Effect of Coexisting HIV-1 Infection on the Diagnosis and Evaluation of Hepatitis C Virus:

Diagnostic accuracy of tests to detect Hepatitis C antibody: a meta-analysis and review of the literature

BACKGROUND

Although direct-acting antivirals can achieve sustained virological response rates greater than 90% in Hepatitis C Virus (HCV) infected persons, at present the majority of HCV-infected individuals remain undiagnosed and therefore untreated. While there are a wide range of HCV serological tests available, there is a lack of formal assessment of their diagnostic performance. We undertook a systematic review and meta-analysis to evaluate he diagnostic accuracy of available rapid diagnostic tests (RDT) and laboratory based EIA assays in detecting antibodies to HCV.

METHODS

We used the PRISMA checklist and Cochrane guidance to develop our search protocol. The search strategy was registered in PROSPERO (CRD42015023567). The search focused on hepatitis C, diagnostic tests, and diagnostic accuracy within eight databases (MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, SCOPUS, Literatura Latino-Americana e do Caribe em Ciências da Saúde and WHO Global Index Medicus. Studies were included if they evaluated an assay to determine the sensitivity and specificity of HCV antibody (HCV Ab) in humans. Two reviewers independently extracted data and performed a quality assessment of the studies using the QUADAS tool. We pooled test estimates using the DerSimonian-Laird method, by using the software R and RevMan. 5.3.

RESULTS

A total of 52 studies were identified that included 52,673 unique test measurements. Based on five studies, the pooled sensitivity and specificity of HCV Ab rapid diagnostic tests (RDTs) were 98% (95% CI 98-100%) and 100% (95% CI 100-100%) compared to an enzyme immunoassay (EIA) reference standard. High HCV Ab RDTs sensitivity and specificity were observed across screening populations (general population, high risk populations, and hospital patients) using different reference standards (EIA, nucleic acid testing, immunoblot). There were insufficient studies to undertake subanalyses based on HIV co-infection. Oral HCV Ab RDTs also had excellent sensitivity and specificity compared to blood reference tests, respectively at 94% (95% CI 93-96%) and 100% (95% CI 100-100%). Among studies that assessed individual oral RDTs, the eight studies revealed that OraQuick ADVANCE® had a slightly higher sensitivity (98%, 95% CI 97-98%) compared to the other oral brands (pooled sensitivity: 88%, 95% CI 84-92%).

CONCLUSIONS

RDTs, including oral tests, have excellent sensitivity and specificity compared to laboratory-based methods for HCV antibody detection across a wide range of settings. Oral HCV Ab RDTs had good sensitivity and specificity compared to blood reference standards.

Single Domain Antibodies as New Biomarker Detectors

Biomarkers are defined as indicators of biological processes, pathogenic processes, or pharmacological responses to a therapeutic intervention. Biomarkers have been widely used for early detection, prediction of response after treatment, and for monitoring the progression of diseases. Antibodies represent promising tools for recognition of biomarkers, and are widely deployed as analytical tools in clinical settings. For immunodiagnostics, antibodies are now exploited as binders for antigens of interest across a range of platforms. More recently, the discovery of antibody surface display and combinatorial chemistry techniques has allowed the exploration of new binders from a range of animals, for instance variable domains of new antigen receptors (V_NAR) from shark and variable heavy chain domains (V_HH) or nanobodies from camelids. These single domain antibodies (sdAbs) have some advantages over conventional murine immunoglobulin owing to the lack of a light chain, making them the smallest natural biomarker binders thus far identified. In this review, we will discuss several biomarkers used as a means to validate diseases progress. The potential functionality of modern singe domain antigen binders derived from phylogenetically early animals as new biomarker detectors for current diagnostic and research platforms development will be described.

Comparison of HCV viral load and its genotype distributions in HCV mono- and HIV/HCV co-infected illicit drug users

BACKGROUND

Because of shared modes of transmission, patients with hepatitis C virus (HCV) infection are often co-infected with other types of hepatitis viruses and/or HIV. We studied HCV viral load and its genotype patterns among HCV mono- and HCV/HIV co-infected Illicit Drug Users in Fars province-Iran.

