[Show abstract][Hide abstract] ABSTRACT: Objective:
We reviewed the current literature regarding antiretroviral (ARV)-sparing therapy strategies to determine whether these novel regimens can be considered appropriate alternatives to standard regimens for the initial treatment of ARV-naive patients or as switch therapy for those patients with virologically suppressed HIV infection.
A search for studies related to HIV dual therapy published from January 2000 through April 2014 was performed using Biosis, Derwent Drug File, Embase, International Pharmaceutical Abstracts, Medline, Pascal, SciSearch, and TOXNET databases; seven major trial registries, and the abstracts of major conferences. Using predetermined criteria for inclusion, an expert review committee critically reviewed and qualitatively evaluated all identified trials for efficacy and safety results and potential limitations.
Sixteen studies of dual therapy regimens were critiqued for the ARV-naive population. Studies of a protease inhibitor/ritonavir in combination with the integrase inhibitor raltegravir or the nucleoside reverse transcriptase inhibitor lamivudine provided the most definitive evidence supporting a role for dual therapy. In particular, lopinavir/ritonavir or darunavir/ritonavir combined with raltegravir and lopinavir/ritonavir combined with lamivudine demonstrated noninferiority to standard of care triple therapy after 48 weeks of treatment. Thirteen trials were critiqued in ARV-experienced, virologically suppressed patients. The virologic efficacy outcomes were mixed. Although overall data regarding toxicity are limited, when compared with standard triple therapy, certain dual therapy regimens may offer advantages in renal function, bone mineral density, and limb fat changes; however, some dual combinations may elevate lipid or bilirubin levels.
The potential benefits of dual therapy regimens include reduced toxicity, improved tolerability and adherence, and reduced cost. Although the data reviewed here provide valuable insights into the effectiveness and tolerability of dual therapy regimens, it remains unclear whether these potential benefits can be maintained long-term. Appropriately powered studies with longer follow-up periods are needed to more definitively assess potential toxicity reduction advantages with dual therapy.
[Show abstract][Hide abstract] ABSTRACT: Background:
The genomic heterogeneity of HIV-1 impedes the ability of consensus sequences in vaccines to elicit effective antiviral immune responses. AGS-004 amplifies translation-competent RNA molecules encoding for Gag, Rev, Vpr, and Nef from the patient's autologous virus and loads them into dendritic cells (DC).
This phase IIB, multicenter, 2:1 randomized, double blind, placebo-controlled study enrolled 54 HIV-1-infected patients on antiretroviral therapy (ART) with viral loads (VL) <50 copies/mL, current CD4 T-cell counts >450 cells/mm, and nadir counts >200 cells/mm, to receive intradermal injections of study product into the axillary lymph node region every 4 weeks. At week 16, a 12-week analytical treatment interruption (ATI) was undertaken.
There was no difference in the end-of-ATI VL (average of values from weeks 11 and 12) between the two arms of the study (4.39 [4.17, 4.69] vs. 4.47 [3.76, 4.64] log10 HIV-1 RNA; P = 0.73). Between arms no change between pre-ART VL and the end-of-ATI VL (-0.06 [0.24, -0.32] vs. -0.17 [0.17, -0.32] log10 HIV-1 RNA; P = 0.43) was observed. When IFN-γ, IL-2, TNF-α, CD107a, and granzyme b expression was measured by multicolor flow cytometry, a greater percentage of AGS-004 than of placebo recipients had multifunctional CTL responses induced in the CD28+/CD45RA- CD8 effector/memory T-cell population to DCs electroporated with autologous antigens. Adverse events consisted of transient, mild (grade 1) local injection site reactions.
Despite the induction of HIV-specific effector/memory CD8 T-cell responses, no antiviral effect was seen after the administration of AGS-004 when compared to placebo.
No preview · Article · Jan 2016 · JAIDS Journal of Acquired Immune Deficiency Syndromes
[Show abstract][Hide abstract] ABSTRACT: Introduction
The development of an effective therapeutic HIV vaccine that induces immunologic control of viral replication, thereby eliminating or reducing the need for antiretroviral therapy (ART), would be of great value. Besides the obvious challenges of developing a therapeutic vaccine that would generate effective, sustained anti-HIV immunity in infected individuals is the issue of how to best assess the efficacy of vaccine candidates.
