Biomarkers of immune dysfunction in HIV

Connecting the dots: could microbial translocation explain commonly reported symptoms in HIV disease?

Microbial translocation within the context of HIV disease has been described as one of the contributing causes of inflammation and disease progression in HIV infection. HIV-associated symptoms have been related to inflammatory markers and sCD14, a surrogate marker for microbial translocation, suggesting a plausible link between microbial translocation and symptom burden in HIV disease. Similar pathophysiological responses and symptoms have been reported in inflammatory bowel disease. We provide a comprehensive review of microbial translocation, HIV-associated symptoms, and symptoms connected with inflammation. We identify studies showing a relationship among inflammatory markers, sCD14, and symptoms reported in HIV disease. A conceptual framework and rationale to investigate the link between microbial translocation and symptoms is presented. The impact of inflammation on symptoms supports recommendations to reduce inflammation as part of HIV symptom management. Research in reducing microbial translocation-induced inflammation is limited, but needed, to further promote positive health outcomes among HIV-infected patients.

Anti-retroviral therapy decreases but does not normalize indoleamine 2,3-dioxygenase activity in HIV-infected patients

Background

Indoleamine 2,3-dioxygenase (IDO), which is mainly expressed in activated dendritic cells, catabolizes tryptophan to kynurenine and other downstream catabolites. It is known to be an immune mediator in HIV pathogenesis. The impact of anti-retroviral therapy on its activity has not been well established.

Methods

We measured systemic IDO activity (the ratio of plasma kynurenine to tryptophan) in HIV-infected patients before and after highly active antiretroviral therapy (HAART) and its association with a microbial translocation marker, soluble CD14 (sCD14).

Results

Among 76 participants, higher baseline IDO activity was associated with lower CD4⁺ T cell counts (P<0.05) and higher plasma sCD14 levels (P<0.001). After 1 year of HAART, IDO activity decreased significantly (P<0.01), but was still higher than in healthy controls (P<0.05). The baseline IDO activity did not predict CD4⁺ T cell recovery after 1 year of therapy. The percentages of myeloid and plasmacytoid dendritic cells were not correlated with IDO activity.

Conclusions

IDO activity is elevated in HIV-infected patients, which is partially associated with microbial translocation. HAART reduced, but did not normalize the activity of IDO.

Use of first-generation HCV protease inhibitors in patients coinfected by HIV and HCV genotype 1

BACKGROUND

In HCV genotype 1-infected patients with HIV co-infection, tritherapy [HCV protease inhibitors (PIs) plus peg-interferon and ribavirin] has been shown to have an increased rate of sustained virological response. However, complex drug-to-drug interactions and tolerability issues remain a concern.

METHODS

Under the auspices of four French scientific societies of medicine, a committee was charged of establishing guidelines on the use of first-generation HCV PIs in these patients. This scientific committee based its work on preliminary results from tritherapy clinical trials in co-infected patients and, since data on these patients are still scarce, on the statements already made by the French Association for the Study of the Liver (AFEF) on the use of tritherapy in HCV mono-infected patients, written in May 2011 and updated in 2012. Each AFEF guideline concerning HCV monoinfection was examined to determine whether it could be used in the context of HIV/HCV coinfection.

RESULTS

These guidelines are addressed for the treatment of coinfected patients with various profiles, including treatment-naïve or patients with failure to previous bitherapy and mention those patients for whom tritherapy should start or those for whom it should be delayed. Preliminary results of triple therapy as well as factors associated to virological response are also discussed. Other issues include virological monitoring, clinical and virological criteria to stop therapy, practical treatment management, treatment adherence and the management of side effects and interactions with antiretroviral drugs. These guidelines were submitted for critical review to independent experts.

HIV-1 infection induces interleukin-1β production via TLR8 protein-dependent and NLRP3 inflammasome mechanisms in human monocytes

The induction of inflammatory cytokines such as IL-1β is associated with the progression of human immunodeficiency virus, type 1 (HIV-1) disease or AIDS. Unlike most inflammatory cytokines that are regulated by NF-κB at the transcriptional level, production of mature IL-1β also depends on inflammasome activation. The mechanism by which HIV-1 induces pro-IL-1β expression and activates inflammasomes to cleave pro-IL-1β into its bioactive form is not clearly defined. We report here that HIV-1 infection in human monocytes efficiently induced IL-1β expression and inflammasome activation. Toll-like receptor 8 (TLR8) was required for inducing pro-IL-1β expression, whereas the NLRP3 inflammasome was required for IL-1β maturation and release. Furthermore, the lysosomal protease cathepsin B and HIV-1 induced production of reactive oxygen species were critical for HIV-induced inflammasome activation and IL-1β production. HIV-1 entry, reverse transcription, and integration were all required for both pro-IL-1β expression and inflammasome activation. Finally, we show that HIV-1-derived RNA was sufficient to induce both pro-IL-1β expression and inflammasome activation. We conclude that HIV-1 infection induced the expression of pro-IL-1β via TLR8-mediated mechanisms and activated caspase-1 through the NLRP3 inflammasome to cleave pro-IL-1β into bioactive IL-1β. These findings help to elucidate mechanisms of HIV-1 disease progression and identify novel targets for treating HIV-1 induced inflammation and immune activation.

Systemic immune activation in HIV and potential therapeutic options

CONTEXT

Advancement in HIV treatment has evolved over the last two decades with the discovery of new drugs and approaches. Studies have demonstrated that HIV-infected individuals have elevated immune activation even during effective antiretroviral therapy. Persistently elevated immune activation has been one of the main obstacles against developing an effective approach for curing HIV.

OBJECTIVE

This review examines the mechanism of microbial translocation in HIV-infected individuals and currently investigated potential therapeutic approaches.

METHODS

We searched PubMed and Medline for peer-reviwed articles and recent HIV/AIDS conference abstracts and papers. Narrative review method was used since the objectives of the study were mechanism of microbial translocation and mechanism of action of multiple drugs against it.

RESULTS

Microbial translocation occurs as a result of the disruption of epithelial barrier and immunological dysfunction within the intestinal tract due to defective tight junctions, loss of TH17 type CD4(+) T cells, impaired liver architecture, and depletion of intestinal myelomonocytic cells. Potent and effective way to intervene microbial translocation is to target the mechanism of actions involved in microbial translocation by restoration of beneficial microbiata with supplemental probiotics/prebiotics, increased clearance of microbial products from systemic circulation with targeted antibodies and restoration of intestinal integrity with antibiotics.

CONCLUSIONS

Number of promising drug molecules against microbial translocation are currently under various stages of trials and the results of these trials will hopefully contribute significantly toward effective therapeutic intervention. However, studies also need to explore the effect of combination drugs to abrogate microbial translocation.

Insights into B cells and HIV-specific B-cell responses in HIV-infected individuals

Human immunodeficiency virus (HIV) disease is associated with dysregulation and dysfunction involving all major lymphocyte populations, including B cells. Such perturbations occur early in the course of infection and are driven in large part by immune activation resulting from ongoing HIV replication leading to bystander effects on B cells. While most of the knowledge regarding immune cell abnormalities in HIV-infected individuals has been gained from studies conducted on the peripheral blood, it is clear that the virus is most active and most damaging in lymphoid tissues. Here, we discuss B-cell perturbations in HIV-infected individuals, focusing on the skewing of B-cell subsets that circulate in the peripheral blood and their counterparts that reside in lymphoid tissues. This review also highlights recent advances in evaluating HIV-specific B-cell responses both in the memory B-cell compartment, as well as in circulating antibody-secreting plasmablasts and the more differentiated plasma cells residing in tissues. Finally, we consider how knowledge gained by investigating B cells in HIV-infected individuals may help inform the development of an effective antibody-based HIV vaccine.

Correlates of elevated interleukin-6 and C-reactive protein in persons with or at high risk for HCV and HIV infections

BACKGROUND

HIV and hepatitis C virus (HCV) infections may increase interleukin-6 (IL-6) and C-reactive protein (CRP). However, relationships between inflammatory biomarkers, chronic viral infections, clinical factors, and behavioral factors remain poorly understood.

METHODS

Using linear regression, we modeled cross-sectional associations between loge IL-6 or loge CRP levels and HCV, HIV, injection drug use, and comorbidity among 1191 injection drug users.

