Antiretroviral therapy interruption guided by CD4 cell counts and plasma HIV-1 RNA levels in chronically HIV-1-infected patients

The effect of care interruptions on mortality in adults resuming antiretroviral therapy

OBJECTIVE

To estimate the relative rate of all-cause mortality amongst those on antiretroviral treatment (ART) with a history of interruptions compared with those with no previous interruptions in care.

DESIGN

Retrospective cohort study.

METHODS

We used data from four South African cohorts participating in the International epidemiology Databases to Evaluate AIDS Southern Africa collaboration. We included adults who started ART between 2004 and 2019. We defined a care interruption as a gap in contact longer than 180 days. Observation time prior to interruption was allocated to a 'no interruption' group. Observation time after interruption was allocated to one of two groups based on whether the first interruption started before 6 months of ART ('early interruption') or later ('late interruption'). We used Cox regression to estimate hazard ratios.

RESULTS

Sixty-three thousand six hundred and ninety-two participants contributed 162 916 person-years of observation. There were 3469 deaths. Most participants were female individuals (67.4%) and the median age at ART initiation was 33.3 years (interquartile range: 27.5-40.7). Seventeen thousand and eleven (26.7%) participants experienced care interruptions. Those resuming ART experienced increased mortality compared with those with no interruptions: early interrupters had a hazard ratio of 4.37 (95% confidence interval (CI) 3.87-4.95) and late interrupters had a hazard ratio of 2.74 (95% CI 2.39-3.15). In sensitivity analyses, effect sizes were found to be proportional to the length of time used to define interruptions.

CONCLUSION

Our findings highlight the need to improve retention in care, regardless of treatment duration. Programmes to encourage return to care also need to be strengthened.

Updates to the Spectrum/AIM model for the UNAIDS 2020 HIV estimates

INTRODUCTION

The Spectrum/AIM model is used by national HIV programs and UNAIDS to prepare annual estimates of key HIV indicators. This article describes key updates to paediatric and adult models for the 2021 round of HIV estimates.

METHODS

Potential updates to Spectrum arise due to newly available data, new analyses of existing data, and the need for new issues to be addressed. Updates are guided by experts through the UNAIDS Reference Group on Estimates, Modelling and Projections. Changes are tested and assessed for impact before being accepted into the final model.

RESULTS

Spectrum tracks children living with HIV by CD4% for ages 0-4 and CD4 count for ages 5-14. Data from IeDEA treatment sites have been used to map the transition from CD4% to CD4 count at age 5. Breastfeeding patterns in sub-Saharan Africa have been updated with the latest survey data and estimates of continuation on antiretroviral therapy (ART) with breastfeeding have been revised based on recent studies. Model assumptions about the CD4 counts of people who drop out of ART have been revised to account for CD4 count increases while on treatment. If available, monthly data on numbers on ART can now be used to estimate the effects of COVID-19-related disruptions during 2020.

CONCLUSIONS

These changes are intended to provide more accurate estimates of HIV burden. The effects of these changes on paediatric indicators are small except in countries with new surveys that might have updated patterns of breastfeeding. Changes to the adult model have little effect on total new infections. AIDS-related deaths will be somewhat lower in countries that have data on ART drop out but might be increased by HIV care disruptions due to COVID-19. The updated model uses newly available data to improve the estimation of paediatric and adult HIV indicators.

Antiretroviral Therapy Interruption (ATI) in HIV-1 Infected Patients Participating in Therapeutic Vaccine Trials: Surrogate Markers of Virological Response

A functional Human immunodeficiency Virus (HIV) cure has been proposed as an alternative to antiretroviral treatment for life, and therapeutic vaccines represent one of the most promising approaches. The goal of therapeutic vaccination is to augment virus-specific immune responses that have an impact on HIV viral load dynamics. To date, the agreed feature to evaluate the effects of these therapeutic interventions is analytical antiretroviral treatment interruption (ATI), at least until we find a reliable biomarker that can predict viral control. Different host, immunologic, and virologic markers have been proposed as predictors of viral control during ATI after therapeutic interventions. This review describes the relevance of ATI and the different surrogate markers of virological control assessed in HIV therapeutic vaccine clinical trials.

Fatal prescriptions: Immigration detention, mismedication, and the necropolitics of uncare

This article focuses on detention care and its deadly consequences in the United States. Between October 2003 and October 2019, there were at least 196 deaths in Immigration and Customs Enforcement custody, many the result of grossly inadequate medical practices. Drawing on the case of Juan Carlos Baires, who was denied antiretroviral medication, the essay argues that, rather than being beneficiaries of care, noncitizens in detention are often victims of uncare-of a dearth or absence of both affective (concern about) and practical (providing for) care. The consequence of this uncare is that migrant lives are imperiled to the point of death.

A minor population of macrophage-tropic HIV-1 variants is identified in recrudescing viremia following analytic treatment interruption

HIV-1 persists in cellular reservoirs that can reignite viremia if antiretroviral therapy (ART) is interrupted. Therefore, insight into the nature of those reservoirs may be revealed from the composition of recrudescing viremia following treatment cessation. A minor population of macrophage-tropic (M-tropic) viruses was identified in a library of recombinant viruses constructed with individual envelope genes that were obtained from plasma of six individuals undergoing analytic treatment interruption (ATI). M-tropic viruses could also be enriched from post-ATI plasma using macrophage-specific (CD14) but not CD4+ T cell-specific (CD3) antibodies, suggesting that M-tropic viruses had a macrophage origin. Molecular clock analysis indicated that the establishment of M-tropic HIV-1 variants predated ATI. Collectively, these data suggest that macrophages are a viral reservoir in HIV-1-infected individuals on effective ART and that M-tropic variants can appear in rebounding viremia when treatment is interrupted. These findings have implications for the design of curative strategies for HIV-1.

Clinical trials of antiretroviral treatment interruption in HIV-infected individuals

: Despite the benefits of antiretroviral therapy (ART) for people living with HIV, there has been a long-standing research interest in interrupting ART as a strategy to minimize adverse effects of ART as well as to test interventions aiming to achieve a degree of virological control without ART. We performed a systematic review of HIV clinical studies involving treatment interruption from 2000 to 2017 to describe the differences between treatment interruption in studies that contained and didn't contain an intervention. We assessed differences in monitoring strategies, threshold to restart ART, duration and adverse outcomes of treatment interruption, and factors aimed at minimizing transmission. We found that treatment interruption has been incorporated into 159 clinical studies since 2000 and is increasingly being included in trials to assess the efficacy of interventions to achieve sustained virological remission off ART. Great heterogeneity was noted in immunological, virological and clinical monitoring strategies, as well as in thresholds to recommence ART. Treatment interruption in recent intervention studies were more closely monitored, had more conservative thresholds to restart ART and had a shorter treatment interruption duration, compared with older treatment interruption studies that didn't include an intervention.

A piecewise model of virus-immune system with two thresholds

The combined antiretroviral therapy with interleukin (IL)-2 treatment may not be enough to preclude exceptionally high growth of HIV virus nor rebuilt the HIV-specific CD4 or CD8 T-cell proliferative immune response for management of HIV infected patients. Whether extra inclusion of immune therapy can induce the HIV-specific immune response and control HIV replication remains challenging. Here a piecewise virus-immune model with two thresholds is proposed to represent the HIV-1 RNA and effector cell-guided therapy strategies. We first analyze the dynamics of the virus-immune system with effector cell-guided immune therapy only and prove that there exists a critical level of the intensity of immune therapy determining whether the HIV-1 RAN virus loads can be controlled below a relative low level. Our analysis of the global dynamics of the proposed model shows that the pseudo-equilibrium can be globally stable or locally bistable with order 1 periodic solution or bistable with the virus-free periodic solution under various appropriate conditions. This indicates that HIV viral loads can either be eradicated or stabilize at a previously given level or go to infinity (corresponding to the effector cells oscillating), depending on the threshold levels and the initial HIV virus loads and effector cell counts. Comparing with the single threshold therapy strategy we obtain that with two thresholds therapy strategies either virus can be eradicated or the controllable region, where HIV viral loads can be maintained below a certain value, can be enlarged.

