HIV and Hepatitis C Virus: Facts and Controversies

Systematic review and meta-analysis of hepatitis C virus infection and HIV viral load: new insights into epidemiologic synergy

INTRODUCTION

Hepatitis C virus (HCV) and HIV infection frequently co-occur due to shared transmission routes. Co-infection is associated with higher HCV viral load (VL), but less is known about the effect of HCV infection on HIV VL and risk of onward transmission.

METHODS

We undertook a systematic review comparing 1) HIV VL among ART-naïve, HCV co-infected individuals versus HIV mono-infected individuals and 2) HIV VL among treated versus untreated HCV co-infected individuals. We performed a random-effects meta-analysis and quantified heterogeneity using the I(2) statistic. We followed Cochrane Collaboration guidelines in conducting our review and PRISMA guidelines in reporting results.

RESULTS AND DISCUSSION

We screened 3925 articles and identified 17 relevant publications. A meta-analysis found no evidence of increased HIV VL associated with HCV co-infection or between HIV VL and HCV treatment with pegylated interferon-alpha-2a/b and ribavirin.

CONCLUSIONS

This finding is in contrast to the substantial increases in HIV VL observed with several other systemic infections. It presents opportunities to elucidate the biological pathways that underpin epidemiological synergy in HIV co-infections and may enable prediction of which co-infections are most important to epidemic control.

GS-9669: a novel non-nucleoside inhibitor of viral polymerase for the treatment of hepatitis C virus infection

Hepatitis C virus (HCV) is an RNA virus that chronically infects 2-3% of the world's population. About 25% of these chronic carriers evolve towards liver cirrhosis, a disease that is significantly associated with reduced survival and quality of life. Antiviral therapy can eradicate the infection - a process that is associated with a reduced disease progression rate. Several oral direct agents have been developed and tested for the treatment of HCV infection. This review focuses on the mechanism of action, pharmacokinetics, efficacy, safety and resistance of GS-9669, a non-nucleoside inhibitor of viral polymerase, active against HCV genotype 1. In combination with other oral antivirals, GS-9669 results: in very high rates of viral eradication (90-100%) in patients with HCV genotype 1 infection, with a good tolerability and safety profile. In conclusion, GS-9669 is a good candidate to be used in interferon-free combinations for the treatment of chronic HCV infection.

Research Note: Perspectives on the Hierarchy of HIV and Hepatitis C Disease: Consequences for Drug Treatment Program Patients

Injection drug users (IDUs) face an increased risk of acquiring blood borne viral infections, including HIV and the hepatitis C virus (HCV). However, the discrepancy in funding for services to address these two diseases has implications. Although drug treatment programs have played an important role in fighting HIV/AIDS, the HCV-related services offered at these programs remain limited. Research from other countries suggests that drug users view HCV as less important than HIV, yet little is known about the extent to which our society's focus on HIV has been adopted within the drug treatment program culture. This qualitative study examines the perceptions of both staff (n = 165) and clients (n = 215) at these programs with regard to HIV and HCV and presents data on how staffs' attitudes toward HCV changed after participating in an HCV training. Clients described a services landscape at drug treatment programs that favors HIV services over those targeting HCV.

Effect of hepatitis C infection on progression of HIV disease and early response to initial antiretroviral therapy

OBJECTIVES

To describe the effect of hepatitis C virus (HCV) on the progression of HIV disease and on early changes in the CD4 cell count and HIV viral load after HAART initiation.

DESIGN AND METHODS

Data were from a longitudinal medical records review project conducted in over 100 US medical clinics from 1998 to 2004. We analysed data from HIV-infected patients who received antiretroviral therapy (ART), calculated adjusted hazard ratios describing the hazard of death or progression to an AIDS-defining opportunistic illness (AIDS-OI) associated with prevalent HCV infection, and estimated the change in CD4 cell count and HIV viral load after HAART initiation, stratified by HCV status.