RESULTS

Mean age was 47 years, 46.0% reported currently injecting drugs, 59.0% were HCV monoinfected, and 27% were HCV/HIV coinfected. In multivariable models, higher loge IL-6 was associated with HCV monoinfection [β = 0.191, 95% confidence interval (CI): 0.043 to 0.339] and HCV/HIV coinfection (β = 0.394, 95% CI: 0.214 to 0.574). In contrast, HCV monoinfection (β = -0.523, 95% CI: -0.275 to -0.789) and HCV/HIV coinfection (β = -0.554 95% CI: -0.260 to -0.847) were associated with lower CRP. Lower CRP with HCV infection was independent of liver fibrosis severity, synthetic function, or liver injury markers; CRP decreased with higher HCV RNA. Increased injection intensity was associated with higher IL-6 (P = 0.003) and CRP (P < 0.001); increasing comorbidity (P < 0.001) and older age (P = 0.028) were associated with higher IL-6; older age was associated with higher CRP among HCV-uninfected participants (P = 0.021).

CONCLUSION

HIV and HCV infections contribute to chronic inflammation; however, reduced CRP possibly occurs through HCV-mediated mechanisms. Findings highlight potentially modifiable contributors to inflammation.

A concise panel of biomarkers identifies neurocognitive functioning changes in HIV-infected individuals

Neurocognitive (NC) impairment (NCI) occurs commonly in people living with HIV. Despite substantial effort, no biomarkers have been sufficiently validated for diagnosis and prognosis of NCI in the clinic. The goal of this project was to identify diagnostic or prognostic biomarkers for NCI in a comprehensively characterized HIV cohort. Multidisciplinary case review selected 98 HIV-infected individuals and categorized them into four NC groups using normative data: stably normal (SN), stably impaired (SI), worsening (Wo), or improving (Im). All subjects underwent comprehensive NC testing, phlebotomy, and lumbar puncture at two timepoints separated by a median of 6.2 months. Eight biomarkers were measured in CSF and blood by immunoassay. Results were analyzed using mixed model linear regression and staged recursive partitioning. At the first visit, subjects were mostly middle-aged (median 45) white (58 %) men (84 %) who had AIDS (70 %). Of the 73 % who took antiretroviral therapy (ART), 54 % had HIV RNA levels below 50 c/mL in plasma. Mixed model linear regression identified that only MCP-1 in CSF was associated with neurocognitive change group. Recursive partitioning models aimed at diagnosis (i.e., correctly classifying neurocognitive status at the first visit) were complex and required most biomarkers to achieve misclassification limits. In contrast, prognostic models were more efficient. A combination of three biomarkers (sCD14, MCP-1, SDF-1α) correctly classified 82 % of Wo and SN subjects, including 88 % of SN subjects. A combination of two biomarkers (MCP-1, TNF-α) correctly classified 81 % of Im and SI subjects, including 100 % of SI subjects. This analysis of well-characterized individuals identified concise panels of biomarkers associated with NC change. Across all analyses, the two most frequently identified biomarkers were sCD14 and MCP-1, indicators of monocyte/macrophage activation. While the panels differed depending on the outcome and on the degree of misclassification, nearly all stable patients were correctly classified.

Large unstained cells: a potentially valuable parameter in the assessment of immune activation levels in HIV infection

INTRODUCTION

Chronic immune activation is associated with the accelerated progression of HIV to AIDS; however, affordable markers reflecting this have not yet been determined. The percentage of large unstained cells (%LUCs) is a differential count parameter measured by certain routine hematology analyzers and reflects activated lymphocytes and peroxidase-negative cells. We hypothesized that the %LUCs would be increased in HIV infection and would correlate with markers of immune activation [i.e. CD38 expression on CD8+ T cells (%CD38onCD8) and lipopolysaccharide-binding protein (LBP)] and CD4 counts.

METHODS

In this cross-sectional study, 78 HIV-infected, antiretroviral therapy-naïve adults and 52 uninfected controls were recruited. %CD38onCD8 and CD4 counts were determined by flow cytometry, LBP levels were assessed by immunoassay, and the %LUCs was tested on a Siemens ADVIA 2120.

RESULTS

Significant differences were found between the HIV-infected and control groups for %LUCs (95% CI 2.3-2.7 vs. 1.8-2.2, respectively; p = 0.001), as well as for %CD38onCD8, LBP, and CD4 counts. Furthermore, %LUCs correlated directly with %CD38onCD8 and LBP and inversely with CD4 counts.

CONCLUSION

The %LUCs was significantly increased in this untreated, asymptomatic, HIV-infected group and correlated with markers of immune activation and CD4 counts. Therefore, the %LUCs may be of value in identifying HIV-infected patients at risk of accelerated disease progression.

Effect of combination antiretroviral therapy on Chinese rhesus macaques of simian immunodeficiency virus infection

Definitive treatment of HIV infection remains a critical but elusive goal, with persistence of residual virus even in the face of prolonged administration of suppressive combination antiretroviral treatment (cART) providing a source for recrudescent infection if treatment is stopped. Characterization of the residual virus and devising strategies to target it for eradication are key goals in HIV treatment research. Indian rhesus macaques (In-RM) infected with SIVmac have been widely used in such research. However, it has proven challenging to achieve and sustain clinically relevant levels of suppression (<30 vRNA copies/ml plasma) with cART in such models. As ease of viral suppression by cART is related to pretreatment levels of viral replication, and levels of replication of SIVmac239/251 are lower in Chinese rhesus macaques (Ch-RM) than in In-RM, we evaluated cART administration to SIVmac-infected Ch-RM as a potential model for studies of residual virus and eradication strategies. Four SIVmac239-infected Ch-RM received cART including reverse transcriptase inhibitors PMPA/FTC and integrase inhibitor L-870812 daily for 8 weeks. Plasma viral loads were promptly reduced to <30 copies/ml upon initiation of cART. Cell-associated SIV DNA levels in lymphocytes from the gut were also significantly reduced. Jejunal and colonic CCR5(+)CD4(+) mucosal memory T cells increased significantly; restoration of these cells was associated with reductions in immune activation. In conclusion, cART effectively suppressed viral replication to <30 vRNA copies/ml in SIVmac239-infected Ch-RM, reducing immune activation and restoring mucosal immune cell populations. SIVmac239-infected Ch-RM may be a useful model for studying responses to cART and persistent tissue reservoirs and evaluating candidate eradication strategies to cure HIV infection.

Is HIV a model of accelerated or accentuated aging?

BACKGROUND

Antiretroviral therapy has reduced the incidence of adverse events and early mortality in HIV-infected persons. Despite these benefits, important comorbidities that increase with age (eg, diabetes, cardiovascular disease, cancer, liver disease, and neurocognitive impairment) are more prevalent in HIV-infected persons than in HIV-uninfected persons at every age, and geriatric syndromes such as falls and frailty occur earlier in HIV-infected persons. This raises a critical research question: Does HIV accelerate aging through pathways and mechanisms common to the aging process or is HIV simply an additional risk factor for a wide number of chronic conditions, thus accentuating aging?

METHODS

Extensive literature review.

RESULTS

The purpose of this review is to briefly outline the evidence that age-related clinical syndromes are exacerbated by HIV, examine the ways in which HIV is similar, and dissimilar from natural aging, and assess the validity of HIV as a model of premature aging. Specific biomarkers of aging are limited in HIV-infected hosts and impacted by antiretroviral therapy, and a high rate of modifiable life style confounders (eg, smoking, substance abuse, alcohol) and coinfections (eg, hepatitis) in HIV-infected participants.

CONCLUSIONS

There is a need for validated biomarkers of aging in the context of HIV. Despite these differences, welldesigned studies of HIV-infected participants are likely to provide new opportunities to better understand the mechanisms that lead to aging and age-related diseases.

Distinct tryptophan catabolism and Th17/Treg balance in HIV progressors and elite controllers

Tryptophan (Trp) catabolism into immunosuppressive kynurenine (Kyn) by indoleamine 2,3-dioxygenase (IDO) was previously linked to Th17/Treg differentiation and immune activation. Here we examined Trp catabolism and its impact on Th17/Treg balance in uninfected healthy subjects (HS) and a large cohort of HIV-infected patients with different clinical outcomes: ART-naïve, Successfully Treated (ST), and elite controllers (EC). In ART-naïve patients, increased IDO activity/expression, together with elevated levels of TNF-α and sCD40L, were associated with Treg expansion and an altered Th17/Treg balance. These alterations were normalized under ART. In contrast, Trp 2,3-dioxegenase (TDO) expression was dramatically lower in EC when compared to all other groups. Interestingly, EC displayed a distinctive Trp metabolism characterized by low Trp plasma levels similar to ART-naïve patients without accumulating immunosuppressive Kyn levels which was accompanied by a preserved Th17/Treg balance. These results suggest a distinctive Trp catabolism and Th17/Treg balance in HIV progressors and EC. Thus, IDO-induced immune-metabolism may be considered as a new inflammation-related marker for HIV-1 disease progression.