This review discusses the various outcome measures assessed in therapeutic HIV vaccine clinical trials involving individuals receiving suppressive ART, with a particular focus on the role of analytical treatment interruption (ATI) as a way to assess the virologic control induced by an immunotherapy. This strategy is critical given that there are otherwise no readily available measures to determine the ability of a vaccine-induced immune response to effectively control HIV replication. The various outcome measures that have been used to assess vaccine efficacy in published therapeutic HIV vaccine clinical trials will also be discussed. Outcome measures have included the kinetics of viral rebound, the new viral set point and changes in the size of the viral reservoir. Clinically relevant outcomes such as the CD4 decline, the time to resume therapy or the time to meet the criterion to resume therapy, the proportion of participants who resume therapy and/or the development of clinical symptoms such as acute retroviral syndrome are also measures of vaccine efficacy.
Given the lack of consistency between therapeutic HIV vaccine trials in how efficacy is assessed, comparing vaccines has been difficult. It would, therefore, be beneficial to determine the most clinically relevant measure for use in future studies. Other recommendations for future clinical trials also include studying compartments in addition to blood and replacing ATIs with single-copy assays in situations in which the use of an ATI is not ideal.
No preview · Article · Nov 2015 · Journal of the International AIDS Society
[Show abstract][Hide abstract] ABSTRACT: Objectives:
To assess whether therapeutic vaccination with ALVAC-HIV ± Remune affects viral reservoir size in antiretroviral therapy-treated individuals.
Participants in CTN 173, a multicentre, randomized, 3-arm, placebo-controlled, double-blind study, were vaccinated with ALVAC-HIV ± Remune (groups 1 and 2, respectively) or with placebos (group 3) over 20 weeks and assessed for changes in the size of their viral reservoirs from weeks 0 to 24.
Sixteen participants completed the viral reservoir substudy. The median sizes (interquartile range) of the viral reservoir at baseline (week 0) were 0.07 (0.03-0.37), 0.04 (0.02-0.33), and 0.13 (0.06-0.99) infectious units per million peripheral blood mononuclear cells for groups 1, 2, and 3, respectively; these baseline viral reservoir sizes were not significantly different (P = 0.37). By week 24, the median sizes of the viral reservoirs were 0.04 (0.01-2.16), 0.04 (0.01-0.34), and 0.12 (0.01-0.44) infectious units per million peripheral blood mononuclear cells for groups 1, 2, and 3 respectively; these week 24 viral reservoir sizes were not significantly different (P = 0.91). Furthermore, there were no statistically significant differences between baseline and week 24 reservoir sizes for any of the 3 groups (P = 0.88, P = 1.00, and P = 0.44, respectively).
Despite evidence that ALVAC-HIV ± Remune was associated with a trend toward a delay in viral rebound and a smaller decrease in CD4 T-cell counts following antiretroviral therapy interruption, ALVAC-HIV ± Remune did not influence the size of the viral reservoir.
Full-text · Article · Jun 2015 · JAIDS Journal of Acquired Immune Deficiency Syndromes
[Show abstract][Hide abstract] ABSTRACT: Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice.
[Show abstract][Hide abstract] ABSTRACT: Resistance to apoptosis is an important characteristic that human macrophages acquire during differentiation from monocytes. However, the intracellular mechanisms that mediate the development of resistance are not well understood. We have used M-CSF-stimulated primary human monocytes and PMA-treated THP1 cells to study apoptosis resistance during differentiation of human macrophages. Our results indicate that PI3K/Akt distinctively regulates survival of macrophages during and after differentiation. More specifically, a signaling pathway consisting of PI3K/Akt-NF-κB-Bcl-xL regulates cell survival during the differentiation process. PI3K/Akt-mediated activation of NF-κB plays a key role in survival of differentiating macrophages by specifically sustaining antiapoptotic Bcl-xL expression. With the use of pharmacological inhibitors and siRNA for Akt and Bcl-xL, we show that in the absence of Akt-dependent Bcl-xL expression during differentiation, cells undergo caspase-mediated apoptosis. In contrast, in differentiated macrophages, Bcl-xL expression is independent of PI3K/Akt activation. Taken together, these results suggest that survival of macrophages is distinctly regulated during and after differentiation. Our results also suggest new, potential therapeutic targets to modulate differentiation and survival of this cell type.
