Residual viraemia in HIV-1-infected patients with plasma viral load <or=20 copies/ml is associated with increased blood levels of soluble immune activation markers

Consequences of low-level viremia among women with HIV in the United States

OBJECTIVE

Investigate the outcomes of women with HIV (WWH) with low-level viremia (LLV).

DESIGN

The prevalence of LLV and potential clinical sequelae, such as virologic failure and non-AIDS comorbidity (NACM) development, are poorly characterized among WWH.

METHODS

We analyzed data from the Women's Interagency HIV Study among WWH enrolled from 2003 to 2020 who reported antiretroviral therapy use at least 1 year followed by an HIV-1 viral load less than 200 copies/ml. Consecutive viral load measurements from four semi-annual visits were used to categorize women at baseline as having: virologic suppression (all viral load undetectable), intermittent LLV (iLLV; nonconsecutive detectable viral load up to 199 copies/ml), persistent LLV (pLLV; at least two consecutive detectable viral load up to 199 copies/ml), or virologic failure (any viral load ≥200 copies/ml). Adjusted hazard ratios quantified the association of virologic category with time to incident virologic failure and multimorbidity (≥2 of 5 NACM) over 5-year follow-up.

RESULTS

Of 1598 WWH, baseline median age was 47 years, 64% were Black, 21% Hispanic, and median CD4 + cell count was 621 cells/μl. After excluding 275 women (17%) who had virologic failure at baseline, 58, 19, and 6% were categorized as having virologic suppression, iLLV, and pLLV, respectively. Compared with WWH with virologic suppression, the adjusted hazard ratio [aHR; 95% confidence interval (CI)] for incident virologic failure was 1.88 (1.44-2.46) and 2.51 (1.66-3.79) for iLLV and pLLV, respectively; and the aHR for incident multimorbidity was 0.81 (0.54-1.21) and 1.54 (0.88-2.71) for iLLV and pLLV, respectively.

CONCLUSION

Women with iLLV and pLLV had an increased risk of virologic failure. Women with pLLV had a trend towards increased multimorbidity risk.

Viral co-infection, autoimmunity, and CSF HIV antibody profiles in HIV central nervous system escape

Antiretroviral therapy (ART) suppresses plasma and cerebrospinal fluid (CSF) HIV replication. Neurosymptomatic (NS) CSF escape is a rare exception in which CNS HIV replication occurs in the setting of neurologic impairment. The origins of NS escape are not fully understood. We performed a case-control study of asymptomatic (AS) escape and NS escape subjects with HIV-negative subjects as controls in which we investigated differential immunoreactivity to self-antigens in the CSF of NS escape by employing neuroanatomic CSF immunostaining and massively multiplexed self-antigen serology (PhIP-Seq). Additionally, we utilized pan-viral serology (VirScan) to deeply profile the CSF anti-viral antibody response and metagenomic next-generation sequencing (mNGS) for pathogen detection. We detected Epstein-Barr virus (EBV) DNA more frequently in the CSF of NS escape subjects than in AS escape subjects. Based on immunostaining and PhIP-Seq, there was evidence for increased immunoreactivity against self-antigens in NS escape CSF. Finally, VirScan revealed several immunodominant epitopes that map to the HIV envelope and gag proteins in the CSF of AS and NS escape subjects. Whether these additional inflammatory markers are byproducts of an HIV-driven process or whether they independently contribute to the neuropathogenesis of NS escape will require further study.

Persistent low-Level viremia in persons living with HIV undertreatment: An unresolved status

Antiretroviral therapy (ART) allows suppressed viremia to reach less than 50 copies/mL in most treated persons living with HIV (PLWH). However, the existence of PLWH that show events of persistent low-level viremia (pLLV) between 50 and 1000 copies/mL and with different virological consequences have been observed. PLLV has been associated with higher virological failure (VF), viral genotype resistance, adherence difficulties and AIDS events. Moreover, some reports show that pLLV status can lead to residual immune activation and inflammation, with an increased risk of immunovirological failure and a pro-inflammatory cytokine level which can lead to a higher occurrence of non-AIDS defining events (NADEs) and other adverse clinical outcomes. Until now, however, published data have shown controversial results that hinder understanding of the true cause(s) and origin(s) of this phenomenon. Molecular mechanisms related to viral reservoir size and clonal expansion have been suggested as the possible origin of pLLV. This review aims to assess recent findings to provide a global view of the role of pLLV in PLWH and the impact this status may cause on the clinical progression of these patients.

A Step Closer to the "Fourth 90": A Practical Narrative Review of Diagnosis and Management of Nutritional Issues of People Living with HIV

The quality of life of people living with HIV (PLWH) has remarkably increased thanks to the introduction of combined antiretroviral therapy. Still, PLWH are exposed to an increased risk of cardiovascular diseases, diabetes, chronic kidney disease, and liver disease. Hence, the purpose of this review is to summarize the current knowledge about diagnosis and nutritional management with specific indication of macro and micronutrients intake for the main comorbidities of PLWH. In fact, a prompt diagnosis and management of lifestyle behaviors are fundamental steps to reach the "fourth 90". To achieve an early diagnosis of these comorbidities, clinicians have at their disposal algorithms such as the Framingham Score to assess cardiovascular risk; transient elastography and liver biopsy to detect NAFLD and NASH; and markers such as the oral glucose tolerance test and GFR to identify glucose impairment and renal failure, respectively. Furthermore, maintenance of ideal body weight is the goal for reducing cardiovascular risk and to improve diabetes, steatosis and fibrosis; while Mediterranean and low-carbohydrate diets are the dietetic approaches proposed for cardioprotective effects and for glycemic control, respectively. Conversely, diet management of chronic kidney disease requires different nutritional assessment, especially regarding protein intake, according to disease stage and eventually concomitant diabetes.

High residual inflammation despite HIV viral suppression: Lessons learned from real-time adherence monitoring among people with HIV in Africa

BACKGROUND

Lower antiretroviral therapy (ART) adherence is associated with higher systemic inflammation in virally suppressed people with HIV (PWH); however, previous studies have mostly relied on subjective adherence measures and have not assessed this association by disease stage upon ART initiation.

METHODS

In the Monitoring Early Treatment Adherence study, adherence was monitored electronically in real time among adult, treatment-naïve PWH in Uganda and South Africa who initiated tenofovir disoproxil fumarate/emtricitabine/efavirenz during early-stage (CD4 > 350 cells/µL) or late-stage (CD4 < 200 cells/µL) disease. Participants who achieved viral suppression (< 400 copies/mL) at 6 months and remained suppressed after 12 months were analysed. The association between average ART adherence and plasma concentrations of interleukin 6 (IL-6), soluble CD14 (sCD14) and D-dimer was evaluated using adjusted multivariable linear regression, stratified by disease stage.

RESULTS

In all, 488 PWH (61% women, mean age 35 years) were included in the analysis. Median ART adherence overall was 87%. In adjusted models, every 10% increase in average adherence was associated with a 3.0% decrease in IL-6 [95% confidence interval (CI): -5.9 to -0.01, p = 0.05] at 12 months. This relationship was observed in PWH with both early-stage (5.9%, 95% CI: -10.1 to -1.6, p = 0.009) and late-stage disease (3.7%, 95% CI: -7.2 to -0.2, p = 0.039). No significant associations were found with sCD14 or D-dimer.

CONCLUSIONS

Objective ART adherence measurement was inversely associated with systemic inflammation in PWH who achieved viral suppression after ART initiation in sub-Saharan Africa, with a greater association in those with early-stage HIV. This finding underscores the importance of ART adherence beyond establishing viral suppression.

How elite controllers and posttreatment controllers inform our search for an HIV-1 cure

A small percentage of people living with HIV-1 can control viral replication without antiretroviral therapy (ART). These patients are called elite controllers (ECs) if they are able to maintain viral suppression without initiating ART and posttreatment controllers (PTCs) if they control HIV replication after ART has been discontinued. Both types of controllers may serve as a model of a functional cure for HIV-1 but the mechanisms responsible for viral control have not been fully elucidated. In this review, we highlight key lessons that have been learned so far in the study of ECs and PTCs and their implications for HIV cure research.