[Association between inflammatory markers and microbial translocation in patients with human immunodeficiency virus infection taking antiretroviral treatment]

BACKGROUND AND OBJECTIVE

Inflammatory biomarkers are increased in patients with human immunodeficiency virus (HIV) infection. Antiretroviral treatment (ART) improves some parameters but do not normalize them. The aim of this study is to determine those factors (including microbial translocation) associated with higher inflammation in HIV treated patients.

PATIENTS AND METHODS

Transversal observational study.

INCLUSION CRITERIA

HIV patients receiving ART with an HIV viral load (VL)<400 copies/mL. Selection of patients: consecutively between November 2011 and January 2012. Main variable: plasma levels of interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). Main explanatory variable: microbial translocation markers (16S ribosomal DNA and sCD14). Patients with IL-6 or TNF-α levels above percentile 75 (group 1) were compared with the rest of patients (group 2). Odds ratio (OR) were determined.

RESULTS

Eighty-one patients were included (73% male, median age 45 years, 48% stage C). Twenty-six percent had chronic hepatitis C. Median CD4 cell was 493/mm(3) and 30% had detectable HIV VL. 16S ribosomal DNA was detected in 21% of patients. Factors associated with the higher levels of inflammatory markers were 16S ribosomal DNA (OR 77, P<.0001), sCD14 levels (P<.0001) and history of cardiovascular disease (OR 15, P<.01). In multivariate analysis, associations remained for 16S ribosomal DNA (OR 62, P<.0001) and previous cardiovascular disease (OR 25, P<.01).

CONCLUSIONS

In patients with HIV infection receiving treatment, the higher levels of inflammatory markers are associated with microbial translocation and past cardiovascular events.

Associations between 25-hydroxyvitamin D and immunologic, metabolic, inflammatory markers in treatment-naive HIV-infected persons: the ANRS CO9 «COPANA» cohort study

Objectives

Low 25(OH)D has been associated with dyslipidemia, insulin resistance and inflammation in both general and HIV-infected (mostly treated) populations. We investigated these associations in antiretroviral-naïve HIV-infected persons.

Design

We measured plasma 25(OH)D, metabolic, immunologic and inflammatory markers in 355 persons (204 Whites, 151 Blacks) at enrollment in the ANRS COPANA cohort.

Methods

25(OH)D levels were categorized <10 ng/mL (severe deficiency) and <20 ng/mL (deficiency). Statistical analyses were adjusted for sampling season, ethnicity and the interaction between season and ethnicity.

Results

25(OH)D insufficiency (<30 ng/mL), deficiency (<20 ng/mL) and severe deficiency (<10 ng/mL) were highly prevalent (93%, 67% and 24% of patients, respectively). Blacks had significantly lower 25(OH)D than Whites (median: 13 vs. 17 ng/mL, P<0.001), with markedly less pronounced seasonal variation. Smoking and drinking alcohol were associated with having a 25 OHD level<10 ng/mL. In patients with 25(OH)D<10 ng/mL, the proportion of persons with a CD4 count<100/mm³ was higher than in patients with 25(OH)D≥10 ng/mL (18.8% vs. 10.7%, P = 0.04). Persons with 25 OHD<10 ng/mL had higher levels of hsCRP (1.60 mg/L [IQR: 0.59–5.76] vs. 1.27 mg/L [0.58–3,39], P = 0.03) and resistin (16.81 ng/L [IQR: 13.82–25.74] vs. 11.56 ng/L [IQR: 8.87–20.46], P = 0.02), and, among Blacks only, sTNFR2 (2.92 ng/mL [2.31–4.13] vs. 2.67 ng/mL, [1.90–3.23], P = 0.04). The strength and significance of the association between CD4<100/mm³ and 25 OHD<10 ng/mL were reduced after adjustment on sTNFR1, sTNFR2, and hsCRP levels. In multivariate analysis, a CD4 count <100/mm³, resistin concentration and smoking were independently associated with 25(OH)D<10 ng/mL.

Conclusions

Severe vitamin D deficiency was associated with low CD4 counts and increased markers of inflammation in ARV-naïve HIV-infected persons.

Plasma and mucosal HIV viral loads are associated with genital tract inflammation in HIV-infected women

BACKGROUND

Systemic and mucosal inflammation may play a role in HIV control. A cross-sectional comparison was conducted among women in the Women's Interagency HIV Study to explore the hypothesis that compared with HIV-uninfected participants, women with HIV, and, in particular, those with high plasma viral load (PVL) have increased levels of mucosal and systemic inflammatory mediators and impaired mucosal endogenous antimicrobial activity.

METHODS

Nineteen HIV-uninfected, 40 HIV-infected on antiretroviral therapy (ART) with PVL ≤ 2600 copies/mL (low viral load) (HIV-LVL), and 19 HIV-infected on or off ART with PVL >10,000 (high viral load) (HIV-HVL) were evaluated. Immune mediators and viral RNA were quantified in plasma and cervicovaginal lavage (CVL). The CVL antimicrobial activity was also determined.

RESULTS

Compared to HIV-uninfected participants, HIV-HVL women had higher levels of mucosal but not systemic proinflammatory cytokines and chemokines, higher Nugent scores, and lower Escherichia coli bactericidal activity. In contrast, there were no significant differences between HIV-LVL and HIV-uninfected controls. After adjusting for PVL, HIV genital tract shedding was significantly associated with higher CVL concentrations of IL-6, IL-1β, MIP-1α, and CCL5 (RANTES) and higher plasma concentrations of MIP-1α. High PVL was associated with higher CVL levels of IL-1β and RANTES, as well as with higher Nugent scores, lower E. coli bactericidal activity, smoking, and lower CD4 counts; smoking and CD4 count retained statistical significance in a multivariate model.

CONCLUSIONS

Further study is needed to determine if the relationship between mucosal inflammation and PVL is causal and to determine if reducing mucosal inflammation is beneficial.

HIV infection and drugs of abuse: role of acute phase proteins

Background

HIV infection and drugs of abuse such as methamphetamine (METH), cocaine, and alcohol use have been identified as risk factors for triggering inflammation. Acute phase proteins such as C-reactive protein (CRP) and serum amyloid A (SAA) are the biomarkers of inflammation. Hence, the interactive effect of drugs of abuse with acute phase proteins in HIV-positive subjects was investigated.

Methods

Plasma samples were utilized from 75 subjects with METH use, cocaine use, alcohol use, and HIV-positive alone and HIV-positive METH, cocaine, and alcohol users, and age-matched control subjects. The plasma CRP and SAA levels were measured by ELISA and western blot respectively and the CD4 counts were also measured.

Results

Observed results indicated that the CRP and SAA levels in HIV-positive subjects who are METH, cocaine and alcohol users were significantly higher when compared with either drugs of abuse or HIV-positive alone. The CD4 counts were also dramatically reduced in HIV-positive with drugs of abuse subjects compared with only HIV-positive subjects.

Conclusions

These results suggest that, in HIV-positive subjects, drugs of abuse increase the levels of CRP and SAA, which may impact on the HIV infection and disease progression.

Aspirin attenuates platelet activation and immune activation in HIV-1-infected subjects on antiretroviral therapy: a pilot study

BACKGROUND

Mechanisms for increased cardiovascular risk in HIV-1-infected adults are incompletely understood, but platelet activation and immune activation leading to a prothrombotic state have been proposed as significant contributors. Aspirin has antiplatelet and immunomodulatory properties. We explored whether 1 week of low-dose aspirin attenuates platelet activation and immune activation in HIV-1-infected and virologically suppressed adults on antiretroviral therapy.

METHODS

Platelet activation and immune activation were measured in HIV-1-infected subjects virologically suppressed on antiretroviral therapy and controls before and after 1 week of low-dose aspirin.

RESULTS

Compared with control subjects, HIV-1-infected subjects had increased platelet activation, as measured by spontaneous platelet aggregation and aggregation in response to adenosine diphosphate, collagen, and arachidonic acid. After aspirin therapy, percent aggregation decreased similarly in both HIV-1-infected and control subjects to all platelet agonists tested except aggregation in response to arachidonic acid, which remained elevated in the HIV-1-infected group. HIV-1-infected subjects exhibited increased markers of T-cell activation (CD38 and HLA-DR) and monocyte activation (sCD14), which decreased after 1 week of aspirin therapy. Moreover, leukocyte responses to Toll-like receptor stimulation were enhanced after 1 week of aspirin therapy. In vitro studies showed that HIV-1 plasma could activate healthy platelets, which in turn activated monocytes, implicating a direct role for activated platelets in immune activation.

CONCLUSIONS

Our data demonstrate that heightened platelet activation and immune activation in treated HIV-1 disease are attenuated by 1 week of aspirin therapy. Aspirin should be further studied for its antithrombotic and immunomodulatory benefits in treated HIV-1 disease.