Piecewise virus-immune dynamic model with HIV-1 RNA-guided therapy

Clinical studies have used CD4 T cell counts to evaluate the safety or risk of plasma HIV-1 RNA-guided structured treatment interruptions (STIs), aimed at maintaining CD4 T cell counts above a safe level and plasma HIV-1 RNA below a certain level. However, quantifying and evaluating the impact of STIs on the control of HIV replication and on activation of the immune response remains challenging. Here we extend the virus-immune dynamic system by including a piecewise smooth function to describe the elimination of HIV viral loads and the activation of effector cells under plasma HIV-1 RNA-guided therapy, in order to quantitatively explore the STI strategies. We theoretically investigate the global dynamics of the proposed Filippov system. Our main results indicate that HIV viral loads could either go to infinity or be maintained below a certain level or stabilize at a previously given level, depending on the threshold level and initial HIV virus loads and effector cell counts. This suggests that proper combinations of threshold and initial HIV virus loads and effector cell counts, based on threshold policy, can successfully preclude exceptionally high growth of HIV virus and, in particular, maximize the controllable region.

Assessment, diagnosis, and treatment of HIV-associated neurocognitive disorder: a consensus report of the mind exchange program

Many practical clinical questions regarding the management of human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) remain unanswered. We sought to identify and develop practical answers to key clinical questions in HAND management. Sixty-six specialists from 30 countries provided input into the program, which was overseen by a steering committee. Fourteen questions were rated as being of greatest clinical importance. Answers were drafted by an expert group based on a comprehensive literature review. Sixty-three experts convened to determine consensus and level of evidence for the answers. Consensus was reached on all answers. For instance, good practice suggests that all HIV patients should be screened for HAND early in disease using standardized tools. Follow-up frequency depends on whether HAND is already present or whether clinical data suggest risk for developing HAND. Worsening neurocognitive impairment may trigger consideration of antiretroviral modification when other causes have been excluded. The Mind Exchange program provides practical guidance in the diagnosis, monitoring, and treatment of HAND.

Virological failure rates and HIV-1 drug resistance patterns in patients on first-line antiretroviral treatment in semirural and rural Gabon

Introduction

As antiretroviral treatment (ART) continues to expand in resource-limited countries, the emergence of HIV drug resistance mutations (DRMs) is challenging in these settings. In Gabon (central Africa), no study has yet reported the virological effectiveness of initial ART given through routine HIV care.

Methods

Following the World Health Organization (WHO) recommendations, a cross-sectional study with a one-time HIV-1 RNA viral load (VL) measurement was conducted in Gabon to assess virological failure (VF) defined by a VL result ≥1000 copies/ml and DRMs among adult patients living with non-B HIV-1 strains and receiving first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy for at least 12 months. Risk factors associated with VF and DRMs were assessed.

Results

Between March 2010 and March 2011, a total of 375 patients were consecutively enrolled from two decentralized (one semirural and one rural) HIV care centres. Median time on ART was 33.6 months (range, 12–107). Overall, the rate of VF was 41.3% (36.4–46.4). Among viremic patients, 56.7% (80/141) had at least one DRM and 37.6% had dual-class resistance to nucleoside reverse transcriptase inhibitors (NRTIs) and NNRTIs. The most frequent DRMs were K103N/S (46.1%) and M184V/I (37.6%). Thymidine analogue mutations were found in 10.6%. Independent risk factors associated with VF were being followed up at the semirural centre (P=0.033), having experienced unstructured treatment interruptions (P=0.0044), and having low CD4⁺ counts at enrolment (P<0.0001). A longer time on ART (P=0.0008) and being followed up at the rural centre (P=0.021) were risk factors for DRMs.

Conclusions

This is the first study conducted in Gabon providing VF rates and DRM patterns in adult patients receiving first-line ART. In sub-Saharan Africa, where NNRTI-based regimens are recommended as the standard for first-line ART, strengthening virological monitoring together with preventing unplanned treatment interruptions are a global public health priority.

Long-term outcome of patients after a single interruption of antiretroviral therapy: a cohort study

Background

To describe the long term outcome of patients who interrupted highly active antiretroviral therapy (HAART) once, identify the variables associated with earlier need to re-start HAART, and the response when therapy was resumed. A retrospective observational cohort of 66 adult patients with HIV-1 infection who interrupted HAART with a CD4+cell count ≥350 cells/μL and undetectable viral load (VL) was performed. The pre-established CD4+ cell count for restarting therapy was 300cells/μL. Cox regression was used to analyse the variables associated with earlier HAART reinitiation.

Results

The median follow-up was 209 weeks (range, 64–395). Rates of HIV-related or possible HIV-related events were 0.37 (one case of acute retroviral syndrome) and 1.49 per 100 patient-years, respectively. Two patients died after re-starting therapy and having reached undetectable VL. Three patients suffered a sexually transmitted disease while off therapy. Fifty patients (76%) resumed therapy after a median of 97 weeks (range, 17–267). Age, a nadir of CD4+ <250 cells/μL, and a mean VL during interruption of >10,000 copies/ml were independent predictors for earlier re-start. The intention-to-treat success rate of the first HAART resumed regimen was 85.4%. There were no differences by regimen used, nor between regimens that were the same as or different from the one that had been interrupted.

Conclusions

Our data suggest highly active antiretroviral therapy may be interrupted in selected patients because in these patients, when the HAART is restarted, the viral and clinical response may be achieved.

Standing genetic variation and the evolution of drug resistance in HIV

Drug resistance remains a major problem for the treatment of HIV. Resistance can occur due to mutations that were present before treatment starts or due to mutations that occur during treatment. The relative importance of these two sources is unknown. Resistance can also be transmitted between patients, but this process is not considered in the current study. We study three different situations in which HIV drug resistance may evolve: starting triple-drug therapy, treatment with a single dose of nevirapine and interruption of treatment. For each of these three cases good data are available from literature, which allows us to estimate the probability that resistance evolves from standing genetic variation. Depending on the treatment we find probabilities of the evolution of drug resistance due to standing genetic variation between and . For patients who start triple-drug combination therapy, we find that drug resistance evolves from standing genetic variation in approximately 6% of the patients. We use a population-dynamic and population-genetic model to understand the observations and to estimate important evolutionary parameters under the assumption that treatment failure is caused by the fixation of a single drug resistance mutation. We find that both the effective population size of the virus before treatment, and the fitness of the resistant mutant during treatment, are key-parameters which determine the probability that resistance evolves from standing genetic variation. Importantly, clinical data indicate that both of these parameters can be manipulated by the kind of treatment that is used.

For HIV patients who are treated with antiretroviral drugs, treatment usually works well. However, the virus can, and sometimes does, become resistant against one or more drugs. HIV drug resistance results from the acquisition of specific and well known mutations. It is currently unknown whether drug resistance mutations usually stem from standing genetic variation, i.e., they were already present at low frequency before treatment started, or whether they tend to occur during treatment. In the current manuscript, I make use of several large datasets and evolutionary modeling to estimate the probability that drug resistance mutations are present before treatment starts and lead to viral failure. I find that for the most common type of treatment with a combination of three drugs, drug resistance evolves from pre-existing mutations in 6% of the patients. With other types of treatment, this probability varies from 0 to 39%. I conclude that there is room for improvement in preventing the evolution of drug resistance from pre-existing mutations.

