Steatohepatitis: Risk factors and impact on disease severity in human immunodeficiency virus/hepatitis C virus coinfection

The pathogenesis of obesity in people living with HIV

PURPOSE OF REVIEW

The public health challenge of overweight and obesity increasingly affects people living with HIV (PWH). These effects have also accelerated as the prevalence of antiretroviral therapy (ART) use has increased among PWH. It is therefore also critical that we examine and understand the pathogenesis of obesity among PWH.This review will aim to summarize relevant and recent literature related to the risks of weight gain and obesity associated with HIV disease progression, cardiometabolic disease, and multimorbidity among PWH. Further, we will discuss adipose tissue changes associated with weight gain and obesity and how these changes relate to metabolic complications.

RECENT FINDINGS

Several observational and experimental studies in recent years have evaluated the role of contemporary ART regimens, particularly integrase strand transfer inhibitors (INSTIs) and tenofovir alafenamide (TAF), as contributors to weight gain, obesity, and cardiometabolic disease, though the mechanisms remain unclear. Metabolic dysregulation has also been linked to ectopic fat deposition and alterations in innate and adaptive immune cell populations in adipose tissue that accompany HIV and obesity. These factors continue to contribute to an increasing burden of metabolic diseases in an aging HIV population.

SUMMARY

Obesity accompanies an increasing burden of metabolic disease among PWH, and understanding the role of fat partitioning and HIV and ART-related adipose tissue dysfunction may guide prevention and treatment strategies.

Burden of fatty liver and hepatic fibrosis in persons with HIV: A diverse cross-sectional US multicenter study

BACKGROUND AIMS

The current prevalence of fatty liver disease (FLD) due to alcohol-associated (AFLD) and nonalcoholic (NAFLD) origins in US persons with HIV (PWH) is not well defined. We prospectively evaluated the burden of FLD and hepatic fibrosis in a diverse cohort of PWH.

APPROACH RESULTS

Consenting participants in outpatient HIV clinics in 3 centers in the US underwent detailed phenotyping, including liver ultrasound and vibration-controlled transient elastography for controlled attenuation parameter and liver stiffness measurement. The prevalence of AFLD, NAFLD, and clinically significant and advanced fibrosis was determined. Univariate and multivariate logistic regression models were used to evaluate factors associated with the risk of NAFLD. Of 342 participants, 95.6% were on antiretroviral therapy, 93.9% had adequate viral suppression, 48.7% (95% CI 43%-54%) had steatosis by ultrasound, and 50.6% (95% CI 45%-56%) had steatosis by controlled attenuation parameter ≥263 dB/m. NAFLD accounted for 90% of FLD. In multivariable analysis, old age, higher body mass index, diabetes, and higher alanine aminotransferase, but not antiretroviral therapy or CD4 + cell count, were independently associated with increased NAFLD risk. In all PWH with fatty liver, the frequency of liver stiffness measurement 8-12 kPa was 13.9% (95% CI 9%-20%) and ≥12 kPa 6.4% (95% CI 3%-11%), with a similar frequency of these liver stiffness measurement cutoffs in NAFLD.

CONCLUSIONS

Nearly half of the virally-suppressed PWH have FLD, 90% of which is due to NAFLD. A fifth of the PWH with FLD has clinically significant fibrosis, and 6% have advanced fibrosis. These data lend support to systematic screening for high-risk NAFLD in PWH.

Relationship of Subcutaneous Adipose Tissue Inflammation-Related Gene Expression With Ectopic Lipid Deposition in Persons With HIV

OBJECTIVE

Fat redistribution from subcutaneous adipose tissue (SAT) to the abdominal viscera, pericardium, liver, and skeletal muscle contributes to the rising burden of cardiometabolic disease among persons with HIV (PWH). Previous studies found SAT inflammation in PWH impairs lipid storage and persists despite plasma viral suppression on antiretroviral therapy (ART). In this study, we identified SAT immune-related genes associated with ectopic fat deposition in PWH on long-term ART.

DESIGN AND METHODS

A total of 92 PWH with well-controlled viremia underwent computed tomography imaging and abdominal SAT biopsy for gene expression analysis. SAT gene expression was measured using a NanoString panel of 255 immune-related genes. Associations between gene expression and computed tomography measurements of the volume and attenuation (radiodensity) of metabolically relevant ectopic fat depots were assessed using multivariable linear regression and network analysis.

RESULTS

Greater SAT volume was associated with higher visceral and pericardial adipose tissue volume, but lower skeletal muscle attenuation. Lower SAT attenuation, a measure of lipid content, was associated with lower visceral adipose tissue attenuation. Hierarchical clustering identified a subset of macrophage-related genes in SAT, including CCL2, CCL22, CCL13, CCR1, CD86, CD163, IL-6, IL-10, MRC1, and TREM2, which were associated with an increased lipid deposition in multiple ectopic depots.

CONCLUSION

Altered expression of macrophage-related genes in SAT is associated with differences in ectopic fat depot morphometrics among PWH on long-term ART, including in the pericardial and visceral compartments. These findings provide basis for future studies to assess host, virus, and treatment factors shaping the SAT immune environment and its effects on morphometric changes and metabolic comorbidities in PWH.

Advancing our understanding of HIV co-infections and neurological disease using the humanized mouse

Humanized mice have become an important workhorse model for HIV research. Advances that enabled development of a human immune system in immune deficient mouse strains have aided new basic research in HIV pathogenesis and immune dysfunction. The small animal features facilitate development of clinical interventions that are difficult to study in clinical cohorts, and avoid the high cost and regulatory burdens of using non-human primates. The model also overcomes the host restriction of HIV for human immune cells which limits discovery and translational research related to important co-infections of people living with HIV. In this review we emphasize recent advances in modeling bacterial and viral co-infections in the setting of HIV in humanized mice, especially neurological disease, and Mycobacterium tuberculosis and HIV co-infections. Applications of current and future co-infection models to address important clinical and research questions are further discussed.

Risk of Incident Diabetes Mellitus, Weight Gain, and their Relationships with Integrase Inhibitor-based Initial Antiretroviral Therapy Among Persons with HIV in the US and Canada

BACKGROUND

Integrase strand transfer inhibitor (INSTI)-based combination antiretroviral therapy (cART) is associated with greater weight gain among persons with HIV, though the metabolic consequences, such as diabetes mellitus (DM), are unclear. We examined the impact of initial cART regimen and weight on incident DM in a large North American HIV cohort (NA-ACCORD).

METHODS

cART-naïve adults (≥18 years) initiating INSTI-, PI-, or NNRTI-based regimens from 01/2007-12/2017 who had weight measured 12 (±6) months after treatment initiation contributed time until clinical DM (HbA1c ≥6.5%, initiation of DM-specific medication, or new DM diagnosis plus DM-related medication), virologic failure, cART regimen switch, administrative close, death, or loss to follow-up. Multivariable Cox regression yielded adjusted hazard ratios (HR) and 95% confidence intervals ([-]) for incident DM by cART class. Mediation analyses, with 12-month weight as mediator, adjusted for all covariates from the primary analysis.

RESULTS

Among 22,884 eligible individuals, 47% started NNRTI-, 30% PI-, and 23% INSTI-based cART with median follow-up of 3.0, 2.3, and 1.6 years, respectively. Overall, 722 (3%) developed DM. Persons starting INSTIs vs. NNRTIs had incident DM risk (HR=1.17 [0.92-1.48]) similar to PI- vs. NNRTI-initiators (HR=1.27 [1.07-1.51]). This effect was most pronounced for raltegravir- (HR=1.42 [1.06-1.91]) vs. NNRTI-initiators. The INSTI-DM association was attenuated (HR=1.03 [0.71-1.49] vs. NNRTIs) when accounting for 12-month weight.

CONCLUSIONS

Initiating first cART regimens with INSTIs or PIs vs. NNRTIs may confer greater risk of DM, likely mediated through weight gain. Further characterization of metabolic changes after INSTI initiation and potential therapeutic interventions are needed.

Hepatitis C virus genotypes 1-3 infections regulate lipogenic signaling and suppress cholesterol biosynthesis in hepatocytes

BACKGROUND

Patients with different hepatitis C virus (HCV) genotype infections are associated with varying metabolic disorders. Although alteration of lipid metabolism has been confirmed as a virus-induced metabolic derangement in chronic hepatitis C patients, the impact of various HCV genotypes on hepatic cholesterol metabolism remains elusive. In this study, we thus investigated the HCV genotype-specific lipogenic and cholesterol metabolism profiles in an in vitro cell culture system.