Ocular parameters of biological ageing in HIV-infected individuals in South Africa: relationship with chronological age and systemic biomarkers of ageing

HIV-infected individuals have an increased risk of age-related morbidity despite antiretroviral treatment (ART). Several anatomic and functional ophthalmological parameters are associated with increasing chronological age. These may, therefore, potentially serve as biomarkers of ageing. We investigated associations between ocular parameters (lens density, retinal vessel calibre, corneal endothelium and retinal nerve fibre layer thickness) and two 'cellular' biomarkers of ageing (leukocyte telomere length and CDKN2A expression) and with frailty in a cross-sectional study of 216 HIV-infected individuals. All ocular parameters, telomere length and frailty were associated with chronological age, whereas CDKN2A expression was not. Retinal venular calibre and lens density were associated with shorter telomere length (p-trend=0.04, and 0.08, respectively), whereas CDKN2A expression and frailty status were not associated with ocular parameters. Longitudinal studies are warranted to assess the integration of retinal vascular calibre and lens density with systemic markers to develop an overall index of biological ageing in HIV infection.

Inhibition of HIV-1 enzymes, antioxidant and anti-inflammatory activities of Plectranthus barbatus

ETHNOPHARMACOLOGICAL RELEVANCE

Plectranthus barbatus is widely used in African countries as an herbal remedy to manage HIV/AIDS and related conditions.

AIM OF THE STUDY

To investigate the HIV-1 inhibitory, anti-inflammatory and antioxidant properties of P. barbatus and thereby provide empirical evidence for the apparent anecdotal success of the extracts.

MATERIALS AND METHODS

Ethanolic extract of P. barbatus's leaves was screened against two HIV-1 enzymes: protease (PR) and reverse transcriptase (RT). Cytotoxicity of the extract was determined through measuring tetrazolium dye uptake of peripheral blood mononuclear cells (PBMCs) and the TZM-bl cell line. Confirmatory assays for cytotoxicity were performed using flow cytometry and real-time cell electronic sensing (RT-CES). The free radical scavenging activity of the extract was investigated with 2,2-diphenyl-1-picrylhydrazyl while the anti-inflammatory properties of the plant extract were investigated using a Th1/Th2/Th17 cytometric bead array technique.

RESULTS

P. barbatus extract inhibited HIV-1PR and the 50% inhibitory concentration (IC50) was 62.0 µg/ml. The extract demonstrated poor inhibition of HIV-1 RT. Cytotoxicity testing presented CC50 values of 83.7 and 50.4 µg/ml in PBMCs and TZM-bl respectively. In addition, the extract stimulated proliferation in HIV negative and positive PBMCs treated. RT-CES also registered substantial TZM-bl proliferation after extract treatment. The extract exhibited strong antioxidant activity with an IC50 of 16 µg/ml and reduced the production of pro-inflammatory cytokines indicating anti-inflammatory potential.

CONCLUSION

This is the first demonstration of the in vitro anti HIV-1 potential of P. barbatus including direct activity as well as through the stimulation of protective immune and inflammation responses. The low cytotoxicity of the extract is also in agreement with the vast anecdotal use of this plant in treating various ailments with no reported side-effects.

HIV-1 infected lymphoid organs upregulate expression and release of the cleaved form of uPAR that modulates chemotaxis and virus expression

Cell-associated receptor for urokinase plasminogen activator (uPAR) is released as both full-length soluble uPAR (suPAR) and cleaved (c-suPAR) form that maintain ability to bind to integrins and other receptors, thus triggering and modulating cell signaling responses. Concerning HIV-1 infection, plasma levels of suPAR have been correlated with the severity of disease, levels of immune activation and ineffective immune recovery also in individuals receiving combination anti-retroviral therapy (cART). However, it is unknown whether and which suPAR forms might contribute to HIV-1 induced pathogenesis and to the related state of immune activation. In this regard, lymphoid organs represent an import site of chronic immune activation and virus persistence even in individuals receiving cART. Lymphoid organs of HIV-1(+) individuals showed an enhanced number of follicular dendritic cells, macrophages and endothelial cells expressing the cell-associated uPAR in comparison to those of uninfected individuals. In order to investigate the potential role of suPAR forms in HIV-1 infection of secondary lymphoid organs, tonsil histocultures were established from HIV-1 seronegative individuals and infected ex vivo with CCR5- and CXCR4-dependent HIV-1 strains. The levels of suPAR and c-suPAR were significantly increased in HIV-infected tonsil histocultures supernatants in comparison to autologous uninfected histocultures. Supernatants from infected and uninfected cultures before and after immunodepletion of suPAR forms were incubated with the chronically infected promonocytic U1 cell line characterized by a state of proviral latency in unstimulated conditions. In the contest of HIV-conditioned supernatants we established that c-suPAR, but not suPAR, inhibited chemotaxis and induced virus expression in U1 cells. In conclusion, lymphoid organs are an important site of production and release of both suPAR and c-suPAR, this latter form being endowed with the capacity of inhibiting chemotaxis and inducing HIV-1 expression.

Endothelial activation biomarkers increase after HIV-1 acquisition: plasma vascular cell adhesion molecule-1 predicts disease progression

OBJECTIVE

We aimed to determine whether endothelial activation biomarkers increase after HIV-1 acquisition, and whether biomarker levels measured in chronic infection would predict disease progression and death in HIV-1 seroconverters.

DESIGN

HIV-1-seronegative Kenyan women were monitored monthly for seroconversion, and followed prospectively after HIV-1 acquisition.

METHODS

Plasma levels of angiopoietin-1 and angiopoietin-2 (ANG-1, ANG-2) and soluble vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin were tested in stored samples from pre-infection, acute infection, and two chronic infection time points. We used nonparametric tests to compare biomarkers before and after HIV-1 acquisition, and Cox proportional-hazards regression to analyze associations with disease progression (CD4 < 200 cells/μl, stage IV disease, or antiretroviral therapy initiation) or death.

RESULTS

Soluble ICAM-1 and VCAM-1 were elevated relative to baseline in all postinfection periods assessed (P < 0.0001). Soluble E-selectin and the ANG-2:ANG-1 ratio increased in acute infection (P = 0.0001), and ANG-1 decreased in chronic infection (P = 0.0004). Among 228 participants followed over 1028 person-years, 115 experienced disease progression or death. Plasma VCAM-1 levels measured during chronic infection were independently associated with time to HIV progression or death (adjusted hazard ratio 5.36, 95% confidence interval 1.99-14.44 per log10 increase), after adjustment for set point plasma viral load, age at infection, and soluble ICAM-1 levels.

CONCLUSION

HIV-1 acquisition was associated with endothelial activation, with sustained elevations of soluble ICAM-1 and VCAM-1 postinfection. Soluble VCAM-1 may be an informative biomarker for predicting the risk of HIV-1 disease progression, morbidity, and mortality.

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

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

Clinical utility of biomarkers of endothelial activation and coagulation for prognosis in HIV infection: a systematic review

Introduction: HIV infection is associated with vascular dysfunction and adverse cardiovascular outcomes. Our objective was to review the evidence regarding the clinical utility of endothelial activation and coagulation biomarkers for the prognosis of HIV-infected patients.

Methods: We searched PubMed and Embase for publications using the keywords “HIV” or “HIV infection” and “endothelium” or “coagulation”. We reviewed reference lists and hand-searched for additional relevant articles. All clinical studies that enrolled non-pregnant, HIV-infected adults, measured biomarkers reflecting endothelial activation or coagulation, and prospectively evaluated their associations with vascular dysfunction or clinical outcomes were included.

Results: Seventeen studies were identified that fulfilled the inclusion criteria, of which 11 investigated endothelial activation biomarkers and 12 investigated coagulation biomarkers. Biomarkers and outcomes varied widely across studies. Overall, published studies support an association between P-selectin and venous thromboembolism in HIV-infected patients, an association between tissue-type plasminogen activator and death, and associations between D-dimer and several clinical outcomes, including venous thromboembolism, cardiovascular disease, and all-cause mortality.

Conclusions: Several studies have demonstrated associations between biomarkers of endothelial activation and coagulation and clinically important outcomes in HIV-1 infection. Additional large-scale prospective investigations to determine the utility of endothelial activation and coagulation biomarkers for risk stratification and prediction of adverse outcomes are clearly warranted.