METHODS

Totally, 580 HCV seropositive IDUs referred to Prof. Alborzi Clinical Microbiology Research Center, Shiraz, Iran, without receiving any anti-HCV treatment, were enrolled. After their HCV infections were reconfirmed by one step rapid diagnostic test, HCV RNA level and HCV genotypes were determined by Taq-man real-time PCR assays. Their HIV serostatus was determined and seropositive patients were excluded from the group. In addition, 104 HIV/HCV co-infected IDUs referred from Shiraz Behavioral Diseases Consultation Center (SBDC) were assessed for HCV RNA level and HCV genotype patterns, as well.

RESULTS

The overall estimated HIV prevalence was 6.7% (39/580) among HCV seropositive IDUs. Genotype 1, the most prevalent genotype in both groups, was detected in 69% and 49% of co- and mono-infected IDUs, respectively. Median HCV viral load was significantly higher in HIV/HCV co-infected patients, compared with that among HCV mono-infected counterparts.

CONCLUSIONS

Given the higher baseline HCV viral load and GT1 attributed to poorer treatments response, HCV treatment must be more considered among HCV/HIV co-infected IDUs, compared to those mono-infected with HCV.

Trends in hepatitis C virus infections among MSM attending a sexually transmitted infection clinic; 1995-2010

BACKGROUND

Since 2000, there is growing evidence that hepatitis C virus (HCV) infection has emerged as a sexually transmitted infection (STI) among HIV-positive MSM. Here, we present a 15-year overview of the HCV epidemic among MSM visiting a large STI-clinic in the Netherlands.

METHODS

During biannual cross-sectional anonymous surveys (1995-2010), participants were interviewed and tested for HIV and HCV-antibodies. Additional HCV RNA tests were performed in all HIV-positives. Determinants of HCV infection were analysed using logistic regression. Phylogenetic analysis provided evidence for sexual transmission.

RESULTS

HCV prevalence among HIV-positive MSM increased from 1995 onwards (5.6%) and peaked in 2008 (20.9%). Prevalent HCV infection was more strongly associated with fisting in 2007-2008 [adjusted odds ratio (aOR) 2.85, 95% confidence interval (CI) 1.19-6.82] than in 2009-2010 (aOR 0.92, 95% CI0.42-2.02). In addition, HCV infection was independently associated with Chlamydia, injecting drug use, unprotected anal intercourse and older age. Phylogenetic analysis revealed a high degree of MSM-specific clustering from 2000 onwards. Identification of a new MSM-specific HCV lineage and the finding of recent HCV infections (0-4%) in established HCV clusters during recent years argue for ongoing transmission of HCV among HIV-positive MSM. HCV prevalence among HIV-negative MSM remained low (2007-2010: 0.5%).

CONCLUSION

HCV prevalence among HIV-positive MSM significantly increased over calendar time but appears to level off in recent years, possibly due to increased awareness, saturation in the population, decreased risk behaviour and earlier HCV screening and treatment. The association with fisting became less strong over time, but our analyses continue to support sexual transmission. Monitoring HIV-positive and HIV-negative MSM for HCV infection remains needed to guide prevention efforts.

Autoimmune hepatitis in an HIV-infected patient: an intriguing association

Abnormal levels of liver enzymes are common in HIV-infected patients and may be caused by multiple factors, including co-infection with hepatitis C virus (HCV) or hepatitis B virus (HBV) infection and in the majority of cases by antiretroviral drug-related liver injury. This report, however, describes a patient with HIV infection and abnormal liver function tests where further diagnostics revealed concomitant autoimmune hepatitis (AIH). The association of immune dysfunction in patients with HIV infection/AIDS and the development of autoimmune diseases is intriguing. The precise mechanism causing the emergence or unmasking of autoimmune conditions in HIV infection remains unclear, but it is important to demonstrate that autoimmune diseases do occur in HIV-infected patients. Therefore, clinicians should include AIH in the differential diagnosis of increased liver enzymes when there is no improvement despite changing antiretroviral therapy.

Hepatitis C and HIV co-infection: new drugs in practice and in the pipeline

HCV/HIV coinfection continues to represent a serious health issue with risk of liver disease progression and development of hepatocellular carcinoma. Pegylated interferon with ribavirin is approved for treatment but results are suboptimal and tolerability poor. First-generation HCV protease inhibitors appear to significantly improve HCV treatment response in the setting of HIV infection. Interactions with HIV protease inhibitors have been documented, but the significance of this in terms of adverse reactions and HCV or HIV viral breakthrough remains uncertain. Next generation agents hold the promise of even better efficacy, with improved dosing schedules and perhaps decreased risk of drug:drug interactions.