METHODS

We first conducted HCV cell culture system (HCVcc) assays by infecting Huh7.5.1 cells with multiple infection-competent HCV strains, including the genotype 2a JFH1 and JFH1-based intergenotypic recombinants 1b and 3a. We then examined the expression levels of various lipid and cholesterol-related genes.

RESULTS

The data showed that infection with individual HCV genotypes exerted unique gene expression regulatory effects on lipoproteins and cholesterol metabolism genes. Of note, all HCV strains suppressed cholesterol biosynthesis in hepatocytes through downregulating the expression of HMG-CoA reductase (HMGCR) and farnesyl-diphosphate farnesyltransferase 1 (FDFT1) - two essential enzymes for cholesterol biosynthesis. These HCV-mediated inhibitory effects could be reversed by treatment with sofosbuvir, a pangenotypic NS5B inhibitor. In addition, overexpression of HCV genotype 1b, 2a or 3a core protein significantly suppressed HMGCR mRNA transcription and translation, thus diminished cellular cholesterol biosynthesis. Nonetheless, the core protein had no effect on FDFT1 expression.

CONCLUSION

Although HCV infection regulates host lipid metabolism in a genotype-specific manner, its inhibition on hepatocellular cholesterogenic gene expression and total cholesterol biosynthesis is a common effect among HCV genotype 1b, 2a and 3a.

The Prevalence and Impact of Hepatic Steatosis on Response to Direct-Acting Antiviral Therapy in HIV-HCV Coinfection

(1) Background: Direct-acting antiviral therapy for chronic hepatitis C virus (HCV) infection is associated with high sustained virologic response (SVR) and overcomes negative predictive factors, including steatosis, in patients without human immunodeficiency virus (HIV) coinfection. The impact of steatosis on SVR in patients with HIV–HCV coinfection is unknown. (2) Methods: A retrospective analysis of patients treated with direct-acting antivirals was performed. Demographic, laboratory and direct-acting antiviral regimen data were prospectively collected. Metabolic syndrome and its components—diabetes mellitus, hypertension, dyslipidemia and obesity—were assessed. Hepatic steatosis (≥5%) was defined by liver biopsy or controlled attenuation parameter (CAP) measurement during vibration-controlled transient elastography (VCTE). (3) Results: A total of 151 HIV–HCV-coinfected patients on combined antiretroviral therapy and direct-acting antiviral therapy were included in this analysis. Prevalence of steatosis by liver biopsy (n = 34) or CAP (≥263 db/m) during VCTE (n = 92) was 27% and was independently associated with obesity (OR 3.11; 95% CI 1.43–6.82; p = 0.004) and the metabolic syndrome (OR 1.08; 95% CI 1.01–0.15; p = 0.01). The overall SVR rate (n = 148) was 95% and was not impacted by the presence of steatosis (p = 0.42). (4) Conclusions: Hepatic steatosis is common in HIV–HCV coinfection, correlates with obesity and the metabolic syndrome and does not impact SVR.

The effects of knowledge transfer on farmers decision making toward sustainable agriculture practices

Purpose

The purpose of this paper is to enhance the adoption decision of farmers and observe the factors that affect the adoption decision of sustainable agriculture practices (SAP) which is the major motivating force of Malaysian economy. The idea behind this study is to transfer knowledge to paddy farmers within regional areas of Malaysia and to comprehend their understanding of social innovation and sustainable agriculture engineering and their overall significance. The outcome of this research will suggest a strategic extensive plan to encourage the use of SAP and also help to develop SAP helping toward building a sustainable society.

Design/methodology/approach

This paper encompasses three phases: analyzing the process of SAP among Malaysian Paddy farmers, to agricultural industrialization, until the stage of SAP led by farmer’s co-operatives, discussing the relevant practice together with literature and historically evidencing that there is no better way to promote SAP among regional paddy farmers within Malaysia.

Findings

Initial objective of this paper is to establish a thoughtful approach to enable the society to bridge a gap between embracing sustainability. The second objective investigates the misconception among farmers about social innovation. Furthermore, the study builds the conceptual framework and examines the relationship among the relevant constructs, this framework is critically examining the literature within paddy farming context. Harmoniously, there has been limited empirical research performed on the decision of adoption toward SAP usage among paddy farmers in Malaysia.

Originality/value

The clear worth of this research paper is the illustration from past reviews and practices to endorse SAP usage among paddy farmers in Malaysia. Another literature review suggests that these countermeasures comprehensively, historically, and theoretically are proven result oriented. The information about SAP will be beneficial for farmers and policy maker who are interested in the advancement. This learning delivers a comparative summary of knowledge transfer influencing farmer’s intention and behavior of sustainable agriculture engineering to adopt green technology. In a future study, these construct will be empirically tested.

HIV-1 viral protein R (Vpr) induces fatty liver in mice via LXRα and PPARα dysregulation: implications for HIV-specific pathogenesis of NAFLD

HIV patients develop hepatic steatosis. We investigated hepatic steatosis in transgenic mice expressing the HIV-1 accessory protein Vpr (Vpr-Tg) in liver and adipose tissues, and WT mice infused with synthetic Vpr. Vpr-Tg mice developed increased liver triglyceride content and elevated ALT, bilirubin and alkaline phosphatase due to three hepatic defects: 1.6-fold accelerated de novo lipogenesis (DNL), 45% slower fatty acid ß-oxidation, and 40% decreased VLDL-triglyceride export. Accelerated hepatic DNL was due to coactivation by Vpr of liver X receptor-α (LXRα) with increased expression of its lipogenic targets Srebp1c, Chrebp, Lpk, Dgat, Fasn and Scd1, and intranuclear SREBP1c and ChREBP. Vpr enhanced association of LXRα with Lxrα and Srebp1c promoters, increased LXRE-LXRα binding, and broadly altered hepatic expression of LXRα-regulated lipid metabolic genes. Diminished hepatic fatty acid ß-oxidation was associated with decreased mRNA expression of Pparα and its targets Cpt1, Aox, Lcad, Ehhadh, Hsd10 and Acaa2, and blunted VLDL export with decreased expression of Mttp and its product microsomal triglyceride transfer protein. With our previous findings that Vpr circulates in HIV patients (including those with undetectable plasma HIV-1 RNA), co-regulates the glucocorticoid receptor and PPARγ and transduces hepatocytes, these data indicate a potential role for Vpr in HIV-associated fatty liver disease.

Clinical and Pathological Risk Factors Associated with Liver Fibrosis and Steatosis in African-Americans with Chronic Hepatitis C

BACKGROUND AND AIM

Several factors involved in the development of liver fibrosis in African-American patients with chronic hepatitis C have not been well studied. We aimed to evaluate some of these risk factors.

METHODS

We reviewed pathology and medical records of 603 African-Americans with chronic hepatitis C virus (HCV) infection at Howard University Hospital from January 2004 to December 2013. Among the clinical and pathological data collected were HIV (human immunodeficiency virus), HCV genotype, hepatitis B virus (HBV), diabetes mellitus (DM), hypertension (HTN), body mass index (BMI), and hepatic steatosis.

RESULTS

The frequency of DM, HTN, HIV, and HBV was 22, 16, 11, and 4%, respectively. Median BMI was 27.3 kg/m2. The frequency of fibrosis stages 0, 1, 2, 3, and 4 was 2, 48, 28, 11, and 11%, respectively. In multivariate logistic regression, we found a significant association between liver fibrosis stage (3-4 vs. 0-2) and HIV infection (OR 2.4, P = 0.026), HTN (OR 3.0, P = 0.001), age (OR 2.6 for every 10 years, P < 0.001), weight (OR 1.1 for every 10 lb increase, P = 0.002), and steatosis grade (OR 1.6, P = 0.002). The frequency of liver steatosis was 73%. In an ordinal logistic regression, significant risk factors for steatosis were female gender (OR 1.5, P = 0.034) and inflammation grade (P = 0.001).

CONCLUSION

This study shows that steatosis is independently associated with fibrosis in African-American patients with HCV infection. Female patients were at higher risk of steatosis.

