Enhancement of chemical hepatocarcinogenesis by the HIV-1 tat gene

HIV-1-Mediated Acceleration of Oncovirus-Related Non-AIDS-Defining Cancers

With the advent of combination antiretroviral therapy (cART), overall survival has been improved, and the incidence of acquired immunodeficiency syndrome (AIDS)-defining cancers has also been remarkably reduced. However, non-AIDS-defining cancers among human immunodeficiency virus-1 (HIV-1)-associated malignancies have increased significantly so that cancer is the leading cause of death in people living with HIV in certain highly developed countries, such as France. However, it is currently unknown how HIV-1 infection raises oncogenic virus-mediated cancer risks in the HIV-1 and oncogenic virus co-infected patients, and thus elucidation of the molecular mechanisms for how HIV-1 expedites the oncogenic viruses-triggered tumorigenesis in the co-infected hosts is imperative for developing therapeutics to cure or impede the carcinogenesis. Hence, this review is focused on HIV-1 and oncogenic virus co-infection-mediated molecular processes in the acceleration of non-AIDS-defining cancers.

Hepatocellular cancer therapy in patients with HIV infection: Disparities in cancer care, trials enrolment, and cancer-related research

In the highly active antiretroviral therapy (HAART) era, hepatocellular carcinoma (HCC) is arising as a common late complication of human immunodeficiency virus (HIV) infection, with a great impact on morbidity and mortality. Though HIV infection alone may not be sufficient to promote hepatocarcinogenesis, the complex interaction of HIV with hepatitis is a main aspect influencing HCC morbidity and mortality.

Data about sorafenib effectiveness and safety in HIV-infected patients are limited, particularly for patients who are on HAART. However, in properly selected subgroups, outcomes may be comparable to those of HIV-uninfected patients. Scarce data are available for those other systemic treatments, either tyrosine kinase inhibitors, as well as immune checkpoint inhibitors (ICIs), which have been added to our therapeutic armamentarium. This review examines the influence of HIV infection on HCC development and natural history, summarizes main data on systemic therapies, offers some insight into possible mechanisms of T cell exhaustion and reversal of HIV latency with ICIs and issues about clinical trials enrollment. Nowadays, routine exclusion of HIV-infected patients from clinical trial participation is totally inappropriate, since it leaves a number of patients deprived of life-prolonging therapies.

HIV-HBV and HIV-HCV Coinfection and Liver Cancer Development

Liver diseases that are caused by the hepatitis B virus (HBV) and hepatitis C virus (HCV), including cirrhosis and hepatocellular carcinoma (HCC), have become increasingly important in patients infected with the human immunodeficiency virus (HIV) as their life expectancy is getting longer with successful anti-HIV therapy. Due to their shared transmission routes, dual infection by HIV and HBV or HIV and HCV, and triple infection by all three viruses are fairly common and affect millions of people worldwide. Whereas the immunodeficiency caused by HIV enhances the likelihood of HBV and HCV persistence, hepatotoxicity associated with anti-HIV therapy can worsen the liver diseases associated with HBV or HCV persistence. Evidence suggests HIV infection increases the risk of HBV- or HCV-associated HCC risk although the precise mechanisms of enhanced hepatocarcinogenesis remain to be fully elucidated. Recent success in curing HCV infection, and the availability of therapeutic options effective in long-term suppression of both HIV and HBV replication, bring hope, fortunately, to those who are coinfected but also highlight the need for judicious selection of antiviral therapies.

Signature molecules expressed differentially in a liver disease stage-specific manner by HIV-1 and HCV co-infection

To elucidate HIV-1 co-infection-induced acceleration of HCV liver disease and identify stage-specific molecular signatures, we applied a new high-resolution molecular screen, the Affymetrix GeneChip Human Transcriptome Array (HTA2.0), to HCV-mono- and HIV/HCV-co-infected liver specimens from subjects with early and advanced disease. Out of 67,528 well-annotated genes, we have analyzed the functional and statistical significance of 75 and 28 genes expressed differentially between early and advanced stages of HCV mono- and HIV/HCV co-infected patient liver samples, respectively. We also evaluated the expression of 25 and 17 genes between early stages of mono- and co-infected liver tissues and between advanced stages of mono- and co-infected patient's samples, respectively. Based on our analysis of fold-change in gene expression as a function of disease stage (i.e., early vs. advanced), coupled with consideration of the known relevant functions of these genes, we focused on four candidate genes, ACSL4, GNMT, IFI27, and miR122, which are expressed stage-specifically in HCV mono- and HIV-1/HCV co-infective liver disease and are known to play a pivotal role in regulating HCV-mediated hepatocellular carcinoma (HCC). Our qRT-PCR analysis of the four genes in patient liver specimens supported the microarray data. Protein products of each gene were detected in the endoplasmic reticulum (ER) where HCV replication takes place, and the genes' expression significantly altered replicability of HCV in the subgenomic replicon harboring regulatory genes of the JFH1 strain of HCV in Huh7.5.1. With respect to three well-known transferrable HIV-1 viral elements-Env, Nef, and Tat-Nef uniquely augmented replicon expression, while Tat, but not the others, substantially modulated expression of the candidate genes in hepatocytic cells. Combinatorial expression of these cellular and viral genes in the replicon cells further altered replicon expression. Taken together, these results showed that HIV-1 viral proteins can exacerbate liver pathology in the co-infected patients by disparate molecular mechanisms-directly or indirectly dysregulating HCV replication, even if lack of association of HCV load and end-stage liver disease in hemophilic patients were reported, and modulating expression of hepatocellular genes critical for disease progression. These findings also provide major insights into development of stage-specific hepatocellular biomarkers for improved diagnosis and prognosis of HCV-mediated liver disease.