Activity of the HIV-1 attachment inhibitor BMS-626529, the active component of the prodrug BMS-663068, against CD4-independent viruses and HIV-1 envelopes resistant to other entry inhibitors

BMS-626529 is a novel small-molecule HIV-1 attachment inhibitor active against both CCR5- and CXCR4-tropic viruses. BMS-626529 functions by preventing gp120 from binding to CD4. A prodrug of this compound, BMS-663068, is currently in clinical development. As a theoretical resistance pathway to BMS-663068 could be the development of a CD4-independent phenotype, we examined the activity of BMS-626529 against CD4-independent viruses and investigated whether resistance to BMS-626529 could be associated with a CD4-independent phenotype. Finally, we evaluated whether cross-resistance exists between BMS-626529 and other HIV-1 entry inhibitors. Two laboratory-derived envelopes with a CD4-independent phenotype (one CXCR4 tropic and one CCR5 tropic), five envelopes from clinical isolates with preexisting BMS-626529 resistance, and several site-specific mutant BMS-626529-resistant envelopes were examined for their dependence on CD4 for infectivity or susceptibility to BMS-626529. Viruses resistant to other entry inhibitors (enfuvirtide, maraviroc, and ibalizumab) were also examined for susceptibility to BMS-626529. Both CD4-independent laboratory isolates retained sensitivity to BMS-626529 in CD4(-) cells, while HIV-1 envelopes from viruses resistant to BMS-626529 exhibited no evidence of a CD4-independent phenotype. BMS-626529 also exhibited inhibitory activity against ibalizumab- and enfuvirtide-resistant envelopes. While there appeared to be some association between maraviroc resistance and reduced susceptibility to BMS-626529, an absolute correlation cannot be presumed, since some CCR5-tropic maraviroc-resistant envelopes remained sensitive to BMS-626529. Clinical use of the prodrug BMS-663068 is unlikely to promote resistance via generation of CD4-independent virus. No cross-resistance between BMS-626529 and other HIV entry inhibitors was observed, which could allow for sequential or concurrent use with different classes of entry inhibitors.

Microbial translocation in the pathogenesis of HIV infection and AIDS

In pathogenic simian immunodeficiency virus (SIV) and human immunodeficiency virus (HIV) infections, the translocation of microbial products from the gastrointestinal (GI) tract to portal and systemic circulation has been proposed as a major driver of the chronic immune activation that is associated with disease progression. Consistently, microbial translocation is not present in nonpathogenic SIV infections of natural host species. In vivo studies demonstrated that HIV/SIV-associated microbial translocation results from a series of immunopathological events occurring at the GI mucosa: (i) early and severe mucosal CD4(+) depletion, (ii) mucosal immune hyperactivation/persistent inflammation; (iii) damage to the integrity of the intestinal epithelium with enterocyte apoptosis and tight junction disruption; and (iv) subverted the gut microbiome, with a predominance of opportunistic bacteria. Direct in situ evidence of microbial translocation has been provided for SIV-infected rhesus macaques showing translocated microbial products in the intestinal lamina propria and distant sites. While the mechanisms by which microbial translocation causes immune activation remain controversial, a key pathogenic event appears to be innate immunity activation via Toll-like receptors and other pathogen recognition receptors. Accumulating clinical observations suggest that microbial translocation might affect HIV disease progression, response to therapy, and non-AIDS comorbidities. Given its detrimental effect on overall immunity, several interventions to prevent/block microbial translocation are currently under investigation as novel therapeutic agents for HIV/AIDS.

A prospective study of endothelial activation biomarkers, including plasma angiopoietin-1 and angiopoietin-2, in Kenyan women initiating antiretroviral therapy

BACKGROUND

HIV-1-related inflammation is associated with increased levels of biomarkers of vascular adhesion and endothelial activation, and may increase production of the inflammatory protein angiopoietin-2 (ANG-2), an adverse prognostic biomarker in severe systemic infection. We hypothesized that antiretroviral therapy (ART) initiation would decrease endothelial activation, reducing plasma levels of ANG-2.

METHODS

Antiretroviral-naïve Kenyan women with advanced HIV infection were followed prospectively. Endothelial activation biomarkers including soluble intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and E-selectin, and plasma ANG-2 and angiopoietin-1 (ANG-1) were tested in stored plasma samples from 0, 6, and 12 months after ART initiation. We used Wilcoxon matched-pairs signed rank tests to compare endothelial activation biomarkers across time-points, generalized estimating equations to analyze associations with change in log10-transformed biomarkers after ART initiation, and Cox proportional-hazards regression to analyze associations with mortality.

RESULTS

The 102 HIV-1-seropositive women studied had advanced infection (median CD4 count, 124 cells/μL). Soluble ICAM-1 and plasma ANG-2 levels decreased at both time-points after ART initiation, with concomitant increases in the beneficial protein ANG-1. Higher ANG-2 levels after ART initiation were associated with higher plasma HIV-1 RNA, oral contraceptive pill use, pregnancy, severe malnutrition, and tuberculosis. Baseline ANG-2 levels were higher among five women who died after ART initiation than among women who did not (median 2.85 ng/mL [inter-quartile range (IQR) 2.47-5.74 ng/mL] versus median 1.32 ng/mL [IQR 0.35-2.18 ng/mL], p = 0.01). Both soluble ICAM-1 and plasma ANG-2 levels predicted mortality after ART initiation.

CONCLUSIONS

Biomarkers of endothelial activation decreased after ART initiation in women with advanced HIV-1 infection. Changes in plasma ANG-2 were associated with HIV-1 RNA levels over 12 months of follow-up. Soluble ICAM-1 and plasma ANG-2 levels represent potential biomarkers for adverse outcomes in advanced HIV-1 infection.

X4 viruses are frequently archived in patients with long-term HIV infection but do not seem to influence the "inflamm-aging" process

Background

Co-receptor tropism (CRT) in patients with a long history of HIV-1 infection and antiretroviral treatment has been rarely investigated to date. The aim of this study was to determine the prevalence of X4 and R5 strains in patients with a >15-year follow-up and to investigate the demographical, viral, immunological, clinical and therapeutic determinants of CRT in this population. The possible influence of CRT on the inflammation state related to chronic HIV infection was also examined.

Methods

A total of 118 HIV-1 infected patients with an initial HIV-1-positive test before 1997, and still on follow-up, were enrolled and consecutively submitted to blood sampling. Of these, 111 were on antiretroviral therapy and 89/111 (80.2%) had a plasma viral load (pVL) <25 copies/ml at testing. HIV-1 DNA was extracted and amplified from PBMCs for env gp120 sequencing. CRT was assigned by using geno2pheno and isolates were classified as X4 (FPR ≤20%) or R5 (FPR >20%). Level of serological inflammation biomarkers including IL-6, hsPCR, and D-dimers were measured.

Results

An X4 virus was evidenced in HIV-1 proviral DNA of 50 patients (42%) while the remaining 68 patients were classified as R5. The median follow-up was 19 years (range 15–25). No association was observed between CRT and sex, age, nationality, subtype, HIV risk factor, HBV/HCV co-infection, baseline CD4+ cell count and pVL, overall duration of antiretroviral therapy, past exposure to mono-or dual therapies, and duration of NNRTI or PI-based therapy. The presence of an X4 strain was associated with CD4 nadir (p = 0.005), CD4 absolute count over time (p < 0.001), and cumulative positive (copy/years) viremia (p <0.001) during the whole patient history. No differences were found between R5 and X4 patients regarding inflammation marker levels including Il-6, hsPCR and D-dimers.

Conclusions

An archived X4 virus was demonstrated in 42% of patients with a >15-year-history of HIV infection. This presence was clearly associated with a greater exposure to positive viremia and a poorer CD4 trend over time compared to R5, independent of type and duration of antiretroviral treatment. CRT does not seem to influence the inflammation rate of patients aging with HIV.

Cell-Mediated Immunity in Elite Controllers Naturally Controlling HIV Viral Load

The natural course of human immunodeficiency virus (HIV) infection is characterized by high viral load, depletion of immune cells, and immunodeficiency, ultimately leading to acquired immunodeficiency syndrome phase and the occurrence of opportunistic infections and diseases. Since the discovery of HIV in the early 1980s a naturally selected population of infected individuals has been emerged in the last years, characterized by being infected for many years, with viremia constantly below detectable level and poor depletion of immune cells. These individuals are classified as “elite controllers (EC) or suppressors” and do not develop disease in the absence of anti-retroviral therapy. Unveiling host factors and immune responses responsible for the elite status will likely provide clues for the design of therapeutic vaccines and functional cures. Scope of this review was to examine and discuss differences of the cell-mediated immune responses between HIV+ individuals with disease progression and EC.

Low-level HIV viremia is associated with microbial translocation and inflammation

BACKGROUND

Decrease in HIV viral load (VL) is accompanied by decrease in microbial translocation (MT) and chronic inflammation, but the behavior of these markers in patients with HIV-VL <20 copies per milliliter is unknown. The aim of this study was to determine whether strict control of HIV-VL is associated with MT and chronic inflammation.