No preview · Article · Sep 2014 · Journal of Leukocyte Biology
[Show abstract][Hide abstract] ABSTRACT: Objectives
Chloroquine (CQ), an anti-inflammatory drug, inhibits Toll-like receptor (TLR) signalling in plasmacytoid dendritic cells (pDCs) and may be beneficial for HIV-infected patients in whom immune activation persists despite effective antiretroviral therapy (ART). The effect of CQ on CD4 T-cell recovery and immune activation in immune nonresponding patients receiving successful ART was therefore studied.Methods
Nineteen adults on ART with CD4 counts ≤350 cells/μL and undetectable viral load (VL) orally received CQ at 250 mg/day for 24 weeks. Side effects, CD4 and CD8 T-cell counts, VL, T-cell activation, pDC proportion and plasma inflammatory markers were assessed at baseline, at 24 weeks, and at 12 weeks after CQ discontinuation (clinicaltrial.org registration #NCT02004314).ResultsCQ was well tolerated and all patients maintained an undetectable VL. The absolute CD4 and CD8 T-cell counts and their percentages, the pDC proportion, T-cell activation, D-dimer and C-reactive protein (CRP) plasma levels and the kynurenine/tryptophan ratio did not change with CQ treatment. Among nine cytokines/chemokines measured, only levels of interferon (IFN)-α2 were significantly increased by CQ treatment.ConclusionsCQ was well tolerated in patients with low CD4 T-cell counts despite long-term effective ART; however, 24 weeks of CQ treatment did not improved CD4 T-cell recovery, lymphoid and myeloid immune activation or inflammatory markers.
[Show abstract][Hide abstract] ABSTRACT: Motherhood is personally, culturally, and historically rooted. Recent publications have focused on medical issues related to pregnancy and HIV, with attention on fetal well-being. There is limited literature on the importance of motherhood for HIV-positive women. Our study's purpose was to investigate the importance of motherhood among HIV-positive women of reproductive age in Ontario, Canada and to analyze the correlates thereof. We present our findings using a secondary analysis of cross-sectionally collected data from a study assessing fertility desires and intentions of HIV-positive women. The sub-analysis's outcome of interest was based on the question: "Being a mother is important to me" with a 5-point Likert scale that was dichotomized into strongly agree/agree vs. neutral/disagree/strongly disagree. Logistic regression models were fit to calculate unadjusted and adjusted odds ratios (ORs) for significant correlates. Of the 497 respondents, median age was 38 (interquartile range [IQR] 32-43), 46% were African, 74% had given birth, and 57% intended to give birth. A total of 452 (91%) agreed (N = 75) or strongly agreed (N = 377) that being a mother was important to them. Age less than 40 years (OR 3.0; 95% confidence interval [CI] 1.6-5.7, African ethnicity (OR 9.2; 95% CI 3.2-26.3), immigration within 10 years (OR 19.6, 95% CI 4.6-83.1), and partner or family desire for a pregnancy (OR 3.3; 95% CI 1.5-7.3) were significant correlates of the importance of motherhood in a univariate analysis. Importance of motherhood was associated with desire (OR 6.2, 95% CI 3.1-12.3) and intention to give birth (OR 6.9, 95% CI 3.1-15.2), and previous birth (OR 8.5, 95% CI 4.2-16.8). In the multivariable model, the significant correlates were of age less than 40 years (OR 3.9; 95% CI 1.8-8.4), immigration within 10 years (OR 14.1; 95% CI 3.2-61.5), and having previously given birth (OR 11.2; 95% CI 5.1-24.4). The majority of women felt strongly that motherhood was important to them particularly among younger women, recent immigrants, and women who were mothers.
[Show abstract][Hide abstract] ABSTRACT: HIV transmitted drug resistance (TDR) surveillance is usually conducted by sampling from a large population. However, overall TDR prevalence results may be inaccurate for many individual clinical setting. We analyzed HIV genotypes at a tertiary care setting in Ottawa, Ontario in order to evaluate local TDR patterns among sub-populations.