Association of Viral Suppression With Lower AIDS-Defining and Non-AIDS-Defining Cancer Incidence in HIV-Infected Veterans: A Prospective Cohort Study

Background

Viral suppression is a primary marker of HIV treatment success. Persons with HIV are at increased risk for AIDS-defining cancer (ADC) and several types of non-AIDS-defining cancer (NADC), some of which are caused by oncogenic viruses.

Objective

To determine whether viral suppression is associated with decreased cancer risk.

Design

Prospective cohort.

Setting

Department of Veterans Affairs.

Participants

HIV-positive veterans (n = 42 441) and demographically matched uninfected veterans (n = 104 712) from 1999 to 2015.

Measurements

Standardized cancer incidence rates and Poisson regression rate ratios (RRs; HIV-positive vs. uninfected persons) by viral suppression status (unsuppressed: person-time with HIV RNA levels ≥500 copies/mL; early suppression: initial 2 years with HIV RNA levels <500 copies/mL; long-term suppression: person-time after early suppression with HIV RNA levels <500 copies/mL).

Results

Cancer incidence for HIV-positive versus uninfected persons was highest for unsuppressed persons (RR, 2.35 [95% CI, 2.19 to 2.51]), lower among persons with early suppression (RR, 1.99 [CI, 1.87 to 2.12]), and lowest among persons with long-term suppression (RR, 1.52 [CI, 1.44 to 1.61]). This trend was strongest for ADC (unsuppressed: RR, 22.73 [CI, 19.01 to 27.19]; early suppression: RR, 9.48 [CI, 7.78 to 11.55]; long-term suppression: RR, 2.22 [CI, 1.69 to 2.93]), much weaker for NADC caused by viruses (unsuppressed: RR, 3.82 [CI, 3.24 to 4.49]; early suppression: RR, 3.42 [CI, 2.95 to 3.97]; long-term suppression: RR, 3.17 [CI, 2.78 to 3.62]), and absent for NADC not caused by viruses.

Limitation

Lower viral suppression thresholds, duration of long-term suppression, and effects of CD4+ and CD8+ T-cell counts were not thoroughly evaluated.

Conclusion

Antiretroviral therapy resulting in long-term viral suppression may contribute to cancer prevention, to a greater degree for ADC than for NADC. Patients with long-term viral suppression still had excess cancer risk.

Primary Funding Source

National Cancer Institute and National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health.

Unusual Presentation of Metastatic Hepatocellular Carcinoma in an HIV/HCV Coinfected Patient: Case Report and Review of the Literature

Hepatocellular carcinoma (HCC) is an increasing cause of mortality in human immunodeficiency virus (HIV) seropositive patients. Concurrent infection with HIV may accelerate the progression from cirrhosis to HCC. Viral hepatitis and alcohol abuse are the main risk factors for HCC in developed countries. Exposure to these risk factors is common among HIV-infected patients. We report the case of a 43-year-old woman affected by HCC, with unusual soft tissue metastases (left masseter muscle) and HIV/HCV coinfection. The usual route of metastatic spread from classic HCC is hematogenous, with the most common extrahepatic site being the lung. Our case, besides the unusual distant metastatic site, showed very rapid clinical progression, as has been commonly observed in HIV-infected patients with HCC. The case series of HCC in HIV-positive individuals published to date does not cumulatively exceed 70 subjects.

Lung cancer in persons with HIV

PURPOSE OF REVIEW

Lung cancer is emerging as a leading cause of death in HIV-infected persons. This review will discuss the latest scientific evidence regarding the mechanisms driving lung cancer risk in HIV infection, the clinical presentation of lung cancer in HIV-infected persons and recent data regarding the outcomes, treatment and prevention of lung cancer in this group.

RECENT FINDINGS

Increased risk of lung cancer in HIV-infected persons is primarily due to higher smoking rates, but emerging evidence also implicates immunosuppression and inflammatory processes. Lung cancer outcomes may be worse in HIV-infected persons in the antiretroviral era, but this may stem, in part, from treatment disparities. Early detection of lung cancer using chest computed tomography (CT) is being increasingly adopted for smokers in the general population, and recent studies suggest that it may be safe and efficacious in HIV-infected smokers.

SUMMARY

Lung cancer is an important complication associated with chronic HIV infection. It is associated with unique HIV-related causal mechanisms, and may be associated with worse outcomes in some HIV-infected persons. Smoking cessation and early cancer detection with chest CT are likely to benefit HIV-infected smokers.

Virologic and immunologic aspects of HIV-hepatitis C virus coinfection

HIV/hepatitis C virus (HCV) coinfection is estimated to affect 2 million individuals globally. The acceleration of HCV-associated complications, particularly hepatic fibrosis, because of HIV coinfection has been well established, whereas the impact of HCV on HIV progression remains unclear. In this review, we summarize the current evidence on the impact of coinfection on the transmission and clinical progression of each infection. We focus on the virological and immunological alterations that contribute to HIV and HCV pathogenesis in coinfection and also review the disease-modifying effects of antiretroviral therapy as they pertain to HCV.

