), South East Asia (34.0), and Africa (19.3). Geographical distribution of publications showed an active contribution of certain countries in the Southern and Eastern region of Sub-Saharan Africa. Harvard University (8.4%; n = 254) was the most active institution. The top cited documents focused on the impact of adherence on disease outcome and the impact of text messages on improving medication adherence.

CONCLUSION

Research on medication adherence in PLWH showed regional variations. International research collaboration with high burden regions such as Sub-Saharan Africa needs to be strengthened to achieve the global target of ending AIDS as a public health threat by 2030.

Tenofovir-Based Highly Active Antiretroviral Therapy Is Associated with Superior CD4 T Cells Repopulation Compared to Zidovudine-Based HAART in HIV 1 Infected Adults

Tenofovir-based highly active antiretroviral therapy (HAART) is one of the preferred first-line therapies in the management of HIV 1 infection. Ghana has since 2014 adopted this recommendation; however there is paucity of scientific data that reflects the safety and efficacy of the tenofovir-based therapy compared to zidovudine in the Ghanaian health system. This study sought to assess the comparative immune reconstitution potential between tenofovir and zidovudine-based HAART regimens, which includes lamivudine and efavirenz in combination therapy. It also aimed to investigate the adverse drug reactions/events (ADREs) associated with pharmacotherapy with these agents in a total of 106 HAART naïve HIV patients. The study included 80 patients in the tenofovir cohort while 26 patients were on the zidovudine regimen. The occurrence of HIV comorbidities profile was assessed at diagnosis and throughout the study period. The baseline CD4 T cells count of the participants was also assessed at diagnosis and repeated at a median period of five months (range 4–6 months), after commencing treatment with either tenofovir- or zidovudine-based HAART. After five months of the HAART, the tenofovir cohort recorded higher CD4 T cell count change from baseline compared to the zidovudine cohort (p < 0.0001). The patients on the tenofovir-based HAART and female sex however appeared to be associated with more multiple ADREs.

Combining CD4 recovery and CD4: CD8 ratio restoration as an indicator for evaluating the outcome of continued antiretroviral therapy: an observational cohort study

OBJECTIVES

Immune recovery following highly active antiretroviral therapy (HAART) is commonly assessed by the degree of CD4 reconstitution alone. In this study, we aimed to assess immune recovery by incorporating both CD4 count and CD4:CD8 ratio.

DESIGN

Observational cohort study SETTING AND PARTICIPANTS: Clinical data from Chinese HIV-positive patients attending the largest HIV service in Hong Kong and who had been on HAART for ≥4 years were accessed.

MAIN OUTCOME MEASURES

Optimal immune outcome was defined as a combination of a CD4 count ≥500/μL and a CD4:CD8 ratio ≥0.8.

RESULTS

A total of 718 patients were included for analysis (6353 person-years). At the end of year 4, 318 out of 715 patients achieved CD4 ≥500/μL, of which only 33% (105 out of 318) concurrently achieved CD4:CD8 ratio ≥0.8. Patients with a pre-HAART CD8 ≤800/μL (428 out of 704) were more likely to be optimal immune outcome achievers with CD4 ≥500/μL and CD4:CD8 ratio ≥0.8, the association of which was stronger after adjusting for pre-HAART CD4 counts. In a multivariable logistic model, optimal immune outcome was positively associated with male gender, younger pre-HAART age and higher pre-HAART CD4 count, longer duration of HAART and pre-HAART CD8 ≤800/μL. Treatment regimen and cumulative viral loads played no significant role in the pattern of immune recovery.

CONCLUSIONS

A combination of CD4 count and CD4:CD8 ratio could be a useful approach for the characterisation of treatment outcome over time, on top of monitoring CD4 count alone.

Modelling the evolution of HIV-1 virulence in response to imperfect therapy and prophylaxis

Average HIV-1 virulence appears to have evolved in different directions in different host populations since antiretroviral therapy first became available, and models predict that HIV drugs can select for either higher or lower virulence, depending on how treatment is administered. However, HIV virulence evolution in response to "leaky" therapy (treatment that imperfectly suppresses viral replication) and the use of preventive drugs (pre-exposure prophylaxis) has not been explored. Using adaptive dynamics, we show that higher virulence can evolve when antiretroviral therapy is imperfectly effective and that this evolution erodes some of the long-term clinical and epidemiological benefits of HIV treatment. The introduction of pre-exposure prophylaxis greatly reduces infection prevalence, but can further amplify virulence evolution when it, too, is leaky. Increasing the uptake rate of these imperfect interventions increases selection for higher virulence and can lead to counterintuitive increases in infection prevalence in some scenarios. Although populations almost always fare better with access to interventions than without, untreated individuals could experience particularly poor clinical outcomes when virulence evolves. These findings predict that antiretroviral drugs may have underappreciated evolutionary consequences, but that maximizing drug efficacy can prevent this evolutionary response. We suggest that HIV virulence evolution should be closely monitored as access to interventions continues to improve.

Paper microchip with a graphene-modified silver nano-composite electrode for electrical sensing of microbial pathogens

Rapid and sensitive point-of-care diagnostics are of paramount importance for early detection of infectious diseases and timely initiation of treatment. Here, we present cellulose paper and flexible plastic chips with printed graphene-modified silver electrodes as universal point-of-care diagnostic tools for the rapid and sensitive detection of microbial pathogens or nucleic acids through utilizing electrical sensing modality and loop-mediated isothermal amplification (LAMP). We evaluated the ability of the developed paper-based assay to detect (i) viruses on cellulose-based paper microchips without implementing amplification in samples with viral loads between 106 and 108 copies per ml, and (ii) amplified HIV-1 nucleic acids in samples with viral loads between 10 fg μl-1 and 108 fg μl-1. The target HIV-1 nucleic acid was amplified using the RT-LAMP technique and detected through the electrical sensing of LAMP amplicons for a broad range of RNA concentrations between 10 fg μl-1 and 108 fg μl-1 after 40 min of amplification time. Our assay may be used for antiretroviral therapy monitoring where it meets the sensitivity requirement of the World Health Organization guidelines. Such a paper microchip assay without the amplification step may also be considered as a simple and inexpensive approach for acute HIV detection where maximum viral replication occurs.