Genotyping reports were digitized from ART naive patients followed at the Immunodeficiency Clinic at the Ottawa Hospital, between 2008 and 2010. Quality controlled, digitized sequence data were assessed for TDR using the Stanford HIV Database. Patient characteristics were analyzed according to TDR patterns. Finally, a phylogenetic tree was constructed to elucidate the observed pattern of HIV TDR.
Among the 155 clinic patients there was no statistically significantly difference in demographics as compared to the Ontario provincial HIV population. The clinic prevalence of TDR was 12.3%; however, in contrast to the data from Ontario, TDR patterns were inverted with a 21% prevalence among MSM and 5.5% among IDU. Furthermore, nearly 80% of the observed TDR was a D67N/K219Q pattern with 87% of these infections arising from a distinct phylogenetic cluster.
Local patterns of TDR were distinct to what had been observed provincially. Phylogenetic analysis uncovered a cluster of related infections among MSM that appeared more likely to be recent infections. Results support a paradigm of routine local TDR surveillance to identify the sub-populations under care. Furthermore, the routine application of phylogenetic analysis in the TDR surveillance context provides insights into how best to target prevention strategies; and how to correctly measure outcomes.
Full-text · Article · Oct 2013 · BMC Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: IL-7 plays an important role in T cell survival, function, and memory cell development, yet the role of cytokine signaling pathways in these processes has not been fully elucidated. Moreover, the underlying mechanisms for the observed impairment of IL-7 activity in diseases, such as HIV infection, breast cancer, and autoimmunity, are not well understood. It was therefore hypothesized that IL-7-induced signaling molecules could be linked with distinct IL-7-associated activities. To address this, the activation and functional associations of IL-7-induced signaling pathways, specifically antigen-independent activities that are relevant to T cell homeostasis, were examined. Low concentrations of IL-7 (100 pg/ml) are capable of activating the Jak-STAT and PI3K signaling pathways, whereas higher concentrations (500-1000 pg/ml) were required to induce Bcl-2 production and glucose uptake. Even higher concentrations of IL-7 (10,000 pg/ml) were needed to induce cell proliferation and intracellular accumulation of perforin. Inhibition of Jak activation reduced IL-7-induced Bcl-2 and perforin production, whereas inhibition of Jak/STAT or PI3K pathways reduced glucose uptake and proliferation. This study suggests a complex control of IL-7-associated activities in the absence of antigen stimulation. These data may provide insights into mechanisms of impaired IL-7 signaling and function in disease and could be relevant for the study of IL-7-based immunotherapeutics. Specifically, this study has linked STAT5 and PI3K activation to shared and distinct IL-7-associated activities in human CD8(+) T cells.
[Show abstract][Hide abstract] ABSTRACT: Objectives:
We determined the proportion and correlates of self-reported pregnancy planning discussions (that is preconception counseling) that HIV-positive women reported to their family physicians (FPs), HIV specialists, and obstetrician/gynecologists (OB/Gyns).
In a cross-sectional substudy, HIV-positive women of reproductive potential were asked whether their care providers discussed pregnancy planning. Logistic regression was used to calculate odds ratios for the correlates of preconception counseling.
A total of 431 eligible participants (median age 38, interquartile range = 32-43) reported having discussion with a physician (92% FP, 96% HIV specialists, and 45% OB/Gyns). In all, 34%, 41%, and 38% had their pregnancy planning discussion with FP, HIV specialist, and Ob/Gyns, respectively; 51% overall. In the multivariable model, significant correlates of preconception counseling were age (P = .02), marital status (P < .01), number of years living in Canada (P < .001), and age of youngest child (P < .01).
Preconception care in our cohort was suboptimal. We recommend that counseling on healthy preconception should be part of routine HIV care.