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in patients with HIV

Liver disease is a leading cause of morbidity and mortality among people with HIV, and in this era of safer and more effective hepatitis C therapy, non-alcoholic fatty liver disease (NAFLD) could soon emerge as the most common liver disease in this population. NAFLD is common among patients with HIV, and might be more likely to progress to non-alcoholic steatohepatitis (NASH) and NAFLD-related fibrosis or cirrhosis in these patients than in individuals without HIV. Several mechanisms of NAFLD pathogenesis are postulated to explain the disease severity in patients with HIV; these mechanisms include the influence of the gut microbiome, and also metabolic, genetic, and immunological factors. Although treatment strategies are currently based on modification of NAFLD risk factors, many new drugs are now in clinical trials, including trials specifically in patients with HIV. Thus, the identification and risk-stratification of patients with HIV and NAFLD are becoming increasingly important for accurately counselling of these patients regarding their prognosis and for establishing the most appropriate disease-altering therapy.

Novel Approaches to Targeting Visceral and Hepatic Adiposities in HIV-Associated Lipodystrophy

Visceral and hepatic adiposities have been associated with both cardiovascular and liver disease and are of concern in HIV-infected persons in the modern era of combination antiretroviral therapy (ART). The development of therapeutic targets to reduce visceral and hepatic adiposities in HIV-infected persons has been slow, because of early reports that attributed the excess adiposity to specific antiretroviral drugs. Visceral adiposity was initially thought to occur as part of a protease inhibitor-induced "HIV-associated lipodystrophy syndrome." Subsequent studies show that visceral adiposity is likely a result of effective ART, recovery of health, and the normal aging process. Visceral adiposity is an established risk factor for hepatic adiposity. Identifying drug targets for non-alcoholic fatty liver disease is under active investigation. The present review summarizes the recent literature on the pathogenesis of visceral and hepatic adiposities in HIV-infected persons, current therapeutic strategies, and novel interventions in HIV-infected and uninfected persons.

Hepatic safety of maraviroc in HIV-1-infected patients with hepatitis C and/or B co-infection. The Maraviroc Cohort Spanish Group

INTRODUCTION

Limited data is available regarding the hepatic safety of maraviroc in patients co-infected with HIV and HCV and/or HBV. Our objective was to compare the hepatic safety profile and fibrosis progression in HIV-mono-infected patients and co-infected with HCV and/or HBV treated with maraviroc.

METHODS

Retrospective multicentre cohort study of HIV-infected patients receiving treatment with a maraviroc-containing regimen in 27 hospitals in Spain.

RESULTS

A total of 667 patients were analyzed, of whom 313 were co-infected with HCV (n=282), HBV (n=14), or both (n=17). Maraviroc main indications were salvage therapy (52%) and drug toxicity (20%). Grade 3-4 hypertransaminasaemia (AST/ALT >5 times ULN) per 100 patient-years of maraviroc exposure, was 5.84 (95% CI, 4.04-8.16) and 1.23 (95% CI, 0.56-2.33) in co-infected and HIV-mono-infected patients, respectively (incidence rate ratio, 4.77; 95% CI, 2.35-10.5). However, the degree of aminotransferase abnormalities remained stable throughout the study in both groups, and no significant between-group differences were seen in the cumulative proportion of patients showing an increase in AST/ALT levels greater than 3.5 times baseline levels. No between-group differences were seen in liver fibrosis over time. With a maraviroc median exposure of 20 months (IQR, 12-41), two patients (0.3%) discontinued maraviroc because of grade 4 hepatitis, and other 2 died due to complications associated to end-stage-liver disease.

CONCLUSIONS

Maraviroc-containing regimens showed a low incidence of hepatitis in a large Spanish cohort of HIV-infected patients, including more than 300 patients co-infected with HCV and/or HBV. Co-infection did not influence the maximum liver enzyme level or the fibrosis progression throughout the study.

Impact of PNPLA3 variants on liver histology of 168 patients with HIV infection and chronic hepatitis C

This study analysed the impact of PNPLA3 variants on liver histology of 168 HIV/hepatitis C virus (HCV)-coinfected patients who were naïve for HCV treatment. A athologist unaware of the patients' condition graded liver fibrosis and necroinflammation (Ishak) and steatosis (Kleiner). Patients were tested for PNPLA3 variants and genotyped for the PNPLA3 rs738409 C to G variant underlying the I148M substitution. All were hepatitis B surface antigen negative and stated no alcohol abuse. The mean age was 40.6 (37.6-44.1) years, 72.6% were males, 42% had HCV genotype 3, 38.9% HCV genotype 1 and 79.2% were receiving highly active antiretroviral therapy. The 79 patients with the PNPLA3 p.148I/M or M/M variants more frequently showed severe steatosis (score 3-4) than the 89 with PNPLA3 p.148I/I (43% vs. 24.7%, p 0.001), whereas no difference was observed in the degree of necroinflammation or fibrosis. Compared with 112 patients with lower scores, 56 with severe steatosis showed higher body mass index (p 0.03), higher rate of HCV genotype 3 (55.6% vs. 35.2%, p 0.01), PNPLA3 p.148I/M or M/M (60.7% vs. 39.3%, p 0.01) and lower CD4(+) cells/mm(3) (514.00 (390.5-673.0) vs. 500.00 (399.0-627.0); p 0.002). At multivariate analysis, body mass index (p 0.01), HCV genotype 3 (p 0.006), CD4(+) cell count (p 0.005) and PNPLA3 p.148I/M or M/M variants (p 0.01) were found to be independent predictors of severe liver steatosis. The PNPLA3 p.148 I/M or M/M variants and CD4(+) cell count were the only independent predictors of severe steatosis in patients with HCV non-3 genotypes. This is the first study to show that among HIV/HCV-coinfected patients the PNPLA3 p.148I/M or M/M variant have substantially less impact on steatosis for those with HCV genotype 3 than non-genotype 3.

A Meta-Analysis of the Metabolic Syndrome Prevalence in the Global HIV-Infected Population

BACKGROUND

Cardio-metabolic risk factors are of increasing concern in HIV-infected individuals, particularly with the advent of antiretroviral therapy (ART) and the subsequent rise in longevity. However, the prevalence of cardio-metabolic abnormalities in this population and the differential contribution, if any, of HIV specific factors to their distribution, are poorly understood. Therefore, we conducted a systematic review and meta-analysis to estimate the global prevalence of metabolic syndrome (MS) in HIV-infected populations, its variation by the different diagnostic criteria, severity of HIV infection, ART used and other major predictive characteristics.

METHODS

We performed a comprehensive search on major databases for original research articles published between 1998 and 2015. The pooled overall prevalence as well as by specific groups and subgroups were computed using random effects models.

RESULTS

A total of 65 studies across five continents comprising 55094 HIV-infected participants aged 17-73 years (median age 41 years) were included in the final meta-analysis. The overall prevalence of MS according to the following criteria were: ATPIII-2001:16.7% (95%CI: 14.6-18.8), IDF-2005: 18% (95%CI: 14.0-22.4), ATPIII-2004-2005: 24.6% (95%CI: 20.6-28.8), Modified ATPIII-2005: 27.9% (95%CI: 6.7-56.5), JIS-2009: 29.6% (95%CI: 22.9-36.8), and EGIR: 31.3% (95%CI: 26.8-36.0). By some MS criteria, the prevalence was significantly higher in women than in men (IDF-2005: 23.2% vs. 13.4, p = 0.030), in ART compared to non-ART users (ATPIII-2001: 18.4% vs. 11.8%, p = 0.001), and varied significantly by participant age, duration of HIV diagnosis, severity of infection, non-nucleoside reverse transcriptase inhibitors (NNRTIs) use and date of study publication. Across criteria, there were significant differences in MS prevalence by sub-groups such as in men, the Americas, older publications, regional studies, younger adults, smokers, ART-naïve participants, NNRTIs users, participants with shorter duration of diagnosed infection and across the spectrum of HIV severity. Substantial heterogeneities across and within criteria were not fully explained by major study characteristics, while evidence of publication bias was marginal.

CONCLUSIONS

The similar range of MS prevalence in the HIV-infected and general populations highlights the common drivers of this condition. Thus, cardio-metabolic assessments need to be routinely included in the holistic management of the HIV-infected individual. Management strategies recommended for MS in the general population will likely provide similar benefits in the HIV-infected.