Differences in virologic and immunologic response to antiretroviral therapy among HIV-1-infected infants and children

BACKGROUND

Virologic and immunologic responses to antiretroviral treatment (ART) in infants may differ from older children due to immunologic, clinical, or epidemiologic characteristics.

METHODS

Longitudinal ART responses were modeled and compared in HIV-infected infants and children enrolled in cohorts in Nairobi, Kenya. Participants were enrolled soon after HIV diagnosis, started on ART, and followed for 2 years. Viral load decline was compared between infant and child cohorts using a nonlinear mixed effects model and CD4% reconstitution using a linear mixed effects model.

RESULTS

Among 121 infants, median age at ART was 3.9 months; among 124 children, median age was 4.8 years. At baseline, viral load was higher among infants than children (6.47 vs. 5.91 log10 copies/ml, P < 0.001). Infants were less likely than children to suppress viral load to less than 250 copies/ml following 6 months of ART (32% infants vs. 73% children, P < 0.0001). CD4% was higher at baseline in infants than children (19 vs. 7.3%, P < 0.001). Older children had more rapid CD4% reconstitution than infants, but failed to catch up to infant CD4%.

CONCLUSION

Despite substantially higher CD4% at ART initiation, viral suppression was significantly slower among infants than older children. New strategies are needed to optimize infant outcomes on ART.

Virologic failure is uncommon after treatment initiation during acute HIV infection

OBJECTIVE

In chronic HIV infection, initiation of antiretroviral therapy (ART) typically induces swift HIV RNA declines and virologic suppression within 24 weeks. The objective of this study was to investigate viral dynamics and common criteria for treatment success after ART initiation during acute HIV infection (AHI).

METHODS

Participants were prospectively enrolled and offered ART during AHI from May 2009-June 2015 in Bangkok, Thailand. Regimens included tenofovir, lamivudine or emtricitabine, and efavirenz with or without raltegravir and maraviroc. Participants were monitored for several HIV RNA end points: one-log reduction at week 2; two-log reduction at week 4; less than 1000 copies/ml at week 24; and less than 200 copies/ml at week 24. Factors associated with each end point, time to suppression, and virologic blips were explored.

RESULTS

Two hundred and sixty-four Thai participants initiated ART during AHI. Their median age was 27 years and 96% were men. At 2 weeks, 6.5% had not achieved a one-log reduction in HIV RNA. At 4 weeks, 11.0% had not achieved a two-log reduction. At 24 weeks, 1.1% had not achieved HIV RNA less than 1000 copies/ml and 1.5% had not achieved HIV RNA less than 200 copies/ml. Participants who initiated ART during Fiebig I demonstrated a shorter median time to virologic suppression than did all other stages combined, [4 (interquartile range 2-8) vs. 8 (interquartile range 4-12) weeks, P < 0.001] and 7.3% had subsequent blips (16.1% in other stages, P = 0.23).

CONCLUSION

Virologic failure is uncommon in individuals who initiate ART during AHI. ART initiation during AHI is efficacious and clinicians can monitor for virologic failure after 24 weeks of therapy.

Factors associated with 10 years of continuous viral load suppression on HAART

Background

The principal goal of HAART is sustained viral load (VL) suppression resulting in immune reconstitution and improved HIV outcomes. We studied the factors associated with 10 years of continuous VL suppression on HAART in the US Military HIV Natural History Study.

Methods

Participants with continuous VL suppression (CS, n = 149) were compared to those who did not have continuous viral load suppression (NCS, n = 127) for ≥10 years on HAART. Factors associated with >10 years of VL suppression were evaluated by multivariate logistic regression. Additionally, association between CS and CD4 reconstitution was analyzed with a mixed effects model.

Results

Compared to NCS participants, a lower proportion of CS participants started HAART in the early HAART era (66 vs 90 %, for years 1996–1999; p < 0.001) and had less antiretroviral use prior to HAART (37 vs 83 %; p < 0.001). At initial HAART, the median CD4 cell count was higher and VL was lower for CS compared to NCS participants (375 cells/uL [256, 499] vs 261 cells/uL [146, 400]; p < 0.001 and 4.4 log₁₀ copies/mL [3.5, 4.9] vs 4.5 log₁₀ copies/mL [3.8, 5.0]; p = 0.048, respectively). New AIDS events were lower during HAART (5 vs 13 %; p = 0.032) and post-HAART CD4 trajectories were greater for the CS compared to NCS group. Factors negatively associated with ≥10 years of VL suppression included log₁₀ VL at first HAART (OR 0.61, 95 % CI 0.4, 0.92; p = 0.020) and antiretroviral use prior to HAART (OR 0.16, 95 % CI 0.06, 0.38; p < .001).

Conclusions

Sustained VL suppression is a key to long-term health in HIV-infected patients, as demonstrated by the lower proportion of AIDS events observed 10 years after HAART initiation. The current use of more potent and well-tolerated regimens may mitigate the negative factors of pre-HAART VL and prior ARV use encountered by treatment initiated in the early HAART era.

Predicting virological decay in patients starting combination antiretroviral therapy

OBJECTIVE

Model trajectories of viral load measurements from time of starting combination antiretroviral therapy (cART), and use the model to predict whether patients will achieve suppressed viral load (≤200 copies/ml) within 6-months of starting cART.

DESIGN

Prospective cohort study including HIV-positive adults (UK Collaborative HIV Cohort Study).

METHODS

Eligible patients were antiretroviral naive and started cART after 1997. Random effects models were used to estimate viral load trends. Patients were randomly selected to form a validation dataset with those remaining used to fit the model. We evaluated predictions of suppression using indices of diagnostic test performance.

