Immune activation and microbial translocation in liver disease progression in HIV/hepatitis co-infected patients: results from the Icona Foundation study

HCV Cascade of Care in HIV/HCV Co-Infected Individuals: Missed Opportunities for Micro-Elimination

People living with HIV-HCV co-infection comprise a target group for HCV-micro-elimination. We conducted an HCV cascade of care (CoC) for HIV-HCV co-infected individuals living in Greece and investigated factors associated with different HCV-CoC stages. We analyzed data from 1213 participants from the Athens Multicenter AIDS Cohort Study. A seven-stage CoC, overall and by subgroup (people who inject drugs (PWID), men having sex with men (MSM), men having sex with women (MSW), and migrants], was constructed, spanning from HCV diagnosis to sustained virologic response (SVR). Logistic/Cox regression models were employed to identify factors associated with passing through each CoC step. Among 1213 anti-HCV-positive individuals, 9.2% died before direct-acting antiviral (DAA) availability. PWID exhibited higher mortality rates than MSM. Of 1101 survivors, 72.2% remained in care and underwent HCV-RNA testing. Migrants and PWID showed the lowest retention rates. HCV-RNA was available for 79.2% of those in care, with 77.8% diagnosed with chronic HCV. Subsequently, 71% initiated DAAs, with individuals with very low CD4 counts (<100 cells/μL) exhibiting lower odds of DAA initiation. SVR testing was available for 203 individuals, with 85.7% achieving SVR. The SVR rates did not differ across risk groups. In 2023, significant gaps and between-group differences persisted in HCV-CoC among HIV-HCV co-infected individuals in Greece.

Effects of statins beyond lipid-lowering agents in ART-treated HIV infection

Antiretroviral therapies (ART) have reduced human immunodeficiency virus (HIV) infection-associated morbidity and mortality improving the life of people with HIV (PWH). However, ART lead to residual HIV production, which in conjunction with microbial translocation and immune dysfunction contributes to chronic inflammation and immune activation. PWH on ART remain at an increased risk for cardiovascular diseases (CVDs) including myocardial infarction and stroke; which in part is explained by chronic inflammation and immune activation. Lifestyle factors and certain ART are associated with dyslipidemia characterized by an increase of low-density lipoprotein (LDL), which further contributes in the increased risk for CVDs. Lipid-lowering agents like statins are emerging as immune modulators in decreasing inflammation in a variety of conditions including HIV. The international randomized clinical trial REPRIEVE has shed light on the reduction of CVDs with statin therapy among PWH. Such reports indicate a more than expected benefit of statins beyond their lipid-lowering effects. Bempedoic acid, a first-in-class non-statin LDL-lowering drug with immune modulatory effects, may further aid PWH in combination with statins. Herein, we critically reviewed studies aimed at lipid-lowering and immune-modulating roles of statins that may benefit aging PWH.

Microbial translocation is associated with advanced liver fibrosis among people with HIV

BACKGROUND

The prevalence of liver complications is increasing among people living with HIV, and microbial translocation (MT) might play a vital role. We conducted a prospective cohort study to evaluate the association between plasma biomarkers of MT and liver fibrosis (LF) among people living with HIV in southwest China.

METHOD

A total of 665 people living with HIV were enrolled at baseline and had at least one follow-up visit during the 3-year study period. We calculated the Liver Fibrosis Index (FIB-4) to evaluate LF and measured plasma soluble CD14 (sCD14) and lipopolysaccharide-binding protein (LBP) as surrogate biomarkers for MT. We used ordinal logistic regression to investigate correlates of LF at baseline and used a linear mixed model to examine the association between dynamic changes in MT biomarkers and LF.

RESULTS

Of the participants, 61 (9.17%) had advanced LF (FIB-4 &gt;3.25), and 193 (29.02%) had moderate LF (1.45 ≤ FIB-4 ≤ 3.25). Patients with advanced LF had higher plasma levels of sCD14 and LBP than those with moderate or no LF, both at baseline and at follow-up. The following factors were significantly associated with advanced LF: the highest quartile of LBP (adjusted odds ratio [aOR] = 1.69; 95% confidence interval [CI] 1.02~2.81), current intravenous drug use (aOR = 1.82; 95% CI 1.06~3.12), baseline CD4 &lt;200 cells/μl (aOR = 3.25; 95% CI 2.13~4.95), hepatitis C virus coinfection (aOR = 2.52; 95% CI 1.41~4.51) and age &gt;50 years (aOR = 32.66; 95% CI 15.89~66.36). LF progression (increasing FIB-4) was significantly associated with increasing sCD14 level (β = 1.11; 95% CI 0.97~1.26; p &lt; 0.001) with covariate adjustment.