Piecewise HIV virus dynamic model with CD4(+) T cell count-guided therapy: I

The strategies of structured treatment interruptions (STIs) of antiretroviral therapies have been proposed for clinical management of HIV infected patients, but clinical studies on STIs failed to achieve a consistent conclusion for this strategy. To evaluate the STI strategies, in particular, CD4(+) T cell count-guided STIs, and explain these controversial conclusions from different clinical studies, in this paper we propose to use piecewise HIV virus dynamic models to quantitatively explore the STI strategies and investigate their dynamic behaviors. Our analysis results indicate that CD4(+) T cell counts can be maintained above a safe level using the STI with a single threshold or a threshold window. Numerical simulations show that the CD4(+) T cell counts either fluctuate or approach a stable level for a patient, depending on the prescribed upper or lower threshold values. In particular, the CD4(+) T cell counts can be stabilized at a desired level if the threshold policy control is applied. The durations of drug-on and drug-off are very sensitive to the prescribed upper or lower threshold levels, which possibly explains why the on-off strategy with fixed schedule or an STI strategy with frequent switches are associated with the high rate of failure. Our findings suggest that it is critical to carefully choose the thresholds of CD4(+) T cell count and individualize the STIs for each individual patient based on initial CD4(+) T cell counts.

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.

Clinical implications of fixed-dose coformulations of antiretrovirals on the outcome of HIV-1 therapy

The substitution by generic equivalents of some of the drugs included in fixed-dose antiretroviral coformulations (FDACs) poses the potential risk of disrupting these combinations and administering the components separately in order to incorporate the new generic drug, which offers a more competitive sales price. This may represent a step backwards in the advances achieved in simplicity and adherence to therapy, posing an increased risk of selective noncompliance of some of the separately administered drug substances. Available antiretroviral drugs must be administered for life in the affected individuals - both children and adults. The FDACs represent a significant advance in the simplification of antiretroviral therapy, facilitating adherence to complex and chronic treatments, and contributing to a quantifiable improvement in patient quality of life. These drug coformulations reduce the risk of treatment error, are associated with a lower risk of hospitalization, and can lessen the possibility of covert monotherapy in situations of selective noncompliance. Thus, FDACs can reduce the risk of selection of HIV-1 resistances, which not only adversely affect the treatment options of the individual patient but also constitute a public health problem, and further increase the cost and complexity of therapy. With the exception of those cases requiring dose adjustments, the preferential use of FDACs should be recommended for the treatment of HIV-1 infection in those situations when the agents included in the coformulation are drugs of choice.

CD4+ T-cell differentiation, regulatory T cells and gag-specific T lymphocytes are unaffected by CD4-guided treatment interruption and therapy resumption

OBJECTIVES

Despite limiting exposure to antiretroviral drugs, structured treatment interruptions can influence multiple aspects of T-cell immunity, particularly those regarding CD4(+) T lymphocytes. We evaluated the impact of CD4-guided treatment interruption (CD4-GTI) and treatment resumption on regulatory T cells (Tregs), T-lymphocyte activation, differentiation and polyfunctional gag-specific response.

METHODS

Patients were analyzed just prior to treatment interruption, at 2 and 6 months after treatment interruption, just prior to treatment resumption and at 2 and 6 months after treatment resumption. Thawed peripheral blood mononuclear cells were stained immediately for phenotype analysis or stimulated with HIV-gag peptides and analyzed by polychromatic flow cytometry.

RESULTS

Treatment interruption resulted in a CD4(+) cell count decrease and plasma viral load (pVL) increase, but did not preclude a good immune reconstitution and a complete suppression of pVL after treatment resumption. Treatment interruption did not influence CD4(+) T-cell differentiation and Treg subsets. During treatment interruption, gag-specific CD4(+) T cells were not lost, although the frequency of HIV-specific CD8(+) cells increased. Most gag-specific CD4(+) T cells were potentially cytotoxic (CD107a(+)) and were not influenced by pVL or by HAART. Most helper (CD154(+)) gag-specific CD4(+) T lymphocytes did not produce interferon-γ or interleukin-2.

CONCLUSION

CD4-GTI did not cause depletion of memory cells, Tregs or HIV-specific CD4(+) cells and, on the contrary, could induce HIV-specific responses. If guided by CD4(+) T-cell count, treatment interruption does not provoke irreversible immune damages.

Postpartum changes in plasma viral load and CD4 percentage among HIV-infected women from Latin American and Caribbean countries: the NISDI Perinatal Study

The goal of this study was to evaluate changes in plasma human immunodeficiency virus (HIV) RNA concentration [viral load (VL)] and CD4+ percentage (CD4%) during 6-12 weeks postpartum (PP) among HIV-infected women and to assess differences according to the reason for receipt of antiretrovirals (ARVs) during pregnancy [prophylaxis (PR) vs. treatment (TR)]. Data from a prospective cohort of HIV-infected pregnant women (National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study) were analyzed. Women experiencing their first pregnancy who received ARVs for PR (started during pregnancy, stopped PP) or for TR (initiated prior to pregnancy and/or continued PP) were included and were followed PP. Increases in plasma VL (> 0.5 log10) and decreases in CD4% (> 20% relative decrease in CD4%) between hospital discharge (HD) and PP were assessed. Of the 1,229 women enrolled, 1,119 met the inclusion criteria (PR: 601; TR: 518). At enrollment, 87% were asymptomatic. The median CD4% values were: HD [34% (PR); 25% (TR)] and PP [29% (PR); 24% (TR)]. The VL increases were 60% (PR) and 19% (TR) (p < 0.0001). The CD4% decreases were 36% (PR) and 18% (TR) (p < 0.0001). Women receiving PR were more likely to exhibit an increase in VL [adjusted odds ratio (AOR) 7.7 (95% CI: 5.5-10.9) and a CD4% decrease (AOR 2.3; 95% CI: 1.6-3.2). Women receiving PR are more likely to have VL increases and CD4% decreases compared to those receiving TR. The clinical implications of these VL and CD4% changes remain to be explored.

Antiretroviral treatment interruption leads to progression of liver fibrosis in HIV-hepatitis C virus co-infection

OBJECTIVE

Despite potential negative consequences, HIV/hepatitis C virus (HCV) co-infected patients may discontinue antiretroviral treatment (ART) for several reasons. We examined the impact of ART interruption on liver fibrosis progression in co-infected adults, using the aspartate aminotransferase-to-platelet ratio index (APRI) as a surrogate marker of liver fibrosis.

METHOD

Data were analyzed from a multisite prospective cohort of 541 HIV-HCV co-infected adults. ART interruption was included as a time-updated variable and defined as the cessation of all antiretrovirals for at least 14 days. The primary endpoint was the development of an APRI score at least 1.5. Time-dependent Cox proportional hazards regression and inverse probability-of-treatment weighting (IPTW) in a marginal structural model were used to evaluate the association of baseline and time-varying covariates with developing significant fibrosis.

RESULTS

Patients were followed for a median of 1.02 years; 10% (n = 53) interrupted ART and 10% (n = 53) developed significant fibrosis. After accounting for potential confounders, including CD4 T-cell count, HIV viral load, baseline APRI score, age and gender, the hazard ratio for ART interruption was 2.52 (95% confidence interval 1.20-5.28). Use of IPTW resulted in a similar effect estimate, suggesting that mediation by time-varying confounders was negligible.

CONCLUSION

ART interruption was associated with an increased risk of fibrosis progression in HIV-HCV co-infection that was only partially accounted for by HIV viral load and CD4 T-cell counts. Our findings suggest that liver disease progression observed in ART-treated co-infected patients is partly due to the consequences of treatment interruptions.