RESULTS

Of 9562 eligible patients 6435 were used to fit the model and 3127 for validation. Mean log10 viral load trajectories declined rapidly during the first 2 weeks post-cART, moderately between 2 weeks and 3 months, and more slowly thereafter. Higher pretreatment viral load predicted steeper declines, whereas older age, white ethnicity, and boosted protease inhibitor/non-nucleoside reverse transcriptase inhibitors based cART-regimen predicted a steeper decline from 3 months onwards. Specificity of predictions and the diagnostic odds ratio substantially improved when predictions were based on viral load measurements up to the 4-month visit compared with the 2 or 3-month visits. Diagnostic performance improved when suppression was defined by two consecutive suppressed viral loads compared with one.

CONCLUSIONS

Viral load measurements can be used to predict if a patient will be suppressed by 6-month post-cART. Graphical presentations of this information could help clinicians decide the optimum time to switch treatment regimen during the first months of cART.

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.

Age-targeted HIV treatment and primary prevention as a 'ring fence' to efficiently interrupt the age patterns of transmission in generalized epidemic settings in South Africa

BACKGROUND

Generalized HIV epidemics propagate to future generations according to the age patterns of transmission. We hypothesized that future generations could be protected from infection using age-targeted prevention, analogous to the ring-fencing strategies used to control the spread of smallpox.

METHODS

We modeled age-targeted or cohort-targeted outreach with HIV treatment and/or prevention using EMOD-HIV v0·8, an individual-based network model of HIV transmission in South Africa.

RESULTS

Targeting ages 20 to 30 with intensified outreach, linkage, and eligibility for antiretroviral therapy (ART) averted 45% as many infections as universal outreach for approximately one-fifth the cost beyond existing HIV services. Though cost-effective, targeting failed to eliminate all infections to those under 20 due to vertical and inter-generational transmission. Cost-effectiveness of optimal prevention strategies included US$6238 per infection averted targeting ages 10-30, US$5031 targeting 20-30, US$4279 targeting 22-27, and US$3967 targeting 25-27, compared to US$10 812 for full-population test-and-treat. Minimizing burden (disability-adjusted life years [DALYs]) rather than infections resulted in older target age ranges because older adults were more likely to receive a direct health benefit from treatment.

CONCLUSIONS

Age-targeted treatment for HIV prevention is unlikely to eliminate HIV epidemics, but is an efficient strategy for reducing new infections in generalized epidemics settings.

Printed Flexible Plastic Microchip for Viral Load Measurement through Quantitative Detection of Viruses in Plasma and Saliva

We report a biosensing platform for viral load measurement through electrical sensing of viruses on a flexible plastic microchip with printed electrodes. Point-of-care (POC) viral load measurement is of paramount importance with significant impact on a broad range of applications, including infectious disease diagnostics and treatment monitoring specifically in resource-constrained settings. Here, we present a broadly applicable and inexpensive biosensing technology for accurate quantification of bioagents, including viruses in biological samples, such as plasma and artificial saliva, at clinically relevant concentrations. Our microchip fabrication is simple and mass-producible as we print microelectrodes on flexible plastic substrates using conductive inks. We evaluated the microchip technology by detecting and quantifying multiple Human Immunodeficiency Virus (HIV) subtypes (A, B, C, D, E, G, and panel), Epstein-Barr Virus (EBV), and Kaposi's Sarcoma-associated Herpes Virus (KSHV) in a fingerprick volume (50 µL) of PBS, plasma, and artificial saliva samples for a broad range of virus concentrations between 10(2) copies/mL and 10(7) copies/mL. We have also evaluated the microchip platform with discarded, de-identified HIV-infected patient samples by comparing our microchip viral load measurement results with reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) as the gold standard method using Bland-Altman Analysis.

Influence of lifelong cumulative HIV viremia on long-term recovery of CD4+ cell count and CD4+/CD8+ ratio among patients on combination antiretroviral therapy

OBJECTIVE

We explored the impact of lifelong cumulative HIV viremia on immunological recovery during antiretroviral therapy, according to the timing of treatment initiation.

METHODS

We estimated lifelong cumulative HIV viremia in patients followed in the ANRS PRIMO cohort since primary infection, including 244 patients who started treatment during PHI and had at least one treatment interruption, and 218 patients who started treatment later but with no interruptions. The impact of cumulative viremia on current immunological status was analysed using linear and logistic regression models.

RESULTS

At the last visit on treatment, median CD4 cell count was 645 cells/μl in the early/intermittent treatment group (median time from infection 9.5 years, 4.8 years of continuous treatment since last resumption), and 654 cells/μl in the deferred/continuous treatment group (median time from infection 6.1 years, 3.0 years of continuous treatment). Only 36.1 and 39.8% of patients achieved a CD4/CD8 ratio of more than 1, respectively. Current CD4 cell count was not associated with cumulative HIV viremia in either group. In contrast, patients with high cumulative HIV viremia (>66th percentile vs. <33rd percentile) were less likely to achieve a CD4/CD8 ratio of more than 1 (26.8 vs. 43.3%, P = 0.003), even after controlling for the baseline CD4/CD8 ratio, treatment duration, sex and age. Much higher CD4 cell count and CD4/CD8 ratio were reached in early/continuous treatment, that is low viremia exposure group.

CONCLUSION

Our results underline the critical need in early-treated patients to maintain adherence, in order to limit cumulative HIV viremia and optimize immunological recovery, notably the CD4/CD8 ratio.

Estimating minimum adult HIV prevalence: a cross-sectional study to assess the characteristics of people living with HIV in Italy

In 2012, we conducted a retrospective cross-sectional study to assess the number of people living with HIV linked to care and, among these, the number of people on antiretroviral therapy. The health authority in each of the 20 Italian Regions provided the list of Public Infectious Diseases Clinics providing antiretroviral therapy and monitoring people with HIV infection. We asked every Public Infectious Diseases Clinic to report the number of HIV-positive people diagnosed and linked to care and the number of those on antiretroviral therapy during 2012. In 2012, 94,146 people diagnosed with HIV and linked to care were reported. The majority were males (70.1%), Italians (84.4%), and aged between 25 and 49 years (63.4%); the probable route of transmission was heterosexual contact in 37.5% of cases, injecting drug use in 28.1%, and male-to-male contact in 27.9%. Among people in care, 20.1% had less than 350 CD4 cells/μl, 87.6% received antiretroviral therapy, and among these, 62.4% had a CD4 cell count higher than 350 cells/μl. The overall estimated prevalence of individuals diagnosed and linked to care in 2012 in Italy was 0.16 per 100 residents (all ages). Adding the estimated proportion of undiagnosed people, the estimated HIV prevalence would range between 0.19 and 0.26 per 100 residents. In Italy, the majority of people diagnosed and linked to care receive antiretroviral therapy. A higher prevalence of individuals diagnosed and linked to care was observed in Northern Italy and among males. More information for developing the HIV care continuum is necessary to improve the entire engagement in care, focusing on test-and-treat strategies to substantially reduce the proportion of people still undiagnosed or with a detectable viral load.