METHODS

Observational cross-sectional study.

INCLUSION CRITERIA

HIV patients receiving antiretroviral therapy and HIV-VL <200 copies per milliliter for more than 6 months.

EXCLUSION CRITERIA

chronic liver disease, active infection, or antibiotic consumption. Recruitment: patients who consecutively visited the outpatient clinic in November 2011. Primary endpoint: molecular MT as determined by detection in plasma of 16S ribosomal DNA. Secondary variables: lipopolysaccharide, soluble CD14, tumor necrosis factor α, and interleukin 6. Primary explanatory variable: HIV-VL (COBAS AmpliPrep/COBAS TaqMan HIV-1 test, version 2.0) with a detection limit of 20 copies per milliliter.

RESULTS

Fifty-two patients were included: 65% men, median age 45 years, HIV acquired predominantly through sex (75%), 40% Centers for Disease Control and Prevention stage C, and median CD4 lymphocyte count 552 cells per cubic millimeter (range, 126-1640 cells/mm). Molecular MT was observed in 46% and 18% of patients with low-level (20-200 copies/mL) and negative (<20 copies/mL) HIV-VL, respectively (P < 0.05). Plasma levels of inflammatory markers (tumor necrosis factor α and interleukin 6) were higher in patients with molecular MT (P < 0.01) and were not influenced for HIV-VL.

CONCLUSIONS

Patients with HIV infection receiving treatment and negative HIV-VL (<20 copies/mL) present less frequently MT than patients with low-level HIV viremias (20-200 copies/mL). MT is associated with higher levels of inflammation markers, independent of HIV-VL.

Cytokines in CSF correlate with HIV-associated neurocognitive disorders in the post-HAART era in China

In the current era of highly active antiretroviral therapy (HAART), the incidence of HIV dementia has declined, but the prevalence of HIV-associated neurocognitive disorder (HAND) remains high. HIV-induced systemic and localized inflammation is considered to be one of the mechanisms of HAND. Changes in cytokine levels in the cerebrospinal fluid (CSF) during HIV infection might help to identify HAND. To investigate whether the cytokine profile of the CSF during HIV infection could be used as a biomarker of HAND, we compared cytokine levels in the CSF of HIV-infected cases with and without neurocognitive impairment. Cytokine concentrations in the CSF were measured by quantification bioassays (Luminex xMAP). HIV-infected cases with neurocognitive impairment demonstrated higher levels of interleukin (IL)-8, monocyte chemotactic protein (MCP)-1, induced protein (IP)-10, and granulocyte colony-stimulating factor (G-CSF) in the CSF than those without neurocognitive impairment (G-CSF (p = 0.0003), IL-8 (p = 0.0046), IP-10 (p < 0.0001), and MCP-1 (p < 0.0001)). There was no significant impact of HAART on cytokine levels in the CSF, except for IP-10, which was higher in HAART-treated patients with impaired cognition (p = 0.0182). Findings from this preliminary study suggest that elevated levels of the cytokines IL-8, MCP-1, G-CSF, and IP-10 in the CSF are associated with neurocognitive impairment in HIV infection, and these cytokines likely represent a biomarker profile for HAND.

Preclinical evaluation of HIV eradication strategies in the simian immunodeficiency virus-infected rhesus macaque: a pilot study testing inhibition of indoleamine 2,3-dioxygenase

Even in the setting of maximally suppressive antiretroviral therapy (ART), HIV persists indefinitely. Several mechanisms might contribute to this persistence, including chronic inflammation and immune dysfunction. In this study, we have explored a preclinical model for the evaluation of potential interventions that might serve to eradicate or to minimize the level of persistent virus. Given data that metabolic products of the inducible enzyme indoleamine 2,3-dioxygeanse (IDO) might foster inflammation and viral persistence, chronically simian immunodeficiency virus (SIV)-infected, ART-treated rhesus macaques were treated with the IDO inhibitor 1-methyl tryptophan (1mT). Orally administered 1mT achieved targeted plasma levels, but did not impact tryptophan metabolism or decrease viral RNA or DNA in plasma or in intestinal tissues beyond levels achieved by ART alone. Animals treated with 1mT showed no difference in the levels of T cell activation or differentiation, or in the kinetics or magnitude of viral rebound following cessation of ART. Notwithstanding these negative results, our observations suggest that the chronically SIV-infected rhesus macaque on suppressive ART can serve as a tractable model in which to test and to prioritize the selection of other potential interventions designed to eradicate HIV in vivo. In addition, this model might be used to optimize the route and dose by which such interventions are administered and the methods by which their effects are monitored.

Immunovirological parameters and cytokines in HIV infection

Although modern combined antiretroviral therapies (cART) result in lower morbidity and mortality and a visible improvement of clinical and laboratory parameters in HIV-infected, it is known that their long-term use contributes to appearance of the many events unrelated to AIDS such as cardiovascular diseases, cancer and osteoporosis, comorbidities which have been proposed as some of the most important that deprive the majority of infected to present an even better prognosis. This is because even with a decrease in inflammation and immune activation after drug intervention to the patient, these parameters remain higher than those shown by healthy individuals and the imbalance of cytokine profiles also persists. Therefore, evaluations of other biomarkers in clinical practice are needed to complement the exams already carried out routinely and allow more effective monitoring of HIV patients. This review aims to investigate the role of cytokines as potential markers showing studies on their behavior in various stages of HIV infection, with or without cART.

Inflammatory status hepatic enzymes and serum creatinine in HIV-, HIV+ and HIV-TB co-infected adult Central Africans

Background and aim

Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome is a major public health issue in Africa. The objective of this study was to determine which of isolated HIV-infection, isolated naive pulmonary tuberculosis (PTB), or naive HIV-PTB coinfection was more harmful to inflammatory, hepatic, and renal functions.

Methods

This cross-sectional study was undertaken among ten patients with isolated HIV infection, ten patients with isolated naive HIV infection, ten patients with isolated PTB and 32 patients with HIV-PTB coinfection, with the aim of determining which group had the highest levels of oxidative stress and hepatic and renal dysfunction markers. Serum aminotransferase (AST), alanine transferase (ALT), gamma-glutamyl transferase (GGT), and creatinine measurements were compared across the three groups of patients, who were managed from admission in the pulmonology division of the Brazzaville Teaching Hospital, Congo.

Results

HIV patients had the highest levels of ALT, GGT, and creatinine before and after adjusting for age and sex. Adjusted levels of AST, ALT, GGT, and creatinine were higher in HIV-PTB coinfection patients than in sero-negative PTB patients.

Conclusion

There is a significant association between HIV infection and increase in concentration of ALT, GGT, and creatinine.

CD8+ T cell-derived IFN-γ prevents infection by a second heterologous virus

Persistent viral infection is often associated with dysfunctional immune responses against unrelated pathogens. Lymphocytic choriomeningitis virus (LCMV) can establish acute or chronic infections in mice and is widely used as a model for persistent virus infections in humans. Mice infected with LCMV develop a transient defect in Ag-specific immunity against heterologous viral infection. Although it has been proposed that LCMV infection induces an immunosuppressed state within the host, our data show that infected mice successfully clear vaccinia virus through a mechanism that involves CD8(+) T cell-derived IFN-γ. This observation demonstrates that chronic LCMV infection does not impair protective immunity against heterologous viral challenge. Rather, a natural sterilizing immunity is induced following a primary infection that prevents a secondary infection. Our findings suggest a need to re-evaluate current thoughts about the immune suppression that might occur during a persistent infection.

HIV infection, aging, and immune function: implications for cancer risk and prevention

PURPOSE OF REVIEW

Combination antiretroviral therapy (ART) has turned HIV infection into a complex chronic disease. This article documents cancer risk among HIV-infected persons, reviews immune system effects of HIV infection in relation to cancer risk, discusses implications for cancer prevention, and suggests future research directions.

RECENT FINDINGS

There has been a shift in the cancer spectrum from AIDS-defining cancers (ADC) to non-ADC, although the burden of ADC remains high. Although a high prevalence of non-HIV cancer risk factors among HIV-infected persons contributes to cancer risk, substantial evidence has accumulated in favor of an independent association between HIV-induced immunodeficiency and elevated risk of many specific cancer types, most of viral cause, although further work is needed to disentangle immunodeficiency and smoking effects for lung cancer, and immunodeficiency and hepatitis virus effects for liver cancer. Relationships between cancer risk and two other immune system hallmarks of HIV infection, chronic inflammation, and immune dysfunction/senescence, remain poorly understood.