Effect of Treatment Interruption and Intensification of Antiretroviral Therapy on Health-Related Quality of Life in Patients with Advanced HIV

Background. The effect of antiretroviral therapy (ART) interruption or intensification on health-related quality of life (HRQoL) in advanced HIV patients is unknown. Objective. To assess the impact of temporary treatment interruption and intensification of ART on HRQoL. Design. A 2 x 2 factorial open label randomized controlled trial. Setting. Hospitals in the United States, Canada, and the United Kingdom. Patients. Multidrug resistant (MDR) HIV patients. Intervention. Patients were randomized to receive a 12-wk interruption or not, and ART intensification or standard ART. Measurements. The Health Utilities Index (HUI3), EQ-5D, standard gamble (SG), time tradeoff (TTO), visual analog scale (VAS), and the Medical Outcomes Study HIV Health Survey (MOS-HIV). Results. There were no significant differences in HRQoL among the four groups during follow-up; however, there was a temporary significant decline in HRQoL on some measures within the interruption group during interruption (HUI3 −0.05, P = 0.03; VAS −5.9, P = 0.002; physical health summary −2.9, P = 0.001; mental health summary −1.9, P = 0.02). Scores declined slightly overall during follow-up. Multivariate analysis showed significantly lower HRQoL associated with some clinical events. Limitations. The results may not apply to HIV patients who have not experienced multiple treatment failures or who have not developed MDR HIV. Conclusions. Temporary ART interruption and ART intensification provided neither superior nor inferior HRQoL compared with no interruption and standard ART. Among surviving patients, HRQoL scores declined only slightly over years of follow-up in this advanced HIV cohort; however, approximately one-third of patients died during the trial follow up. Lower HRQoL was associated with adverse clinical events.

CD8 T-Cell Responses before and after Structured Treatment Interruption in Ugandan Adults Who Initiated ART with CD4 T Cells <200 Cell/μL: The DART Trial STI Substudy

Objective. To better understand attributes of ART-associated HIV-induced T-cell responses that might be therapeutically harnessed. Methods. CD8(+) T-cell responses were evaluated in some HIV-1 chronically infected participants of the fixed duration STI substudy of the DART trial. Magnitudes, breadths, and functionality of IFN-γ and Perforin responses were compared in STI (n = 42) and continuous treatment (CT) (n = 46) before and after a single STI cycle when the DART STI trial was stopped early due to inferior clinical outcome in STI participants. Results. STI and CT had comparable magnitudes and breadths of monofunctional CD8(+)IFNγ(+) and CD8(+)Perforin(+) responses. However, STI was associated with significant decline in breadth of bi-functional (CD8(+)IFNγ(+)Perforin(+)) responses; P = .02, Mann-Whitney test. Conclusions. STI in individuals initiated onto ART at <200 CD4(+) T-cell counts/μl significantly reduced occurrence of bifunctional CD8(+)IFNγ(+)/Perforin(+) responses. These data add to others that found no evidence to support STI as a strategy to improve HIV-specific immunity during ART.

Quality of life and adherence to HAART in HIV-infected patients

A review on adherence to highly active antiretroviral therapy and the quality of life of patients living with HIV in the scientific literature, indexed in MEDLINE between 1998 and 2008, was performed. Studies published in Portuguese, Spanish or English with patients over 18 years of age were included. Reviews, case reports and letters were excluded. Of the 21 studies found, 12 were included (three clinical trials, three prospective cohorts and six cross-sectional studies). The relationship between quality of life and treatment adherence remains controversial, despite descriptive studies indicating the possibility of a positive association. The results may have been influenced by the specific characteristics of the described clinical trials and do not show a consensus regarding the impact of treatment adherence on patients' quality of life.

CD4+ T-cell-guided structured treatment interruptions of antiretroviral therapy in HIV disease: projecting beyond clinical trials

BACKGROUND

International trials have shown that CD4+ T-cell-guided structured treatment interruptions (STI) of antiretroviral therapy (ART) lead to worse outcomes than continuous treatment. We simulated continuous ART and STI strategies with higher CD4+ T-cell interruption/reintroduction thresholds than those assessed in actual trials.

METHODS

Using a model of HIV, we simulated cohorts of African adults with different baseline CD4+ T-cell counts (< or = 200; 201-350; and 351-500 cells/microl). We varied ART initiation criteria (immediate; CD4+ T-cell count < 350 cells/microl or > or = 350 cells/microl with severe HIV-related disease; and CD4+ T-cell count <200 cells/microl or > or = 200 cells/microl with severe HIV-related disease), and ART interruption/reintroduction thresholds (350/250; 500/350; and 700/500 cells/microl). First-line therapy was non-nucleoside reverse transcriptase inhibitor (NNRTI)-based and second-line therapy was protease inhibitor (PI)-based.

RESULTS

STI generally reduced life expectancy compared with continuous ART. Life expectancy increased with earlier ART initiation and higher interruption/reintroduction thresholds. STI reduced life expectancy by 48-69 and 11-30 months compared with continuous ART when interruption/reintroduction thresholds were 350/250 and 500/350 cells/microl, depending on ART initiation criteria. When patients interrupted/reintroduced ART at 700/500 cells/microl, life expectancies ranged from 2 months lower to 1 month higher than continuous ART. STI-related life expectancy increased with decreased risk of virological resistance after ART interruptions.

CONCLUSIONS

STI with NNRTI-based regimens was almost always less effective than continuous treatment, regardless of interruption/reintroduction thresholds. The risks associated with STI decrease only if patients start ART earlier, interrupt/reintroduce treatment at very high CD4+ T-cell thresholds (700/500 cells/microl) and use first-line medications with higher resistance barriers, such as PIs.

Interruptions of antiretroviral therapy in human immunodeficiency virus infection: are they detrimental to neurocognitive functioning?

Because interruptions of antiretroviral treatment may entail clinical risks for human immunodeficiency virus (HIV)-infected individuals, we investigated their impact on neurocognitive functioning. Cross-sectional study was carried out, comparing HIV-infected persons who had interrupted antiretroviral therapy in the past (interruption group, IG) with persons who had never discontinued therapy (noninterruption group, NIG). Interruption was defined as the discontinuation of highly active antiretroviral therapy (HAART) for more than 15 days after previous treatment of at least 15 days. All the participants were on therapy. Demographic, clinical, and neurocognitive variables were assessed. The primary end point was the percentage of people with neurocognitive impairment. The score in different neurocognitive domains was a secondary end point. A total of 83 subjects participated in the study (IG: n = 27; NIG: n = 56). Demographic and clinical characteristics were balanced between the groups, except for years since HIV diagnosis (IG, 13.8; NIG, 10.2 [P = .003]). The percentage of people with neurocognitive impairment was significantly higher in the IG group (IG, 59.25%; NIG, 33.92% [P = 0.02]). As for scores in neurocognitive domains, individuals in the IG showed worse neurocognitive functioning, and significant differences in attention/working memory and information processing speed were found. The adjusted analysis supported the unadjusted analysis. In this study, a higher prevalence of neurocognitive impairment was detected in HIV-infected persons who had interrupted antiretroviral therapy in the past. Additionally, neurocognitive functioning was observed to be more impaired in the same individuals. Further studies should examine the potential negative effects of antiretroviral therapy interruptions on neurocognitive functioning.

[AIDS Study Group/Spanish AIDS Plan consensus document on antiretroviral therapy in adults with human immunodeficiency virus infection (updated January 2010)]

OBJECTIVE

This consensus document is an update of antiretroviral therapy recommendations for adult patients with human immunodeficiency virus infection.

METHODS

To formulate these recommendations a panel made up of members of the Grupo de Estudio de Sida (Gesida, AIDS Study Group) and the Plan Nacional sobre el Sida (PNS, Spanish AIDS Plan) reviewed the advances in the current understanding of the pathophysiology of human immunodeficiency virus (HIV) infection, the efficacy and safety of clinical trials, and cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings. Three levels of evidence were defined according to the data source: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not to recommend ART was established in each situation.