Influence of the timing of antiretroviral therapy on the potential for normalization of immune status in human immunodeficiency virus 1-infected individuals

IMPORTANCE

In individuals with human immunodeficiency virus 1 (HIV-1) infection who are receiving antiretroviral therapy (ART), factors that promote full immune recovery are not well characterized.

OBJECTIVE

To investigate the influence of the timing of ART relative to HIV-1 infection on normalization of CD4+ T-cell counts, AIDS risk, and immune function.

DESIGN, SETTING, AND PARTICIPANTS

Participants in the observational US Military HIV Natural History Study with documented estimated dates of seroconversion (EDS) who achieved virologic suppression with ART were evaluated. Markers indicative of immune activation, dysfunction, and responsiveness were determined. Responses to hepatitis B virus (HBV) vaccine, an indicator of in vivo immune function, were also assessed. The timing of ART was indexed to the EDS and/or entry into the cohort. The CD4+ counts in HIV-1-uninfected populations were surveyed.

MAIN OUTCOMES AND MEASURES

Normalization of CD4+ counts to 900 cells/μL or higher, AIDS development, HBV vaccine response, as well as T-cell activation, dysfunction, and responsiveness.

RESULTS

The median CD4+ count in HIV-1-uninfected populations was approximately 900 cells/μL. Among 1119 HIV-1-infected participants, CD4+ normalization was achieved in 38.4% vs 28.3% of those initiating ART within 12 months vs after 12 months from the EDS (P = .001). Incrementally higher CD4+ recovery (<500, 500-899, and ≥900 cells/μL) was associated with stepwise decreases in AIDS risk and reversion of markers of immune activation, dysfunction, and responsiveness to levels approximating those found in HIV-1-uninfected persons. Participants with CD4+ counts of 500 cells/μL or higher at study entry (adjusted odds ratio [aOR], 2.00; 95% CI, 1.51-2.64; P < .001) or ART initiation (aOR, 4.08; 95% CI, 3.14-5.30; P < .001) had significantly increased CD4+ normalization rates compared with other participants. However, even among individuals with a CD4+ count of 500 cells/μL or higher at both study entry and before ART, the odds of CD4+ normalization were 80% lower in those initiating ART after 12 months from the EDS and study entry (aOR, 0.20; 95% CI, 0.07-0.53; P = 001). Initiation of ART within 12 months of EDS vs later was associated with a significantly lower risk of AIDS (7.8% vs 15.3%; P = .002), reduced T-cell activation (percent CD4+HLA-DR+ effector memory T cells, 12.0% vs 15.6%; P = .03), and increased responsiveness to HBV vaccine (67.9% vs 50.9%; P = .07).

CONCLUSIONS AND RELEVANCE

Deferral of ART beyond 12 months of the EDS diminishes the likelihood of restoring immunologic health in HIV-1-infected individuals.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

A quantitative comparison of anti-HIV gene therapy delivered to hematopoietic stem cells versus CD4+ T cells

Gene therapy represents an alternative and promising anti-HIV modality to highly active antiretroviral therapy. It involves the introduction of a protective gene into a cell, thereby conferring protection against HIV. While clinical trials to date have delivered gene therapy to CD4+T cells or to CD34+ hematopoietic stem cells (HSC), the relative benefits of each of these two cellular targets have not been conclusively determined. In the present analysis, we investigated the relative merits of delivering a dual construct (CCR5 entry inhibitor + C46 fusion inhibitor) to either CD4+T cells or to CD34+ HSC. Using mathematical modelling, we determined the impact of each scenario in terms of total CD4+T cell counts over a 10 year period, and also in terms of inhibition of CCR5 and CXCR4 tropic virus. Our modelling determined that therapy delivery to CD34+ HSC generally resulted in better outcomes than delivery to CD4+T cells. An early one-off therapy delivery to CD34+ HSC, assuming that 20% of CD34+ HSC in the bone marrow were gene-modified (G+), resulted in total CD4+T cell counts ≥ 180 cells/ µL in peripheral blood after 10 years. If the uninfected G+ CD4+T cells (in addition to exhibiting lower likelihood of becoming productively infected) also exhibited reduced levels of bystander apoptosis (92.5% reduction) over non gene-modified (G-) CD4+T cells, then total CD4+T cell counts of ≥ 350 cells/ µL were observed after 10 years, even if initially only 10% of CD34+ HSC in the bone marrow received the protective gene. Taken together our results indicate that: 1.) therapy delivery to CD34+ HSC will result in better outcomes than delivery to CD4+T cells, and 2.) a greater impact of gene therapy will be observed if G+ CD4+T cells exhibit reduced levels of bystander apoptosis over G- CD4+T cells.

African ancestry influences CCR5 -2459G>A genotype-associated virologic success of highly active antiretroviral therapy

INTRODUCTION

In a North American, HIV-positive, highly active antiretroviral therapy (HAART)-treated, adherent cohort of self-identified white and black patients, we previously observed that chemokine (C-C motif) receptor 5 (CCR5) -2459G>A genotype had a strong association with time to achieve virologic success (TVLS) in black but not in white patients.

METHODS

Using 128 genome-wide ancestry informative markers, we performed a quantitative assessment of ancestry in these patients (n = 310) to determine (1) whether CCR5 -2459G>A genotype is still associated with TVLS of HAART when ancestry, not self-identified race, is considered and (2) whether this association is influenced by varying African ancestry.