Cell-Associated HIV-1 Unspliced-to-Multiply-Spliced RNA Ratio at 12 Weeks of ART Predicts Immune Reconstitution on Therapy

Human immunodeficiency virus (HIV) infection is currently managed by antiretroviral drugs, which block virus replication and promote immune restoration. However, the latter effect is not universal, with a proportion of infected individuals failing to sufficiently reconstitute their immune function despite a successful virological response to antiretroviral therapy (ART).

Incomplete restoration of CD4⁺ T-cell counts on antiretroviral therapy (ART) is a major predictor of HIV-related morbidity and mortality. To understand the possible mechanisms behind this poor immunological response despite viral suppression, we longitudinally measured more than 50 virological and immunological biomarkers in a cohort of HIV-infected individuals at several time points during the first 96 weeks of virologically suppressive ART. No baseline virological or immunological marker was predictive of the degree of immune reconstitution. However, the cell-associated HIV-1 unspliced-to-multiply-spliced (US/MS) RNA ratio at 12 weeks of ART positively correlated with markers of CD4⁺ T-cell activation and apoptosis and negatively predicted both the absolute and relative CD4⁺ T-cell counts at 48 and 96 weeks. A higher US/MS RNA ratio may reflect the higher frequency of productively infected cells that could exert pressure on the immune system, contributing to persistent immune activation and apoptosis and subsequently to a poor immunological response to ART.

Association of Incomplete Adherence to Antiretroviral Therapy With Cardiovascular Events and Mortality in Virologically Suppressed Persons With HIV: The Swiss HIV Cohort Study

BACKGROUND

Incomplete antiretroviral therapy (ART) adherence, even if sufficient to maintain viral suppression, is associated with enhanced inflammation in persons with HIV (PWH). However, its clinical implications remain unknown.

METHODS

PWH enrolled in the Swiss HIV Cohort Study without a history of cardiovascular disease (CVD) who initiated ART between 2003 and 2018 and had viral suppression (<50 copies/mL) for ≥6 months were evaluated. The association between incomplete self-reported ART adherence (≥1 or ≥2 missed doses in the last month) and (1) any CVD event (myocardial infarction, revascularization, cerebral hemorrhage, stroke, and/or death due to CVD event) or (2) non-CVD-related death was evaluated using adjusted Cox proportional hazards models.

RESULTS

A total of 6971 PWH (74% male) were included in the analysis (median age [interquartile range {IQR}], 39 [32-47] years). The median (IQR) follow-up was 8 (4-11) years, with 14 (8-23) adherence questionnaires collected per participant. In total, 205 (3%) participants experienced a CVD event, and 186 (3%) died a non-CVD-related death. In an adjusted competing risk model where missing data were imputed, missing ≥1 ART dose showed an increased, but not statistically significant, risk for CVD events (hazard ratio [HR], 1.23; 95% CI, 0.85-1.79; P = .28). Non-CVD-related mortality showed a statistically significantly increased risk with missing ≥1 ART dose (HR, 1.44; 95% CI, 1.00-2.07; P = .05) and missing ≥2 ART doses (HR, 2.21; 95% CI, 1.37-3.57; P = .001).

CONCLUSIONS

Incomplete ART adherence was significantly associated with an increased risk for non-CVD-related mortality in PWH with virologic suppression. This highlights the potential role of nonadherence to ART as a driver of non-AIDS clinical outcomes.

Antiretroviral Therapy Reduces T-cell Activation and Immune Exhaustion Markers in Human Immunodeficiency Virus Controllers

BACKGROUND

Despite low plasma human immunodeficiency virus (HIV) RNA, HIV controllers have evidence of viral replication and elevated inflammation. We assessed the effect of antiretroviral therapy (ART) on HIV suppression, immune activation, and quality of life (QoL).

METHODS

A5308 was a prospective, open-label study of rilpivirine/emtricitabine/tenofovir disoproxil fumarate in ART-naive HIV controllers (N = 35), defined as having HIV RNA <500 copies/mL for ≥12 months. The primary outcome measured change in %CD38+HLA-DR+ CD8+ T cells. Residual plasma viremia was measured using the integrase single-copy assay. QoL was measured using the EQ-5D questionnaire. Outcomes were evaluated using repeated measures general estimating equations models.

RESULTS

Before ART, HIV controllers with undetectable residual viremia <0.6 HIV-1 RNA copies/mL had higher CD4+ counts and lower levels of T-cell activation than those with detectable residual viremia. ART use was effective in further increasing the proportion of individuals with undetectable residual viremia (pre-ART vs after 24-48 weeks of ART: 19% vs 94%, P < .001). Significant declines were observed in the %CD38+HLA-DR+CD8+ T cells at 24-48 (-4.0%, P = .001) and 72-96 (-7.2%, P < .001) weeks after ART initiation. ART use resulted in decreases of several cellular markers of immune exhaustion and in a modest but significant improvement in self-reported QoL. There were no significant changes in CD4+ counts or HIV DNA.

CONCLUSIONS

ART in HIV controllers reduces T-cell activation and improves markers of immune exhaustion. These results support the possible clinical benefits of ART in this population.

Dysfunctional Immunometabolism in HIV Infection: Contributing Factors and Implications for Age-Related Comorbid Diseases

PURPOSE OF REVIEW

An increasing body of evidence indicates that persons living with HIV (PLWH) display dysfunctional immunometabolism. Here, we provide an updated review of this topic and its relationship to HIV-associated immune stimuli and age-related disease.

RECENT FINDINGS

HIV infection alters immunometabolism by increasing reliance on aerobic glycolysis for energy and productive infection and repurposing oxidative phosphorylation machinery for immune cell proliferation and survival. Recent studies in PLWH with diabetes mellitus or cardiovascular disease have identified an association with elevated T cell and monocyte glucose metabolism, respectively. Immunometabolic dysfunction has also been observed in PLWH in frailty and additional studies suggest a role for immunometabolism in non-AIDS defining cancers and neurocognitive disease. There is a plethora of HIV-associated immune stimuli that could drive immunometabolic dysfunction and age-related disease in PLWH, but studies directly examining their relationship are lacking. Immunometabolic dysfunction is characteristic of HIV infection and is a potential link between HIV-associated stimuli and age-related comorbidities.

Initiation of Antiretroviral Therapy Differentially Influences Genital and Systemic Immune Activation in HIV-Infected Women

Antiretroviral therapy (ART) has significantly improved the quality of life of HIV-infected individuals: reducing plasma viremia, restoring CD4⁺ T cell numbers, and correcting imbalances in blood memory T cell subsets. While ART improves immune correlates at mucosal sites, including the lower female genital tract (FGT), ART initiation has been associated with reactivation of common FGT infections. We investigated the effect of ART on immune activation and inflammation in the genital tract. We measured blood and genital T cell activation, proliferation, and immunosenescence (CD38, HLADR, Ki67, CD127, and CD57), and cytokine levels in women on ART for ∼7 years (cross-sectional analysis) or initiating ART (immediately before and 1 month after). Effector memory T cells predominated in blood and FGT during chronic infection, irrespective of ART status. In women initiating ART, 1 month was insufficient for T cell reconstitution, or alterations in T cell subset distribution, despite both plasma and genital viral loads decreasing to undetectable levels in most participants. Initiating ART was accompanied by a decline in plasma IP-10 that correlated with decreased blood CD38 expression in blood (p = .0204) but not in the FGT. The reduction in plasma (but not genital) cytokine levels due to ART initiation was dependent on their concentrations before treatment. While T cell activation decreased significantly in blood (CD4: p = .032; CD8: p = .0137), activation levels remained similar in the genital tract despite 1 month of treatment. Overall, the decrease in cellular activation and inflammation seen in blood with ART initiation was not evident in the FGT.

Partial Normalization of Biomarkers of Inflammation and Immune Activation Among Virally Suppressed Men With HIV Infection and High ART Adherence

Background

The objective of this study was to investigate whether 100% antiretroviral therapy (ART) adherence in men with HIV (MWH) is associated with normalization of concentrations of biomarkers of inflammation and immune activation compared with HIV-uninfected men.