Lung Malignancies in HIV Infection

Pulmonary malignancies are a major source of morbidity and mortality in HIV-infected persons. Non-AIDS-defining lung cancers (mostly non-small cell lung cancers) are now a leading cause of cancer death among HIV-infected persons. HIV-associated factors appear to affect the risk of lung cancer and may adversely impact cancer treatment and outcomes. HIV infection also may modify the potential harms and benefits of lung cancer screening with computed tomography. AIDS-defining lung malignancies include pulmonary Kaposi sarcoma and pulmonary lymphoma, both of which are less prevalent with widespread adoption of antiretroviral therapy.

Impact of non-oncological factors on tumor recurrence after liver transplantation in hepatocellular carcinoma patients

Hepatocellular carcinoma (HCC) is the most common primary neoplasm of the liver and is one of the leading causes of cancer-related death worldwide. Liver transplantation (LT) has become one of the best curative therapeutic options for patients with HCC, although tumor recurrence after LT is a major and unaddressed cause of mortality. Furthermore, the factors that are associated with recurrence are not fully understood, and most previous studies have focused on the biological properties of HCC, such as the number and size of the HCC nodules, the degree of differentiation, the presence of hepatic vascular invasion, elevated serum levels of alpha-fetoprotein, and the tumor stage outside of the Milan criteria. Thus, little attention has been given to factors that are not directly related to HCC (i.e., “non-oncological factors”), which have emerged as predictors of tumor recurrence. This review was performed to assess the effects of non-oncological factors on tumor recurrence after LT. The identification of these factors may provide new research directions and clinical strategies for the prophylaxis and surveillance of tumor recurrence after LT, which can help reduce recurrence and improve patient survival.

Lung cancer in HIV-infected patients in the combination antiretroviral treatment era

The advent of combination antiretroviral treatment (cART) has been followed by a decrease in HIV-associated morbidity and mortality, but also by an apparent increase in the incidence of non-AIDS-defining cancers (NADCs). The risk of lung cancer is substantially higher in HIV-infected patients than in the general population, in part due to aging and tobacco use, and it is the most frequent NADC. The management of lung cancer in HIV-infected patients has some peculiarities that need to be taken into account. This review focuses on the epidemiology, risk factors, and clinical management of lung cancer in HIV-infected patients. In addition, screening tools and future perspectives are also discussed.

Impact of HIV on lung tumorigenesis in an animal model

Many HIV patients on antiretroviral therapy have controlled viremia and restored (albeit partially) immunity. Yet, they have high rates of lung cancer, even after controlling for smoking. We tested the hypothesis that HIV proteins accelerate development/progression of lung cancer in an immunocompetent HIV transgenic mouse model. The expression of HIV proteins did not enhance lung tumorigenesis caused by two different tobacco carcinogens, suggesting that incompletely restored immunity and/or inflammation, which persist(s) in most HIV patients despite controlled viremia, underlie(s) excess risk of lung cancer. Adjuvant therapies that restore immunity and lower inflammation may decrease lung cancer mortality in HIV patients.

Factors contributing to risk for cancer among HIV-infected individuals, and evidence that earlier combination antiretroviral therapy will alter this risk

PURPOSE OF REVIEW

To critically appraise recent published literature about factors associated with cancer risk likely to be influenced by combination antiretroviral therapy (cART) in HIV-infected individuals, and the potential of earlier cART initiation to reduce this risk.

RECENT FINDINGS

Factors leading to increased risk of non-AIDS-defining malignancies (NADMs) in particular remain poorly understood. Immunodeficiency appears to be key, whereas evidence is emerging that a direct pro-oncogenic effect of HIV, activated inflammatory and coagulation pathways, and cART toxicity may also contribute. By reducing HIV replication, improving immune function, and limiting chronic inflammation, cART initiation at higher CD4 cell counts may, therefore, reduce NADM risk. However, cART only partly normalizes enhanced inflammation and coagulation seen during HIV infection and conflicting laboratory and epidemiological data have been reported as to whether (and how) cART affects NADM risk. Furthermore, secondary analyses of randomized controlled trials comparing early versus delayed cART initiation were inconclusive.

SUMMARY

Continuous epidemiological surveillance is warranted to monitor trends in cancer incidence among HIV-infected individuals and to better understand the impact of earlier cART on NADM risk. The role of adjuvant anti-inflammatory or antithrombotic therapies to reduce cancer risk deserves further investigation.

HIV-1 Nef is transferred from expressing T cells to hepatocytic cells through conduits and enhances HCV replication

HIV-1 infection enhances HCV replication and as a consequence accelerates HCV-mediated hepatocellular carcinoma (HCC). However, the precise molecular mechanism by which this takes place is currently unknown. Our data showed that infectious HIV-1 failed to replicate in human hepatocytic cell lines. No discernible virus replication was observed, even when the cell lines transfected with HIV-1 proviral DNA were co-cultured with Jurkat T cells, indicating that the problem of liver deterioration in the co-infected patient is not due to the replication of HIV-1 in the hepatocytes of the HCV infected host. Instead, HIV-1 Nef protein was transferred from nef-expressing T cells to hepatocytic cells through conduits, wherein up to 16% (average 10%) of the cells harbored the transferred Nef, when the hepatocytic cells were co-cultured with nef-expressing Jurkat cells for 24 h. Further, Nef altered the size and numbers of lipid droplets (LD), and consistently up-regulated HCV replication by 1.5∼2.5 fold in the target subgenomic replicon cells, which is remarkable in relation to the initially indolent viral replication. Nef also dramatically augmented reactive oxygen species (ROS) production and enhanced ethanol-mediated up-regulation of HCV replication so as to accelerate HCC. Taken together, these data indicate that HIV-1 Nef is a critical element in accelerating progression of liver pathogenesis via enhancing HCV replication and coordinating modulation of key intra- and extra-cellular molecules for liver decay.