RESULTS

We found that the interaction between CCR5 -2459G>A genotype and African ancestry (≤ 0.125 vs. ≥ 0.425 and <0.71 vs. ≥ 0.71) was significantly associated with TVLS (GG compared with AA, P = 0.044 and 0.018, respectively). Furthermore, the association between CCR5 -2459G>A genotype and TVLS was stronger in patients with African ancestry ≥ 0.71 than in patients with African ancestry ≥ 0.452, in both Kaplan-Meier (log-rank P = 0.039 and 0.057, respectively, for AA, GA, and GG) and Cox proportional hazards regression (relative hazard for GG compared with AA 2.59 [95% confidence interval: 1.27 to 5.22; P = 0.01] and 2.26 [95% confidence interval: 1.18 to 4.32; P = 0.01], respectively) analyses.

CONCLUSIONS

We observed that the association between CCR5 -2459G>A genotype and TVLS of HAART increased with stronger African ancestry. Understanding the genomic mechanisms by which African ancestry influences this association is critical and requires further studies.

Beyond the Brain: The Role of Brain-Derived Neurotrophic Factor in Viroimmune Responses to Antiretroviral Therapy among People Living with HIV with and without Alcohol Use

OBJECTIVE

Given the emerging data suggesting the key role of brain-derived neurotrophic factor (BDNF) in the immune system, we assessed longitudinally whether BDNF depletions induced by hazardous alcohol use (HAU) would impact a response to antiretroviral therapy (ART).

METHODS

In a prospective single-site cohort, virological and immunological responses to ART in 200 hazardous and 200 nonhazardous users were obtained, along with plasma BDNF levels.

RESULTS

Hazardous drinkers were more likely to have BDNF levels <4000 pg/mL (odds ratio [OR] = 1.6, P = .01). Participants with BDNF <4000 pg/mL were less likely to have CD4 counts of more than 500 cells/mm(3) (P = .02) and to achieve viral suppression over the follow-up period (OR = 1.5, P = .03). Multivariate analysis confirmed the significant role of HAU and low BDNF in predicting viroimmune responses.

CONCLUSION

Hazardous alcohol use was associated with BDNF alterations, which in turn were linked to a limited response to ART in terms of viral suppression and CD4 count improvements.

Impact on life expectancy of HIV-1 positive individuals of CD4+ cell count and viral load response to antiretroviral therapy

OBJECTIVE

The objective of this study is to estimate life expectancies of HIV-positive patients conditional on response to antiretroviral therapy (ART).

METHODS

Patients aged more than 20 years who started ART during 2000-2010 (excluding IDU) in HIV clinics contributing to the UK CHIC Study were followed for mortality until 2012. We determined the latest CD4 cell count and viral load before ART and in each of years 1-5 of ART. For each duration of ART, life tables based on estimated mortality rates by sex, age, latest CD4 cell count and viral suppression (HIV-1 RNA <400 copies/ml), were used to estimate expected age at death for ages 20-85 years.

RESULTS

Of 21 388 patients who started ART, 961 (4.5%) died during 110 697 person-years. At start of ART, expected age at death [95% confidence interval (CI)] of 35-year-old men with CD4 cell count less than 200, 200-349, at least 350 cells/μl was 71 (68-73), 78 (74-82) and 77 (72-81) years, respectively, compared with 78 years for men in the general UK population. Thirty-five-year-old men who increased their CD4 cell count in the first year of ART from less than 200 to 200-349 or at least 350 cells/μl and achieved viral suppression gained 7 and 10 years, respectively. After 5 years on ART, expected age at death of 35-year-old men varied from 54 (48-61) (CD4 cell count <200 cells/μl and no viral suppression) to 80 (76-83) years (CD4 cell count ≥350 cells/μl and viral suppression).

CONCLUSION

Successfully treated HIV-positive individuals have a normal life expectancy. Patients who started ART with a low CD4 cell count significantly improve their life expectancy if they have a good CD4 cell count response and undetectable viral load.

Delayed-type hypersensitivity (DTH) test anergy does not impact CD4 reconstitution or normalization of DTH responses during antiretroviral therapy

Introduction

Delayed-type hypersensitivity (DTH) testing is an in vivo assessment of cell-mediated immunity. Although highly active antiretroviral therapy (HAART) improves immunologic parameters, the relationship between DTH responsiveness and CD4 gains on HAART is not completely understood. We investigated CD4 reconstitution and the change in DTH responses from treatment baseline through 24 months of viral load (VL)-suppressive HAART in the U.S. Military HIV Natural History Study.

Methods

Treatment-naïve subjects with VL <400 copies/mL after ≥24 months on HAART were included (n=302). DTH testing consisted of ≥3 recall antigens, and responses were classified by the number of positive skin tests: anergic (0–1) or non-anergic (≥2). Pre-HAART DTH results were compared for the outcome of CD4 reconstitution at 24 months of HAART. Improvement in DTH responses was also analyzed for those anergic before HAART initiation.

Results

Non-anergic responses were observed in 216 (72%) participants, while 86 (28%) individuals were anergic prior to HAART initiation. Demographically there were similar distributions of age at HIV diagnosis and HAART initiation, as well as gender and race or ethnicity. There were no significant differences between non-anergic and anergic participants in pre-HAART CD4 count (409 cells/μL, interquartile range (IQR) 315–517 vs. 373 cells/μL, IQR 228–487; p=0.104) and VL (4.3 log₁₀ copies/mL, IQR 3.4–4.9 vs. 4.4 log₁₀ copies/mL, IQR 3.6–5.0; p=0.292). Median CD4 gains 24 months after HAART initiation were similar between the non-anergic (220 cells/μL, IQR 115–358) and anergic groups (246 cells/μL, IQR 136–358; p=0.498). For individuals anergic before HAART initiation, DTH normalization occurred at 24 months post-HAART in the majority of participants (51 of 86, 59%). Normalization of DTH responses was not associated with CD4 count at HAART initiation (OR 0.73, 95% CI 0.47, 1.09 per 100 cells; p=0.129) nor with AIDS diagnoses prior to HAART (OR 0.34, 95% CI 0.04, 2.51; p=0.283).