Methods

We analyzed person-visits with available biomarker data from the Multicenter AIDS Cohort Study (MACS) among MWH receiving ART with HIV RNA <50 copies/mL and among HIV-uninfected men. Self-reported adherence was classified as 100% if no missed ART doses in the past 4 days were reported. We evaluated associations between ART adherence and concentrations of 24 serum biomarkers compared with HIV-uninfected visits using a generalized gamma model, adjusting for potential confounders.

Results

Person-visits (2565 from MWH reporting 100% ART adherence and 1588 from HIV-uninfected men) from a total of 1469 men were included in the analysis. Serum concentrations of interleukin-6 (IL-6), soluble interleukin-6 receptor (sIL-6R), IL-1β, interferon-γ (IFN-γ), chemokine C-C motif ligand 2 (CCL2), and CCL14 from person-visits among MWH who reported 100% adherence were similar to HIV-uninfected person-visits. Comparatively higher concentrations of 11 biomarkers and lower concentrations of 7 biomarkers were observed in person-visits from MWH who reported 100% ART adherence, compared with HIV-uninfected person-visits.

Conclusions

Although MWH with virologic suppression who reported 100% ART adherence exhibited overall higher concentrations of biomarkers of inflammation and immune activation compared with HIV-uninfected men, some biomarker concentrations were similar in both groups. These findings suggest that optimal ART adherence could have clinical implications beyond achieving and sustaining viral suppression.

Association of Low Vitamin D with Complications of HIV and AIDS: A literature Review

With the advent of combination antiretroviral therapy (cART), the survival of HIV patients has improved dramatically, but the complications of the disease and treatment have become an important issue in the management of HIV patients. Vitamin-D deficiency is common in HIV patients. Low vitamin-D is associated with different comorbidities in the HIV uninfected general population. In this review, we first briefly describe vitamin D synthesis and mechanism of action and we focus on the epidemiological and clinical data dealing with the relationship between vitamin D deficiency in HIV infection with several comorbidities which has been found to be increasingly common in patients living with HIV infection. We searched the PubMed database using the keywords "HIV," "vitamin D" and other common disorders or conditions that are relatively common in HIV infection. The other conditions included in the search were osteoporosis and fracture, cardiovascular disease, diabetes and insulin resistance, active tuberculosis, hepatitis-C co-infection, and HIV disease progression. Articles presenting original data as well as systematic reviews and met analysis related to HIV population were included in our analysis. Vitamin-D deficiency seems to be associated with several adverse outcomes in HIV patients but a definite cause and effect relationship with vitamin-D is yet to be confirmed in most of the cases. However, the literature supporting the efficacy of vitamin-D supplementation is lacking.

Ultrasensitive Human Immunodeficiency Virus Type 1 Viral Load as a Marker of Treatment Choice for Simplification Strategies

Background

Using 3 randomized Protease inhibitor (PI) monotherapy studies: Kalesolo, Dream and Monoi, we performed a pooled-analysis. Our objective was to determine in PI monotherapy and standard tritherapy: 1) distribution of ultrasensitive viral load (USVL) at week 96 (W96); 2) factors associated with virological failure (VF) at W96 and 3) factors associated with USVL<1 copy at W96.

Methods

VF was defined as 2 consecutive measurements of Human Immunodeficiency Virus Type 1 RNA viral load>50 copies/mL and analysed in Intention-To-Treat. A logistic model was used to investigate which variables were predictive of a VF and Fisher test to investigate differences in USVL at W96.

Results

Among 609 patients, 73% were male with median age of 44.4 years (IQR 39.8-52.1), baseline CD4/CD8 ratio was 0.8 (IQR 0.6-1.10), baseline CD4 was 564.5/mm3 (IQR 422-707) and 59% presented a baseline USVL<1 copy/mL. At W96, the proportion of USVL<1 copy/mL was significantly different between PI monotherapy and standard tritherapy in pooled-analysis (65% versus 74%; p=0.04). Overall, baseline USVL<1copy/mL, tritherapy and to be a female were associated with USVL<1 copy/mL at W96 (p<0.0001, p=0.049 and p=0.006). In PI monotherapy receiving DRV/r was associated with USVL<1 copy/mL at W96 (p=0.003). Factors associated to virological succes at W96 were higher baseline CD4 (p=0.034) and baseline USVL<1 copy/mL (p=0.0005).

Conclusion

Pooled-analysis of 3 PI monotherapy trials showed better efficacy of tritherapy in terms of USVL at W96. Furthermore regarding USVL at W96, to receive LPV/r seems to be more deleterious than DRV/r. Baseline USVL impacts VF at W96 more specifically in tritherapy arm.

Clinical Trials Registration

NCT00421551, NCT00946595, and NCT00140751.

Learning From the Exceptions: HIV Remission in Post-treatment Controllers

Among the top priorities of the HIV field is the search for therapeutic interventions that can lead to sustained antiretroviral therapy (ART)-free HIV remission. Although the majority of HIV-infected persons will experience rapid viral rebound after ART interruption, there are rare individuals, termed post-treatment controllers (PTCs), who demonstrate sustained virologic suppression for months or years after treatment cessation. These individuals are considered an ideal example of durable HIV control, with direct implications for HIV cure research. However, understanding of the mechanisms behind the capacity of PTCs to control HIV remains incomplete. This is in part due to the scarcity of PTCs identified through any one research center or clinical trial, and in part because of the limited scope of studies that have been performed in these remarkable individuals. In this review, we summarize the results of both clinical and basic research studies of PTCs to date, explore key differences between PTCs and HIV spontaneous controllers, examine potential mechanisms of post-treatment control, and discuss unanswered questions and future research directions in this field.

Changing concepts of HIV infection and renal disease

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) was identified as the major renal manifestation of HIV infection early in the HIV epidemic. However, HIV infection now is associated with a different spectrum of renal lesions leading to chronic kidney disease. This review examines the changes in kidney injury occurring in the current HIV era and the factors involved in this transformation of disease expression.

RECENT FINDINGS

The incidence of HIVAN and opportunistic infections in HIV-infected individuals has declined in concert with the use of effective combination antiretroviral agents. Chronic kidney disease has become more prevalent as patients infected with HIV are living longer and developing non-HIV-associated diseases such as hypertension and diabetes. Additionally, noncollapsing focal and segmental glomerulosclerosis, co-infection with hepatitis C, HIV-associated immune complex kidney disease, HIV-related accelerated aging, and antiretroviral therapies contribute to progressive loss of renal function.

SUMMARY

HIV infection is now associated with a variety of renal lesions causing chronic kidney disease, not all of which are virally induced. It is important to determine the cause of renal functional decline in an HIV-infected patient, as this will impact patient management and prognosis.

Monotypic low-level HIV viremias during antiretroviral therapy are associated with disproportionate production of X4 virions and systemic immune activation

OBJECTIVE

During effective antiretroviral therapy (ART), low-level plasma viremias (LLV) (HIV RNA >30-1000 copies/ml) can be detected intermittently. We hypothesized that systemic inflammation is associated with LLV either as the cause or result of the production of virions from clonally expanded cells.

METHODS

Prospective cohort study of HIV-infected ART-naive Peruvians enrolled prior to ART and followed for 2 years. Plasma HIV RNA and peripheral blood mononuclear cell (PBMC) HIV DNA concentrations were quantified pre-ART from individuals whose plasma HIV RNA was ART-suppressed. Inflammatory biomarker concentrations were measured pre and during ART. Single-genome amplification (SGA) derived HIV env and pol genotypes from pre-ART and LLV specimens. Antiretroviral levels during ART assessed adherence. Statistical associations and phylogenetic relationships were examined.

RESULTS

Among 82 participants with median plasma HIV RNA less than 30 copies/ml, LLV were detected in 33 of 82 (40%), with a LLV median HIV RNA of 73 copies/ml. Participants with vs. without LLV had significantly higher pre-ART plasma HIV RNA (P < 0.001) and PBMC HIV DNA (P < 0.007); but, during ART, their antiretroviral drug levels were similar. LLV env sequences were monotypic in 17 of 28 (61%) and diverse in 11 of 28 (39%) participants. Those with the monotypic vs. diverse LLV pattern had elevated hsCRP and sCD163 (P = 0.004) and LLV with more X4 variants (P = 0.02).