Transcriptional profiling suggests that Nevirapine and Ritonavir cause drug induced liver injury through distinct mechanisms in primary human hepatocytes

Drug induced liver injury (DILI), a major cause of pre- and post-approval failure, is challenging to predict pre-clinically due to varied underlying direct and indirect mechanisms. Nevirapine, a non-nucleoside reverse transcriptase inhibitor (NNRTI) and Ritonavir, a protease inhibitor, are antiviral drugs that cause clinical DILI with different phenotypes via different mechanisms. Assessing DILI in vitro in hepatocyte cultures typically requires drug exposures significantly higher than clinical plasma Cmax concentrations, making clinical interpretations of mechanistic pathway changes challenging. We previously described a system that uses liver-derived hemodynamic blood flow and transport parameters to restore primary human hepatocyte biology, and drug responses at concentrations relevant to in vivo or clinical exposure levels. Using this system, primary hepatocytes from 5 human donors were exposed to concentrations approximating clinical therapeutic and supra-therapeutic levels of Nevirapine (11.3 and 175.0 μM) and Ritonavir (3.5 and 62.4 μM) for 48 h. Whole genome transcriptomics was performed by RNAseq along with functional assays for metabolic activity and function. We observed effects at both doses, but a greater number of genes were differentially expressed with higher probability at the toxic concentrations. At the toxic doses, both drugs showed direct cholestatic potential with Nevirapine increasing bile synthesis and Ritonavir inhibiting bile acid transport. Clear differences in antigen presentation were noted, with marked activation of MHC Class I by Nevirapine and suppression by Ritonavir. This suggests CD8+ T cell involvement for Nevirapine and possibly NK Killer cells for Ritonavir. Both compounds induced several drug metabolizing genes (including CYP2B6, CYP3A4 and UGT1A1), mediated by CAR activation in Nevirapine and PXR in Ritonavir. Unlike Ritonavir, Nevirapine did not increase fatty acid synthesis or activate the respiratory electron chain with simultaneous mitochondrial uncoupling supporting clinical reports of a lower propensity for steatosis. This in vitro study offers insights into the disparate direct and immune-mediated toxicity mechanisms underlying Nevirapine and Ritonavir toxicity in the clinic.

The Impact of PNPLA3 rs738409 SNP on Liver Fibrosis Progression, Portal Hypertension and Hepatic Steatosis in HIV/HCV Coinfection

BACKGROUND

Faster fibrosis progression and hepatic steatosis are hallmarks of HIV/HCV coinfection. A single nucleotide polymorphism (SNP) of the PNPLA3-gene is associated with development of non-alcoholic steatohepatitis and a worse outcome in alcoholic liver disease. However, the role of PNPLA3 rs738409 SNP on liver fibrosis and steatosis, portal hypertension, and virological response in HIV/HCV coinfection remains unclear.

METHODS

In this cross-sectional study PNPLA3 (rs738409) and IL28B (rs12979860) SNPs were determined in 177 HIV/HCV coinfected patients. Liver fibrosis and steatosis-staged by liver biopsy and transient elastography using the Controlled Attenuation Parameter (CAP)-and portal hypertension (hepatic venous pressure gradient, HVPG) were compared across PNPLA3 genotypes.

RESULTS

75 (42.4%) patients tested positive for a PNPLA3 minor/major risk allele (G/C:66; G/G:9) showed comparable fibrosis stages (median F2 vs. F2; p = 0.292) and similar amounts of hepatic steatosis (CAP: 203.5 ± 41.9 vs. 215.5 ± 59.7 dB/m; p = 0.563) as compared to patients without a PNPLA3 risk allele. Advanced liver fibrosis was neither associated with PNPLA3 (p = 0.253) nor IL28B-genotype (p = 0.628), but with HCV-GT3 (p = 0.003), higher BMI (p = 0.008) and higher age (p = 0.007). Fibrosis progression rate (0.27 ± 0.41 vs. 0.20 ± 0.26 units/year; p = 0.984) and HVPG (3.9 ± 2.6 vs. 4.4 ± 3.0 mmHg; p = 0.472) were similar in patients with and without PNPLA3 risk alleles. SVR rates to PEGIFN/RBV therapy were similar across PNPLA3 genotypes.

CONCLUSIONS

The presence of a PNPLA3 risk allele had no independent impact on liver disease or virological response rates to PEGIFN/RBV therapy in our cohort of HIV/HCV coinfected patients.

Chronic liver disease in the human immunodeficiency virus patient

There are an estimated 40 million HIV infected individuals worldwide, with chronic liver disease being the 2nd leading cause of mortality in this population. Elevated liver functions are commonly noted in HIV patients and the etiologies are varied. Viral hepatitis B and C, fatty liver and drug induced liver injury are more common. Treatment options for viral hepatitis C are rapidly evolving and are promising, but treatments are limited for the other conditions and is primarily supportive. Opportunistic infections of the liver are now uncommon. Irrespective of etiology, management requires referral to specialized centers and with due diligence mortality can be reduced.

Liver stiffness and aspartate aminotransferase levels predict the risk for liver fibrosis progression in hepatitis C virus/HIV-coinfected patients

OBJECTIVES

The aim of the study was to investigate liver fibrosis outcome and the risk factors associated with liver fibrosis progression in hepatitis C virus (HCV)/HIV-coinfected patients.

METHODS

We prospectively obtained liver stiffness measurements by transient elastography in a cohort of 154 HCV/HIV-coinfected patients, mostly Caucasian men on suppressive antiretroviral treatment, with the aim of determining the risk for liver stiffness measurement (LSM) increase and to identify the predictive factors for liver fibrosis progression. To evaluate LSM trends over time, a linear mixed regression model with LSM level as the outcome and duration of follow-up in years as the main covariate was fitted.

RESULTS

After a median follow-up time of 40 months, the median increase in LSM was 1.05 kPa/year [95% confidence interval (CI) 0.72-1.38 kPa/year]. Fibrosis stage progression was seen in 47% of patients, and 17% progressed to cirrhosis. Aspartate aminotransferase (AST) levels and liver fibrosis stage at baseline were identified as independent predictors of LSM change. Patients with F3 (LSM 9.6-14.5 kPa) or AST levels ≥ 64 IU/L at baseline were at higher risk for accelerated LSM increase (ranging from 1.45 to 2.61 kPa/year), whereas LSM change was very slow among patients with both F0-F1 (LSM  ≤ 7.5 kPa) and AST levels ≤ 64 IU/L at baseline (0.34 to 0.58 kPa/year). An intermediate risk for LSM increase (from 0.78 to 1.03 kPa/year) was seen in patients with F2 (LSM 7.6-9.5 kPa) and AST baseline levels ≤  64 IU/L.

CONCLUSIONS

AST levels and liver stiffness at baseline allow stratification of the risk for fibrosis progression and might be clinically useful to guide HCV treatment decisions in HIV-infected patients.

Anti-hepatitis C virus treatment may prevent the progression of liver fibrosis in non-responder human immunodeficiency virus/hepatitis C virus coinfected patients

AIM

To evaluate changes in liver histology in patients with human immunodeficiency virus/hepatitis C virus coinfection non-responders to a suboptimal Interferon+Ribavirine regimen.

MATERIALS AND METHODS

We investigated 49 patients with two sequential liver biopsies: 18 were non-responders to Interferon+Ribavirine treatment (Group hepatitis C virus Rx) administered after the 1st liver biopsy who underwent a 2nd liver biopsy after a median period of 3.92 year and 31 were patients who remained untreated for hepatitis C virus disease (Group hepatitis C virus untreated) after the 1st liver biopsy because of refusal and underwent a 2nd liver biopsy after a median period of 5.05-years. Most patients in both groups were under highly active antiretroviral therapy. At the time of 1st liver biopsy similar degrees of necro-inflammation, fibrosis and steatosis were observed in both groups. Changes in liver lesions between 1st and 2nd liver biopsys were adjusted for different intervals between liver biopsys by a mathematic formula.

RESULTS

Liver fibrosis did not change in 88.9% of patients in Group hepatitis C virus Rx and in 77.4% in Group hepatitis C virus untreated. A marked deterioration in liver fibrosis was observed in 5 (16%) patients in Group hepatitis C virus untreated and in none in Group hepatitis C virus treated. Necro-inflammation and steatosis remained substantially unchanged in both groups.