RESULTS

A total of 10 481 HIV-infected individuals were followed for a median of 1.9 years; 19% had HCV. HCV infection was not associated with progression to AIDS-OI or death after controlling for important confounding conditions. Factors significantly confounding the risk of both death and diagnosis of an AIDS-OI were alcoholism, drug-induced hepatitis, and the type of ART prescribed. Acute and chronic hepatitis B infection confounded the risk of AIDS-OI diagnosis. During the 12 months after starting HAART, proportional increases in CD4 cell counts did not differ between HCV-infected and HCV-uninfected individuals. Likewise, the short-term change in viral load did not differ.

CONCLUSION

In our cohort, HCV did not increase the risk of death or AIDS-OI, and did not affect the early immunological or virological response to initial HAART. Clinicians should evaluate patients with HCV for other, manageable problems, including alcoholism and other viral hepatitis.

Vertically acquired paediatric coinfection with HIV and hepatitis C virus

Both HIV and hepatitis C virus (HCV) can be transmitted from mother to child during pregnancy and delivery. Vertical transmission of HIV and HCV separately is most likely from HIV/HCV-coinfected mothers; however, transmission of both infections is less frequent. The effect of HCV coinfection on HIV-related disease remains unclear; whereas most studies indicate no effect, recent results suggest HCV in adults accelerates HIV progression. Little is known about how HIV coinfection affects HCV progression in children and the information available is based on small numbers of patients. Paediatric HIV treatment is extremely successful and it is vital to determine if HCV coinfection alters the effectiveness of this treatment. The hepatotoxicity of many HIV therapies and the possible negative impact of HCV on this treatment, alongside the interactions and contraindications of many HIV and HCV therapies, further limits the choice of paediatric treatments for coinfected children. Future research must therefore focus on vertically acquired HIV/HCV coinfection to inform treatment trials addressing coinfection management.

Integrating hepatitis C services into existing HIV services: the experiences of a sample of U.S. drug treatment units

Hepatitis C virus (HCV) is the most prevalent blood-borne infectious disease in the United States, especially among drug users, and coinfection with HIV is common. Because drug users are often medically underserved, drug treatment units are important sites of opportunity for providing services for these infectious diseases. Given the commonalities in the routes of transmission of HIV and HCV, and the fact that many drug treatment units have established an infrastructure to provide HIV services, some have suggested integrating HCV services into those already established for HIV. Using data collected in a telephone survey with 89 drug treatment units throughout the United States, this paper examines the extent to which drug treatment units have expanded their HIV services to include those for HCV, and the extent to which this expansion was facilitated by having HIV services in place. Overall, a greater proportion of methadone maintenance than drug-free treatment units provided services for HIV and HCV. The majority of units in both modalities that provided HIV- and HCV-related services expanded their HIV service delivery to include similar HCV services, and one third expanded all of their HIV services. A large number of these units, however, indicated that having an HIV service infrastructure did not facilitate this expansion, often because the units wanted to emphasize differences in the two viral infections. Policy makers and individual treatment units need to develop strategies that capitalize on existing infrastructures while maintaining the distinction between HIV and HCV primary and secondary prevention efforts.

Clinical laboratory assessment of hepatitis C and HIV coinfected patients according to the antiretroviral therapy received

During the year of 2001, a retrospective, descriptive study in order to determine the influence of the antiretroviral therapy received by 111 HIV-HCV coinfected patients who had undergone at least one liver biopsy was conduced, 74 of them were treated with a protease inhibitor regimen (WPI), and 37 with a non-protease inhibitor regimen (NPI). The main characteristics found were: a young patient population (mean age 41 years old in both groups), composed in most part of male individuals (74.3% WPI and 51.4% NPI) with previous risk factors for both infections (WPI 93.2% and NPI 89.2%). The most significant findings included AIDS-defining disease (WPI 18.9% and NPI 13.5% of the cases), elevated hepatic enzyme levels (WPI: SGOT 52.1 and NPI 53.2), absence of liver disease-related symptoms (16.2% for both groups), average CD4 count > 350 for both groups (WPI 362.2 and NPI 378.1), predominantly low-grade fibrosis in both populations (0-2 in 63.6% of WPI patients and in 80% of NPI patients), with necro-inflammatory activity ranging from 5-7 in 51.3% and 42.9% of WPI patients and NPI patients, respectively. It is suggested a sequential biopsy to better evaluate the evolution of the hepatic disease, according to the HAART regimen received.