Pros and cons of liver transplantation in human immunodeficiency virus infected recipients

Before the introduction of combined highly active antiretroviral therapy, a positive human immunodeficiency virus (HIV) serological status represented an absolute contraindication for solid organ transplant (SOT). The advent of highly effective combined antiretroviral therapy in 1996 largely contributed to the increased demand for SOT in HIV-positive individuals due to increased patients’ life expectancy associated with the increasing prevalence of end-stage liver disease (ESLD). Nowadays, liver failure represents a frequent cause of mortality in the HIV-infected population mainly due to coinfection with hepatitis viruses sharing the same way of transmission. Thus, liver transplantation (LT) represents a reasonable approach in HIV patients with stable infection and ESLD. Available data presently supports with good evidence the practice of LT in the HIV-positive population. Thus, the issue is no longer “whether it is correct to transplant HIV-infected patients”, but “who are the patients who can be safely transplanted” and “when is the best time to perform LT”. Indeed, the benefits of LT in HIV-infected patients, especially in terms of mid- and long-term patient and graft survivals, are strictly related to the patients’ selection and to the correct timing for transplantation, especially when hepatitis C virus coinfection is present. Aim of this article is to review the pros and cons of LT in the cohort of HIV infected recipients.

Hepatocellular cancer in HIV-infected individuals: tomorrow’s problem?

A number of cancers occur with increased frequency in individuals with HIV infection. There is a debate as to whether or not hepatocellular cancer is one of these tumors. This article reviews the current data regarding incidence etiology, treatment and outcome for HIV-related hepatocellular cancer. It also attempts to predict future areas of importance in the management of these patients in the era of highly active antiretroviral therapy.

Non-AIDS-defining cancers among HIV-infected patients

In the highly active antiretroviral therapy (HAART) era, the incidence of non-AIDS-defining cancers (NADC) has increased and contributes to a growing proportion of mortality in the aging HIV-infected population. The underlying pathogenic mechanisms of increased cancer risk are incompletely understood. Potential contributors include oncogenic effects of the HIV virus, immunosuppression, chronic inflammation and immune activation, exposure to HAART, higher rates of oncogenic viral coinfections and traditional cancer risk factors. HIV-infected patients often present with NADC at younger ages with more aggressive or advanced stage disease. However, when standard cancer therapy is given, treatment outcomes appear similar to the non-HIV population. These facts highlight the importance of clinicians' maintaining a high index of suspicion, performing age-appropriate screening, and optimizing cancer therapy. Development of novel strategies for screening, prevention, and treatment of NADC will be required to reverse these epidemiologic trends and improve the survival of HIV-infected patients.

Multicenter italian experience in liver transplantation for hepatocellular carcinoma in HIV-infected patients

BACKGROUND

The aim of our work is to assess the clinical outcomes of liver transplantation (LT) for hepatocellular carcinoma (HCC) in HIV-coinfected patients. This is a multicenter study involving three Italian transplant centers in northern Italy: University of Modena, University of Bologna, and University of Udine.

PATIENTS AND METHODS

We compared 30 HIV-positive patients affected by HCC who underwent LT with 125 HIV-uninfected patients who received the same treatment from September 2004 to June 2009. At listing, there were no differences between HIV-infected and -uninfected patients regarding HCC features. Patients outside the University of California, San Francisco criteria (UCSF) were considered eligible for LT if a down-staging program permitted a reduction of tumor burden.

RESULTS

HIV-infected patients were younger, they were more frequently anti-HCV positive, and a higher number of HIV-infected patients presented a coinfection HBV-HCV. Pre-LT treatments (liver resection and or locoregional treatments) were similar between the two groups. Histological characteristics of the tumor were similar in patients with and without HIV infection. No differences were observed in terms of overall survival and HCC recurrence rates.

CONCLUSION

LT for HCC is a feasible procedure and the presence of HIV does not particularly affect the post-LT outcome.

Hepatitis B virus / human immunodeficiency virus co-infection and its hepatocarcinogenic potential in sub-saharan black africans

CONTEXT

Since the introduction of highly active anti-retroviral regimen for human immunodeficiency virus-1 infection, a significant increase in the incidence of hepatocellular carcinoma has been reported in patients already chronically infected with hepatitis B virus and then given this form of regimen for their retroviral infection.

EVIDENCE ACQUISITION

This phenomenon was initially attributed to the far more prolonged survival of those patients who received this new regimen, which provided sufficient time, allowing hepatitis B virus-induced hepatocellular carcinoma to develop.