CONCLUSION

Liver histology remained substantially unchanged in human immunodeficiency virus/hepatitis C virus patients non-responder to anti-hepatitis C virus therapy over 4 years observation, suggesting an effective anti-hepatitis C virus early treatment for all hepatitis C virus/human immunodeficiency virus coinfected patients who can reasonably tolerate therapy.

Fibrosis progression in human immunodeficiency virus/hepatitis C virus coinfected adults: prospective analysis of 435 liver biopsy pairs

Human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection is associated with progressive liver disease. However, the rate of progression is variable and the ability to differentiate patients with stable versus progressive HCV disease is limited. The objective of this study was to assess the incidence of and risk factors for fibrosis progression in a prospective cohort of coinfected patients. Overall, 435 liver biopsy pairs from 282 patients without cirrhosis were analyzed. Biopsies were scored according to the METAVIR system by a single pathologist blind to biopsy sequence. Fibrosis progression was defined as an increase of at least one METAVIR fibrosis stage between paired biopsies. The majority of patients were African American (84.8%), male (67.7%), and infected with HCV genotype 1 (93.4%). On initial biopsy, no or minimal fibrosis was identified in 243 patients (86%). The median interval between biopsies was 2.5 years. Fibrosis progression was observed in 97 of 282 (34%) patients and 149 of 435 (34%) biopsy pairs. After adjustment, greater body mass index (adjusted odds ratio [aOR]: 1.04 per 1 unit increase), diabetes (aOR: 1.56), and hepatic steatosis (aOR: 1.78) at the time of initial biopsy were marginally associated with subsequent fibrosis progression. Between biopsies, elevated serum aspartate and alanine aminotransferase (AST, ALT) (aOR AST: 3.34, ALT: 2.18 for >25% values >100 U/L versus <25% values >100 U/L) were strongly associated with fibrosis progression.

CONCLUSION

Fibrosis progression is common among HIV/HCV coinfected patients; these data suggest that progression can be rapid. Persistent elevations in serum transaminase levels may serve as important noninvasive markers to identify subsets of patients who are more likely to progress and thus warrant closer monitoring and consideration of HCV treatment.

Genome-wide mRNA and miRNA analysis of peripheral blood mononuclear cells (PBMC) reveals different miRNAs regulating HIV/HCV co-infection

Co-infection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is common due to shared transmission routes. The genomic basis of HIV/HCV co-infection and its regulation by microRNA (miRNA) is unknown. Therefore, our objective was to investigate genome-wide mRNA expression and its regulation by miRNA in primary PBMCs derived from 27 patients (5 HCV - mono-infected, 5 HIV-mono-infected, 12 HCV/HIV co-infected, and 5 healthy controls). This revealed 27 miRNAs and 476 mRNAs as differentially expressed (DE) in HCV/HIV co-infection when compared to controls (adj p<0.05). Our study shows the first evidence of miRNAs specific for co-infection, several of which are correlated with key gene targets demonstrating functional relationships to pathways in cancer, immune-function, and metabolism. Notable was the up regulation of HCV-specific miR-122 in co-infection (FC>50, p=4.02E-06), which may have clinical/biological implications.

Hepatic steatosis in human immunodeficiency virus: a prospective study in patients without viral hepatitis, diabetes, or alcohol abuse

BACKGROUND AND AIMS

Abnormal liver enzymes (LEs) are common in those infected with human immunodeficiency virus (HIV). Histologic data on those with abnormal LE without viral hepatitis are lacking.

METHODS

HIV-positive subjects without hepatitis C virus, hepatitis B virus, alcohol abuse, and diabetes mellitus with more than 1 abnormal LE, defined as 1.25 ULN in aspartate aminotransferase, alanine aminotransferase, or alkaline phosphatase, over 6 months were included. Subjects underwent a 2-hour oral glucose tolerance test, fasting lipids, insulin and glucose for insulin resistance (IR) by homeostasis model assessment for insulin resistance (HOMA-IR) and dual-energy X-ray absorptiometry for fat distribution. Biopsies were read blindly to clinical data, and scored by Ishak histologic activity index for inflammation and fibrosis and NAFLD activity score.

RESULTS

Fourteen patients underwent biopsy. All were on highly active antiretroviral therapy with undetectable HIV RNA and mean CD4 614. The histologic activity index scores for inflammation and fibrosis were 3.43(1.4) and 1.71(1.26), respectively, and 2 patients had advanced fibrosis (bridging fibrosis/cirrhosis). The majority (65%) of patients had steatosis: grade 1: 21%, grade 2: 28%, and grade 3: 14%. Hepatocyte ballooning was seen in 7 (40%) but nonalcoholic steatohepatitis (NASH) was diagnosed only in 4 (26%). NAFLD activity score of all biopsies of 3.07 (2.2; range, 0 to 5). HOMA-IR was higher in those with compared with those without steatosis (3.52 vs. 1.91; P = 0.11) and highest in those with NASH (4.89). Using multivariate logistic regression, only increased γ-glutamyl transpeptidase (P = 0.0009) predicted steatosis whereas HOMA-IR (P = 0.0046) predicted NASH.

CONCLUSIONS

Although steatosis is common in HIV patients with abnormal LE without diabetes mellitus, alcohol, or viral hepatitis coinfection, NASH was observed in only 26%. The only clinical or laboratory feature associated with biopsy proven steatosis and NASH were γ-glutamyl transpeptidase and a calculated measure of insulin resistance, respectively. Further studies are needed in this population to determine the long-term clinical significance.

Hepatic steatosis and steatohepatitis in human immunodeficiency virus/hepatitis C virus-coinfected patients

Hepatic steatosis (HS) is frequent in human immunodeficiency virus (HIV)- and hepatitis C virus (HCV)-coinfected patients. Antiretroviral therapy (ART) and metabolic alterations could induce HS. However, a protective effect of ART has been reported in a paired biopsy study. Thus, our aim was to examine the changes and predictors of HS progression among HIV/HCV-coinfected patients with sequential biopsies. We also evaluated the rates of steatohepatitis and factors associated thereof. HIV-infected patients with detectable serum HCV RNA, who underwent two biopsies, separated at least by 1 year, were included in this retrospective study. HS progression was defined as increase in one or more HS grades. The median (interquartile range) time between biopsies was 3.3 (2.0-5.2) years. Among 146 individuals, HS at baseline was observed in 86 (60%) patients and in 113 (77%) in the follow-up biopsy (P < 0.001). Progression of HS was observed in 60 (40%) patients. HS regressed in 11 (8%) patients. Factors associated with HS progression were changes in fasting plasma glucose (FPG) between biopsies (per 10 mg/dL increase; odds ratio [OR] [95% confidence interval; CI] = 1.4 [1.04-1.8]; P = 0.024) and cumulative use of dideoxynucleoside analogs (per year; OR [95% CI] = 1.5 [1.2-1.8]; P = 0.001). Persistent steatohepatitis or progression to steatohepatitis between biopsies was observed in 27 (18%) patients. Persistence of or progression to steatohepatitis was associated with progression ≥ 1 fibrosis stages between biopsies (OR [95% CI] = 2.4 [1.01-5.7]; P = 0.047).

CONCLUSIONS

HS progresses frequently and regression is rarely observed in HIV/HCV-coinfected patients, including in those on ART. Cumulative exposure to dideoxynucleoside analogs and increases in FPG are related with HS progression. Stetatohepatitis is frequently observed in these patients and is linked to fibrosis progression.

Hepatic steatosis in HIV-HCV coinfected patients receiving antiretroviral therapy is associated with HCV-related factors but not antiretrovirals

Background

In HIV and hepatitis C virus (HCV) coinfected patients, the role of antiretroviral therapy (ART) on hepatic steatosis (HS) remains controversial.

Methods

HIV/HCV coinfected patients receiving ART and previously untreated for HCV who underwent a liver biopsy were included. Cumulative duration of exposure to each antiretroviral was recorded up to liver biopsy date. Logistic regression analyses evaluated factors associated with steatosis and its severity.