Conclusions

DTH responsiveness has been shown to predict HIV disease progression independent of CD4 count in untreated individuals. In the setting of HAART, pre-HAART anergy does not appear to impact CD4 gains or the ability to normalize DTH responses after 24 months of VL-suppressive HAART.

Safety, immunogenicity and efficacy assessment of HIV immunotherapy in a multi-centre, double-blind, randomised, Placebo-controlled Phase Ib human trial

BACKGROUND

Combination antiretroviral therapy (cART) is the main therapeutic management tool for HIV/AIDS. Despite its success in controlling viral load and disease progression, cART is expensive, associated with a range of significant side effects and depends for its efficacy on the patient's life-long commitment to high levels of treatment adherence. Immunotherapeutic agents can provide potential solutions to these shortcomings. Here we describe a Phase Ib trial of HIV-v, a synthetic immunotherapy that elicits T- and B-cell effector responses against HIV infected cells.

METHODS

Fifty-nine cART-naive HIV-infected males aged 18-50 years with viral load of 5000-500,000 copies/ml and CD4 counts >350/μl were recruited for this multi-centre, randomised, double blind study. Volunteers received one low (250 μg) or high (500 μg) dose of HIV-v, either alone or adjuvanted (ISA-51). Safety, immunogenicity, CD4 count and viral load were monitored over 168 Days.

RESULTS

HIV-v was well tolerated and the adjuvanted formulations elicited IgG responses in up to 75% of volunteers. The high adjuvanted dose also elicited cellular responses in 45% of tested volunteers. In these responding subjects viral loads were reduced by over 1 log (p=0.04) compared to Placebo and non-responders. No changes in CD4 count were observed.

CONCLUSIONS

HIV-v is safe and can elicit T- and B-cell responses in ART-naive HIV patients that significantly reduce viral load. Improved dosing regimens and further research on long term efficacy are required, but HIV-v appears to have potential as an immunotherapeutic anti-viral agent. Trial registered as EudraCT-2009-010593-37 (ClinicalTrials.gov Identifier: NCT01071031).

On the role of resonance in drug failure under HIV treatment interruption

Background

The application of highly active antiretroviral therapy (HAART) against HIV can reduce and maintain viral load below detection limit in many patients. Continuous HAART, however, can have severe side effects. In this context, structured treatment interruptions (STI) were considered to be a promising strategy. However, using CD4 cell count to guide intermittent therapy starting and stopping points, the SMART study (strategies for management of antiretroviral therapy), revealed that STI were associated with increased risk of AIDS and other complications. Additionally, short-term periodic (e.g. one week on / one week off) interruption therapies have shown virus rebound exceeding a given “failure threshold”, without any evidence for the evolution of drug resistance. Currently, the only hypothesis explaining the failure of STI is the “resonance hypothesis”, which posits that treatment failure is due to a resonance effect between the drug treatment and the viral population. In the present study we used a mathematical model to analyse the parameters affecting the output of drug treatment interruption and the premises of the resonance hypothesis.

Methods

We used a population dynamic model of HIV infection. Simulations and analytical approximations of deterministic and stochastic versions of the model were studied.

Results and Conclusion

The present study examines the roles of the most important parameters affecting the viral rebound, responsible for drug failure. We related these findings to the resonance hypothesis, and showed that the degree of sustainability of damping oscillations present in the model after the acute phase is strongly linked to their amplitude, which determines the resonance level. Stochastic simulations of the same model even revealed sustained oscillations in virus population for small virus population sizes. Given that pronounced viral load oscillations have not been observed in HIV-1 patients, the link between oscillations and resonance level suggests that treatment failure due to a resonance effect is not plausible. Moreover, the failure threshold is attained before the virus population crosses the set point while growing. As the maximum virus population is reached even after the set point is crossed, the role of resonance effects in the context of treatment interruptions cannot explain drug failure.

EVOLUTION OF PATIENTS WITH AIDS AFTER cART: CLINICAL AND LABORATORY EVOLUTION OF PATIENTS WITH AIDS AFTER 48 WEEKS OF ANTIRETROVIRAL TREATMENT

SUMMARY Combination Antiretroviral Therapy (cART) aims to inhibit viral replication, delay immunodeficiency progression and improve survival in AIDS patients. The objective of this study was to compare two different schemes of cART, based on plasma viral load (VL) and CD4+ T lymphocyte count, during 48 weeks of treatment. For this purpose, 472 medical charts of a Specialized Outpatient Service were reviewed from 1998 to 2005. Out of these, 58 AIDS patients who had received a triple drug scheme as the initial treatment were included in the study and two groups were formed: Group 1 (G1): 47 individuals treated with two nucleoside reverse-transcriptase inhibitors (NRTI) and one non-nucleoside reverse-transcriptase inhibitor; Group 2 (G2): 11 patients treated with two NRTI and one protease inhibitor. In G1 and G2, 53.2% and 81.8% respectively were patients with an AIDS-defining disease. The T CD4+ lymphocyte count increased progressively up until the 24th week of treatment in all patients, while VL became undetectable in 68.1% of G1 and in 63.6% of G2. The study concluded that the evolutions of laboratory tests were similar in the two treatment groups and that both presented a favorable clinical evolution.

Improved HIV-related outcomes associated with implementation of a novel public health information exchange

PURPOSE

The purpose of this study was to evaluate HIV-related outcomes associated with use of a novel public health information exchange that was designed to identify out of care HIV-infected individuals seen within a large, integrated delivery network (IDN).

METHODS

A novel, secure, bidirectional health care delivery-public health information exchange, the Louisiana Public Health Information Exchange (LaPHIE) was developed between a multi-geographical IDN and the Louisiana public health authority in response to the high proportion of out of care HIV-infected persons. The system provides real-time provider alerts when any HIV-infected person who has not had CD4 or HIV viral load (VL) monitoring in >1 year receives non-HIV care within the IDN, allowing immediate linkage to HIV specialty care. Persons identified over the first 30 months of the system's implementation were characterized using a case-cohort approach to compare out-of-care individuals with randomly sampled, time-matched in-care controls.