RESULTS

The current belief is that the increased incidence of hepatocellular carcinoma is because of co-infection with the two viruses, one known to be hepatocarcinogenic and the other suspected to increase the carcinogenic potential of the other. Because both hepatitis B virus and human immunodeficiency virus -1 are endemic in the Black population of sub-Saharan Africa and are transmitted in similar ways, as many as 20% of this population are co-infected with the two viruses. In this way, the already high risk of Black African patients developing hepatitis B virus-induced hepatocellular carcinoma is further increased.

CONCLUSIONS

The pathogenetic mechanism or mechanisms involved in the carcinogenic interaction between the hepatitis B virus and the human immunodeficiency virus-1 in sub-Saharan Black Africans and other populations co-infected with these viruses have yet to be determined.

Increasing incidence of hepatocellular carcinoma in HIV-infected patients in Spain

BACKGROUND

To report the clinical and epidemiological characteristics of hepatocellular carcinoma (HCC) diagnosed in a cohort of human immunodeficiency virus (HIV)-infected patients in Spain.

METHODS

All HIV-infected patients diagnosed of HCC in 18 hospitals in Spain before 31 December 2010 were included. The main characteristics of HCC cases are described and comparisons between cases according to the year of diagnosis are presented.

RESULTS

Eighty-two cases of HCC in HIV-infected patients were included, all of them related to viral hepatitis coinfection: hepatitis C virus (HCV) in 66 (81%), hepatitis B virus (HBV) in 6 (7%), and HBV/HCV in 10 (12%). From 1999, when the first case of HCC was diagnosed, a progressive increment in the incidence of HCC in the cohort has occurred. In patients coinfected with HIV/HCV-coinfected patients, the incidence HCC increased from 0.2 to 2.8 cases per 1000 person-years between 2000 and 2009. Death occurred in 65 patients (79%), with a median survival of 91 days (interquartile range, 31-227 days). Three of 11 patients (28%) who received potentially curative therapy died, compared with 62 of 71 patients (87%) who did not receive curative therapy (P = .0001). Compared with cases of HCC diagnosed before 2005, cases diagnosed later did not show a higher survival rate.

CONCLUSIONS

HCC is an emerging complication of cirrhosis in HIV-infected patients. A sharp increase in its incidence has occurred in those also infected by HCV in the recent years. Unfortunately, HCC is frequently diagnosed at an advanced stage, and mortality continues to be very high, with no significant changes in recent years. Earlier diagnosis, which may allow potentially curative therapy, is necessary.

The rising challenge of non-AIDS-defining cancers in HIV-infected patients

Since the advent of HAART, patients with HIV infection have seen a significant improvement in their morbidity, mortality, and life expectancy. The incidence of AIDS-defining illnesses, including AIDS-defining malignancies, has been on the decline. However, deaths due to non-AIDS-defining illnesses have been on the rise. These so-called non-AIDS-defining cancers (NADCs) include cancers of the lung, liver, kidney, anus, head and neck, and skin, as well as Hodgkin's lymphoma. It is poorly understood why this higher rate of NADCs is occurring. The key challenge facing oncologists is how to administer chemotherapy effectively and safely to patients on antiretroviral therapy. The challenge to clinicians caring for HIV-infected patients is to develop and implement effective means to screen, treat, and prevent NADCs in the future. This review presents data on the epidemiology and etiology of NADCs, as well as ongoing research into this evolving aspect of the HIV epidemic.

University of Modena experience in HIV-positive patients undergoing liver transplantation

INTRODUCTION

Highly effective antiretroviral therapy in the last decade has increased the survival rates of HIV-positive patients, yielding a greater number of HIV patients suffering from liver-related disease. Liver transplantation (LT) is the only curative treatment for end-stage liver disease (ESLD) associated or not with hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

From June 2003 to September 2010, 23 patients underwent cadaveric donor LT for ESLD at our institution. Inclusion criteria followed the Italian Protocol for LT in HIV-positive patients. Immunosuppressive regimens were based on cyclosporine or tacrolimus, eventually switched to Rapamycin.

RESULTS

The median CD4 T-cell count was 275/mmc (range=119-924). All patients were affected by ESLD, which was associated with HCC in 14 cases. Ten patients were within the Milan criteria and four patients exceeded them but were within the San Francisco criteria. Conversion from calcineurin inhibitors (CNI) to rapamycin occurred in ten cases. Hepatitis C virus (HCV) recurrence occurred in 13/21 HCV-positive patients. Acute cellular rejection occurred in eight patients with one developing chronic cellular rejection. Overall patient and graft survivals at 80 months were 50% and 45% respectively.

DISCUSSION

LT in HIV-positive patients is a feasible procedure, even if in our experience was burdened by a greater incidence of complications including HCV recurrence and infection compared with HIV-negative patients.

Increasing burden of liver disease in patients with HIV infection

Introduction of effective combined antiretroviral therapy has made HIV infection a chronic illness. Substantial reductions in the number of AIDS-related deaths have been accompanied by an increase in liver-related morbidity and mortality due to co-infection with chronic hepatitis B and C viruses. Increases in non-alcoholic fatty liver disease and drug-induced hepatotoxicity, together with development of hepatocellular carcinoma, also potentiate the burden of liver disease in individuals with HIV infection. We provide an overview of the key causes, disease mechanisms of pathogenesis, and recommendations for treatment options including the evolving role of liver transplantation.