CONCLUSION

The significant relationship between MT and LF may reveal pathogenic mechanisms and potential intervention targets of liver complications among people living with HIV in China.

Gamma-Delta T-Cell Phenotype and Function in DAA-Treated HIV-HCV Co-Infected and HCV-Mono-Infected Subjects

HIV-HCV co-infected subjects are at risk of liver fibrosis which may be linked to immune imbalances. Direct-acting antivirals (DAAs) represent the mainstay of HCV treatment in co-infected individuals, yet their effects on immune cell populations playing a role in fibrogenesis is unknown. We assessed γδ T-cell phenotype and function, Treg and Th17 frequencies, as well as γ-globulins and B-cell activation in 47 HIV-HCV co-infected and 35 HCV mono-infected individuals prior to and following DAA treatment (SVR12). Γδ T-cell activation decreased in both groups yet persisted at higher levels in the HIV-HCV co-infected subjects. No differences were registered in terms of γδT-cell function. Of note, the Vδ2/Th17 ratio, inversely linked to liver damage, increased significantly in the two groups upon treatment, yet a negative correlation between the Vδ2/Th17 ratio and liver function enzymes was found in the co-infected subjects alone. B-cell activation and γ-globulin levels decreased in both settings, yet B-cell activation remained higher in the HIV-HCV co-infected individuals. In HIV-HCV co-infected and HCV mono-infected participants, the effect of DAA was limited to γδ T- and B-cell activation as well as γ-globulin concentrations and the Vδ2/Th17 ratio, with no changes in γδ T-cell function and Treg frequencies. Importantly, γδ T- and B-cell activation remained at higher levels in the co-infected individuals than in those with HCV mono-infection alone. The persistence of such alterations within these cell subsets may be associated with the risk of hepatic and extrahepatic complications.

Combination antiretroviral therapy is associated with reduction in liver fibrosis scores in patients with HIV and HBV co-infection

Background

Liver fibrosis is common in individuals with HIV/HBV co-infection, but whether cART could reverses liver fibrosis is unclear.

Methods

This was a retrospective observational study. Binary logistic regression was used to assess predictors of liver fibrosis in individuals with HIV/HBV co-infection. Comparison of FIB-4 scores before and after cART were compared using X² test and t test.

Results

Four hundred and fifty-eight individuals with HIV/HBV co-infection were included in this study. It was found that cART (HR 0.016, 95% CI: 0.009–0.136; P < 0.001) was one of protection factors to against liver fibrosis. Forty individuals who had normal levels of ALT, AST and PLT during the whole course of diseases were stratified into FIB-4 < 1.45 (n = 14), 1.45 ≤ FIB-4 ≤ 3.25 (n = 19) and FIB-4 > 3.25 (n = 7) groups by their FIB-4 scores before cART. In 1.45 ≤ FIB-4 ≤ 3.25 group, 57.9%(11/19) of the individuals dropped to FIB-4 < 1.45 group by cART; in FIB-4 > 3.25 group, 85.7%(6/79) dropped to 1.45 ≤ FIB-4 ≤ 3.25 group, while 14.3%(1/7) dropped to FIB-4 < 1.45 group. In cART-naive group, 1 year, 2–5 years and 5–10 years post-cART groups, FIB-4 scores were 4.29 ± 0.43, 3.63 ± 0.38, 2.90 ± 0.36 and 2.52 ± 0.38, respectively (P = 0.034); and the incidence of liver fibrosis were 7.38%(104/141), 63.6%(98/154), 60.8%(62/102) and 47.5%(29/61), respectively (P = 0.004).

Conclusion

cART was associated with decreased FIB-4 scores and the benefit of cART in reversing liver fibrosis can sustain for a decade in patients with HIV/HBV co-infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-021-00419-y.

Jejunal epithelial barrier disruption triggered by reactive oxygen species in early SIV infected rhesus macaques