RESULTS

Currently, the treatment of choice for chronic HIV infection is the combination of three drugs of two different classes, including 2 nucleosides or nucleotide analogs (NRTI) plus 1 non-nucleoside (NNRTI) or 1 boosted protease inhibitor (PI/r), but other combinations are possible. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts below 350 cells/microl; 2) When CD4 counts are between 350 and 500 cells/microl, therapy should be started in case of cirrhosis, chronic hepatitis C, high cardiovascular risk, HIV nephropathy, HIV viral load above 100,000 copies/ml, proportion of CD4 cells under 14%, and in people aged over 55; 3) Therapy should be deferred when CD4 are above 500 cells/microl, but could be considered if any of previous considerations concurs. Treatment should be initiated in case of hepatitis B requiring treatment and should be considered for reduce sexual transmission. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures but undetectable viral loads maybe possible with the new drugs even in highly drug experienced patients. Genotype studies are useful in these situations. Drug toxicity of ART therapy is losing importance as benefits exceed adverse effects. Criteria for antiretroviral treatment in acute infection, pregnancy and post-exposure prophylaxis are mentioned as well as the management of HIV co-infection with hepatitis B or C.

CONCLUSIONS

CD4 cells counts, viral load and patient co-morbidities are the most important reference factors to consider when initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the ability to determine viral resistance is leading to a more individualized therapy approach in order to achieve undetectable viral load under any circumstances.

Incidence and risk factors of thrombocytopenia in patients receiving intermittent antiretroviral therapy: a substudy of the ANRS 106-window trial

BACKGROUND

Incidence and risk factors for thrombocytopenia in patients discontinuing highly active antiretroviral therapy (HAART) have not been fully investigated.

METHODS

Well-suppressed patients on HAART were randomized to continuous (CT) or intermittent therapy (IT) for 96 weeks. Incidence of thrombocytopenia (<150 x 10(3) platelets/mm(3)) was assessed and multivariate analysis performed to identify baseline predictors. Correlations were assessed between platelet, CD4, CD8 T-cell counts, and viral load after treatment interruption.

RESULTS

Three hundred ninety-one patients were included, with a median baseline platelet count of 243,000/mm(3). The incidence of thrombocytopenia at week 96 was significantly higher in the IT versus the CT arm (25.4% versus 9.8%, respectively, P < 0.001) and median time to thrombocytopenia was 9 weeks. In multivariate analysis, the IT strategy: odds ratio (OR) = 4.1 (2.1-7.9; P < 0.0001), a history of thrombocytopenia: OR = 11.9 (2.4-57.9; P = 0.002), and a low baseline platelet count: OR = 3.4 (2.3-5.1; P < 0.0001) were associated with an increased risk of thrombocytopenia. Also, after treatment interruption, changes from baseline in platelet counts were correlated with changes in CD4 T-cell counts and plasma HIV RNA levels (P < 0.001 for both).

CONCLUSIONS

Intermittent therapy is associated with a high incidence of thrombocytopenia, especially among patients with low platelet counts and a history of thrombocytopenia.

The impact of combination antiretroviral therapy and its interruption on anxiety, stress, depression and quality of life in Thai patients

OBJECTIVE

Investigation on anxiety, stress, depression, and quality of life (QoL) within STACCATO, a randomised trial of two treatment strategies: CD4 guided scheduled treatment interruption (STI) compared to continuous treatment (CT).

PARTICIPANTS

Thai patients with HIV-infection enrolled in the STACCATO trial.

METHODS

Anxiety, depression assessed by the questionnaires Hospital Anxiety and Depression Scale (HADS) and DASS, stress assessed by the Depression Anxiety Stress Scale (DASS), and QoL evaluated by the HIV Medical Outcome Study (MOS-HIV) questionnaires. Answers to questionnaires were evaluated at 4 time-points: baseline, 24 weeks, 48 weeks and at the end of STACCATO.

RESULTS

A total of 251 patients answered the HADS/DASS and 241 answered the MOS-HIV of the 379 Thai patients enrolled into STACCATO (66.2 and 63.6% respectively). At baseline 16.3% and 7.2% of patients reported anxiety and depression using HADS scale. Using the DASS scale, 35.1% reported mild to moderate and 9.6% reported severe anxiety; 8.8% reported mild to moderate and 2.0% reported severe depression; 42.6% reported mild to moderate and 4.8% reported severe stress. We showed a significant improvement of the MHS across time (p=0.001), but no difference between arms (p=0.17). The summarized physical health status score (PHS) did not change during the trial (p=0.15) nor between arm (p=0.45). There was no change of MHS or PHS in the STI arm, taking into account the number of STI cycle (p=0.30 and 0.57) but MHS significant increased across time-points (p=0.007).

CONCLUSION

Antiretroviral therapy improved mental health and QOL, irrespective of the treatment strategy.

Novel targets for antiretroviral therapy: clinical progress to date

The advent of HIV-1 resistance to antiretroviral medications, the need for lifelong antiretroviral therapy (ART) for HIV-infected individuals, and the goal of minimizing ART-related adverse effects and toxicity all drive the need for new antiretroviral drugs. Two new classes of antiretroviral medications for HIV treatment, the CCR5 and integrase inhibitors, have recently been approved for use in patients in whom previous HIV treatment regimens have failed. These new agent classes are a welcome addition to other antiretroviral classes, which include nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and fusion inhibitors. Maraviroc is a CCR5 co-receptor antagonist that blocks HIV binding to the CCR5 receptor, which is a CD4 co-receptor necessary for cell entry. It is approved for use in ART-experienced patients with CCR5-tropic HIV, and was found to significantly reduce HIV viral load and increase CD4+ cell count when combined with an optimized background ART regimen (OBR). Treatment failure with maraviroc has been described and is primarily associated with the presence of CXCR4-tropic virus. Vicriviroc is another CCR5 co-receptor antagonist that is in late clinical trials. Raltegravir is the first US FDA-approved HIV-1 integrase inhibitor. It is approved for use in ART-experienced patients and was found to significantly reduce HIV viral load and increase CD4+ cell counts compared with placebo in combination with an OBR. Raltegravir has also been studied in treatment-naive patients and was found to be non-inferior to an efavirenz-based regimen. Elvitegravir is another HIV-1 integrase inhibitor in clinical development. Other new antiretroviral agents in clinical development include PRO140, a monoclonal antibody against CCR5, and bevirimat, a maturation inhibitor that prevents late-stage gag polyprotein processing. A number of other drug targets, such as CCR5 co-receptor agonists, CXCR4 co-receptor antagonists, novel fusion inhibitors, and alternative antiretroviral strategies, such as immune stimulation and gene therapy, are under investigation.

CD4 cell-guided scheduled treatment interruptions in HIV-infected patients with sustained immunologic response to HAART

OBJECTIVE

To compare continuous HAART with a CD4 cell-driven scheduled treatment interruption (STI) strategy.

METHODS

LOng Term Treatment Interruption study is a randomized, controlled, prospective trial. Patients with CD4 cell counts more than 700 cells/microl were eligible, and the immunologic threshold to resume HAART was 350 cells/microl. The primary end point was the development of an opportunistic disease, death from any cause or the occurrence of diseases, other than opportunistic, requiring hospital admission. Secondary end points were major adverse effects, virologic failures and therapeutic costs.

RESULTS

Three hundred and twenty-nine patients were randomized 1: 1. Total follow-up was 1388 person-years (mean 4.2 years). Patients in the STI group stopped therapy for a total of 241 STI cycles, their mean off-therapy period was 65.3% of the follow-up. The primary end point occurred in 12.1% of patients on STI and in 11.6% of controls [odds ratio 1.05; 95% confidence interval 0.54-2.05]. A higher proportion of patients in the STI arm were diagnosed with pneumonia (P = 0.037), whereas clinical events influencing the cardiovascular risk of patients were significantly (P < 0.0001) more frequent among controls. Eight patients (4.8%) in the STI group and 11 (6.7%) controls developed viral resistance [odds ratio 0.79, 95% confidence interval 0.27-1.81]. The mean daily therapeutic cost was 20.29 euro for controls and dropped to 9.07 euro in the STI arm (P < 0.0001).

CONCLUSION

The two strategies may be considered clinically equivalent. CD4 cell-guided STIs seem a possible alternative for chronically infected individuals responding to HAART provided that CD4 cell decrements would be steadily maintained above a safe threshold.