Hepatocellular carcinoma in African Blacks: Recent progress in etiology and pathogenesis

Occult hepatitis B virus (HBV) infection was shown to be present in 75% of Black Africans with hepatocellular carcinoma (HCC) in whom the tumor was hitherto not thought to be caused by chronic HBV infection. The association between chronic HBV infection and the development of the tumor is thus even closer than was originally thought. HBV viral load was found to be significantly higher in patients with HCC than in Black African controls. As in other populations, HBV e antigen-positive patients with hepatocellular carcinoma had significantly higher viral loads than patients negative for this antigen. The significance of this finding is discussed. The risk for HCC development with genotype A of HBV, the predominant genotype in African isolates, has not been investigated. Genotype A was shown to be 4.5 times more likely than other genotypes to cause HCC in Black Africans, and tumours occurred at a significantly younger age. Increasing numbers of patients with human immunodeficiency virus (HIV) and HBV co-infection are being reported to develop HCC. A preliminary case/control comparison supports the belief that HIV co-infection enhances the hepatocarcinogenic potential of HBV. A study from The Gambia provides the first evidence that dietary exposure to aflatoxin B(1) may cause cirrhosis and that this may play a contributory role in the pathogenesis of aflatoxin-induced HCC. An animal model has provided experimental support for the clinical evidence that dietary iron overload in the African is directly hepatocarcinogenic, in addition to causing the tumor indirectly through the development of cirrhosis.

HCV/ HIV co-infection: time to re-evaluate the role of HIV in the liver?

Because of major advances in the treatment of HIV/AIDS, HIV-positive persons now live longer, healthier lives; however, hepatitis C virus (HCV) is increasingly recognized as a major cause of morbidity and mortality in this population. Among HCV-infected persons, HIV co-infection is associated with increased HCV RNA levels, increased hepatic inflammation and fibrosis, and more rapid progression to cirrhosis and end-stage liver disease. Compounding this problem are reduced HCV treatment response rates among HCV/HIV co-infected persons. Moreover, antiretroviral therapy used to suppress HIV replication is often associated with a paradoxical increase in HCV RNA levels, as well as hepatotoxicity. Despite the adverse clinical consequences of HCV/HIV co-infection, the mechanisms by which these two viruses interact at the cellular level remain largely unexplored. This review focuses on the evidence demonstrating direct infection of hepatocytes by HIV, as well as the indirect mechanisms by which HIV may regulate HCV replication at the cellular level. A comprehensive understanding of virus-virus and virus-cell interactions is critical to the development of novel treatment strategies to combat HCV/HIV co-infection.

First-time use of bevacizumab for aggressive, metastatic hepatocellular carcinoma in an HIV/hepatitis B virus coinfected patient: a case report

We present a case of an HIV-1 infected patient with history of chronic hepatitis B and chronic alcohol use without cirrhosis, who presented with aggressive hepatocellular carcinoma with multiple metastases. Systemic chemotherapy combined with use of bevacizumab (anti-vascular endothelium growth factor monoclonal antibody) was without effect and the patient succumbed to his disease within few weeks. To our knowledge, this is the first report in the English literature of bevacizumab use for metastatic hepatocellular carcinoma in HIV-infected patients.

Different Effects of Regulatory Genes (tat, nef) of Human Immunodeficiency Virus Type 1 (HIV-1) on the Proliferation and Differentiation of Mouse Embryonic Stem Cells in vitro

To examine the effects of the tat and nef regulatory genes of human immunodeficiency virus (HIV-1) on cell differentiation we used the mouse embryonic stem cells (ESC) as a model. Proliferation, embryoid bodies (EB) formation and subsequent differentiation into cardiomyocytes, glial and neuronal cells were investigated in ESC lines transfected with these genes. It has been shown that the transfection of ESC by the tat gene increased their proliferating activity, whereas the nef gene transfected ESC showed its decrease. The number of embryoid bodies formed was higher in the cultures of ESC transfected by the nef and lower in the cells transfected by the tat in comparison with controls. The percentage of embryoid bodies with contracting cardiomyocytes was higher against control in the nef transfected cells and lower in ESC transfected with the tat. There were no reliable differences in the appearance of glial cells between control and the nef and tat transfected cell lines. Spontaneous differentiation of ESC into neuronal cells was almost not observed in the nef transfected cells, in contrast to control and the tat transfected cells. However, addition of retinoic acid (RA) to the nef transfected cells caused even a slight increase in neuron formation as compared to control ESC treated with RA. Thus, for the first time we have shown that the tat and nef regulatory genes of HIV-1 had a visible effect on proliferation of ESC and some first steps of their differentiation. In general, the reverse correlation between the effects of these two viral genes on ESC proliferation and differentiation were observed.

Understanding the pathogenesis and management of hepatitis B/HIV and hepatitis B/hepatitis C virus coinfection

The approach to the hepatitis B virus (HBV)-infected patient who is also infected with HIV or hepatitis C virus (HCV) is very different from the approach to the patient with only one virus infection. HBV/HIV coinfection is common. Agents that have dual activity against HBV and HIV should be considered as treatment of choice in combination regimens in HBV/HIV-coinfected patients beginning antiretroviral therapy. In HBV/HCV coinfection HCV usually tends to predominate over HBV. More investigation is needed into the mechanisms by which viral pathogenesis is altered and the optimal treatment modalities for coinfected patients.