Intestinal epithelial barrier destruction occurs earlier than mucosal immune dysfunction in the acute stage of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections. At present, however, the cause of compromised gastrointestinal integrity in early SIV infection remains unknown. In the current study, we investigated the effects of SIV infection on epithelial barrier integrity and explored oxidative stress-mediated DNA damage and apoptosis in epithelial cells from early acute SIVmac239-infected Chinese rhesus macaques (Macaca mulatta). Results showed that the sensitive molecular marker of small intestinal barrier dysfunction, i.e., intestinal fatty acid-binding protein (IFABP), was significantly increased in plasma at 14 days post-SIV infection. SIV infection induced a profound decrease in the expression of tight junction proteins, including claudin-1, claudin-3, and zonula occludens (ZO)-1, as well as a significant increase in the active form of caspase-3 level in epithelial cells. RNA sequencing (RNA-seq) analysis suggested that differentially expressed genes between pre- and post-SIV-infected jejuna were enriched in pathways involved in cell redox homeostasis, oxidoreductase activity, and mitochondria. Indeed, a SIV-mediated increase in reactive oxygen species (ROS) in the epithelium and macrophages, as well as an increase in hydrogen peroxide (H₂O₂) and decrease in glutathione (GSH)/glutathione disulfide (GSSG) antioxidant defense, were observed in SIV-infected jejuna. In addition, the accumulation of mitochondrial dysfunction and DNA oxidative damage led to an increase in senescence-associated β-galactosidase (SA-β-gal) and early apoptosis in intestinal epithelial cells. Furthermore, HIV-1 Tat protein-induced epithelial monolayer disruption in HT-29 cells was rescued by antioxidant N-acetylcysteine (NAC). These results indicate that mitochondrial dysfunction and oxidative stress in jejunal epithelial cells are primary contributors to gut epithelial barrier disruption in early SIV-infected rhesus macaques.

Translocating lipopolysaccharide correlates with the severity of enterovirus A71-induced HFMD by promoting pro-inflammation and viral IRES activity

BACKGROUND

The increase of inflammation-inducing enterobacteria was recently observed in severe hand, foot, and mouth disease (HFMD) caused by Enterovirus A71 (EV-A71). This study aimed to verify the occurrence of bacterial translocation (BT) and further explore the contributory role of BT to severity of EV-A71-mediated HFMD cases.

METHODS

Serum specimens from 65 mild and 65 severe EV-A71-associated HFMD cases and 65 healthy children were collected. EV-A71 VP1 in serum, inflammatory mediators including C-reactive protein, IL-1β, IL-6, interferon-γ and tumor necrosis factor-α, BT related biomarkers including Claudin-3, intestinal fatty acid binding protein, lipopolysaccharide (LPS), soluble CD14 (sCD14) and endotoxin core antibody were measured by ELISA. Bacterial DNA (BactDNA) fragments were quantified by quantified PCR (qPCR). Rhabdomyosarcoma (RD) or SH-SY5Y cells, infected with LPS-pre-incubated EV-A71 or transfected with plasmid containing viral 2Apro or mRNA containing viral internal ribosomal entry site (IRES), were post-treated with or without LPS in vitro. EV-A71 RNA and viral or cellular proteins were determined by qPCR and western blot, respectively.

RESULTS

Compared to mild HFMD patients, remarkably higher inflammatory mediators as well as BT-related biomarkers except BactDNA were observed in severe HFMD cases (all P < 0.05). In severe HFMD group, circulating concentrations of LPS and sCD14 showed statistical correlations with inflammation indices (all P < 0.05), serum levels of EV-A71 VP1 were found to be positively correlated with serum LPS (r = 0.341, P = 0.005) and serum sCD14 (r = 0.458, P < 0.001). In vitro, EV-A71 attachment and internalization were only slightly promoted by LPS pre-incubation; however, EV-A71 proliferation and viral 2Apro-mediated IRES activity were significantly accelerated by LPS post-treatment.

CONCLUSIONS

Our results collectively indicate that gut-derived translocating LPS contributes to the severity of EV-A71-induced HFMD by driving inflammatory response and viral proliferation via viral 2Apro-mediated IRES.

Brief Report: Increased Inflammation and Liver Disease in HIV/HBV-Coinfected Individuals

OBJECTIVE

HIV and hepatitis B virus (HBV) coinfection can accelerate morbidity and mortality, especially in sub-Saharan Africa where both infections are common. Although inflammation contributes to disease progression, more information is needed to better understand the pathology. This study compared markers of cirrhosis and inflammation in HIV/HBV-coinfected individuals compared with monoinfected and uninfected patients.

SETTING

The HIV/HBV-coinfected subjects from the Ugandan arm of the prospective African Cohort Study were selected for evaluation and matched by age and gender with HIV-monoinfected, HBV-monoinfected, and uninfected controls.

METHODS

Plasma samples were used to quantify markers of immune activation and inflammation. The FIB-4 (a simple index to predict significant liver fibrosis) score was used to estimate liver fibrosis. Demographic and laboratory characteristics were compared across the groups.