SUMMARY

Early, sustained ART is a crucial component of cancer prevention. Continued epidemiologic monitoring is needed to detect possible effects on cancer risk of specific ART classes or medications, long-term exposure to systemic inflammation or immune dysfunction, or earlier or more effective ART.

Acute plasma biomarkers of T cell activation set-point levels and of disease progression in HIV-1 infection

T cell activation levels, viral load and CD4(+) T cell counts at early stages of HIV-1 infection are predictive of the rate of progression towards AIDS. We evaluated whether the inflammatory profile during primary HIV-1 infection is predictive of the virological and immunological set-points and of disease progression. We quantified 28 plasma proteins during acute and post-acute HIV-1 infection in individuals with known disease progression profiles. Forty-six untreated patients, enrolled during primary HIV-1 infection, were categorized into rapid progressors, progressors and slow progressors according to their spontaneous progression profile over 42 months of follow-up. Already during primary infection, rapid progressors showed a higher number of increased plasma proteins than progressors or slow progressors. The plasma levels of TGF-β1 and IL-18 in primary HIV-1 infection were both positively associated with T cell activation level at set-point (6 months after acute infection) and together able to predict 74% of the T cell activation variation at set-point. Plasma IP-10 was positively and negatively associated with, respectively, T cell activation and CD4(+) T cell counts at set-point and capable to predict 30% of the CD4(+) T cell count variation at set-point. Moreover, plasma IP-10 levels during primary infection were predictive of rapid progression. In primary infection, IP-10 was an even better predictor of rapid disease progression than viremia or CD4(+) T cell levels at this time point. The superior predictive capacity of IP-10 was confirmed in an independent group of 88 HIV-1 infected individuals. Altogether, this study shows that the inflammatory profile in primary HIV-1 infection is associated with T cell activation levels and CD4(+) T cell counts at set-point. Plasma IP-10 levels were of strong predictive value for rapid disease progression. The data suggest IP-10 being an earlier marker of disease progression than CD4(+) T cell counts or viremia levels.

Aging, inflammation, and HIV infection

Prolonged survival in HIV infection is accompanied by an increased frequency of non-HIV-related comorbidities. A number of age-related comorbidities occur earlier in HIV-infected patients than in individuals without HIV infection. This "accelerated aging" appears to be largely related to chronic inflammation, chronic immune activation, and immunosenescence in HIV infection. Levels of markers of inflammation and coagulopathy are elevated in HIV-infected patients, and elevations in markers such as high-sensitivity C-reactive protein, D-dimer, and interleukin 6 (IL-6) have been associated with increased risk for cardiovascular disease, opportunistic conditions, or all-cause mortality. In both HIV infection and aging, immunosenescence is marked by an increased proportion of CD28-, CD57+ memory CD8+ T cells with reduced capacity to produce interleukin 2 (IL-2), increased production of IL-6, resistance to apoptosis, and shortened telomeres. A number of AIDS Clinical Trials Group studies are under way to examine treatment aimed at reducing chronic inflammation and immune activation in HIV infection. This article summarizes a presentation by Judith A. Aberg, MD, at the IAS-USA live continuing medical education course held in New York City in October 2011.

Effects of hydroxychloroquine on immune activation and disease progression among HIV-infected patients not receiving antiretroviral therapy: a randomized controlled trial

CONTEXT

Therapies to decrease immune activation might be of benefit in slowing HIV disease progression.

OBJECTIVE

To determine whether hydroxychloroquine decreases immune activation and slows CD4 cell decline.

DESIGN, SETTING, AND PATIENTS

Randomized, double-blind, placebo-controlled trial performed at 10 HIV outpatient clinics in the United Kingdom between June 2008 and February 2011. The 83 patients enrolled had asymptomatic HIV infection, were not taking antiretroviral therapy, and had CD4 cell counts greater than 400 cells/μL.

INTERVENTION

Hydroxychloroquine, 400 mg, or matching placebo once daily for 48 weeks.

MAIN OUTCOME MEASURES

The primary outcome measure was change in the proportion of activated CD8 cells (measured by the expression of CD38 and HLA-DR surface markers), with CD4 cell count and HIV viral load as secondary outcomes. Analysis was by intention to treat using mixed linear models.

RESULTS

There was no significant difference in CD8 cell activation between the 2 groups (-4.8% and -4.2% in the hydroxychloroquine and placebo groups, respectively, at week 48; difference, -0.6%; 95% CI, -4.8% to 3.6%; P = .80). Decline in CD4 cell count was greater in the hydroxychloroquine than placebo group (-85 cells/μL vs -23 cells/μL at week 48; difference, -62 cells/μL; 95% CI, -115 to -8; P = .03). Viral load increased in the hydroxychloroquine group compared with placebo (0.61 log10 copies/mL vs 0.23 log10 copies/mL at week 48; difference, 0.38 log10 copies/mL; 95% CI, 0.13 to 0.63; P = .003). Antiretroviral therapy was started in 9 patients in the hydroxychloroquine group and 1 in the placebo group. Trial medication was well tolerated, but more patients reported influenza-like illness in the hydroxychloroquine group compared with the placebo group (29% vs 10%; P = .03).

CONCLUSION

Among HIV-infected patients not taking antiretroviral therapy, the use of hydroxychloroquine compared with placebo did not reduce CD8 cell activation but did result in a greater decline in CD4 cell count and increased viral replication.

TRIAL REGISTRATION

isrctn.org Identifier: ISRCTN30019040.

Acute phase response to Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' infection in FIV-infected and non-FIV-infected cats

The pathogenicity of Haemoplasma spp. in cats varies with 'Candidatus Mycoplasma haemominutum' (CMhm) causing subclinical infection while Mycoplasma haemofelis (Mhf) often induces haemolytic anaemia. The aims of this study were to characterise the acute phase response (APR) of the cat to experimental infection with Mhf or CMhm, and to determine whether chronic feline immunodeficiency virus (FIV) infection influences this response. The acute phase proteins serum amyloid A (SAA), haptoglobin (Hp) and α-1-acid glycoprotein (AGP) concentrations were measured pre-infection and every 7-14 days up to day 100 post-infection (pi) in cats infected with either Mhf or CMhm. Half of each group of cats (6/12) were chronically and subclinically infected with FIV. Marbofloxacin treatment was given on days 16-44 pi to half of the Mhf-infected cats, and on days 49-77 pi to half of the CMhm-infected cats. FIV-infected animals had significantly lower AGP concentrations, and significantly greater Hp concentrations than non-FIV-infected cats when infected with CMhm and Mhf, respectively. Both CMhm and Mhf infection were associated with significant increases in SAA concentrations, while AGP concentrations were only significantly increased by Mhf infection. Mhf-infected cats had significantly greater SAA concentrations than CMhm-infected animals. Both Mhf and CMhm infections were associated with an APR, with Mhf infection inducing a greater response. Chronic FIV infection appeared to modify the APR, which varied with the infecting Haemoplasma species.

Different biological significance of sCD14 and LPS in HIV-infection: importance of the immunovirology stage and association with HIV-disease progression markers

OBJECTIVES

Bacterial lipopolysaccharide (LPS) and soluble CD14 (sCD14) levels have been indistinctly used to measure bacterial translocation independently of the immunovirological stage in HIV infection; however, when the association of both markers with different HIV-progression end-points has been studied, discrepant results have been reported. The aim of this study was to assess the relationship between LPS and sCD14 in different HIV-infection immune stages and to determine the relationship between these biomarkers with established HIV-disease-progression-related markers, as T-cell immune activation, high-sensitivity C-reactive protein and D-dimer.

METHODS

Seventy-three chronically HIV-1-infected patients with detectable HIV-1 RNA levels were analyzed. LPS levels by use of limulus lysate assay, sCD14, intestinal fatty acid binding protein and inflammation-coagulation-associated biomarkers were assessed.

RESULTS

In this study, we found that LPS and sCD14 levels were only associated when low CD4+ T-cell levels and high HIV RNA levels were present. In addition, only sCD14 levels, but not LPS, were independently associated with HIV-disease progression-related markers, supporting the clinical importance of sCD14.

CONCLUSIONS

These results indicate that LPS and sCD14 have a different biological significance and should not be indistinctly used without taking the HIV immunovirological stage into account.

ICOS, SLAM and PD-1 expression and regulation on T lymphocytes reflect the immune dysregulation in patients with HIV-related illness with pulmonary tuberculosis

Background

Tuberculosis (TB) continues to be the most frequent cause of illness and death from an infectious agent globally, and its interaction with HIV is having devastating effects. To investigate how HIV alters the immune response to Mycobacterium tuberculosis (Mtb), we assessed basal and Mtb-induced proliferation, cytokine production, and expression of signalling lymphocytic activation molecule (SLAM), inducible costimulator (ICOS) and programmed death-1 (PD-1) on T lymphocytes from HIV-positive individuals coinfected with TB, HIV-positive subjects, TB patients and healthy donors (HD).