Results

184 patients were included: median age 41years, 84% male, 89% Caucasian, 61% with a past history of intravenous drug use. HCV genotypes were 1 (55%), 2 (6%), 3 (26%), and 4 (13%). Median HCV-RNA was 6.18 log₁₀ IU/ml. HIV-RNA was undetectable (<400 copies/ml) in 67% of patients. Median CD4 count was 321/mm³. All patients had been exposed to nucleoside reverse transcriptase inhibitors (median cumulative exposure 56months); 126 received protease inhibitors (23months), and 79 non-nucleoside reverse transcriptase inhibitors (16months). HS was observed in 102 patients (55%): 41% grade 1; 5% grade 2, and 9% grade 3. In multivariate analysis, HCV genotype 3 and HCV viral load were moderately associated with mild steatosis but strongly with grade 2-3 steatosis. After adjustment for the period of biopsy, no association was detected between HS and exposure to any antiretroviral class or drug, or duration of ART globally or comparing genotype 3 to others.

Conclusions

Among our ART-treated HIV-HCV cohort predominantly infected with genotype 1, 55% of patients had HS which was associated with HCV-related factors, but not ART class or duration of exposure.

The risk of hepatocellular carcinoma among individuals with acquired immunodeficiency syndrome in the United States

BACKGROUND

Hepatocellular carcinoma (HCC) is a concern among individuals with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS).

METHODS

The authors analyzed population-based registry linkage data from the US HIV/AIDS Cancer Match Study (1980-2009) to examine the risk and trends of HCC among individuals with AIDS. Standardized incidence ratios (SIRs) were used to measure HCC risk relative to the general population, and Poisson regression was used to calculate incidence rate ratios (RR) comparing incidence among individuals with AIDS. People with AIDS were categorized according to their HIV risk group into high and low hepatitis C virus (HCV) prevalence groups based on their HIV transmission risk category.

RESULTS

Among 615,150 individuals with AIDS, HCC risk was elevated almost 4 times compared with the risk in the general population (N = 366; SIR, 3.8; 95% confidence interval, 3.5-4.3). Although HCC incidence increased steadily across calendar periods (P(trend) < .0001; adjusted for sex and age), the excess risk in individuals with AIDS compared with the general population remained somewhat constant (SIRs range, 3.5-3.9) between the monotherapy/dual therapy era (1990-1995) and the recent highly active antiretroviral therapy era (2001-2009). In a multivariate model adjusting for sex, race/ethnicity, and attained calendar period, HCC incidence increased with advancing age (P(trend) < .0001) and was associated with HIV risk groups with a known higher prevalence of HCV (adjusted RR, 2.2; 95% confidence interval, 1.8-2.8).

CONCLUSIONS

HCC incidence in individuals with AIDS has increased over time despite improved HIV treatment regimens, likely reflecting prolonged survival with chronic liver disease. The high incidence in older adults suggests that this cancer will increase in importance with aging of the HIV-infected population.

Impact of hepatitis B virus infection on metabolic profiles and modifying factors

The metabolic syndrome may cause disease progression in patients with chronic hepatitis B (CHB). However, the interactions between hepatitis B virus (HBV) infection and metabolic factors remain unknown. We investigated the association of HBV infection with metabolic profiles in HBV-infected and noninfected subjects. In addition, the impacts of serum HBV DNA level on metabolic profiles were studied. Initially, a case-control analysis of patients with and without chronic HBV infection was performed. The HBV group consisted of 322 patients with chronic HBV infection, and the control group consisted of 870 matched subjects without HBV infection. Fasting blood glucose, lipid profiles and adiponectin levels were compared. The results were then confirmed in a second retrospective cohort study in 122 CHB patients with serum HBV DNA levels and HOMA-IR index values. In the case-control analysis, the HBV group had significantly higher serum adiponectin, but lower triglyceride (TG) and high-density lipoprotein cholesterol (HDL) levels than the control group. These relationships already existed in subjects younger than 45 years of age and were modified by serum alanine aminotransferase (ALT) levels. In the retrospective cohort, serum HBV DNA levels were negatively proportional to TG levels, but not to other metabolic parameters. Moreover, this relationship was significant only in subjects with higher ALT levels. Compared with healthy adults, patients with chronic HBV infection have significantly higher serum adiponectin, but lower TG and HDL levels. These relationships are modified by ALT levels and already exist in middle-age patients with chronic HBV infection, implying HBV may interact with host metabolism.

HIV and hepatitis C co-infection: the role of HAART in HIV/hepatitis C virus management

PURPOSE OF REVIEW

Highly active antiretroviral therapy (HAART)-related hepatotoxicity, a relevant side effect in HIV/hepatitis C virus (HCV) co-infected patients, has evolved over time. Antiretroviral therapy might have a positive effect on the liver of HIV/HCV co-infected patients, but data are conflicting.

RECENT FINDINGS

HIV treatments have evolved and we have currently a drug armamentarium with a good liver safety profile. Most of the current first-line HAART regimens recommended by guidelines fit well to HIV/HCV co-infected patients. There are now multiple retrospective studies that suggest a possible benefit of HIV control and protection of CD4 cell counts to the liver of HIV/HCV co-infected patients. However, data are conflicting at times. This factor along with the methodological limitations of these studies prevent us from drawing definitive conclusions. Even assuming a positive effect, HAART does not appear to fully correct the adverse effect of HIV infection on HCV-related outcomes. In the era of HCV direct antiviral agents, the timing of HIV and HCV therapies has to be individualized in HIV/HCV co-infected patients given the variety of scenarios.

SUMMARY

With current HIV drug armamentarium it is possible to construct HAART regimens with optimal liver safety profile for HCV co-infected patients. The possible positive effect of HAART on the HCV-infected liver should not distract from the main intervention, which is HCV eradication with specific treatment.

The HIV/HCV-coinfected patient and new treatment options

Hepatitis C (HCV) treatment is on the cusp of change with the approval of the first direct-acting antivirals: telaprevir and boceprevir. Drug-drug interactions with HIV antiretrovirals, increased toxicity, and rapid selection of HCV-resistant mutants are among the treatment complexities expected in this difficult-to-treat population. Until the current standard of care changes, focus should be on strategies to optimize management of HIV/HCV-coinfected patients with currently available options. This article reviews the latest predictive factors of response to HCV treatment with the current standard of care in HIV-coinfected patients, and new treatment options.

NASH: A global health problem

Non-alcoholic fatty liver disease (NAFLD) is a major public health problem both in the Western world and in the East. This is mainly due to the high prevalence of the disease and its effects on the individual with NAFLD. In the USA, it is estimated that approximately a third of the general population has NAFLD. Increasing age, obesity and the presence of multiple features of metabolic syndrome, especially diabetes, are associated with a higher probability of having non-alcoholic steatohepatitis (NASH). In the individual with NAFLD, excess hepatic fat is associated with an increased risk of developing diabetes, hypertension, cardiovascular events, abnormal resting electrocardiography and endothelial dysfunction. These findings have been corroborated in studies in teenagers as well as adults. There is also an increase in cardiovascular mortality, especially in those with NASH. In addition, there is an increased risk of death from a variety of non-hepatocellular cancers. From a liver perspective, NAFLD is associated with a 15-20% risk of progression to cirrhosis. The disease progresses more rapidly in those with diabetes, increasing age and obesity. The PNPLA3 gene mutation at position 148 is associated with not only steatosis, but with the likelihood of having steatohepatitis and increased inflammation and fibrosis. Once cirrhosis develops, the liver disease decompensates at the rate of 3-4% per year. NASH-related cirrhosis is a risk factor for hepatocellular cancer. All of these factors indicate that NAFLD is a common condition that has significant adverse health consequences for those who are afflicted. It is therefore a major public health hazard throughout the world.

Incidence and risk factors for steatosis progression in adults coinfected with HIV and hepatitis C virus

BACKGROUND & AIMS

Hepatic steatosis is a common histologic finding in patients coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV), although little is known about its natural history. We prospectively examined the natural history of steatosis in patients coinfected with HIV and HCV who attended an urban HIV clinic.

METHODS

The study cohort consisted of 222 coinfected patients (87% black, 94% with HCV genotype 1 infection) who had at least 2 liver biopsies performed between 1993 and 2008. Biopsy specimens were scored by a single pathologist; samples were classified as having trivial (<5% of hepatocytes affected) or significant (>5%) levels of fat (steatosis). We characterized progression to significant levels of fat among patients whose first biopsy samples had no or trivial levels of fat, and regression among those with significant fat, using logistic regression.