CONCLUSION

In individuals with monotypic LLV sequences, higher levels of pre-ART HIV DNA and RNA, systemic inflammation and X4 viruses suggest an interaction between inflammation and the production of virions from proliferating infected cells, and that naïve T cells may be a source of LLV.

Brief Report: Higher ART Adherence Is Associated With Lower Systemic Inflammation in Treatment-Naive Ugandans Who Achieve Virologic Suppression

BACKGROUND

Residual systemic inflammation persists despite suppressive antiretroviral therapy (ART) and is associated with non-AIDS clinical outcomes. We aimed to evaluate the association between ART adherence and inflammation in Ugandans living with HIV who were predominantly receiving nevirapine-based ART with a thymidine analog backbone and were virologically suppressed by conventional assays.

METHODS

Plasma concentrations of interleukin-6 (IL-6), D-dimer, soluble (s)CD14, sCD163, and the kynurenine/tryptophan ratio, in addition to CD8 T-cell activation, were measured at baseline and 6 months after ART initiation in treatment-naive adults who achieved an undetectable plasma HIV RNA (<400 copies/mL) at their 6-month visit. Adherence was measured through medication event monitoring system and calculated as the ratio of observed/prescribed device openings per participant. We fit adjusted linear regression models to estimate the association between ART adherence and the log-transformed plasma concentrations of inflammatory biomarkers.

RESULTS

We evaluated 282 participants (median age, 35 years; 70% women). The median (interquartile range) adherence was 93% (84-98). In the adjusted analyses, for every 10% increase in average ART adherence, we found a 15% [P < 0.0001; 95% confidence interval (CI), -21.0 to -7.9], 11% (P = 0.017; 95% CI, -18.3 to -2.0), and 3% (P = 0.028; 95% CI, -5.0 to -0.3) decrease in IL-6, D-dimer, and sCD14, respectively.

CONCLUSIONS

Higher ART adherence was associated with lower levels of biomarkers of inflammation, immune activation, and coagulopathy among Ugandans living with HIV who achieved viral suppression shortly after ART initiation. This suggests that ART adherence could have biological consequences beyond viral suppression. Whether ART adherence optimization in virologically suppressed individuals could reduce residual inflammation remains unknown.

Frontline Science: Plasma and immunoglobulin G galactosylation associate with HIV persistence during antiretroviral therapy

Global antibody glycosylation is dynamic and plays critical roles in shaping different immunological outcomes and direct antibody functionality during HIV infection. However, the relevance of global antibody or plasma glycosylation patterns to HIV persistence after antiretroviral therapy (ART) has not been characterized. First, we compared glycomes of total plasma and isolated immunoglobulin G (IgG) from HIV+ ART-suppressed, HIV+ viremic, and HIV-negative individuals. Second, in ART-suppressed individuals, we examined the associations between glycomes and (1) levels of cell-associated HIV DNA and RNA in PBMCs and isolated CD4+ T cells, (2) CD4 count and CD4%, and (3) expression of CD4+ T-cell activation markers. HIV infection is associated with persistent alterations in the IgG glycome including decreased levels of disialylated glycans, which is associated with a lower anti-inflammatory activity, and increased levels of fucosylated glycans, which is associated with lower antibody-dependent cell-mediated cytotoxicity (ADCC). We also show that levels of certain mono- and digalactosylated nonfucosylated glycomic traits (A2G1, A2G2, and A2BG2), which have been reported to be associated with higher ADCC and higher anti-inflammatory activities, exhibit significant negative correlations with levels of cell-associated total HIV DNA and HIV RNA in ART-suppressed individuals. Finally, levels of certain circulating anti-inflammatory glycans are associated with higher levels of CD4 T cells and lower levels of T-cell activation. Our findings represent the first proof-of-concept evidence that glycomic alterations, known to be associated with differential states of inflammation and ADCC activities, are also associated with levels of HIV persistence in the setting of ART suppression.

Expression of TIM-3 on Plasmacytoid Dendritic Cells as a Predictive Biomarker of Decline in HIV-1 RNA Level during ART

Depletion and functional impairment of circulating plasmacytoid dendritic cells (pDCs) are characteristic attributes of HIV-1-infection. The mechanism of dysfunction of pDCs is unclear. Here, we studied the development of phenotype of pDCs in a cohort of HIV-1-infected individuals monitored before the initiation and during a 9-month follow up with antiretroviral therapy (ART). Using polychromatic flow cytometry, we detected significantly higher pDC-surface expression of the HIV-1 receptor CD4, regulatory receptor BDCA-2, Fc&gamma; receptor CD32, pDC dysfunction marker TIM-3, and the marker of killer pDC, TRAIL, in treatment-na&iuml;ve HIV-1-infected individuals before initiation of ART when compared to healthy donors. After 9 months of ART, all of these markers approached but did not reach the expression levels observed in healthy donors. We found that the rate of decline in HIV-1 RNA level over the first 3 months of ART negatively correlated with the expression of TIM-3 on pDCs. We conclude that immunogenic phenotype of pDCs is not significantly restored after sustained suppression of HIV-1 RNA level in ART-treated patients and that the level of the TIM-3 expressed on pDCs in treatment na&iuml;ve patients could be a predictive marker of the rate of decline in the HIV-1 RNA level during ART.

[Arterial hemodynamic parameters and cardiovascular risk in HIV patients with controlled infection]

Although viral replication is apparently controlled with highly active antiretroviral therapy, cardiovascular risk of patients living with HIV remains a concern in clinical practice with population ageing. Cardiovascular risk profile in patients living with HIV is changing with the emergence of new parameters related to the persistence of residual viral replication, the antecedent and severity of immunodepression, the resulting chronic inflammation, as well as prolonged exposure to antiretroviral drugs and "classical" cardiovascular risk factors. Estimating risk models in patients living with HIV are not sufficient to integrate duration of exposure and control quality of all cardiovascular risk factors at the individual level. Aortic stiffness is a marker of the alteration of structural and functional properties of the wall of the large arterial trunks. This marker has an independent predictive value for total and cardiovascular mortality in the general population but also in the presence of risk factors and may offer clinical information about accelerated vascular ageing in people living with HIV. Aortic stiffness can be estimated non-invasively by applanation tonometry with carotid-femoral pulse wave velocity. This measure may be useful in clinical practice for early identification of at risk patients. Study of the determinants of aortic stiffening process in this population may optimize cardiovascular prevention.

Association of Suboptimal Antiretroviral Therapy Adherence With Inflammation in Virologically Suppressed Individuals Enrolled in the SMART Study

Suboptimal (ie, <100%) antiretroviral therapy (ART) adherence has been associated with heightened inflammation in cohort studies, even among people with virologic suppression. We aimed to evaluate this association among participants in the Strategies for Management of Antiretroviral Therapy (SMART) study who had virologic suppression (HIV-1 VL < 200 copies/mL) at enrollment. Based on self-reported adherence (7-day recall), plasma concentrations of interleukin 6 and D-dimer were 9% (95% confidence interval [CI], 1%-18%; P = .02) and 11% (95% CI, 1%-22%; P = .03) higher in participants who reported suboptimal vs 100% adherence, respectively. These findings confirm previous observations and support the hypothesis that suboptimal ART adherence, even in the context of virologic suppression, may have significant biological consequences. ClinicalTrials.gov number NCT00027352.