RESULTS

Together, 31 HIV/HBV-coinfected participants were identified and compared with 62 HIV-monoinfected, 7 HBV-monoinfected, and 62 uninfected controls. The HIV/HBV-coinfected group had generally higher levels of inflammation. Most notably, matrix metalloproteinase-2, matrix metalloproteinase-9, and fibroblast growth factor-19 levels were dysregulated among the HIV/HBV-coinfected individuals. Furthermore, the FIB-4 score was higher in the HIV/HBV-coinfected group compared with the HIV-monoinfected group and revealed that 11% of HIV/HBV-coinfected individuals had evidence of undiagnosed advanced liver disease.

CONCLUSIONS

Differences in levels of inflammation exist between individuals with HIV/HBV coinfection compared with monoinfected and uninfected controls. A distinct signature of inflammation was associated with HIV/HBV coinfection that could reflect the mechanism of liver fibrosis and increased risk for disease progression. Finally, there may be an underappreciated amount of undiagnosed advanced liver disease in sub-Saharan Africa.

Adiponectin Role in Neurodegenerative Diseases: Focus on Nutrition Review

Adiponectin is an adipokine produced by adipose tissue. It has numerous beneficial effects. In particular, it improves metabolic effects and glucose homeostasis, lipid profile, and is involved in the regulation of cytokine profile and immune cell production, having anti-inflammatory and immune-regulatory effects. Adiponectin’s role is already known in immune diseases and also in neurodegenerative diseases. Neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease, are a set of diseases of the central nervous system, characterized by a chronic and selective process of neuron cell death, which occurs mainly in relation to oxidative stress and neuroinflammation. Lifestyle is able to influence the development of these diseases. In particular, unhealthy nutrition on gut microbiota, influences its composition and predisposition to develop many diseases such as neurodegenerative diseases, given the importance of the “gut-brain” axis. There is a strong interplay between Adiponectin, gut microbiota, and brain-gut axis. For these reasons, a healthy diet composed of healthy nutrients such as probiotics, prebiotics, polyphenols, can prevent many metabolic and inflammatory diseases such as neurodegenerative diseases and obesity. The special Adiponectin role should be taken into account also, in order to be able to use this component as a therapeutic molecule.

Effect of Stopping Cotrimoxazole Preventive Therapy on Microbial Translocation and Inflammatory Markers Among Human Immunodeficiency Virus-Infected Ugandan Adults on Antiretroviral Therapy: The COSTOP Trial Immunology Substudy

BACKGROUND

Cotrimoxazole preventive therapy (CPT) in human immunodeficiency virus (HIV) infection is a World Health Organization-recommended standard of care in resource-limited settings, but the mechanism of CPT's beneficial effects is unclear. The COSTOP trial (ISRCTN44723643) evaluated the noninferiority of discontinuing CPT in stabilized patients on antiretroviral therapy. The COSTOP immunology substudy was conducted on a subset of COSTOP participants randomized to continue CPT (n = 86) or discontinue CPT (placebo, n = 86) as daily treatment for 1 year.

METHODS

We evaluated whether CPT reduces microbial translocation, indicated by the presence of bacterial lipopolysaccharide (LPS) and LPS control factors such as soluble CD14 (sCD14) and endotoxin core antibody (EndoCAb immunoglobulin M [IgM]) in plasma. Intestinal barrier damage as indicated by plasma intestinal fatty acid binding protein (IFABP), T-cell activation, and the inflammatory markers C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were also evaluated.

RESULTS

We found no significant change in markers of microbial translocation (LPS, IFABP, sCD14, and T-cell activation), with decreased EndoCAb IgM. There was significant increase in inflammation markers (CRP and IL-6) after stopping CPT compared to those who continued CPT.

CONCLUSIONS

These results add to the evidence of immunological benefits of CPT among HIV-infected populations in resource-limited settings. However, no evidence of reducing microbial translocation was observed.

Nutritional modulation of the intestinal microbiota; future opportunities for the prevention and treatment of neuroimmune and neuroinflammatory disease

The gut-brain axis refers to the bidirectional communication between the enteric nervous system and the central nervous system. Mounting evidence supports the premise that the intestinal microbiota plays a pivotal role in its function and has led to the more common and perhaps more accurate term gut-microbiota-brain axis. Numerous studies have identified associations between an altered microbiome and neuroimmune and neuroinflammatory diseases. In most cases, it is unknown if these associations are cause or effect; notwithstanding, maintaining or restoring homeostasis of the microbiota may represent future opportunities when treating or preventing these diseases. In recent years, several studies have identified the diet as a primary contributing factor in shaping the composition of the gut microbiota and, in turn, the mucosal and systemic immune systems. In this review, we will discuss the potential opportunities and challenges with respect to modifying and shaping the microbiota through diet and nutrition in order to treat or prevent neuroimmune and neuroinflammatory disease.