Transient treatment exclusively containing nucleoside analogue reverse transcriptase inhibitors in highly antiretroviral-experienced patients preserves viral benefit when a fully active therapy was initiated

BACKGROUND

We determined whether coformulated zidovudine/lamivudine/abacavir plus tenofovir could maintain immune status in comparison with a genotype-guided salvage regimen in highly pretreated patients.

METHOD

This was a randomized pilot control-arm study. The primary endpoint was the proportion of patients who maintained their CD4+ T-cell count at Week 48.

RESULTS

Thirteen patients were randomized to the study arm and 10 to the control arm. At 48 weeks, 8 (64%) patients in the study arm and 10 (100%) in the control arm maintained their immune status (p = .09). No new AIDS-defining events occurred. Three patients (27%) in the study arm and 5 (50%) in the control arm achieved an undetectable viral load (p = .39). When a fully suppressive regimen was initiated, 69% of patients in the study arm (9 patients) and 60% (6 patients) in the control arm reached <50 copies at 96 weeks (p = .98).

CONCLUSION

Although no statistically significant differences in immunological course were observed between the arms, the control group achieved better results after 48 weeks. This transient therapy could be reserved for specific patients in whom the risk of incomplete adherence or toxicity compromises efficacy while they are awaiting a fully active drug, without jeopardizing viral efficacy when a fully suppressive regimen is initiated.

Predictive value of immune parameters before treatment interruption (TI) for CD4+ T-cell count change during TI in HIV infection

Background

Despite the contraindications, stopping treatment for HIV infection continues to be a common practice. Understanding whether T-cell proliferative capacity and phenotypic markers before treatment interruption (TI) can predict CD4+ T-cell count change and nadir during TI would be clinically useful.

Methods

This retrospective study included 27 HIV- infected patients in the chronic phase of infection while on combination antiretroviral therapy (cART) who underwent a TI. Peripheral blood mononuclear cells from a baseline pre-TI time point were screened for T-cell proliferation to cytomegalovirus (CMV) lysate, an HIV Gag p55 peptide pool as well as positive and negative control stimuli. CD28 and CD57 expression on CD4+ and CD8+ T-cells were measured.

Results

Baseline viral load, CD4+ T-cell count, pre-cART nadir CD4+ T-cell and percentage CD4+CD28+ T-cells were all predictive of the lowest CD4+ T-cell count during TI (Spearman's correlation P<0.05 for all analyses). In addition, CD4+ and CD8+ T-cells proliferation to CMV lysate, baseline CD4+ T-cell count and percentage CD4+CD57+ T-cells correlated negatively with CD4+ T-cell decrease during TI (Spearman's correlation P<0.05 for all analyses).

Conclusions

In treated chronic HIV-infected patients, pre-TI immune parameters are potential predictors for both the nadir CD4+ T-cell count and CD4+ T-cell count decrease during TI.

The magnitude of interferon-gamma responses to human cytomegalovirus is predictive for HIV-1 disease progression

BACKGROUND

Human cytomegalovirus (HCMV) infection has been strongly associated to HIV-1 progression. We have investigated whether the magnitude of the overall peripheral blood mononuclear cell responses to HCMV stimulation correlated with HIV-1 progression.

METHODS

Blood samples were collected from 75 HIV-1-positive individuals on highly active antiretroviral therapy with CD4 count>500 cells per cubic millimeter and undetectable HIV RNA just before interrupting treatment. Specific interferon-gamma (IFN-gamma) HCMV cell responses were measured by an enzyme-linked immunospot (ELISPOT) assay. The results were analyzed by Kaplan-Meier survival curves, contingency tests, and the Cox proportional hazard models to evaluate the predictive value of peripheral blood responses to HCMV and the length of time that patients were off treatment.

RESULTS

Patients were stratified into those with weak (<500 spot-forming units) or strong (>500 spot-forming units) IFN-gamma responses to HCMV. During the 3-year follow-up, 51% of patients with strong responses remained untreated compared with 14% of patients with weak HCMV responses (P=0.0015). Length of time without therapy was also longer in patients with stronger responses (hazard ratio=2.08; P=0.001). HCMV responses were still predictive of restarting therapy after adjusting for the CD4 nadir counts.

CONCLUSION

Specific IFN-gamma responses to HCMV may be employed as a predictive useful marker for the evolution of HIV-1 infection.

Two-months-off, four-months-on antiretroviral regimen increases the risk of resistance, compared with continuous therapy: a randomized trial involving West African adults

BACKGROUND

A randomized trial was launched in Côte d'Ivoire in 2002 to compare continuous antiretroviral treatment (hereafter, "C-ART") to an ART regimen of 2 months off and 4 months on therapy (hereafter, "2/4-ART"). We report the final analysis.

METHODS

A total of 435 adults who were receiving successful ART ((median CD4 cell count prior to ART, 272 cells/mm(3); 88% were receiving a zidovudine-lamivudine-efavirenz regimen) were randomized to receive C-ART or 2/4-ART. The main primary end point was the percentage of patients with <350 CD4 cells/mm(3) at 24 months. The sample size ensured 80% power to demonstrate noninferiority (noninferiority bound, -15%), assuming that 30% of the patients in the C-ART arm would have <350 CD4 cells/mm(3). Other end points were mortality, morbidity, cost of care, genotypic resistance, adherence, and toxicity.

RESULTS

The percentage of patients with <350 CD4 cells/mm(3) at 24 months was 5.6% (6 of 107) in the C-ART arm and 14.6% (46 of 315) in the 2/4-ART arm (lower bound of the 95% CI for the difference, -14%). Cost was 18% higher in the C-ART arm, and resistance to nonnucleoside reverse-transcriptase inhibitors (NNRTIs) was 20% higher in the 2/4-ART arm. Other end points were nonconclusive.

CONCLUSIONS

Although 2/4-ART met the predetermined criteria for noninferiority, the percentage of patients with <350 CD4 cells/mm(3) in the C-ART arm was lower than anticipated, which makes the clinical significance of this noninferiority uncertain. In addition, 2/4-ART led to an unacceptable additional risk of selecting for drug-resistant virus. This new argument against episodic ART strategies is also a caveat against any unplanned ART interruptions in Africa, where most patients receive NNRTIs.

Improved measures of quality of life, lipid profile, and lipoatrophy after treatment interruption in HIV-infected patients with immune preservation: results of ACTG 5170

BACKGROUND

Antiretroviral treatment interruption (TI) occurs frequently in routine clinical practice. The consequences of TI on quality of life (QOL), body habitus, and lipid parameters have not been studied.

METHODS

We assessed QOL, symptoms, lipid measurements, and body circumference changes in patients who underwent prolonged TI (up to 96 weeks) in AIDS Clinical Trials Group 5170, a multicenter, prospective study. Major entry criteria were pre-antiretroviral therapy (ART) and entry CD4 count > 350 cells/mm3, entry HIV RNA < 55,000 copies/mL, and on ART for > 6 months. QOL was assessed at baseline and subsequent time points (to week 96) by patient self-report (0-100 scale), by patient-reported Symptoms Distress Module, and by the Multidimensional Health Status tool. Fasting total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, and triglycerides were measured at baseline and subsequent time points to week 24. Neck, arm, mid-thigh, waist, and hip circumferences were measured through week 96. Paired t tests, Wilcoxon signed rank tests, and the generalized estimating equation approach were used in the data analysis.