Time course of cellular HIV-DNA and low-level HIV viremia in HIV-HCV co-infected patients whose HCV infection had been successfully treated with directly acting antivirals

This longitudinal study described cellular HIV-DNA changes and their correlation with HIV low-level plasma viremia (LLV) in HIV-HCV co-infected patients on successful antiretroviral and anti-HCV therapy by treatment with direct-acting antivirals (DAA). Thirty-nine patients were examined prior to the start of DAA (T0), after week 12 (T1) and 24 weeks (T2) of anti-HCV therapy. Cellular PBMC HIV-DNA was analysed as an absolute value and as the percentage of increase or decrease from T0 to T2. Patients were classified as having undetectable plasma HIV viraemia (UV) or LLV in the year before the start of anti-HCV treatment and within the T0-T2 study period. Thirty-five patients (89.7%) of the 39 subjects enrolled had the same plasma HIV viraemia control in the year before HCV treatment and in the T0-T2 interval. The HIV-DNA value at T0 and at T2 was higher in patients with LLV than in subjects with UV (p = 0.015 and p = 0.014, respectively). A similar proportion of patients with LLV and UV experienced an increase or decrease of HIV-DNA from T0 to T2. The percentage increase in HIV-DNA value (262.8%) from T0 to T2 was higher compared to the decrease (43.5%) in patients with UV (p = 0.012), and it was higher compared to the percentage increase in HIV-DNA value reported in subjects with LLV (262.8 versus 49%, p = 0.026). HIV-HCV co-infected patients experienced a multifaceted perturbation of cellular HIV-DNA levels within a 24-week period during anti-HCV treatment; the extent of the phenomenon was greater in subjects with UV. Fast HCV-RNA clearance seemed to have a greater influence on the cellular reservoir than on plasma HIV-RNA.

Differences in serum IgA responses to HIV-1 gp41 in elite controllers compared to viral suppressors on highly active antiretroviral therapy

Mechanisms responsible for natural control of human immunodeficiency type 1 (HIV) replication in elite controllers (EC) remain incompletely defined. To determine if EC generate high quality HIV-specific IgA responses, we used Western blotting to compare the specificities and frequencies of IgA to HIV antigens in serum of gender-, age- and race-matched EC and aviremic controllers (HC) and viremic noncontrollers (HN) on highly active antiretroviral therapy (HAART). Concentrations and avidity of IgA to HIV antigens were measured using ELISA or multiplex assays. Measurements for IgG were performed in parallel. EC were found to have stronger p24- and V1V2-specific IgG responses than HN, but there were no IgG differences for EC and HC. In contrast, IgA in EC serum bound more frequently to gp160 and gag proteins than IgA in HC or HN. The avidity of anti-gp41 IgA was also greater in EC, and these subjects had stronger IgA responses to the gp41 heptad repeat region 1 (HR1), a reported target of anti-bacterial RNA polymerase antibodies that cross react with gp41. However, EC did not demonstrate greater IgA responses to E. coli RNA polymerase or to peptides containing the shared LRAI sequence, suggesting that most of their HR1-specific IgA antibodies were not induced by intestinal microbiota. In both EC and HAART recipients, the concentrations of HIV-specific IgG were greater than HIV-specific IgA, but their avidities were comparable, implying that they could compete for antigen. Exceptions were C1 peptides and V1V2 loops. IgG and IgA responses to these antigens were discordant, with IgG reacting to V1V2, and IgA reacting to C1, especially in EC. Interestingly, EC with IgG hypergammaglobulinemia had greater HIV-specific IgA and IgG responses than EC with normal total IgG levels. Heterogeneity in EC antibody responses may therefore be due to a more focused HIV-specific B cell response in some of these individuals. Overall, these data suggest that development of HIV-specific IgA responses and affinity maturation of anti-gp41 IgA antibodies occurs to a greater extent in EC than in subjects on HAART. Future studies will be required to determine if IgA antibodies in EC may contribute in control of viral replication.

Coronary artery endothelial dysfunction is present in HIV-positive individuals without significant coronary artery disease

OBJECTIVE

HIV-positive (HIV+) individuals experience an increased burden of coronary artery disease (CAD) not adequately accounted for by traditional CAD risk factors. Coronary endothelial function (CEF), a barometer of vascular health, is depressed early in atherosclerosis and predict future events but has not been studied in HIV+ individuals. We tested whether CEF is impaired in HIV+ patients without CAD as compared with an HIV-negative (HIV-) population matched for cardiac risk factors.

DESIGN/METHODS

In this observational study, CEF was measured noninvasively by quantifying isometric handgrip exercise-induced changes in coronary vasoreactivity with MRI in 18 participants with HIV but no CAD (HIV+CAD-, based on prior imaging), 36 age-matched and cardiac risk factor-matched healthy participants with neither HIV nor CAD (HIV-CAD-), 41 patients with no HIV but with known CAD (HIV-CAD+), and 17 patients with both HIV and CAD (HIV+CAD+).

RESULTS

CEF was significantly depressed in HIV+CAD- patients as compared with that of risk-factor-matched HIV-CAD- patients (P < 0.0001) and was depressed to the level of that in HIV- participants with established CAD. Mean IL-6 levels were higher in HIV+ participants (P < 0.0001) and inversely related to CEF in the HIV+ patients (P = 0.007).

CONCLUSION

Marked coronary endothelial dysfunction is present in HIV+ patients without significant CAD and is as severe as that in clinical CAD patients. Furthermore, endothelial dysfunction appears inversely related to the degree of inflammation in HIV+ patients as measured by IL-6. CEF testing in HIV+ patients may be useful for assessing cardiovascular risk and testing new CAD treatment strategies, including those targeting inflammation.

Serious Non-AIDS Events: Therapeutic Targets of Immune Activation and Chronic Inflammation in HIV Infection

In the antiretroviral therapy (ART) era, serious non-AIDS events (SNAEs) have become the major causes of morbidity and mortality in HIV-infected persons. Early ART initiation has the strongest evidence for reducing SNAEs and mortality. Biomarkers of immune activation, inflammation and coagulopathy do not fully normalize despite virologic suppression and persistent immune activation is an important contributor to SNAEs. A number of strategies aimed to reduce persistent immune activation including ART intensification to reduce residual viremia; treatment of co-infections to reduce chronic antigen stimulation; the use of anti-inflammatory agents, reducing microbial translocation as well as interventions to improve immune recovery through cytokine administration and reducing lymphoid tissue fibrosis, have been investigated. To date, there is little conclusive evidence on which strategies beyond treatment of hepatitis B and C co-infections and reducing cardiovascular risk factors will result in clinical benefits in patients already on ART with viral suppression. The use of statins seems to show early promise and larger clinical trials are underway to confirm their efficacy. At this stage, clinical care of HIV-infected patients should therefore focus on early diagnosis and prompt ART initiation, treatment of active co-infections and the aggressive management of co-morbidities until further data are available.

Characterizing Patients with Very-Low-Level HIV Viremia: A Community-Based Study

OBJECTIVE

Very-low-level viremia (VLLV) is a relatively new concept in the realm of human immunodeficiency virus (HIV) care. Newer generation assays are now able to detect plasma HIV RNA Viral Load (VL) levels as low as 20 copies/mL. The authors characterized patients with VLLV (VL between 20 and 50 copies/mL) in order to identify possible risk factors associated with virologic failure and poor clinical outcomes.

METHODS

The authors reviewed 119 consecutive charts of patients with VLLV. Sociodemographic data were extracted and viral load and CD4 counts were trended over a 12 month period (February 2013-February 2014). Regression analysis was used to assess the role of different factors on virologic failure at 1 year.

RESULTS

Of the study participants with evaluable data (n = 100), the median age was 53 years (interquartile range: 43-57.5), 67% were nonwhite, 34% were women, 58% were smokers, 47% were alcoholics, 58% had a history of intravenous drug use, and 40% were coinfected with hepatitis C virus. More than half of the participants had 3 or more comorbidities and their HIV pill burden was high (more than 2 pills daily). After 12 months, 65 participants achieved undetectable viral load levels, whereas 15 experienced virologic failure (2 consecutive viral loads > 50 copies/mL) and the remaining 20 had persistent VLLV. In the virologic failure group, there was a predominance of white males (66%) with a significant number of comorbidities and pill burden. Univariate logistic regression suggested that there was a difference between the failure versus nonfailure groups in terms of race, ethnicity, and alcohol use. Multivariate regression with virological failure as the outcome suggested a trend only in terms of participant's alcohol use.