Evaluation of three rapid screening assays for detection of antibodies to hepatitis C virus

BACKGROUND

The Centers for Disease Control and Prevention (CDC) estimates that 3.2 million Americans are living with chronic hepatitis C virus (HCV) infection and 50%-70% are unaware of their status. Although therapies are available that can suppress or eliminate infection, identifying persons infected with HCV is challenging. Rapid tests could help identify many of these persons more expeditiously.

METHODS

Three manufacturers, Chembio, OraSure, and MedMira, submitted HCV antibody (anti-HCV) rapid screening assays to the CDC for evaluation and comparison with established anti-HCV screening assays. The panel consisted of 1100 specimens drawn during 1997-1999 from persons reporting injection drug use. Sensitivity and specificity were assessed using 2 reference approaches, one based on the reactivity of samples in an anti-HCV screening assay and the other based on CDC HCV testing algorithm.

RESULTS

The sensitivities of the Chembio, MedMira, and OraSure assays across the 2 approaches were 96.2%-98.0%, 86.8%-88.3%, and 97.8%-99.3%, respectively. The 3 assays had specificity of 99.5% or higher with no differences between assays. False rapid assay results were associated with human immunodeficiency virus positivity for both approaches for Chembio and MedMira.

CONCLUSIONS

Rapid anti-HCV tests can provide sensitive and specific anti-HCV results for high-risk patients.

Trends in hepatitis C virus infection among patients in the HIV Outpatient Study, 1996-2007

BACKGROUND

Coinfection with hepatitis C virus (HCV) contributes increasingly to the morbidity and mortality of persons infected with HIV. We assessed HCV infection screening practices and determined trends in the prevalence of HCV infection in the HIV Outpatient Study (HOPS) from 1996 to 2007.

METHODS

We calculated the proportion of patients eligible to be tested for HCV infection (i.e., never tested or previously tested negative) and the prevalence of HCV infection annually from 1996 to 2007 by sociodemographic, clinical, and HIV risk category characteristics. We used multiple logistic regression analyses to evaluate factors independently associated with HCV testing.

RESULTS

A total of 7618 patients were active in the HOPS from 1996 through 2007. The proportion of eligible patients tested for HCV infection increased from 10.7% in 1996 to 76.6% in 2007 and increased among all demographic and risk groups. Overall HCV prevalence decreased from 36.7% in 1996 to 19.7% in 2007; decreases in prevalence occurred among all groups except for injection drug users (IDUs). In multivariable analysis, age older than 35 years, nonwhite race, Hispanic ethnicity, high-risk heterosexual and IDU risk categories, and at least 3 years of enrollment in the HOPS were associated with increased odds of having been tested for HCV infection.

CONCLUSIONS

Screening for HCV infection in the HOPS has improved, although a sizable fraction of patients remain unscreened. The decline in overall HCV infection prevalence from 1996 to 2007 resulted primarily from a decline in the fraction of all prevalent infections in the cohort attributable to IDU patients.

HCV NS3/4A protein activates HIV-1 transcription from its long terminal repeat

Approximately 30-40% of patients infected with the human immunodeficiency virus (HIV) in the U.S. are also infected with the hepatitis C virus (HCV). Studies have shown that HIV can worsen hepatitis C, while the impact of hepatitis C on HIV disease is less clear. In this study, we described that HCV NS3/4A protein can activate HIV-1 transcription from its long terminal repeat (LTR) region, while the serine protease-inactive mutant of NS3/4A fails to do so. The activation effect of NS3/4A to HIV-1 transcription can be explained by its ability to enhance DNA binding activities of the transcription factor AP-1. These results have provided insights into the mechanism involved in the co-infection of HCV and HIV.