RESULTS

Between 2/1/09 and 7/31/11, 549 alerts identified 419 unduplicated HIV-infected individuals without a CD4 count or VL in >1 year. Patients were identified at 60 clinics and alerts shown to 223 clinicians in 7 participating facilities. A quarter (24%) of those identified had not had a CD4 count or VL conducted since their initial diagnosis. Of the remaining 76% who had been in care previously, over half (55%) had been out of care for ≥18 months, with a median time of 19.4 months [IQR 15.0-32.5] since their previous visit. Following LaPHIE identification, 42% had CD4 counts<200 cells/mm(3) and 62% had VL>10,000 RNA copies/mL. Of the 344 patients with at least 6 months of follow up, 85% had at least one CD4 and/or VL test after being identified.

CONCLUSIONS

The results of this study demonstrate that an information exchange can effectively facilitate engagement, re-engagement, and retention of out-of care HIV-infected persons in HIV specialty care. Within two years, we were able to observe significant improvements in HIV-related utilization and disease progression indices. Future programs should consider adopting this innovative strategy to improve HIV care at both the individual and population levels.

Evaluating the Effect of Early Versus Late ARV Regimen Change if Failure on an Initial Regimen: Results From the AIDS Clinical Trials Group Study A5095

The current goal of initial antiretroviral (ARV) therapy is suppression of plasma human immunodeficiency virus (HIV)-1 RNA levels to below 200 copies per milliliter. A proportion of HIV-infected patients who initiate antiretroviral therapy in clinical practice or antiretroviral clinical trials either fail to suppress HIV-1 RNA or have HIV-1 RNA levels rebound on therapy. Frequently, these patients have sustained CD4 cell counts responses and limited or no clinical symptoms and, therefore, have potentially limited indications for altering therapy which they may be tolerating well despite increased viral replication. On the other hand, increased viral replication on therapy leads to selection of resistance mutations to the antiretroviral agents comprising their therapy and potentially cross-resistance to other agents in the same class decreasing the likelihood of response to subsequent antiretroviral therapy. The optimal time to switch antiretroviral therapy to ensure sustained virologic suppression and prevent clinical events in patients who have rebound in their HIV-1 RNA, yet are stable, is not known. Randomized clinical trials to compare early versus delayed switching have been difficult to design and more difficult to enroll. In some clinical trials, such as the AIDS Clinical Trials Group (ACTG) Study A5095, patients randomized to initial antiretroviral treatment combinations, who fail to suppress HIV-1 RNA or have a rebound of HIV-1 RNA on therapy are allowed to switch from the initial ARV regimen to a new regimen, based on clinician and patient decisions. We delineate a statistical framework to estimate the effect of early versus late regimen change using data from ACTG A5095 in the context of two-stage designs.In causal inference, a large class of doubly robust estimators are derived through semiparametric theory with applications to missing data problems. This class of estimators is motivated through geometric arguments and relies on large samples for good performance. By now, several authors have noted that a doubly robust estimator may be suboptimal when the outcome model is misspecified even if it is semiparametric efficient when the outcome regression model is correctly specified. Through auxiliary variables, two-stage designs, and within the contextual backdrop of our scientific problem and clinical study, we propose improved doubly robust, locally efficient estimators of a population mean and average causal effect for early versus delayed switching to second-line ARV treatment regimens. Our analysis of the ACTG A5095 data further demonstrates how methods that use auxiliary variables can improve over methods that ignore them. Using the methods developed here, we conclude that patients who switch within 8 weeks of virologic failure have better clinical outcomes, on average, than patients who delay switching to a new second-line ARV regimen after failing on the initial regimen. Ordinary statistical methods fail to find such differences. This article has online supplementary material.

Gene array studies in HIV-1 infection

HIV-1-infected individuals exhibit remarkable variation in the onset of disease. Virus replication and disease progression depend on host cellular transcription and gene regulation in virus-specific target cells. Both viral and host factors are implicated in this differential regulation. Gene arrays and transcriptome analyses might shed light on why some infected individuals remain asymptomatic while others progress rapidly to AIDS. Here we review developments in HIV research using gene array technologies and the unifying concepts that have emerged from these studies. Gene set enrichment analysis has revealed gene signatures linked to disease progression involving pathways related to metabolism, apoptosis, cell-cycle dysregulation, and T-cell signaling. Macrophages contain anti-apoptotic signatures. Also, HIV-1 regulates previously under-emphasized cholesterol biosynthesis and energy production pathways. Notably, cellular pathways linked to a subset of HIV-infected individuals known as non-progressors contribute to survival and anti-viral responses.

Early retention in HIV care and viral load suppression: implications for a test and treat approach to HIV prevention

BACKGROUND

After HIV diagnosis and linkage to care, achieving and sustaining viral load (VL) suppression has implications for patient outcomes and secondary HIV prevention. We evaluated factors associated with expeditious VL suppression and cumulative VL burden among patients establishing outpatient HIV care.

METHODS

Patients initiating HIV medical care from January 2007 to October 2010 at the University of Alabama at Birmingham and University of Washington were included. Multivariable Cox proportional hazards and linear regression models were used to evaluate factors associated with time to VL suppression (<50 copies/mL) and cumulative VL burden, respectively. Viremia copy-years, a novel area under the longitudinal VL curve measure, was used to estimate 2-year cumulative VL burden from clinic enrollment.

RESULTS

Among 676 patients, 63% achieved VL <50 copies per milliliter in a median 308 days. In multivariable analysis, patients with more time-updated "no show" visits experienced delayed VL suppression (hazard ratio = 0.84 per "no show" visit, 95% confidence interval = 0.76 to 0.92). In multivariable linear regression, visit nonadherence was independently associated with greater cumulative VL burden (log(10) viremia copy-years) during the first 2 years in care (Beta coefficient = 0.11 per 10% visit nonadherence, 95% confidence interval = 0.04 to 0.17). Across increasing visit adherence categories, lower cumulative VL burden was observed (mean ± standard deviation log(10) copy × years/mL); 0%-79% adherence: 4.6 ± 0.8; 80%-99% adherence: 4.3 ± 0.7; and 100% adherence: 4.1 ± 0.7 log(10) copy × years/mL, respectively (P < 0.01).