CONCLUSION

Most patients with initial VLLV (70%) achieved virologic suppression at 1 year with no antiretroviral therapy changes. Thus, VLLV does not necessarily predict virologic failure and should not prompt more frequent clinic visits or antiretroviral regimen changes. Further research is needed in order to determine the predictors of virologic failure in this subset of patients and the clinicians' attitude toward VLLV.

Plasma CXCL10, sCD163 and sCD14 Levels Have Distinct Associations with Antiretroviral Treatment and Cardiovascular Disease Risk Factors

We investigate the associations of three established plasma biomarkers in the context of HIV and treatment-related variables including a comprehensive cardiovascular disease risk assessment, within a large ambulatory HIV cohort. Patients were recruited in 2010 to form the Royal Perth Hospital HIV/CVD risk cohort. Plasma sCD14, sCD163 and CXCL10 levels were measured in 475 consecutive patients with documented CVD risk (age, ethnicity, gender, smoking, blood pressure, BMI, fasting metabolic profile) and HIV treatment history including immunological/virological outcomes. The biomarkers assessed showed distinct associations with virological response: CXCL10 strongly correlated with HIV-1 RNA (p<0.001), sCD163 was significantly reduced among 'aviraemic' patients only (p = 0.02), while sCD14 was unaffected by virological status under 10,000 copies/mL (p>0.2). Associations between higher sCD163 and protease inhibitor therapy (p = 0.05) and lower sCD14 with integrase inhibitor therapy (p = 0.02) were observed. Levels of sCD163 were also associated with CVD risk factors (age, ethnicity, HDL, BMI), with a favourable influence of Framingham score <10% (p = 0.04). Soluble CD14 levels were higher among smokers (p = 0.002), with no effect of other CVD risk factors, except age (p = 0.045). Our findings confirm CXCL10, sCD163 and sCD14 have distinct associations with different aspects of HIV infection and treatment. Levels of CXCL10 correlated with routinely monitored variables, sCD163 levels reflect a deeper level of virological suppression and influence of CVD risk factors, while sCD14 levels were not associated with routinely monitored variables, with evidence of specific effects of smoking and integrase inhibitor therapy warranting further investigation.

HIV Replication at Low Copy Number and its Correlation with the HIV Reservoir: A Clinical Perspective

The efficacy of combination therapy (antiretroviral therapy - ARV) is demonstrated by the high rates of viral suppression achieved in most treated HIV patients. Whereas contemporary treatments may continuously suppress HIV replication, they do not eliminate the latent reservoir, which can reactivate HIV infection if ARV is discontinued. The persistence of HIV proviral DNA and infectious viruses in CD4+ T cells and others cells has long been considered a major obstacle in eradicating the HIV virus in treated patients. Moreover, recent studies have demonstrated the persistence of HIV replication at low copies in most patients on suppressive ARV. The source of this ‘residual viraemia’ and whether it declines over years of therapy remain unknown. Similarly, little is known regarding the biological relationships between the HIV reservoir and viral replication at low copies. The question of whether this ‘residual viraemia’ represents active replication or the release of non-productive virus from the reservoir has not been adequately resolved.

From a clinical perspective, both the quantification of the HIV reservoir and the detection of low levels of replication in full-responder patients on prolonged ARV may provide important information regarding the effectiveness of treatment and the eradication of HIV. To date, the monitoring of these two parameters has been conducted only for research purposes; the routine use of standardised tests procedure is lacking. This review aims to assess the current data regarding the correlation between HIV replication at low copies and the HIV reservoir and to provide useful information for clinicians.

Determinants of residual viraemia during combination HIV treatment: Impacts of baseline HIV RNA levels and treatment choice

OBJECTIVES

Effective HIV therapy reflects suppression of plasma HIV RNA levels below assay detection thresholds, although lower levels of "residual viraemia" have also been demonstrated over extended periods of effective antiretroviral treatment. Here we examine the determinants of HIV RNA suppression below the standard assay threshold (40 HIV-1 RNA copies/mL) as well as factors associated with detectable HIV RNA below this reported detection limit.

METHODS

Between 2007 and 2010, 11 575 consecutive viral load (VL) tests were obtained from 1540 patients, including 356 on effective antiretroviral therapy followed since initiation (1996-2001: n = 165; 2002-2009: n = 191). Analyses modelled the probability of an undetectable VL given successful suppression to < 200 copies/mL, and the probability of residual viraemia given an undetectable result.

RESULTS

Detectable HIV RNA amplification was demonstrated in 20% of samples with a VL result < 40 copies/mL. Longitudinal analyses from 356 patients revealed that the likelihood of achieving results < 40 copies/mL was increased with current nonnucleoside reverse transcriptase inhibitor (NNRTI) therapy [odds ratio (OR) 2.0; P < 0.05] and reduced with prior virological rebound (OR 0.5; P < 0.05). In contrast, the presence of detectable HIV RNA < 40 copies/mL was strongly associated with pretreatment HIV RNA levels among those on current protease inhibitor (PI) treatment (OR 1.5 per log10 copies/mL increase; P = 0.02) as well as those on NNRTIs (OR 1.7; P = 0.002).

CONCLUSIONS

While HIV treatment history was associated with plasma HIV RNA levels below the detection limit, residual viraemia results were dominantly determined by pretreatment VL. These findings support the concept of a stable, long-lived reservoir of latently infected cells as a source of residual viraemia despite effective HIV treatment.

Impact of antiretroviral therapy (ART) timing on chronic immune activation/inflammation and end-organ damage

PURPOSE OF REVIEW

The purpose of this review was to summarize recent studies on the effect of early antiretroviral therapy (ART) in HIV-infected patients on markers of immune activation/inflammation, viral persistence and serious non-AIDS events.

RECENT FINDINGS

Early ART, initiated within days to months of HIV infection, was associated with marked reduction in T-cell activation often reaching levels observed in HIV-uninfected individuals. However, the impact of early ART on markers of innate immune activation, microbial translocation and inflammation/coagulation was less clear. Early ART has also been associated with a significant reduction in the frequency of latently infected cells, which was greater if ART was initiated within days to weeks rather than months following infection. However, few studies have evaluated the relationship between immune activation and viral reservoirs, specifically following early ART. Early ART may potentially reduce serious non-AIDS events and associated mortality, but most of these studies have extrapolated from changes in surrogate markers, such as CD4 : CD8 ratio.

SUMMARY

Early ART was associated with beneficial effects on multiple markers of immune activation, inflammation and viral persistence. Longer term prospective studies are still needed to determine whether early ART translates to a significant reduction in serious non-AIDS events and mortality.

Vitamin D Deficiency in HIV Infection: Not Only a Bone Disorder

Hypovitaminosis D is a worldwide disorder, with a high prevalence in the general population of both Western and developing countries. In HIV patients, several studies have linked vitamin D status with bone disease, neurocognitive impairment, depression, cardiovascular disease, high blood pressure, metabolic syndrome, type 2 diabetes mellitus, infections, autoimmune diseases like type 1 diabetes mellitus, and cancer. In this review, we focus on the most recent epidemiological and experimental data dealing with the relationship between vitamin D deficiency and HIV infection. We analysed the extent of the problem, pathogenic mechanisms, clinical implications, and potential benefits of vitamin D supplementation in HIV-infected subjects.