HIV-HBV and HIV-HCV coinfection and liver cancer development

Liver diseases caused by chronic HBV or HCV infection, including cirrhosis and HCC, are emerging as an increasingly important problem faced by millions of HIV-infected patients who are coinfected with HBV or HCV. On one hand, HIV-induced immune suppression enhances the risk of chronic viral hepatitis, increases HBV or HCV load, and may hasten the progression to cirrhosis and liver cancer. On the other hand, significant hepatotoxicity is associated with a number of antiretroviral drugs, further exacerbating liver damage associated with chronic viral hepatitis. The exact risk of HCC in HIV and HBV or HCV coinfected patients remains to be fully assessed. The elucidation of the multiple virus-virus and virus-host interactions that underlie viral hepatocarcinogenesis and potential HIV enhancement awaits the establishment of appropriate in vitro and in vivo model systems. As millions of HIV-infected patients in the developing countries are gaining access to HAART therapy for their HIV infections, endemic HBV and HCV infections and their associated liver diseases will only become more problematic on a global level. To ameliorate the suffering from HBV- and HCV-induced liver cancer in HIV patients, more effective treatment for chronic HBV and HCV infections are needed. The long time frame of viral hepatocarcinogenesis may afford a window of opportunity to develop and improve such treatment.

Hepatocellular carcinoma in HIV patients treated by liver transplantation

INTRODUCTION

Several reports have shown the effectiveness of liver transplantation (LT) as a therapeutic option in HIV-patients affected by end-stage liver disease. HCC on cirrhosis is another major indication for LT. However, no reports, to our knowledge, have been published as yet addressing the important questions of indications and outcome of LT in HIV-patients with HCC, mainly because of concerns regarding a more aggressive course of HCC with respect to HCC seen in HIV-negative individuals.

METHODS

The aim of this report is to focus on indications, preliminary results and complications of LT in a group of 7 HIV-patients who underwent LT at our department for HCC on cirrhosis.

RESULTS

Indications to listing HIV-patients were HCC using the internationally accepted Milan criteria. All patients were HBV-and/or HCV-infected. The mean CD4+ cell-count was 249 (range 144-353), and the HIV-RNA load was undetectable in all but one case. After a mean follow-up period of 232days (range 33-774), no recurrence of HCC was seen; one patient died.

CONCLUSION

Characteristics of the study protocol, the patients, virological and immunological features, tumor stage and pre-transplantation treatment, complications and survival are herein described in an effort to provide new insights into methodology for an aggressive management of HCC in HIV patients, and possibly give a greater chance of cure.

Natural history of chronic hepatitis B in co-infected patients

HIV co-infection influences the course and natural history of hepatitis B virus (HBV) infection by impairing the quantity and quality of the innate and adaptive immune response. The rates of spontaneous resolution after acute infection and spontaneous anti-HBe and anti-HBs seroconversions are decreased, and levels of HBV replication are increased in HIV-infected patients. A more rapid progression of liver fibrosis and a higher rate of cirrhosis decompensation (but not hepatocellular carcinoma) have been demonstrated in co-infected patients. The risk of HBV-associated end-stage liver disease and liver-related mortality may be increased by HIV co-infection. Antiretroviral therapy may trigger spontaneous anti-HBe and anti-HBs seroconversion and/or a better immune control of HBV replication by restoring adaptive immunity, but can also increase hepatitis flares. Reactivation of chronic hepatitis B has been observed after suspension of anti-retrovirals with anti-HBV activity or after occurrence of HBV resistance to lamivudine. Future research should focus on: the impact of HIV-induced changes in innate and adaptive immune response and modifications induced by anti-retroviral therapy that may impact on progression of advanced chronic hepatitis B; the association between HBV genotype and clinical course of disease; and the role of occult HBV infection as a co-factor with other causes of liver injury.

Different roles of Sp family members in HIV-1 Tat-mediated manganese superoxide dismutase suppression in hepatocellular carcinoma cells

The expression of manganese superoxide dismutase (MnSOD) is regulated by agents associated with cancer development. It has been shown that infection with the human immunodeficiency virus type 1 (HIV-1) is associated with the development of liver cancer and that the transactivating transcriptional factor (Tat) of human HIV-1 reduces the expression of MnSOD in several cell types. However, the role of Tat in the expression of MnSOD in hepatocellular carcinoma is unknown. Furthermore, the precise mechanisms whereby Tat suppresses MnSOD expression in hepatocellular carcinoma cells remain unclear. In this report, we build on our original observations that Tat changes the distribution of Sp family members on the MnSOD promoter, which accounts for Tat-dependent changes in basal expression. In hepatic cells, Tat expression upregulates Sp1/Sp3, which play different roles in regulating MnSOD transcription. While overexpression of Sp1 stimulates, overexpression of Sp3 represses transcriptional activity. The transcription repression effect of Sp3 is not due to Sp3 competing for the binding site with Sp1 because only the full-length Sp3 but not the truncated Sp3 suppresses MnSOD promoter activity. These findings suggest a novel mechanism by which Tat modulates the repression of the MnSOD gene and establish a link between HIV infection and liver cancer.