No preview · Article · Sep 2013 · Journal of the International Association of Providers of AIDS Care
[Show abstract][Hide abstract] ABSTRACT: IL-27, a member of the IL-12 cytokine family, is a key immunoregulatory cytokine produced predominantly by monocytic cells and mediates innate and adaptive immune responses. IL-27 has been shown to be produced by human monocytic cells primed with IFN-γ and in response to a second stimulus such as LPS. In this study, we show for the first time that IFN-γ alone without any second stimulus can induce IL-27p28 gene expression and IL-27 protein production by human monocytic cells. The signaling pathways that govern IL-27 production in general, and particularly following stimulation of monocytic cells with IFN-γ are not known. We investigated the signaling pathways governing the regulation of IL-27 protein and its subunit IL-27p28 following stimulation with IFN-γ in primary human monocytic cells. Our results suggest that IFN-γ-mediated IL-27 protein but not IL-27p28 gene expression is positively regulated by the C-Jun N-terminal kinases (JNK), mitogen-activated protein kinases (MAPKs) and the phosphoinositide 3-kinase (PI3K), independent of the Janus kinase (Jak)/signal transducers and activators of transcription (STAT) signaling in primary human monocytes.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Although some studies show higher antiretroviral concentrations in women compared to men, data are limited. We conducted a cross-sectional study of HIV-positive women to determine if protease inhibitor (PI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) Cmin and Cmax values were significantly different than historical general population (predominantly male) averages and to evaluate correlates of higher concentrations. METHODS: HIV-positive women with virologic suppression (viral load < 50copies/mL) on their first antiretroviral regimen were enrolled. Timed blood samples for Cmin and Cmax were drawn weekly for 3 weeks. The ratio of each individual's median Cmin and Cmax to the published population mean values for their PI or NNRTI was calculated and assessed using Wilcoxon sign-rank. Intra- and inter-patient variability of antiretroviral drug levels was assessed using coefficient of variation and intra-class correlation. Linear regression was used to identify correlates of the square root-transformed Cmin and Cmax ratios. RESULTS: Data from 82 women were analyzed. Their median age was 41 years (IQR=36-48) and duration of antiretrovirals was 20 months (IQR=9-45). Median antiretroviral Cmin and Cmax ratios were 1.21 (IQR=0.72-1.89, p=0.003) (highest ratios for nevirapine and lopinavir) and 0.82 (IQR=0.59-1.14, p=0.004), respectively. Nevirapine and efavirenz showed the least and unboosted atazanavir showed the most intra- and inter-patient variability. Higher CD4+ count correlated with higher Cmin. No significant correlates for Cmax were found. CONCLUSIONS: Compared to historical control data, Cmin in the women enrolled was significantly higher whereas Cmax was significantly lower. Antiretroviral Cmin ratios were highly variable within and between participants. There were no clinically relevant correlates of drug concentrations.Trial registration: http://clinicaltrials.gov/show/NCT00433979.
Full-text · Article · Jun 2013 · BMC Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Interferon (IFN)-γ is a potent stimulator of the IL-12 family Th1 cytokines, including IL-12/23p40 and IL-23, responsible for coordinating the innate and adaptive immune responses. Our results show that IFN-γ induced the production of IL-12/23p40 and IL-23p19 mRNA as well as IL-12p40 and IL-23 proteins in primary human monocytes isolated by positive selection through anti-CD14 microbeads. These results were confirmed by IFN-γ stimulation of CD14-activated monocytes resulting in IL-12/23p40 and IL-23 production. We investigated the signaling pathways governing the regulation of IL-23 and its subunits IL-23p40 and IL-23p19 following IFN-γ stimulation. We observed a differential regulation of IL-23p19, IL-12/23p40, and IL-23 following IFN-γ stimulation. IFN-γ-induced IL-23 and IL-12/23p40 expression was positively regulated by the p38 mitogen-activated protein kinases (MAPKs), independent of the Janus kinase (Jak)/signal transducers and activators of transcription (STAT) signaling. In contrast, IL-12 and IL-23 were negatively regulated by the Jak/STAT, phosphatidylinositol 3-kinase (PI3K), and the c-Jun-N-terminal kinase (JNK) MAPKs in IFN-γ-stimulated monocytes. Overall, our results suggest for the first time a differential positive regulation of IL-12p40 and IL-23 by p38 MAPKs independent of the Jak/STAT pathways and negative regulation by the Jak/STAT, JNK, and PI3K pathways in CD14-activated primary human monocytes stimulated with IFN-γ.