RESULTS

A total of 167 subjects enrolled with median baseline and nadir CD4 count of 833 and 436 cells/mm3, respectively, and median time on ART 4.5 years. One hundred forty-nine subjects were receiving a thymidine analog-containing regimen (zidovudine or stavudine before TI). Self-reported QOL score on ART started high (mean 83.4 at baseline) and remained so after TI (83.0 at week 96, P = 0.49). Mean number of symptoms decreased from 8.2 at baseline to 7.0 at week 96, P = 0.016. The overall symptom summary score decreased from baseline to week 96, P = 0.01. The symptoms most frequently reported during TI were fatigue, feeling sad, nervousness, insomnia, myalgias, and changes in body appearance. There were no significant changes from baseline in the Multidimensional Health Status mental or physical domain scores. After TI, lipids (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides) decreased at weeks 12 and 24. Lipid changes were similar in patients stopping a nonnucleoside reverse transcriptase inhibitor vs a protease inhibitor regimen, except for HDL, which showed greater decreases in those interrupting an nonnucleoside reverse transcriptase inhibitor. Body circumference measurements of arm, waist, hip, and mid-thigh increased after TI.

CONCLUSIONS

In a cohort of individuals with high QOL and preserved immune function, QOL did not change during a prolonged TI. Modest decreases in total cholesterol, LDL and HDL cholesterol, and triglycerides and a modest increase in limb fat were observed.

Implementation of the Medicare Part D prescription drug benefit is associated with antiretroviral therapy interruptions

Antiretroviral (ARV) treatment interruptions are associated with virologic rebound, drug resistance, and increased morbidity and mortality. The Medicare Part D prescription drug benefit, implemented on January 1st, 2006, increased consumer cost-sharing. Consumer cost-sharing is associated with decreased access to medications and adverse clinical outcomes. We assessed the association of Part D implementation with treatment interruptions by studying 125 HIV-infected homeless and marginally housed individuals with drug coverage receiving ARV therapy. Thirty-five percent of respondents reported Medicare coverage and 11% reported ARV interruptions. The odds of ARV interruptions were six times higher among those with Part D coverage and remained significant after adjustment. The majority of Part D-covered respondents reporting ARV interruptions cited increased cost as their primary barrier. Directed interventions to monitor the long-term effects of increased cost burden on interruptions and clinical outcomes and to reduce cost burden are necessary to avoid preventable increases in morbidity and mortality.

Inferiority of IL-2 alone versus IL-2 with HAART in maintaining CD4 T cell counts during HAART interruption: a randomized controlled trial

OBJECTIVE

To evaluate whether interleukin (IL)-2 in patients with chronic HIV infection can maintain CD4 T cell counts during 6 months of HAART interruption.

DESIGN

Prospective, randomized, controlled, open-label phase II noninferiority trial comparing IL-2 with HAART interruption or continuous HAART.

METHODS

Forty-one IL-2-experienced (three or more prior cycles) HIV-1-infected adults with CD4 cell count at least 500 cells/microl were randomized in the ratio 2: 1 to interrupted (I = 27) or continuous (C = 14) HAART for 6 months following an initial IL-2 cycle. Subsequent IL-2 cycles were triggered by CD4 T cell counts less than 90% of baseline. Immune, metabolic, and quality of life indices were compared (Mann-Whitney and Fisher's exact tests), defining noninferiority as a percentage difference (C- I) in treatment success (CD4 T cells > or =90% of baseline at 6 months) with a 95% confidence interval (CI) lower limit greater than -20%.

RESULTS

Demographic and immune parameters were similar between the groups at baseline. Median CD4 T cell count, HIV viral load, and treatment success differed significantly at 6 months (I: 866 cells/microl, 39,389 copies/ml, 48.1%; C: 1246 cells/microl, <50 copies/ml, 92.3%; P < or = 0.001). Group I was inferior to C (% difference = -44.2%; 95% CI: -64.2%, -11.2%; P = 0.013). Minor statistically significant differences in HgbA1c and energy level occurred at 6 months (I > C). Following HAART interruption, single cases of acute retroviral syndrome, secondary syphilis, non-Hodgkin's lymphoma, and Kaposi's sarcoma recurrence were observed.

CONCLUSION

IL-2 alone was inferior to IL-2 with HAART in maintaining baseline CD4 T cell counts. HAART interruption had a small impact on metabolic parameters and quality of life.

Dynamics of NRTI resistance mutations during therapy interruption

Abstract To date, very little information is available regarding the evolution of drug resistance mutations during treatment interruption (TI). Using a survival analysis approach, we investigated the dynamics of mutations associated with resistance to nucleoside analogue reverse transcriptase inhibitors (NRTIs) during TI. Analyzing 132 patients having at least two consecutive genotypes, one at last NRTI-containing regimen failure, and at least one during TI, we observed that the NRTI resistance mutations disappear at different rates during TI and are lost independently of each other in the majority of patients. The disappearance of the K65R and M184I/V mutations occurred in the majority of patients, was rapid, and was associated with the reemergence of wild-type virus, thus showing their negative impact on viral fitness. Overall, it seems that the loss of NRTI drug resistance mutations during TI is not an ordered process, and in the majority of patients occurs without specific interaction among mutations.

Sustained antiretroviral treatment adherence in survivors of the pre-HAART era: attitudes and beliefs

The objective of this study was to assess adherence of HIV-1-infected patients who started treatment in the pre-HAART era and to determine variables associated with better adherence, including relevant attitudes and beliefs. This is a cross-sectional study enrolling patients who had received antiretroviral therapy for >or=10 years. Adherence was evaluated through self-reporting and plasma drug concentrations. Treatment variables, attitudes and beliefs were collected during structured interviews. The results show that for 87 patients the median (interquartile range) time on therapy was 13 (10-19) years; 80 were on therapy at the time of analysis. Adherence was >or=95% in 54 patients (67.5%), 90-94% in 22 (27.5%) and <90% in 4 (5%). Drug concentrations were below the lower limit of detection in five patients. Younger age (p=0.014), female gender (p=0.005), current substance abuse (p=0.004) and hepatitis C virus co-infection (p<0.001) were related to lower adherence. Adherence did not differ in relation to different drug families or once- or twice-daily regimens. Patients with adherence <95% were more likely to have interrupted treatment without doctor's recommendation (p=0.009). Adherent patients exhibited a higher perception of risk of developing the illness and of benefits of therapy, higher self-efficacy and intention to adhere and were more influenced by events that motivate medication intake. To conclude, adherence was >90% in most patients on antiretroviral therapy for >or=10 years. Adherence was more related to beliefs about health and illness than to the characteristics of medication or level of knowledge about treatment. Care adherence interventions should include assessment of health beliefs.

Viral resuppression and detection of drug resistance following interruption of a suppressive non-nucleoside reverse transcriptase inhibitor-based regimen

BACKGROUND

Interruption of a non-nucleoside reverse transcriptase inhibitor (NNRTI)-regimen is often necessary, but must be performed with caution because NNRTIs have a low genetic barrier to resistance. Limited data exist to guide clinical practice on the best interruption strategy to use.

METHODS

Patients in the drug-conservation arm of the Strategies for Management of Antiretroviral Therapy (SMART) trial who interrupted a fully suppressive NNRTI-regimen were evaluated. From 2003, SMART recommended interruption of an NNRTI by a staggered interruption, in which the NNRTI was stopped before the NRTIs, or by replacing the NNRTI with another drug before interruption. Simultaneous interruption of all antiretrovirals was discouraged. Resuppression rates 4-8 months after reinitiating NNRTI-therapy were assessed, as was the detection of drug-resistance mutations within 2 months of the treatment interruption in a subset (N = 141).

RESULTS

Overall, 601/688 (87.4%) patients who restarted an NNRTI achieved viral resuppression. The adjusted odds ratio (95% confidence interval) for achieving resuppression was 1.94 (1.02-3.69) for patients with a staggered interruption and 3.64 (1.37-9.64) for those with a switched interruption compared with patients with a simultaneous interruption. At least one NNRTI-mutation was detected in the virus of 16.4% patients with simultaneous interruption, 12.5% patients with staggered interruption and 4.2% patients with switched interruption. Fewer patients with detectable mutations (i.e. 69.2%) achieved HIV-RNA of 400 copies/ml or less compared with those in whom no mutations were detected (i.e. 86.7%; P = 0.05).