Interleukin-37 Expression Is Increased in Chronic HIV-1-Infected Individuals and Is Associated with Inflammation and the Size of the Total Viral Reservoir

Interleukin-37 (IL-37) is a recently identified cytokine with potent antiinflammatory and immunosuppressive functions. The objective of this study was to compare levels of IL-37 mRNA in immunological subgroups of chronic human immunodeficiency virus-1 (HIV-1)-infected individuals and noninfected controls, to determine IL-37's association with biomarkers of inflammation and reservoir size. This was a cross-sectional study. The HIV-1-infected patients were categorized in three subgroups depending on their combination antiretroviral therapy (cART) treatment status and CD4(+) T-cell count. Quantitative RT-PCR was used for the detection of IL-37 mRNA and HIV-1 DNA in peripheral blood mononuclear cells (PBMCs). Biomarkers in plasma were quantified by enzyme-linked immunosorbent assay (ELISA), whereas T-cell activation was determined by flow cytometry. Lastly, lipopolysaccharide (LPS) stimulations of patients PBMCs were carried out to determine differences in IL-37 mRNA response between the subgroups. Sixty HIV-1-infected patients and 20 noninfected controls were included in the study. Steady-state IL-37 mRNA levels in PBMCs were significantly higher in HIV-1-infected individuals compared with noninfected controls: 2.4-fold (p ≤ 0.01) cART-naïve subjects; 3.9-fold (p ≤ 0.0001) inadequate immunological responders; and 4.0-fold (p ≤ 0.0001) in immunological responders compared with non-infected controls. Additionally, levels of the monocyte inflammatory marker sCD14 correlated with IL-37 mRNA (p = 0.03), whereas there was no association with T-cell activation. Finally, we observed a significant correlation between total viral HIV-1 DNA and IL-37 mRNA in PBMCs (p < 0.0001). Collectively, our data shows that the level of IL-37 mRNA is affected by chronic HIV-1-infection. A relationship with the activation of the monocyte compartment is suggested by the correlation with sCD14 and, interestingly, IL-37 could be related to the size of the total viral HIV-1 reservoir.

Cardiovascular disease in HIV patients: from bench to bedside and backwards

HIV patients are exposed to a higher risk of adverse cardiovascular events, due to complex interactions between traditional risk factors and HIV infection itself in terms of ongoing endothelial dysfunctional immune activation/inflammation and increased risk of thrombosis. On the other hand, long-span antiretroviral therapy administration still raises questions on its long-term safety in an era in which life expectancy is becoming longer and longer while treatment of non-HIV-related serious events is increasingly raising concern. In this article, we will critically analyse the current knowledge of pathological and clinical aspects pertaining to the increased risk of cardiovascular events associated with HIV.

Vitamin D and calcium abnormalities in the HIV-infected population

The prevalence of vitamin D deficiency among HIV-infected persons is substantial and comparable to the general population. The factors associated with vitamin D deficiency are similar for both populations but additional factors (ie, use of certain antiretroviral agents) also contribute to vitamin D deficiency among HIV-infected persons. The adverse outcomes associated with vitamin D deficiency considerably overlap with non-AIDS defining illnesses (NADIs) that are increasingly becoming widespread in the aging HIV-infected population. However, there is scant evidence to support any causal inference. Further studies are warranted as efforts to identify and address modifiable risk factors contributing to NADIs continue.

Significance and clinical management of persistent low-level viremia and very-low-level viremia in HIV-1-infected patients

A goal of HIV therapy is to sustain suppression of the plasma viral load below the detection limits of clinical assays. However, widely followed treatment guidelines diverge in their interpretation and recommended management of persistent viremia of low magnitude, reflecting the limited evidence base for this common clinical finding. Here, we review the incidence, risk factors, and potential consequences of low-level HIV viremia (LLV; defined in this review as a viremia level of 50 to 500 copies/ml) and very-low-level viremia (VLLV; defined as a viremia level of <50 copies/ml detected by clinical assays that have quantification cutoffs of <50 copies/ml). Using this framework, we discuss practical issues related to the diagnosis and management of patients experiencing persistent LLV and VLLV. Compared to viral suppression at <50 or 40 copies/ml, persistent LLV is associated with increased risk of antiretroviral drug resistance and overt virologic failure. Higher immune activation and HIV transmission may be additional undesirable consequences in this population. It is uncertain whether LLV of <200 copies/ml confers independent risks, as this level of viremia may reflect assay-dependent artifacts or biologically meaningful events during suppression. Resistance genotyping should be considered in patients with persistent LLV when feasible, and treatment should be modified if resistance is detected. There is a dearth of clinical evidence to guide management when genotyping is not feasible. Increased availability of genotypic assays for samples with viral loads of <400 copies/ml is needed.

Association between latent proviral characteristics and immune activation in antiretrovirus-treated human immunodeficiency virus type 1-infected adults

Generalized immune activation during HIV infection is associated with an increased risk of cardiovascular disease, neurocognitive disease, osteoporosis, metabolic disorders, and physical frailty. The mechanisms driving this immune activation are poorly understood, particularly for individuals effectively treated with antiretroviral medications. We hypothesized that viral characteristics such as sequence diversity may play a role in driving HIV-associated immune activation. We therefore sequenced proviral DNA isolated from peripheral blood mononuclear cells from HIV-infected individuals on fully suppressive antiretroviral therapy. We performed phylogenetic analyses, calculated viral diversity and divergence in the env and pol genes, and determined coreceptor tropism and the frequency of drug resistance mutations. Comprehensive immune profiling included quantification of immune cell subsets, plasma cytokine levels, and intracellular signaling responses in T cells, B cells, and monocytes. These antiretroviral therapy-treated HIV-infected individuals exhibited a wide range of diversity and divergence in both env and pol genes. However, proviral diversity and divergence in env and pol, coreceptor tropism, and the level of drug resistance did not significantly correlate with markers of immune activation. A clinical history of virologic failure was also not significantly associated with levels of immune activation, indicating that a history of virologic failure does not inexorably lead to increased immune activation as long as suppressive antiretroviral medications are provided. Overall, this study demonstrates that latent viral diversity is unlikely to be a major driver of persistent HIV-associated immune activation.

IMPORTANCE

Chronic immune activation, which is associated with cardiovascular disease, neurologic disease, and early aging, is likely to be a major driver of morbidity and mortality in HIV-infected individuals. Although treatment of HIV with antiretroviral medications decreases the level of immune activation, levels do not return to normal. The factors driving this persistent immune activation, particularly during effective treatment, are poorly understood. In this study, we investigated whether characteristics of the latent, integrated HIV provirus that persists during treatment are associated with immune activation. We found no relationship between latent viral characteristics and immune activation in treated individuals, indicating that qualities of the provirus are unlikely to be a major driver of persistent inflammation. We also found that individuals who had previously failed treatment but were currently effectively treated did not have significantly increased levels of immune activation, providing hope that past treatment failures do not have a lifelong "legacy" impact.

HIV-infected adolescent, young adult and pregnant smokers: important targets for effective tobacco control programs

Tobacco use is inextricably linked to a number of health risks both in the general and HIV-infected populations. There is, however, a dearth of research on effective tobacco control programs among people living with HIV, and especially among adolescents, young adults and pregnant women, groups with heightened or increased vulnerability secondary to tobacco use. Adolescents and young adults constitute a growing population of persons living with HIV infection. Early and continued tobacco use in this population living with a disease characterized by premature onset multimorbidity and chronic inflammation is of concern. Additionally, there is an increased acuity for tobacco control among HIV-infected pregnant women to reduce pregnancy morbidity and improve fetal outcome. This review will provide an important summary of current knowledge of tobacco use among HIV-infected adolescents, young adults and pregnant women. The effects of tobacco use in these specific populations will be presented and the current state of tobacco control within these populations, assessed.

Effects of human immunodeficiency virus on the erythrocyte and megakaryocyte lineages

Anaemia and thrombocytopenia are haematological disorders that can be detected in many human immunodeficiency virus (HIV)-positive patients during the development of HIV infection. The progressive decline of erythrocytes and platelets plays an important role both in HIV disease progression and in the clinical and therapeutic management of HIV-positive patients. HIV-dependent impairment of the megakaryocyte and erythrocyte lineages is multifactorial and particularly affects survival, proliferation and differentiation of bone marrow (BM) CD34+ haematopoietic progenitor cells, the activity of BM stromal cells and the regulation of cytokine networks. In this review, we analyse the major HIV-related mechanisms that are involved in the genesis and development of the anaemia and thrombocytopenia observed in HIV positive patients.

Lack of correlation between the size of HIV proviral DNA reservoir and the level of immune activation in HIV-infected patients with a sustained undetectable HIV viral load for 10 years

BACKGROUND

The persistence of HIV residual replication in patients with an undetectable plasma viral load (pVL) may limit immune recovery and facilitate inflammation-induced comorbidities.

OBJECTIVE

The objective was to evaluate any correlation between immune restoration and intracellular [IC] HIV-DNA in cART-treated patients with a sustained undetectable pVL.