Soluble CD14 levels in plasma and breastmilk of Malawian HIV+ women: Lack of association with morbidity and mortality in their exposed infants

PROBLEM

Data on soluble CD14 (sCD14) during pregnancy and lactation are scarce. We assessed the levels of sCD14 in plasma and breastmilk of Malawian HIV-positive women and evaluated the possible association with morbidity and mortality in the HIV-exposed children.

METHOD OF STUDY

One hundred and forty-nine mother/child pairs were studied. Women received antiretroviral therapy from 26 weeks of gestation to at least 6 months of exclusive breastfeeding. sCD14 concentrations were determined using an enzyme-linked immunosorbent assay.

RESULTS

sCD14 levels measured at 26 weeks of pregnancy (median: 1418 ng/mL, IQR: 1086-1757) were inversely correlated to maternal CD4+ cell count (r = -.283, P = .001) and to neonatal birthweight (r = -.233, P = .008). At 6 months, sCD14 plasma levels were significantly higher compared to baseline (1993 ng/mL, IQR: 1482-2604, P < .001), and breastmilk sCD14 levels (7668 ng/mL, IQR: 5495-10207) were 4-fold higher than in plasma (although the concentrations in the two compartments were not correlated). No association was found between sCD14 levels in plasma or breastmilk and morbidity or mortality in children.

CONCLUSION

Higher sCD14 levels in HIV-positive women were associated with a more compromised maternal immunological status and to a lower neonatal birthweight, but not to poorer clinical outcomes in the HIV-exposed children.

HIV-1 co-receptor tropism and liver fibrosis in HIV-infected patients

Background

In vitro, gp120 of both X4 and R5 HIV-1 strains activates human hepatic stellate cells, but if it can promote liver fibrosis in vivo is unknown. We aimed to evaluate if patients carrying X4 or R5 strains have a different liver fibrosis (LF) progression over time.

Methods

A total of 1,137 HIV-infected patients in ICONA cohort (21% females, 7% HCV co-infected) with an available determination of HIV-1 co-receptor tropism (CRT), a Fibrosis-4 Index for Liver Fibrosis (FIB-4) <3.25 and at least one-year follow-up were included. CRT was assessed by gp120 sequencing on plasma RNA and geno2pheno algorithm (10% false positive rate) or by Trofile. LF was assessed by means of FIB-4. LF progression was defined as an absolute score increase or a transition to higher fibrosis stratum and/or occurrence of liver-related clinical events.

Results

A total of 249 (22%) patients carried X4 strains, which were associated with older age, lower CD4 count, lower nadir CD4, and intravenous drug use. Overall, X4 and R5 patients had similar baseline FIB-4 scores and similar mean FIB-4 slope after a median follow-up of 35 months. There was no difference between X4 and R5 for time to LF progression (p = 0.925). Estimated risk of LF at 24 months (95% CI) after baseline in X4 and R5 was 10.6% (8.3–12.9) and 9.9% (5.9–14.0), respectively. Age, HCV co-infection, diabetes, HIV-duration, HIV-RNA>100.000 cp/mL, antiretroviral therapy exposure were associated with LF progression at multivariate analysis.

Conclusions

A slight LF progression over time was observed in HIV-infected patients. No difference was demonstrated for X4 and R5 HIV-1 strains in accelerating LF evolution.

HCV coinfection of the HIV-infected patients with discordant CD4+ T-cell response to antiretroviral therapy leads to intense systemic inflammation

The level of proinflammatory markers was assessed in HIV-infected patients that were coinfected with hepatitis C virus (HCV) and had failed to restore the CD4⁺ T cell counts (immunological nonresponders, INR) during the antiretroviral therapy (ART). Among four patient groups (HIV⁺HCV^- and HIV⁺HCV⁺ subjects with the concordant response to ART; HIV⁺HCV^- and HIV⁺HCV⁺ subjects that were INR), the greatest systemic inflammation was in the latter group. The maximum difference was between the subjects HIV⁺HCV^-INR and HIV⁺HCV⁺ INR: the blood of coinfected patients contained significantly higher concentrations of the IP-10, sCD163, sTNF-RI, and sTNF-RII and of bacterial lipopolysaccharide. Systemic inflammation in HIV/HCV coinfected patients with the discordant response to ART is probably caused by a breach of hepatic barrier for the intestine products.