RESULTS

Initial biopsy specimens from most patients (88%) had no or trivial amounts of fat. Among second biopsy samples, 74% had no or trivial fat and 13% had significant amounts of fat. The strongest risk factors for progression of steatosis were alcohol abuse and overweight/obesity; cumulative exposure to antiretroviral therapy between biopsies and high counts of CD4(+) T cells were associated with reduced progression of steatosis. Among the 28 patients whose initial biopsy specimen had significant fat levels, most (75%) regressed.

CONCLUSIONS

Antiretroviral therapy and high counts of CD4(+) T cells are associated with reduced progression of steatosis in patients coinfected with HIV and HCV. Efforts to diagnose and prevent steatosis should focus on persons with a high body mass index and excessive alcohol intake.

HIV/HCV co-infection: pathogenesis, clinical complications, treatment, and new therapeutic technologies

World-wide, hepatitis C virus (HCV) accounts for approximately 130 million chronic infections, with an overall 3% prevalence. Four to 5 million persons are co-infected with HIV. It is well established that HIV has a negative impact on the natural history of HCV, including a higher rate of viral persistence, increased viral load, and more rapid progression to fibrosis, end-stage liver disease, and death. Whether HCV has a negative impact on HIV disease progression continues to be debated. However, following the introduction of effective combination antiretroviral therapy, the survival of coinfected individuals has significantly improved and HCV-associated diseases have emerged as the most important co-morbidities. In this review, we summarize the newest studies regarding the pathogenesis of HIV/HCV coinfection, including effects of coinfection on HIV disease progression, HCV-associated liver disease, the immune system, kidney and cardiovascular disease, and neurologic status; and effectiveness of current anti-HIV and HCV therapies and proposed new treatment strategies.

Risk factors for advanced liver fibrosis in HIV-infected individuals: role of antiretroviral drugs and insulin resistance

Liver damage may result from multiple factors in HIV-infected patients. The availability of reliable noninvasive tools to measure liver fibrosis has permitted the screening of large patient populations. Cross-sectional study of all consecutive HIV outpatients who underwent examination by transient elastometry (FibroScan) at one HIV reference clinic during 2007. Advanced liver fibrosis (ALF) was defined as hepatic stiffness >9.5 kilopascals, which corresponds to Metavir stages F3-F4 in the liver biopsy. A total of 681 consecutive HIV-infected patients (64% injecting drug users; mean age 43; 78% male; 98% on antiretroviral therapy) had at least one valid FibroScan evaluation. ALF was diagnosed in 215 (32%) of them. In the univariate analysis, ALF was significantly associated with older age, low CD4 counts, chronic hepatitis C, past alcohol abuse, elevated ALT, high triglycerides, low cholesterol, high homeostasis model assessment (HOMA) index and exposure to didanosine and/or stavudine. In a multivariate model (OR, 95% CI), chronic hepatitis C (2.83, 1.57-5.08), past alcohol abuse (2.26, 1.37-3.74), exposure to didanosine and/or stavudine (1.85, 1.14-3.01), high HOMA index (1.25, 1.04-1.51), older age (1.09, 1.05-1.14) and elevated ALT (1.04, 1.03-1.06) remained as independently associated with ALF. Therefore, in addition to chronic hepatitis C and alcohol abuse, insulin resistance and/or exposure to dideoxy-nucleosides may contribute to ALF in HIV-infected patients.

Incidence of liver cirrhosis in HIV-infected patients with chronic hepatitis B or C in the era of highly active antiretroviral therapy

BACKGROUND

Longitudinal assessment of liver fibrosis with transient elastometry (TE) in patients with chronic viral hepatitis is becoming routine clinical practice in many clinics, as this procedure is non-invasive, easy to perform and relatively inexpensive, allowing early detection of cirrhosis. Herein, we examine the incidence of cirrhosis, using TE assessment, in HIV-infected individuals with chronic hepatitis B or C receiving highly active antiretroviral therapy (HAART).

METHODS

A longitudinal study was performed on a cohort of HIV-infected patients with chronic hepatitis B or C who were followed since 2004 at Hospital Carlos III (Madrid, Spain) with periodic TE assessments. The primary outcome was the development of cirrhosis, defined as liver stiffness >12.5 KPa.

RESULTS

A total of 508 HIV-infected patients were examined, of whom 54 developed liver cirrhosis during a mean ±(SD) follow-up of 2.6 ±1.0 years (overall incidence was 41.13 cases per 1,000 person-years). The risk of developing cirrhosis was significantly higher in 297 HCV-RNA-positive patients (either untreated or non-responders to hepatitis C therapy) compared with 55 patients who had cleared HCV with therapy (odds ratio 3.73, 95% confidence interval 1.06-13.17; P=0.04). By contrast, the risk of developing cirrhosis was low and similar in 24 HIV-HBV-coinfected patients under long-term suppressive HBV therapy (mainly tenofovir disoproxil fumarate), 132 HIV-infected patients without chronic liver disease and those who had cleared HCV with therapy.

CONCLUSIONS

Development of liver cirrhosis in HIV-infected individuals in the HAART era is mainly associated with active HCV coinfection. The risk of developing cirrhosis is negligible in patients who cleared HCV with therapy, as well as in HIV-HBV-coinfected patients on long-term suppressive tenofovir disoproxil fumarate therapy.

Transient elastography: a non-invasive tool for assessing liver fibrosis in HIV/HCV patients

AIM

To assess the prevalence of advanced liver fibrosis (ALF) in human immunodeficiency virus (HIV), hepatitis C virus (HCV) and HIV/HCV patients using transient elastography, and to identify factors associated with ALF.

METHODS

Between September 2008 and October 2009, 71 HIV mono-infected, 57 HIV/HCV co-infected and 53 HCV mono-infected patients on regular follow-up at our Center were enrolled in this study. Alcohol intake, the main parameters of liver function, presence of HCV-RNA, HIV-RNA, duration of highly active anti-retroviral therapy (HAART) and CD4 cell count were recorded. ALF was defined as liver stiffness (LS) ≥ 9.5 kPa. To estimate liver fibrosis (LF) a further 2 reliable biochemical scores, aspartate aminotransferase platelet ratio index (APRI) and FIB-4, were also used.

RESULTS

LS values of co-infected patients were higher than in either HIV or HCV mono-infected patients (χ(2)(MH) = 4, P < 0.04). In fact, LS ≥ 9.5 was significantly higher in co-infected than in HIV and HCV mono-infected patients (χ(2) = 5, P < 0.03). Also APRI and the FIB-4 index showed more LF in co-infected than in HIV mono-infected patients (P < 0.0001), but not in HCV mono-infected patients. In HIV⁄HCV co-infected patients, the extent of LS was significantly associated with alcohol intake (P < 0.04) and lower CD4+ cell count (P < 0.02). In HCV patients, LS was correlated with alcohol intake (P < 0.001) and cholesterol levels (P < 0.03). Body mass index, diabetes, HCV- and HIV-viremia were not significantly correlated with LS. In addition, 20% of co-infected patients had virologically unsuccessful HAART; in 50% compliance was low, CD4+ levels were < 400 cells/mm(3) and LS was > 9.5 kPa. There was no significant correlation between extent of LF and HAART exposure or duration of HAART exposure, in particular with specific dideoxynucleoside analogues.

CONCLUSION

ALF was more frequent in co-infected than mono-infected patients. This result correlated with lower CD4 levels. Protective immunological effects of HAART on LF progression outweigh its hepatotoxic effects.