STUDY DESIGN

This retrospective cross sectional study included 62 patients with a median duration of undetectable pVL of 10.3 years. IC HIV DNA in peripheral mononuclear blood cells (PBMCs) and T cell subsets were measured at the last visit. pVL, CD4(+) and CD8(+) T cell counts were retrospectively collected from the onset of long-term inhibition by antiretroviral treatment. The patients were separated into two groups: 27 non-blippers (sustained pVL< threshold value during all the visits) and 35 blippers ( ≥ 1 episodes of pVL> threshold but < 1000 copies/ml). The median pVL in blippers was 115 copies/ml.

RESULTS

The median IC HIV DNA rate was 34 copies/10(6) PBMCs (71% ≥ 20 copies/10(6) PBMCs) with no significant difference between the groups. The proportion of CD8(+)CD38(+) and CD8(+)DR(+) T cells was higher in blipper patients, but the difference was only significant for the CD8(+)DR(+) marker (p = 0.036). No correlation was found between markers of immune activation on CD4(+) and CD8(+) T cells and the IC HIV-DNA level.

CONCLUSION

No relation was found between the size of HIV reservoirs and immune activation in patients with sustained undetectable pVL. Mechanisms of immune activation have to be better understood in order to define specific therapeutic interventions.

T cell subsets in HIV infected patients after successful combination antiretroviral therapy: impact on survival after 12 years

OBJECTIVES

Immune activation is decreased by combination antiretroviral therapy (cART) in patients infected with human immunodeficiency virus (HIV), but residual activation remains and has been proposed as a cause of premature aging and death, but data are lacking. We analyzed the relationship between T-cell subsets after 18 months of cART and overall survival during 12 years of follow up.

METHODS

A cohort of 101 HIV infected patients who had undetectable plasma HIV after starting cART was included in 1997-1998. T cell subsets were analyzed by flowcytometry after 18 months of cART. Relation to survival was calculated using Kaplan-Meier curves and multiple Cox regression.

RESULTS

Seventeen patients died during the observation period. The leading causes of death were non-AIDS cancer and cardiovascular disease. Higher levels of CD8 memory T cells (CD8+,CD45RO+,CD45RA-) showed a significant beneficiary effect on survival, HR of 0.95 (95% confidence interval 0.91-0.99, P = 0.016) when adjusted for age, nadir CD4 count, CD4 count, and AIDS and hepatitis C status. T cell activation was not associated with increased risk of death.

CONCLUSIONS

Larger and longitudinal studies are needed to accurately establish prognostic factors, but overall results seem to suggest that prognostic information exists within the CD8 compartment.

Beyond virological suppression: the role of adherence in the late HAART era

HAART has increased the life expectancy of HIV-infected individuals significantly. Optimal adherence to HAART results in viral suppression and immune recovery in the majority of HIV-infected persons. Data from the early HAART era suggest that adherence levels of greater than 95% are necessary to achieve and maintain virological suppression. However, the optimal threshold of adherence required to maximize the pharmacological benefits of contemporary antiretroviral regimens, particularly in the virologically suppressed patient, is unknown. This review examines new data on the role of adherence in the late HAART era, focusing on virological, immunological and epidemiological aspects. We begin with a discussion of the impact of adherence on viral dynamics and immunological parameters in the virologically suppressed patient. We then review the importance of adherence in emerging antiretroviral treatment strategies. Finally, we summarize accumulating data on the role of antiretroviral adherence in the prevention of HIV transmission. Taken together, the data reviewed reinforce the critical importance of adherence in the management of HIV infection in the late HAART era.

Modification of the Abbott RealTime assay for detection of HIV-1 plasma RNA viral loads less than one copy per milliliter

Although commercial tests are approved for detection of HIV-1 plasma viral loads ≥ 20 copies per milliliter (ml), only one specialized research assay has been reported to detect plasma viral loads as low as 1 copy/ml. This manuscript describes a method of concentrating HIV-1 virions from up to 30 ml of plasma, which can be combined with a commercial viral load test to create a widely available, reproducible assay for quantifying plasma HIV RNA levels less than 1 copy/ml. Using this pre-analytically modified assay, samples with a known level of 0.5 copy/ml were detected in 8 of 12 replicates (mean 0.47 copy/ml; 95% confidence interval (CI) 0.14-0.81 copy/ml) and samples with a known level of 1.0 copy/ml were detected in 13 of 13 replicates (mean 1.96 copy/ml; 95% CI 1.42-2.50 copy/ml). By concentrating virus from 30 ml of plasma, HIV RNA could be measured in 16 of 19 samples (84%) from 12 of 12 subjects (mean 2.77 copy/ml; 95% CI 0.86-4.68 copy/ml). The measured viral load correlated inversely (r = -0.78; p = 0.028) with the total duration of viral suppression (viral load<40 copies/ml).

Carbohydrate targets in HIV vaccine research: lessons from failures

Learning from the successes of other vaccines that enhance natural and existing protective responses to pathogens, the current effort in HIV vaccine research is directed toward inducing cytotoxic responses. Nevertheless, antibodies are fundamental players in vaccine development and are still considered in the context of passive specific immunotherapy of HIV, especially since several broadly neutralizing monoclonals are available. Special interest is directed toward antibodies binding to the glycan array on gp120 since they have the potential of broader reactivity and cross-clade neutralizing capacity. Humoral responses to carbohydrate antigens have proven effective against other pathogens, why not HIV? The variability of the epitope targets on HIV may not be the only problem to developing active or passive immunotherapeutic strategies. The dynamics of the infected immune system leads to ambiguous effects of most of the effector mechanisms calling for new approaches; some may already be available, while others are in the making.

The macrophage: the intersection between HIV infection and atherosclerosis

HIV-infected individuals are at increased risk of coronary artery disease (CAD) with underlying mechanisms including chronic immune activation and inflammation secondary to HIV-induced microbial translocation and low-grade endotoxemia; direct effects of HIV and viral proteins on macrophage cholesterol metabolism; and dyslipidemia related to HIV infection and specific antiretroviral therapies. Monocytes are the precursors of the lipid-laden foam cells within the atherosclerotic plaque and produce high levels of proinflammatory cytokines such as IL-6. The minor CD14+/CD16+ "proinflammatory" monocyte subpopulation is preferentially susceptible to HIV infection and may play a critical role in the pathogenesis of HIV-related CAD. In this review, the central role of monocytes/macrophages in HIV-related CAD and the importance of inflammation and cholesterol metabolism are discussed.

HIV-1 residual viremia correlates with persistent T-cell activation in poor immunological responders to combination antiretroviral therapy

BACKGROUND

The clinical significance and cellular sources of residual human immunodeficiency virus type 1 (HIV-1) production despite suppressive combination antiretroviral therapy (cART) remain unclear and the effect of low-level viremia on T-cell homeostasis is still debated.

METHODOLOGY/PRINCIPAL FINDINGS

We characterized the recently produced residual viruses in the plasma and short-lived blood monocytes of 23 patients with various immunological responses to sustained suppressive cART. We quantified the residual HIV-1 in the plasma below 50 copies/ml, and in the CD14(high) CD16(-) and CD16+ monocyte subsets sorted by flow cytometry, and predicted coreceptor usage by genotyping V3 env sequences. We detected residual viremia in the plasma of 8 of 10 patients with poor CD4+ T-cell reconstitution in response to cART and in only 5 of 13 patients with good CD4+ T-cell reconstitution. CXCR4-using viruses were frequent among the recently produced viruses in the plasma and in the main CD14(high) CD16(-) monocyte subset. Finally, the residual viremia was correlated with persistent CD4+ and CD8+ T-cell activation in patients with poor immune reconstitution.

CONCLUSIONS

Low-level viremia could result from the release of archived viruses from cellular reservoirs and/or from ongoing virus replication in some patients. The compartmentalization of the viruses between the plasma and the blood monocytes suggests at least two origins of residual virus production during effective cART. CXCR4-using viruses might be produced preferentially in patients on cART. Our results also suggest that low-level HIV-1 production in some patients may contribute to persistent immune dysfunction despite cART.