Increased incidence of hepatocellular carcinoma (HCC) in HIV-1 infected patients

BACKGROUND: The likely increased incidence of hepatocarcinoma (HCC) in HIV-1 infected patients has not yet been demonstrated. METHODS: We studied all cases of HCC occurring in HIV-1 infected patients in our hospital during the past 15 years. Incidence and survival time were compared with those of the general population in the same area and the same time of the study. RESULTS: We found 6 cases of HCC in a cohort of 2383 HIV-1 infected patients between 1986 and 2001. This is a higher than expected incidence rate of HCC compared with the general population, with a standardized incidence ratio of 13.95. Chronic hepatitis virus infection and alcohol abuse were present in four and two cases, respectively. In one patient, no liver disease was known before the HCC and the surrounding liver was normal in the necropsy study. CONCLUSION: The improved survival of patients on highly active antiretroviral treatment (HAART) and the increasing incidence of end-stage liver disease in these patients caused by chronic hepatitis virus infection and alcohol abuse may be responsible for an increase in the incidence of HCC in HIV-1 infected patients.

Hepatocellular carcinoma in HIV-infected patients: epidemiological features, clinical presentation and outcome

OBJECTIVE

Hepatocellular carcinoma (HCC) is an increasing cause of mortality in HIV-seropositive individuals. The aim of the study was to compare the main features of HCC in HIV-seropositive individuals with those in to HIV-negative patients.

PATIENTS AND METHODS

All HIV-infected subjects with a diagnosis of HCC included in three cancer registry databases were enrolled in the study as cases. HCC cases that occurred in the province of Brescia, North Italy, in the period 1995-1998 and all cases reported at the Italian Liver Cancer Project were enrolled as controls. All data were collected using a standardized case report form. The main clinical and epidemiological characteristics of patients with HCC and their survival were compared between HIV-positive and uninfected subjects.

RESULTS

Forty-one HIV-infected subjects with HCC were identified. Multivariate analysis adjusted for age and sex identified an association between HIV infection and HCV infection [odds ratio (OR), 11; P = 0.005], and infiltrating tumours and/or extranodal metastasis at presentation (OR = 11.8; P < 0.001). HIV infection was independently associated with shorter survival (hazard ratio, 1.63; P = 0.015).

CONCLUSIONS

HCC in HIV-infected patients is mainly associated with underlying chronic hepatitis C and has a more aggressive clinical course. Thus, preventative strategies (including the treatment of hepatitis C) should be implemented in the management of HIV/HCV-coinfected patients.

Prevalence of liver tumours in HIV-1 tat-transgenic mice treated with urethane

The human immunodeficiency virus type 1 (HIV-1) Tat protein stimulates cell proliferation, inhibits apoptosis, displays angiogenic functions and is believed to be involved in the pathogenesis of Kaposi's sarcoma (KS) and other tumours arising in AIDS patients. Tat-transgenic (TT) mice, which constitutively express Tat in all tissues and organs, may therefore be predisposed to tumorigenesis. To test this hypothesis, we treated TT mice with urethane, a general carcinogen inducing tumours of various organs. The results indicate that, after injection of urethane, the incidence of lung tumours and lymphomas is not significantly different in the TT and control (CC) mice, whereas liver preneoplastic lesions and tumours show a significantly greater incidence in TT than in CC mice. This remarkable carcinogenic effect of urethane for the liver may be due to a tat-induced predisposition, manifested as a liver cell dysplasia (LCD), spontaneously affecting most of the TT mice. LCD may exert a promoting effect by stimulating proliferation of cell clones initiated by the mutagenic effect of urethane. In addition, LCD, which is associated with aneuploidy and chromosome instability, may enhance the progression to malignancy of the preneoplastic lesions induced by urethane. Interestingly, a significantly greater incidence of vascular ectasias and haemangiomas was detected in the liver of urethane-treated TT mice, most likely due to the marked angiogenic properties of Tat. This study suggests a role for Tat in the promotion and progression of tumours initiated by exogenous and endogenous carcinogens in HIV-1-infected patients, thereby contributing to the tumorigenesis in the course of AIDS.

Heterogeneity of toxicant response: sources of human variability

While risk assessment models attempt to predict human risk to toxicant exposure, in many cases these models cannot account for the wide variety of human responses. This review addresses several primary sources of heterogeneity that may affect individual responses to drug or toxicant exposure. Consideration was given to genetic polymorphisms, age-related factors during development and senescence, gender differences associated with hormonal function, and preexisting diseases influenced by toxicant exposure. These selected examples demonstrate the need for additional steps in risk assessment that are needed to more accurately predict human responses to toxicants and drugs.

Liver pathology and hepatocarcinogenesis in a long-term mouse model of erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is an inherited disease of haem synthesis caused by a mutation in one of the alleles of the enzyme ferrochelatase. This mutation leads to partial deficiency of the enzyme, resulting in increased concentrations of protoporphyrin (PP) in blood, liver, and faeces. Five to ten per cent of patients with EPP develop severe liver disease characterized by the presence of PP deposits. This study used histochemistry and immunohistochemistry to investigate the histopathological features present in the livers of 44 mice with a heterozygous or homozygous point mutation in the ferrochelatase gene (fch/+ and fch/fch mice, respectively). Some fch/+ mouse livers showed mixed steatosis and large cell dysplasia. The livers of fch/fch mice showed periportal or septal fibrosis accompanied by an atypical ductular reaction. These findings suggest that the obstruction and damage of a proportion of large and small bile ducts by PP deposits cause an accumulation of PP in the parenchyma, which leads to damage and loss of hepatocytes due to the toxic effects of PP. The classical stages of hepatocarcinogenesis were observed and hepatic progenitor cells appear to be involved in this process. PP acts as the promoting agent and is probably also the initiating agent.