Active HCV infection is associated with increased circulating levels of interferon-gamma (IFN-γ)-inducible protein-10 (IP-10), soluble CD163 and inflammatory monocytes regardless of liver fibrosis and HIV coinfection

BACKGROUND AND OBJECTIVE

Interferon-gamma (IFN-γ)-inducible protein-10 (IP-10), soluble (s) CD163 and sCD14 play an important role in the pathogenesis of HCV and HIV infection and are involved in inflammation and liver fibrosis. The aim of the present study was to evaluate at a single time point, plasma soluble biomarkers and inflammatory monocytes subsets in different groups of subjects: (i) HIV monoinfected patients on suppressive ART; (ii) HIV/HCV coinfected patients on ART, with undetectable HIV viremia (including either subjects who had active HCV replication or those who cleared HCV); (iii) HCV monoinfected individual with active viral replication.

METHODS

Hundred and twenty-nine plasma samples were analyzed including HCV and HIV monoinfected patients, HIV/HCV coinfected patients, with active HCV infection (AHI) or with HCV viral clearance (VHC) and healthy donors (HD). Levels of IP-10, sCD163 and sCD14 were measured by ELISA. Absolute cell counts of monocyte subpopulations were enumerated in whole blood by using flow cytometric analyses.

RESULTS

IP-10 and sCD163 plasma levels were higher in HCV monoinfected and in AHI coinfected pts compared to HIV monoinfected and HD, whereas sCD14 levels were higher only in HIV monoinfected patients. Considering the degree of fibrosis, sCD163 and sCD14 levels positively correlated with kPa values (as assessed by fibroscan) and FIB-4 in HCV monoinfected group. On the other hand, IP-10 did not correlate with the fibrosis stage and it was found increased also in patients with low fibrosis. Moreover, we found an increase of the inflammatory NCM subset, in non-cirrhotic HCV subjects, while no alterations were observed in HIV, AHI and VHC.

CONCLUSIONS

Our study suggests a scenario in which active HCV infection is associated with a strong pro-inflammatory state, even in the initial stage of liver fibrosis, regardless the presence of HIV coinfection, thus underlying the need of an early anti-HCV treatment.

A Review of Management of Inflammation in the HIV Population

Advancements in antiretroviral therapy have drastically increased the life expectancy for those infected with HIV. Today, a new subgroup of older patients with long-term controlled HIV exists, and its populace is continuously mounting. Therefore, it is essential to understand the enduring effects of chronic suppressed HIV infection in order to further improve HIV management in these patients. This paper will examine the role of HIV in chronic inflammation and immune dysfunction, the dynamic interaction that exists between comorbidity and HIV, and the potential consequences of long-term antiretroviral therapy in an effort to provide the best management options for the virally suppressed HIV patient.

Role of microbial translocation in soluble CD14 up-regulation in HIV-, but not in HCV-, infected chimpanzees

During human immunodeficiency virus (HIV) infection, soluble CD14 (sCD14) is up-regulated as a consequence of pathological disruption of the gut epithelial barrier, and subsequent increased microbial translocation. Also in hepatitis C virus (HCV)-infected patients with advanced liver fibrosis, increased levels of sCD14 have been reported. Since the liver plays an important role in clearance of translocated bacterial products, hepatic fibrosis may negatively affect clearance and thus contribute to higher sCD14 levels. Chimpanzees (Pan troglodytes) infected with HCV typically show no signs of liver fibrosis. Here, we have tested the hypothesis that increased levels of sCD14 occur in the absence of hepatic fibrosis or microbial translocation in chimpanzees chronically infected with HCV. sCD14 was up-regulated in both HIV/simian immunodeficiency virus (SIV)- and HCV-infected chimpanzees. In HIV/SIV-infected chimpanzees, intestinal fatty acid-binding protein, a marker for gut perturbation, lipopolysaccharide (LPS)-binding-protein and LPS core antibodies, confirm that sCD14 up-regulation was caused by increased microbial translocation. In HCV-infected chimpanzees, no evidence was found for increased microbial translocation despite up-regulation of sCD14. Additionally, the impact of liver fibrosis on microbial translocation was addressed by direct comparison of chimpanzees with a high HCV load and human patients with advanced fibrosis. These data suggest that only in a small minority of HCV patients, hepatic fibrosis corroborates microbial translocation.

Liver fibrosis in HIV-infected individuals on long-term antiretroviral therapy: associated with immune activation, immunodeficiency and prior use of didanosine

BACKGROUND

It is unclear whether HIV infection is associated with liver fibrosis in the absence of chronic hepatitis B or C virus (HBV/HCV) coinfection. We compared prevalence of liver fibrosis, noninvasively assessed by the Fibrosis-4 (FIB-4) index, between HIV-infected patients and uninfected controls, and explored determinants of a higher FIB-4 score, indicative of more liver fibrosis.