CONCLUSION

In patients who interrupt a suppressive NNRTI-regimen, the choice of interruption strategy may influence resuppression rates when restarting a similar regimen. NNRTI drug-resistance mutations were observed in a relatively high proportion of patients. These data provide additional support for a staggered or switched interruption strategy for NNRTI drugs.

Variability in the Plasma Concentration of Efavirenz and Nevirapine is Associated with Genotypic Resistance after Treatment Interruption

Background

Selection and persistence of non-nucleoside reverse transcriptase inhibitor (NNRTI)-associated mutations during treatment interruptions (TIs) has been attributed to the long plasma half-life of these drugs. However, little is known about the contribution of variable NNRTI plasma levels before a TI. We evaluated the selection of NNRTI-related mutations and the coefficient of variation of NNRTI plasma concentrations during different TI periods.

Methods

The selection of NNRTI-related mutations was examined in 50 HIV type-1 (HIV-1)-infected patients on a virologically suppressive regimen who underwent TI guided by CD4+ T-cell counts and plasma viraemia. Population and clone-based sequencing of the reverse transcriptase coding region was performed using plasma HIV-1 RNA samples during TI and proviral DNA from peripheral blood mononuclear cells before TI. NNRTI plasma concentrations were determined by HPLC.

Results

In 7/50 treated patients, de novo and transient NNRTI-related mutations appeared when treatment was interrupted. Emergence of resistant variants (including K103N, Y181C or G190S) after interruption was associated with a higher coefficient of variation in NNRTI plasma concentrations during the treatment period. Moreover, minority HIV-1 variants containing different resistance patterns (V106I/A, K103R/E or Y188C/D/H) were detected regardless of NNRTI concentrations.

Conclusions

The emergence of NNRTI-associated mutations during TI appears to be associated with the variation of NNRTI plasma concentrations during the preceding treatment period. The selection of minority HIV-1 variants with different patterns of NNRTI resistance in the absence of drug pressure should be considered for the efficacy of future NNRTI-containing antiretroviral regimens.

Increased regimen durability in the era of once-daily fixed-dose combination antiretroviral therapy

INTRODUCTION

Data on initial antiretroviral regimen longevity predates the arrival of newer nucleoside reverse transcriptase inhibitor backbones and once-daily regimens. Modern regimens are thought to possess greater tolerability and convenience. We hypothesized this would translate into greater durability.

METHODS

Retrospective study of antiretroviral-naive patients starting treatment at the University of Alabama at Birmingham 1917 HIV/AIDS Clinic 1 January 2000-31 July 2007. Two periods of antiretroviral initiation were identified, prior and after August 2004 (arrival of once-daily fixed-dose regimens). Kaplan-Meier survival analyses of regimen durability by time period and regimen characteristics were performed. Staged Cox proportional hazards models evaluated the roles of dosing complexity and composition in explaining differences in regimen durability between study periods.

RESULTS

Overall 542 patients started antiretroviral drugs (n = 309, January 2000-July 2004; n = 233, August 2004-July 2007). Median durability was 263 days longer in after August 2004 regimens. Regimens started before August 2004 had increased hazards for discontinuation relative to after August 2004 regimens [hazard ratio (HR) = 1.44; 95% confidence interval (CI) = 1.03-2.02]. Time period of initiation lost statistical significance when the model included dosing frequency (HR = 1.92 for at least twice daily vs. daily; 95% CI = 1.29-2.88). As regimen composition variables were added, time period and dosing frequency lost significance. Increased hazards of discontinuation were observed with didanosine or stavudine relative to abacavir or tenofovir use (HR = 1.92; 95% CI = 1.29-2.88) and all third drugs compared with non-nucleoside reverse transcriptase inhibitor-based regimens (triple-nucleoside reverse transcriptase inhibitor HR = 1.76; 95% CI = 1.14-2.73; unboosted-protease inhibitor HR = 1.58; 95% CI = 1.02-2.46; boosted-protease inhibitor HR = 1.57; 95% CI = 1.02-2.41). Affective mental health disorders increased the hazard of discontinuation in all models.

CONCLUSION

Durability of contemporary once-daily fixed-dose antiretroviral regimens has significantly eclipsed the duration of earlier antiretroviral drug options. Our results indicate this is due to both more convenient dosing and improved tolerability of modern antiretroviral regimens.

Lipid and apoprotein profile in HIV-1-infected patients after CD4-guided treatment interruption

OBJECTIVES

The aims of the present study were to determine if metabolic abnormalities and cytokine derangements are modified in HIV-1-infected patients after 12 months on treatment interruption (TI).

DESIGN

The design of this study was prospective randomized study.

METHODS

Longitudinal multicenter study in HIV-1-infected patients with a 12-month follow-up. Patients on stable highly active antiretroviral therapy, with CD4 count >600/microL and HIV RNA <50 copies/mL for at least 6 months, were randomized to interrupt therapy or continue ongoing highly active antiretroviral therapy. Lipids (total cholesterol, triglycerides), apoproteins (A1, B, and E), and adipocytokines (leptin, adiponectin, plasminogen activator inhibitor-1, monocyte chemotactic protein-1, Interleukin-6, Interleukin-8, and tumor necrosis factor-alpha) were measured at baseline and at month 12. Multiplex suspension bead array immunoassay was performed using the Luminex 100 analyzer to identify protein expression in plasma.

RESULTS

Patients who underwent TI (n = 19) had a significant decrease in median cholesterol levels (P < 0.001), while median triglyceride levels remained unchanged. There was a significant decrease in Apo-A1 levels (P = 0.048) and Apo-B levels (P < 0.001) and an increase in tumor necrosis factor-alpha levels (P = 0.034). Given the greater decrease in Apo-B, the ratio Apo-A1/Apo-B increased after 12 months of TI (from 3.4 to 5.1, P = 0.008). We did not find significant variations in leptin or adiponectin levels. In patients who continued on highly active antiretroviral therapy (n = 18), there were no significant changes in any of the measured parameters.

CONCLUSION

The lipid profile and apoproteins levels change toward a less atherogenic profile after TI, arguing against a lipid-mediated mechanism to explain the increased cardiovascular risk in patients who interrupt treatment.

Not all missed doses are the same: sustained NNRTI treatment interruptions predict HIV rebound at low-to-moderate adherence levels

BACKGROUND

While the relationship between average adherence to HIV potent antiretroviral therapy is well defined, the relationship between patterns of adherence within adherence strata has not been investigated. We examined medication event monitoring system (MEMS) defined adherence patterns and their relation to subsequent virologic rebound.

METHODS AND RESULTS

We selected subjects with at least 3-months of previous virologic suppression on a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen from two prospective cohorts in France and North America. We assessed the risk of virologic rebound, defined as HIV RNA of >400 copies/mL according to several MEMS adherence measurements. Seventy two subjects were studied, five of them experienced virologic rebound. Subjects with and without virologic rebound had similar baseline characteristics including treatment durations, regimen (efavirenz vs nevirapine), and dosing schedule. Each 10% increase in average adherence decreased the risk of virologic rebound (OR = 0.56; 95% confidence interval (CI) [0.37, 0.81], P<0.002). Each additional consecutive day off therapy for the longest treatment interruption (OR = 1.34; 95%CI [1.15, 1.68], P<0.0001) and each additional treatment interruption for more than 2 days (OR = 1.38; 95%CI [1.13, 1.77], P<0.002) increased the risk of virologic rebound. In those with low-to-moderate adherence (i.e. <80%), treatment interruption duration (16.2 days versus 6.1 days in the control group, P<0.02), but not average adherence (53.1% vs 55.9%, respectively, P = 0.65) was significantly associated with virologic rebound.

CONCLUSIONS

Sustained treatment interruption may pose a greater risk of virologic rebound on NNRTI therapy than the same number of interspersed missed doses at low-to-moderate adherence.