CONCLUSIONS

Higher rates of early retention in HIV care are associated with achieving VL suppression and lower cumulative VL burden. These findings are germane for a test and treat approach to HIV prevention.

Chronic hypoxia compromises repair of DNA double-strand breaks to drive genetic instability

Hypoxic cells have been linked to genetic instability and tumor progression. However, little is known about the exact relationship between DNA repair and genetic instability in hypoxic cells. We therefore tested whether the sensing and repair of DNA double-strand breaks (DNA-dsbs) is altered in irradiated cells kept under continual oxic, hypoxic or anoxic conditions. Synchronized G0–G1 human fibroblasts were irradiated (0–10 Gy) after initial gassing with 0% O2 (anoxia), 0.2% O2 (hypoxia) or 21% O2 (oxia) for 16 hours. The response of phosphorylated histone H2AX (γ-H2AX), phosphorylated ataxia telangiectasia mutated [ATM(Ser1981)], and the p53 binding protein 1 (53BP1) was quantified by intranuclear DNA repair foci and western blotting. At 24 hours following DNA damage, residual γ-H2AX, ATM(Ser1981) and 53BP1 foci were observed in hypoxic cells. This increase in residual DNA-dsbs under hypoxic conditions was confirmed using neutral comet assays. Clonogenic survival was also reduced in chronically hypoxic cells, which is consistent with the observation of elevated G1-associated residual DNA-dsbs. We also observed an increase in the frequency of chromosomal aberrations in chronically hypoxic cells. We conclude that DNA repair under continued hypoxia leads to decreased repair of G1-associated DNA-dsbs, resulting in increased chromosomal instability. Our findings suggest that aberrant DNA-dsb repair under hypoxia is a potential factor in hypoxia-mediated genetic instability.

Short-term additional enfuvirtide therapy is associated with a greater immunological recovery in HIV very late presenters: a controlled pilot study

OBJECTIVES

To evaluate whether the addition of enfuvirtide to standard highly active antiretroviral therapy (HAART) could confer immunovirological benefits in human immunodeficiency virus (HIV)-infected very late presenters. The current study is an open comparative therapeutic trial of standard protease inhibitor (PI)-based HAART ± additional enfuvirtide in treatment-naïve deeply immunologically impaired HIV-positive patients.

METHODS

Very late presenters (CD4 <50/mm(3)), without tuberculosis and neoplasms, were alternatively allocated to two nucleoside reverse transcriptase inhibitors (NRTIs) and lopinavir/ritonavir without (control arm, CO) or with (ENF arm) enfuvirtide 90 mg bid. Enfuvirtide was administered until the achievement of viral load <50 copies/ml and for at least 24 weeks. The primary objective was the magnitude of CD4+ cell recovery at 6 months. HIV RNA was intensively monitored in the first month, and, thereafter, monthly, as for CD4+ cell count and percentage, clinical data, and plasma drug concentrations.

RESULTS

Of 22 enrolled patients (11 per arm), 19 completed the study (10 in the ENF arm). Baseline CD4+ cell counts and % were comparable, with 20 CD4+/mm(3) (12-37) and a percentage of 3.3 (1.7-7.1) in the ENF arm, and 16 CD4+/mm(3) (9-29) and a percentage of 3.1 (2.3-3.8) in the CO arm, respectively. The baseline viral load was also comparable between the two arms, with 5.77 log10 (5.42-6) and 5.39 log10 (5.06-6) in the ENF and CO arms, respectively. Enfuvirtide recipients had higher CD4+ percentage at week 8 (7.6 vs. 3.6%, p = 0.02) and at week 24 (10.7 vs. 5.9%, p = 0.02), and a greater CD4+ increase at week 24 (207 vs. 134 cells/mm(3), p = 0.04), with 70% of enfuvirtide intakers versus 12.5% of controls who achieved a CD4+ cell count >200/mm(3) (p = 0.01). At 48 weeks, patients in the ENF arm had CD4+ cell counts higher than controls (251 vs. 153cells/mm(3), p = 0.04) and were also found to be faster in reaching a CD4 cell count over 200/mm(3): 18 (8-24) versus 48 (36-108) weeks (p = 0.01). Viral load decay at week 4 was greater in the ENF arm (-3 vs. -2.2 log, p = 0.04), while the proportion of patients with viral load <50 copies/ml at week 24 was comparable.

CONCLUSIONS

In this pilot study, the addition of enfuvirtide to a lopinavir-based HAART was shown to be associated with a significantly faster and greater immunological recovery in newly discovered HIV-positive patients with very low CD4+ cell counts. Induction strategies using an enfuvirtide-based approach in such subjects warrant further investigation.

Early postseroconversion CD4 cell counts independently predict CD4 cell count recovery in HIV-1-postive subjects receiving antiretroviral therapy

BACKGROUND

The relationship between CD4 T-cell counts determined soon after seroconversion with HIV-1 (baseline CD4), nadir CD4, and CD4 levels attained during highly active antiretroviral therapy (HAART) is unknown.

METHODS

Longitudinal, including baseline (at or soon after HIV diagnosis), intermediate (nadir), and distal (post-HAART) CD4 T-cell counts were assessed in 1085 seroconverting subjects who achieved viral load suppression from a large well-characterized cohort. The association of baseline with post-HAART CD4 T-cell count was determined after adjustment for other relevant covariates.

RESULTS

A higher baseline CD4 T-cell count predicted a greater post-HAART CD4 T-cell count, independent of the nadir and other explanatory variables. Together, baseline and nadir strongly predicted the post-HAART CD4 count such that a high baseline and lower nadir were associated with a maximal immune recovery after HAART. Likelihood of recovery of the baseline count after HAART was significantly higher when the nadir/baseline count ratio was consistently ≥ 0.6.

CONCLUSIONS

Among viral load suppressing seroconverters, the absolute CD4 T-cell count attained post-HAART is highly dependent on both baseline and nadir CD4 T-cell counts. These associations further support the early diagnosis and initiation of HAART among HIV-infected persons.