METHODS

FIB-4 was assessed in HIV-uninfected and HIV-1-infected, predominantly virologically suppressed participants of the AGEhIV Cohort Study without HBV and/or HCV coinfection, and aged at least 45. Using multivariable regression, we investigated associations between FIB-4 and HIV-status, HIV-disease characteristics, antiretroviral drugs and markers of microbial translocation and immune activation.

RESULTS

Prevalence of advanced liver fibrosis (FIB-4 ≥ 3.25) was low: 1.4% in HIV-infected and 1.0% in HIV-uninfected participants. After adjustment for age, sex, ethnicity, detectable anti-hepatitis B core/anti-HCV antibodies and excessive alcohol intake, HIV remained significantly associated with higher FIB-4 (+4.2%, P = 0.05). Prior exposure to didanosine, longer duration of a CD4 cell count below 500 cells/μl and a lower CD4 cell count at enrollment were each associated with a higher FIB-4. Markers of immune activation (soluble CD163, activated CD8 T-lymphocytes and regulatory T-lymphocytes) were associated with a higher FIB-4 in HIV-infected but not HIV-uninfected study participants.

CONCLUSION

HIV infection was independently associated with higher FIB-4 scores, indicating more advanced liver fibrosis, though the difference in FIB-4 scores between HIV-infected and HIV-uninfected was small. Higher levels of immune activation were associated with liver fibrosis in HIV-infected, even in the absence of HBV or HCV infection, but not in HIV-uninfected individuals.

Combination Antiretroviral Therapy Is Associated With Reduction in Liver Fibrosis Scores in HIV-1-Infected Subjects

HIV increases the risk of liver disease as do two common coinfections, hepatitis B and C viruses (HBV and HCV). However, whether combination antiretroviral therapy (cART) reverses or exacerbates hepatic fibrosis remains unclear.This was an observational retrospective study. cART-naïve HIV-infected subjects without a history of substance abuse (including alcohol) had liver disease stage determined by aspartate aminotransferase-to-platelet ratio indices (APRIs) and fibrosis-4 (FIB-4) before and 24 and 48 weeks after cART. All the data were retrieved from previously established cohorts. Values before and after cART were compared using Wilcoxon test for paired samples. Regression analyses were used to determine factors associated with moderate-to-severe liver disease.Of the 1105 HIV-infected subjects, 120 were HBV coinfected and 64 were HCV coinfected. About 20% of HIV monoinfected participants had APRI and FIB-4 scores consistent with moderate-to-significant fibrosis compared to ∼36% of HIV-HBV coinfected and 67% to 77% of HIV-HCV coinfected participants. In adjusted analyses compared with HIV monoinfection, HBV coinfection was associated with 1.18-fold higher APRI (P < 0.001) and a 1.12-fold higher FIB-4 (P = 0.007) prior to cART; while HCV coinfection was associated with 1.94-fold higher APRI (P < 0.001) and a 1.43-fold higher FIB-4 (P < 0.001). After 48 weeks of cART, both fibrosis scores decreased in all subjects; however, HCV coinfection was still associated with higher fibrosis scores at week 48 compared to HIV monoinfection.cART was associated with improvement in hepatic fibrosis scores in the majority of HIV-hepatitis coinfected and HIV-monoinfected Chinese participants.

HIV-1 Very Low Level Viremia Is Associated with Virological Failure in Highly Active Antiretroviral Treatment-Treated Patients

The aim of this study was to evaluate the impact of HIV-1 very low-level viremia (<50 copies/ml) on the 2-year risk of virological failure. A retrospective analysis including HIV-positive patients presenting two consecutive HIV RNA below 50 copies/ml (outpatient clinic in Italy, first semester of 2010) was performed. HIV RNA was measured through real time polymerase chain reaction (PCR) assay CAP/CTM HIV-1 version 2.0 (detection limit: 20 copies/ml) and stratified as undetectable RNA ("Target Not Detected", TND), <20 copies/ml, 20-50 copies/ml. After 96 weeks virological failure was defined as two consecutive viral loads above 50 copies/ml. Log-rank tests and a multivariate Cox proportional hazard model were used for univariate and multivariate analysis. A total of 1,055 patients (71.4% male, 87.4% white, aged 46.7 years) were included: nadir and current CD4 cell counts were 203 cells/mm(3) (106-292) and 554 cells/mm(3) (413-713.5). HIV RNA was undetectable in 781 patients (74%), <20 copies/ml in 190 patients (18%) and 20-50 copies/ml in 84 patients (8%). Virological failure was observed in 81 patients (7.7%); at multivariate analysis detectable RNA at baseline (p=0.017), HCV infection (p=0.020), more than three pills in the regimen (p=0.003), and duration of HIV RNA <50 copies/ml below 2 years (p<0.001) were independently associated with virological failure. In 14 patients newly selected resistance-associated mutations were observed. Undetectable HIV RNA by real-time PCR is significantly associated with a lower 2-year risk of virological failure along with Ab HCV negativity, longer viral control, and lower pill burden. Studies investigating the management of residual viremia under antiretroviral treatment are warranted.