Full-text · Article · May 2013 · Journal of interferon & cytokine research: the official journal of the International Society for Interferon and Cytokine Research
[Show abstract][Hide abstract] ABSTRACT: Human Immunodeficiency Virus (HIV)-infected individuals have a cardiovascular disease risk that is almost thrice than that of their HIV-uninfected counterparts. Given the critical role of endothelial progenitor cells (EPCs) in vascular homeostasis and arterial repair postinjury, coupled with their strength as biomarkers predictive of cardiovascular events, interest has arisen in characterizing EPCs in the context of HIV infection. We conducted a systematic review of the literature to determine the current state of knowledge on EPCs in the context of HIV infection. Herein, we summarize the pertinent findings of these studies and discuss important differences in the subpopulations of EPCs examined and the methodologies used for their enumeration which likely contributed to the heterogeneity observed across studies.
No preview · Article · Feb 2013 · Trends in cardiovascular medicine
[Show abstract][Hide abstract] ABSTRACT: Background
The introduction of highly active antiretroviral therapy (HAART) has enabled the dramatic reduction in viral replication and the partial restoration of host immune function, albeit at the expense of drug toxicity. Strategies to enhance HIV-specific immunity are required in order to limit ART exposure. Therapeutic vaccination is a promising new approach to enhance immunogenicity and anti-viral activity in people infected with HIV.PurposeEfficient clinical trial designs are required to optimize therapeutic HIV vaccination strategies. Herein, we describe unique design features and investigational procedures that were applied to a prime-boost therapeutic vaccine trial (CTN 173) to enhance HIV immunity.MethodsCTN 173 was a multicentre, randomized, 3-arm, double-blind placebo controlled trial to evaluate anti-viral activity of therapeutic vaccination with ALVAC ± Remune in chronically infected individuals on HAART. CTN 173 was developed with the specific aim to better characterize patient factors and immunologic parameters associated with vaccine response. This paper discusses the relevance of choice of primary endpoint and statistical approach used in this trial, in relation to vaccine response, patient safety and the identification of optimal target populations for future vaccine trials.ResultsTime to event surrogate endpoints of viral response and frequent immunologic monitoring allow for a better characterization of immunologic correlates of vaccine response.LimitationsThe clinical implications of delayed viral rebound associated with therapeutic vaccination with ALVAC + Remune are not yet known and will need to be evaluated on long-term follow-up.Conclusions
Randomized controlled trials such as CTN 173, with well-defined surrogate endpoints and frequent immunologic and virologic monitoring, are necessary to streamline the approach to effective vaccine discovery and to ensure patient safety.
Full-text · Article · Dec 2012 · Trials in Vaccinology
[Show abstract][Hide abstract] ABSTRACT: Background:
HIV reservoirs represent the major obstacles for eradication and are defined as a cell type that allows persistence of replication-competent HIV in patients on optimal long-term antiretroviral therapy (HAART). Several pilot clinical trials have been implemented to assess the value of experimental therapy to reduce reservoir size or eradicate HIV. In order to eradicate HIV, valproic acid was used as a new strategy to increase viral gene expression in the nucleus of infected cells with the expectation of generating a direct cell death or destruction by nearby cytotoxic cells. Previous pilot studies using VPA have showed conflicting results on the ability of VPA to reduce the size of HIV reservoirs.
As the role of VPA on HIV reservoirs remains unclear, we conducted a multicenter clinical trial with a specific study design to obtain optimal information on reservoir changes while exposing the smallest number of individuals to the experimental medication.
To this aim, a randomized, crossover design with 2 different treatment durations was implemented. By doubling the therapeutic period in one study arm, we were in a position to assess the impact of an extended duration of VPA on the size of the HIV reservoir and to evaluate the duration of treatment effects upon VPA withdrawal in the other arm. However, limitations for this type of study design included the logistical complexity of 2 uneven study arms and longer study duration.
Despite the absence of demonstrable impact of VPA on reservoir size, such crossover study design should be considered in the early stage testing of novel HIV therapeutics targeted to reduce reservoir size or eradicate HIV.
Full-text · Article · Nov 2012 · HIV Clinical Trials