Findings

HIV-TB patients showed increased ICOS, SLAM and PD-1 basal levels on T lymphocytes, whereas HIV-positive individuals displayed elevated levels of SLAM and PD-1, TB patients high levels of SLAM, and HD low levels of the three proteins. Mtb-stimulation enhanced ICOS expression in the four groups, but only TB and HD increased SLAM and PD-1 levels.

Conclusions

These data show the immune deregulation that takes place during the immune response against TB in different study populations.

Levels of soluble endothelial protein C receptor are associated with CD4+ changes in Maraviroc-treated HIV-infected patients

Background

Inflammation is a key feature of HIV infection and is correlated with long-term negative cardiovascular outcomes. Therapy-induced increases in CD4⁺ cell counts can control inflammation, as shown by decreases of coagulation and inflammation markers during efficacious therapy. Maraviroc, a CCR5-antagonist, has resulted in larger increases in CD4⁺ counts both in naïve and experienced subjects compared to traditional antiretroviral therapy.

Objectives and Methods

To examine if a member of the protein C anticoagulant and anti-inflammatory pathway, and marker of coagulation and inflammation, the soluble endothelial protein C receptor, is modified by infection and therapy-related variables in patients treated with Maraviroc. Endothelial protein C receptor, together with other established markers of inflammation and coagulation (CRP, IL-6, D-dimer and soluble thrombomodulin) was studied in 43 patients on traditional antiretroviral therapy and in 45 on Maraviroc during 48 weeks of follow-up.

Results

Soluble endothelial protein C receptor was the only marker that could discriminate at least partially between patients with a good response to Maraviroc and patients who did not respond with an adequate increase in CD4⁺ cell counts (more than 500 cells/µL by week 48).

Conclusions

Elevated levels of soluble endothelial protein C receptor, a sensitive marker of endothelial damage, indicated a low level of inflammation and coagulation activation in Maraviroc treated patients not picked up by other widely used markers. Persistent elevated levels of this marker at 48 weeks from beginning of treatment with Maraviroc were related to a poor increase in CD4⁺ cells.

Circulating microbial products and acute phase proteins as markers of pathogenesis in lymphatic filarial disease

Lymphatic filariasis can be associated with development of serious pathology in the form of lymphedema, hydrocele, and elephantiasis in a subset of infected patients. Dysregulated host inflammatory responses leading to systemic immune activation are thought to play a central role in filarial disease pathogenesis. We measured the plasma levels of microbial translocation markers, acute phase proteins, and inflammatory cytokines in individuals with chronic filarial pathology with (CP Ag+) or without (CP Ag−) active infection; with clinically asymptomatic infections (INF); and in those without infection (endemic normal [EN]). Comparisons between the two actively infected groups (CP Ag+ compared to INF) and those without active infection (CP Ag− compared to EN) were used preliminarily to identify markers of pathogenesis. Thereafter, we tested for group effects among all the four groups using linear models on the log transformed responses of the markers. Our data suggest that circulating levels of microbial translocation products (lipopolysaccharide and LPS-binding protein), acute phase proteins (haptoglobin and serum amyloid protein-A), and inflammatory cytokines (IL-1β, IL-12, and TNF-α) are associated with pathogenesis of disease in lymphatic filarial infection and implicate an important role for circulating microbial products and acute phase proteins.

Lymphatic filariasis afflicts over 120 million people worldwide. While the infection is mostly clinically asymptomatic, approximately 40 million people suffer from overt, morbid clinical pathology, characterized by swelling of the scrotal area and lower limbs (hydrocele and lymphedema). Host immunologic factors that influence the pathogenesis of disease in these individuals are not completely understood. Circulating microbial products such as LPS and markers associated with microbial translocation have been shown to play an important role in disease pathogenesis of certain infections like HIV. Similarly, proteins associated with the acute phase response and related cytokines also play an important role in pathogenesis. We have attempted to elucidate the role of the above mentioned factors in disease pathogenesis by comparing the plasma levels of the various markers in four groups of individuals: chronic pathology individuals with or without active filarial infection, asymptomatic, filarial infected individuals and uninfected, endemic normal individuals. We show that circulating levels of LPS, acute phase proteins and certain cytokines are significantly elevated in filarial disease with active infection but not in the other groups indicating that filarial infection induced increased production of these factors correlated with the development of filarial lymphatic pathology.

Immune activation in the pathogenesis of treated chronic HIV disease: a workshop summary

With the advent of highly effective antiretroviral therapy (ART), infection with human immunodeficiency virus (HIV) has become a chronic disease rather than a death sentence. Nevertheless, effectively treated individuals have a higher than normal risk for developing noninfectious comorbidities, including cardiovascular and renal disease. Although traditional risk factors of aging as well as treatment toxicity contribute to this risk, many investigators consider chronic HIV-associated inflammation a significant factor in such end-organ disease. Despite effective viral suppression, chronic inflammation persists at levels higher than in uninfected people, yet the stimuli for the inflammation and the mechanism by which inflammation persists and promotes disease pathology remain incompletely understood. This critical gap in scientific understanding complicates and hampers effective decision making about appropriate medical intervention. To better understand the mechanism(s) of chronic immune activation in treated HIV disease, three questions need answers: (1) what is the cause of persistent immune activation during treated HIV infection, (2) what are the best surrogate markers of chronic immune activation in this setting, and (3) what therapeutic intervention(s) could prevent or reverse this process? The NIH sponsored and convened a meeting to discuss the state of knowledge concerning these questions and the best course for developing effective therapeutic strategies. This report summarizes the findings of that NIH meeting.

Circulating interleukin-6 levels correlate with residual HIV viraemia and markers of immune dysfunction in treatment-controlled HIV-infected patients

BACKGROUND

Antiretroviral therapy (ART)-controlled HIV-infected patients have elevated levels of systemic inflammatory markers, C-reactive protein (CRP) and interleukin (IL)-6, which correlate with increased cardiovascular risk and/or mortality. Persistent low-level viral replication could be involved in this inflammatory state. We evaluated whether residual viral load (VL) correlated with the level of systemic inflammatory/immune markers in ART-controlled HIV-infected patients.

METHODS

We evaluated 122 antiretroviral-controlled patients with VL 1-500 copies/ml for circulating levels of high-sensitivity (hs)CRP, hsIL-6, IL-8, soluble (s)CD14 and soluble tumour necrosis factor (TNF) receptors, sTNFR1 and sTNFR2.

RESULTS

The patients were 80.3% men, the median age was 47 years, the median CD4(+) T-cell count was 519 cells/mm(3), the median nadir CD4(+) T-cell count was 180 cells/mm(3), the median VL was 28 copies/ml and the median body mass index was 23.3 kg/m(2). The median (range) values for IL-6, CRP, IL-8, sCD14, sTNFR1 and sTNFR2 were 0.685 pg/ml (0.15-5.46), 1.8 mg/l (0.2-9.7), 10.0 pg/ml (1.6-71.1), 1,174 ng/ml (214-3,145), 1,112 pg/ml (583-5,834) and 2,412 pg/ml (1,142-7,688), respectively. IL-6 values correlated positively with HIV VL (rho=0.217, P=0.017). The VL threshold value for significantly increased IL-6 was 31 copies/ml (P=0.023). IL-6 values correlated with markers of immune dysfunction: the CD4/CD8 ratio (rho=-0.248, P=0.011), CD4 nadir level (rho=-0.186, P=0.04) and nadir CD4/CD8 ratio (rho=-0.257, P=0.008). They negatively correlated with markers of immune activation sCD14 (rho=-0.236, P=0.011) and IL-8 (rho=-0.290, P=0.002). We found no correlation between VL and CRP or other markers of inflammation/immune dysfunction including sTNFR1, sTNFR2, sCD14 and IL-8.

CONCLUSIONS

We report here that low-range IL-6 levels correlated with low-range VL and inversely with sCD14 and IL-8. Our findings suggest that maintaining VL<30 copies/ml in HIV-infected patients might therefore reduce IL-6.

Role of endogenous biological response modifiers in pathogenesis of infectious diseases

Biologic response modifiers (BRMs) interact with the host immune system and modify the immune response. BRMs can be therapeutically used to restore, augment, or dampen the host immune response. Although they have been used for decades, their clinical applications have been expanded in the past decade for diagnosis and treatment of many diseases including cancers, immunologic disorders, and infections. This article discusses endogenous biological response modifiers (ie, naturally occurring immunomodulators as a part of the host immune system), which play vital roles as regulators of both innate and adaptive immune responses.