Immunologic Predictors of Liver Transplantation Outcomes in HIV-HCV Co-Infected Persons

Liver disease is a leading cause of mortality among HIV-infected persons in the highly active anti-retroviral therapy (HAART) era. Hepatitis C Virus (HCV) co-infection is prevalent in, and worsened by HIV; consequently many co-infected persons require liver transplantation (LT). Despite the need, post-LT outcomes are poor in co-infection. We examined predictors of outcomes post-LT. Immunologic biomarkers of immune activation, microbial translocation, and Th1/Th2 skewing were measured pre-LT in participants enrolled in a cohort of HIV infected persons requiring solid organ transplant (HIVTR). Predictive biomarkers were analyzed in Cox-proportional hazards models; multivariate models included known predictors of outcome and biomarkers from univariate analyses. Sixty-nine HIV-HCV co-infected persons with available pre-LT samples were tested: median (IQR) CD4+ T-cell count was 286 (210-429) cells mm-3; 6 (9%) had detectable HIV RNA. Median (IQR) follow-up was 2.1 (0.7-4.0) years, 29 (42%) people died, 35 (51%) had graft loss, 22 (32%) were treated for acute rejection, and 14 (20%) had severe recurrent HCV. In multivariate models, sCD14 levels were significantly lower in persons with graft loss post-LT (HR 0.10 [95%CI 0.02-0.68]). IL-10 levels were higher in persons with rejection (HR 2.10 [95%CI 1.01-4.34]). No markers predicted severe recurrent HCV. Monocyte activation pre-LT may be mechanistically linked to graft health in HIV-HCV co-infection.

Latent and Active Tuberculosis Infection Increase Immune Activation in Individuals Co-Infected with HIV

In recent years, chronic immune activation and systemic inflammation have emerged as hallmarks of HIV disease progression and mortality. Several studies indicate that soluble inflammatory biomarkers (sCD14, IL-6, IL-8, CRP and hyaluronic acid), as well as surface markers of T-cell activation (CD38, HLA-DR) independently predict progression to AIDS and mortality in HIV-infected individuals. While co-infections have been shown to contribute to immune activation, the impact of latent tuberculosis infection (LTBI), which is widely endemic in the areas most affected by the global AIDS epidemic, has not been evaluated. We hypothesized that both active and latent states of Mycobacterium tuberculosis co-infection contribute to elevated immune activation as measured by these markers. In HIV-infected individuals with active, but not latent TB, we found elevated levels of soluble markers associated with monocyte activation. Interestingly, T-cell activation was elevated individuals with both latent and active TB. These results suggest that in the highly TB- and HIV-endemic settings of southern Africa, latent TB-associated T-cell activation may contribute to HIV disease progression and exacerbate the HIV epidemic. In addition, our findings indicate that aggressive campaigns to treat LTBI in HIV-infected individuals in high-burden countries will not only impact TB rates, but may also slow HIV progression.

Significance

Latent tuberculosis, which affects an estimated 1/3 of the world's population, has long been thought to be a relatively benign, quiescent state of M. tuberculosis infection. While HIV co-infection is known to exacerbate M. tuberculosis infection and increase the risk of developing active TB, little is known about the potential effect of latent TB infection on HIV disease. This study shows that HIV-infected individuals with both active and latent TB have elevated levels of inflammation and immune activation, biomarkers of HIV disease progression and elevated risk of mortality. These results suggest that, in the context of HIV, latent TB infection may be associated with increased risk of progression to AIDS and mortality.

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While HIV co-infection is known to exacerbate TB, little is known about the effect of latent TB infection on HIV disease.

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In HIV-infected individuals, active and latent TB elevate immunological biomarkers of HIV morbidity and mortality.

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In the context of HIV, latent TB infection may be associated with increased risk of progression to AIDS and mortality.

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In addition to reducing TB transmission, aggressive treatment of latent TB infection may also reduce the progression of HIV.