Hepatic steatosis in patients coinfected with human immunodeficiency virus/hepatitis C virus: a meta-analysis of the risk factors

Hepatic steatosis (HS) is frequent in patients with hepatitis C virus (HCV) infection, occurring in 40%-80%, associating with metabolic and virus-related factors, namely, genotype 3 and viral load. Human immunodeficiency virus (HIV) infection and antiretroviral treatment seem to be risk factors for HS. Several studies addressed this issue in coinfected patients, with discrepant results. A meta-analysis was performed on the HS risk factors in coinfected patients. Eligible studies were identified through structured keywords including coinfection, HCV, HIV, and steatosis in relevant databases including PubMed. Pooled odds ratios (ORs) and confidence limits (CIs) were obtained with the random-effects model and the DerSimonian-Laird method. Twelve studies, including 1,989 coinfected patients, were selected. Twenty percent were infected with HCV genotype 3. The overall prevalence of HS was 50.8% (23%-72%). Four studies also included 1,540 HCV monoinfected patients, not showing an increased risk for HS in coinfected patients (OR 1.61, 95% CI 0.84-3.10, P = 0.151). In coinfected patients, HS was associated with higher body mass index (OR 1.13, 95% CI 1.07-1.19, P < 0.001), diabetes mellitus (OR 2.32, 95% CI 1.32-4.07, P = 0.003), elevated alanine aminotransferase levels (OR 1.28, 95% CI 1.02-1.61, P = 0.035), necroinflammatory activity (OR 1.72, 95% CI 1.11-2.67, P = 0.016), and fibrosis (OR 1.67, 95% CI 1.20-2.34, P = 0.003). No associations were found between HS and gender, other metabolic factors (dyslipidemia, glucose, metabolic syndrome), HCV-related factors (genotype, viral load), or HIV-related factors (viral load, CD4 count, antiretroviral therapy, and class of medication).

CONCLUSION

In coinfected patients, HS does not seem to be more frequent than in HCV monoinfected patients and is mostly associated with metabolic factors, such as increased weight, diabetes mellitus, and more severe liver disease. The fact that no associations with HCV factors were found may be due to the small percentage of genotype 3-infected patients.

Association of metabolic profiles with hepatic fibrosis in chronic hepatitis C patients with genotype 1 or 2 infection

BACKGROUND AND AIMS

Metabolic profiles are associated with severity of liver histology in chronic hepatitis C (CHC) infection. However, the influence of hepatitis C virus (HCV) genotypes, especially genotype 1 and 2, on the association between metabolic profiles and hepatic fibrosis remains unknown.

METHODS

We consecutively enrolled 528 CHC patients infected by HCV genotype 1 or 2, and used univariate and multivariate approaches to determine the influence of HCV genotype on the association of metabolic characteristics with severity of liver histology.

RESULTS

In univariate analysis, diabetes mellitus, obesity, higher grades of hepatic steatosis, homeostasis model assessment-insulin resistance index and alanine aminotransferase level, but lower serum total cholesterol and low-density lipoprotein level, were associated with advanced hepatic fibrosis. Advanced hepatic fibrosis was associated with an adjusted odds ratio of 13.72 (95% confidence interval, 2.15-87.7) for serum fasting blood glucose, 1.07 (1.01 to 1.13) for body mass index (BMI), and 0.03 (0.00-0.32) for total cholesterol level. Older age, lower serum total cholesterol level and more necro-inflammatory activity were associated with advanced hepatic fibrosis in both genotype 1 and 2 patients (P < 0.05). Advanced hepatic fibrosis was associated with an adjusted odds ratio of 31.18 (2.31-421.4) for fasting blood glucose level in genotype 1 infection, whereas 1.16 (1.05-1.28) for BMI in genotype 2 infection.

CONCLUSIONS

Age, serum total cholesterol, and hepatic necro-inflammation have important associations with severity of hepatic fibrosis in CHC patients. Moreover, these associations are different between HCV genotype: the effects of fasting blood glucose level and BMI are increased on genotype 1 and genotype 2 patients, respectively.

Influence of insulin resistance on hepatic fibrosis and steatosis in hepatitis C virus (HCV) mono-infected compared with HIV-HCV co-infected patients

BACKGROUND

Insulin resistance (IR), the major feature of the metabolic syndrome, is also common in patients with chronic HCV infection. Liver fibrosis and steatosis are known potential outcome of chronic hepatitis B or C infection. Studies have shown that HIV positive individuals co-infected with HCV have more rapid live disease progression than those with HIV alone. Few data have reported the influence of IR on steatosis and fibrosis in the context of HIV-HCV coinfection.

AIM

To test the association among insulin resistance (IR), liver fibrosis and liver steatosis in HIV-HCV and HCV-infected patients.

PATIENTS AND METHODS

A total of 170 HIV-HCV-infected patients matched by age, gender and genotype with 170 HCV mono-infected patients were included. Patients were considered to be IR when the homeostasis model assessment of IR >2. Significant fibrosis was considered if METAVIR >or=F2 and significant steatosis if >or=10%.

RESULTS

Insulin resistance was independently associated in HCV patients with fibrosis [odds ratio (OR) = 2.04 (95% CI 1.02-4)], a body mass index (BMI) >25 kg/m(2) [OR = 3.33 (1.47-7.69)] and steatosis [OR = 3.33 (1.67-6.67)]. Fibrosis >or=F2 was associated in HCV patients with high liver activity grade (>or=A2) [OR = 8.33 (3.85-16.67)], male gender [OR = 3.03 (1.33-7.14)] and IR [OR = 2.44 (1.15-5)]. In HIV-HCV patients, >or=A2 [OR = 5.56 (1.64-20)] was associated with fibrosis. Steatosis >or=10% was associated in HCV patients with IR [OR = 3.13 (1.59-6.25) and >or=F2 (OR = 2.22 (1.15-4.17)]. In HIV-HCV, a BMI >25 kg/m(2) [OR = 3.85 (1.64-9.10)], >or=A2 [OR = 2.16 (1.02-4.55); P = 0.044] and nucleoside reverse transcriptase inhibitor [OR = 3.61 (1.19-10.96); P = 0.023] were independently associated with significant liver steatosis.

CONCLUSIONS

Insulin resistance is associated with liver fibrosis and steatosis in HCV mono-infected, but not in HIV-HCV co-infected patients. Significant liver fibrosis is associated with IR independent of liver steatosis only in HCV mono-infected patients.

[Non alcoholic steatosis in HIV infection]

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatosis (NASH) are common conditions in the setting of HIV infection, especially if HCV coinfection or metabolic syndrome's features are present. The factors that contribute to the progression of NAFLD to NASH and fibrosis are not completely known and the role of antiretroviral therapy is especially controversial. Although the natural history of NASH in the setting of HIV infection is unknown, it may emerge as one of the leading causes of liver disease over the long term in these patients. Liver biopsy is still the gold standard for the diagnosis of NASH. Indeed, although non-invasive techniques are promising tools for the diagnosis of NAFLD, they do not assess liver damage. There is no specific therapy for NASH in HIV infection, as the role of glitazones has not been evaluated in these patients.

Accuracy of simple biochemical tests in identifying liver fibrosis in patients co-infected with human immunodeficiency virus and hepatitis C virus

BACKGROUND & AIMS

We assessed the ability of 3 simple biochemical tests to stage liver fibrosis in patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV).

METHODS

We analyzed liver biopsy samples from 324 consecutive HIV/HCV-positive patients (72% men; mean age, 38 y; mean CD4+ T-cell counts, 548 cells/mm(3)). Scheuer fibrosis scores were as follows: 30% had F0, 22% had F1, 19% had F2, 23% had F3, and 6% had F4. Logistic regression analyses were used to predict the probability of significant (>or=F2) or advanced (>or=F3) fibrosis, based on numeric scores from the APRI, FORNS, or FIB-4 tests (alone and in combination). Area under the receiver operating characteristic curves were analyzed to assess diagnostic performance.

RESULTS

Area under the receiver operating characteristic curves analyses indicated that the 3 tests had similar abilities to identify F2 and F3; the ability of APRI, FORNS, and FIB-4 were as follows: F2 or greater: 0.72, 0.67, and 0.72, respectively; F3 or greater: 0.75, 0.73, and 0.78, respectively. The accuracy of each test in predicting which samples were F3 or greater was significantly higher than for F2 or greater (APRI, FORNS, and FIB-4: >or=F3: 75%, 76%, and 76%, respectively; >or=F2: 66%, 62%, and 68%, respectively). By using the lowest cut-off values for all 3 tests, F3 or greater was ruled out with sensitivity and negative predictive values of 79% to 94% and 87% to 91%, respectively, and 47% to 70% accuracy. Advanced liver fibrosis (>or=F3) was identified using the highest cut-off value, with specificity and positive predictive values of 90% to 96% and 63% to 73%, respectively, and 75% to 77% accuracy.

CONCLUSIONS

Simple biochemical tests accurately predicted liver fibrosis in more than half the HIV/HCV co-infected patients. The absence and presence of liver fibrosis are predicted fairly using the lowest and highest cut-off levels, respectively.