Hepatitis C in the HIV-infected patient

Hepatitis C virus (HCV) coinfection in the presence of HIV raises several challenging issues for the treating clinician. Some evidence indicates that concomitant HIV infection alters HCV virology in ways that are relevant for treatment. Pegylated interferon plus ribavirin is the recommended therapy for HCV in HIV-infected patients. Proportionately fewer HIV/HCV-coinfected patients achieve a sustained virologic response (SVR) compared with those infected with HCV alone. Possible reasons for this include higher levels of HCV viremia and inadequate ribavirin exposure. Strategies under study for optimizing therapeutic response include weight-based ribavirin dosing, use of growth factors to avoid dose reduction, and longer duration of therapy. Aggressive management of adverse effects to avoid dose reduction or treatment discontinuation is also crucial. An integrated multidisciplinary team, including a psychiatrist and addictions specialist, can increase the proportion of HIV/HCV-coinfected patients eligible for treatment. Investigational options exist for patients who relapse after treatment is discontinued and for those with a partial virologic response. Promising therapies that are under development include protease and polymerase inhibitors.

Hepatitis C Virus in the HIV-infected patient

Treatment of HCV in the coinfected patient poses numerous challenges to the clinician: difficult comorbidities, an increased risk of medication side effects, and a therapy with limited response rates. End-stage liver disease from HCV has become a leading cause of death in coinfected patients. Without focused disease management, the burden of chronic liver disease in this population will rise. This article discusses the major trials investigating the use of interferon and ribavirin in coinfected patients, proposes a treatment algorithm for HCV/HIV coinfection, and considers approaches to patients who do not respond to this treatment.

Racial difference in mortality among U.S. veterans with HCV/HIV coinfection

OBJECTIVES

This study was performed to examine the impact of viral coinfections and race on clinical and virological outcome of hepatitis C virus (HCV) infection.

METHODS

Three groups of patients (265 HCV/HIV coinfected, 251 HCV monoinfected, 227 HIV monoinfected) were identified between 2000 and 2002 from the computerized patient record system at the Philadelphia VA Medical Center and analyzed for clinical and virological parameters.

RESULTS

HCV/HIV coinfection was associated with higher frequency of liver function abnormalities (37% vs 21% vs 20%; p < 0.0003) and greater mortality (17% vs 6% vs 9% over 3 yr period, p = 0.0003, p = 0.027) compared to HCV or HIV monoinfection, respectively. However, HCV/HIV coinfection was not associated with worsened HIV-related parameters (CD4 count, HIV titer, and use of antiretroviral therapy) or increased HCV titers compared to HIV or HCV monoinfection in our population, respectively. Interestingly, mortality among HCV/HIV coinfected patients was significantly greater in white than in black patients (31% vs 15%, p = 0.011). This racial disparity in mortality was not apparent in the monoinfected groups and not explained by HBV coinfection or history of alcohol use disorder.

CONCLUSIONS

We conclude that HCV/HIV coinfection is associated with worsened liver disease and higher mortality than HCV- or HIV-monoinfection without directly influencing CD4 count and HCV or HIV titers. Furthermore, we demonstrated a racial disparity in survival of HCV/HIV-coinfected patients that needs further investigation.

Clinical presentation and course of acute hepatitis C infection in HIV-infected patients

Hepatitis C virus (HCV) has become a significant source of morbidity and mortality in HIV-infected patients. However, little is known about the clinical presentation and course of acute HCV infection in this population. This study reports the outcomes of acute HCV infection in 9 HIV-infected men. Sex with men was the only reported risk factor for HCV infection in 6 of the subjects. Clinical presentation of acute HCV ranged from incidentally discovered elevated transaminases to severe liver dysfunction requiring hospitalization. At the time of HCV diagnosis, 8 of 9 patients had CD4+ counts >250 cells/mm(3), and 6 had HIV viral loads of < or =5000 copies/mL. Eight patients were receiving antiretroviral therapy. Outcome of these acute HCV infections varied. Five patients experienced virologic clearance, 2 in whom virus cleared spontaneously and 3 who were treated with pegylated interferon and ribavirin. Four patients developed chronic infection, one of whom had a relapse during HCV treatment and 3 of whom were untreated. All 4 patients to whom HCV therapy was administered experienced significant anemia or neutropenia, necessitating dose reduction or support with growth factors. Prompt recognition of acute HCV infection may minimize antiretroviral treatment interruption and will allow early treatment, which may improve virologic clearance. Unexplained transaminase elevations in HIV-infected patients, including men who have sex with men, should trigger an evaluation for acute HCV infection.

Diagnostic discordance for hepatitis C virus infection in hemodialysis patients

BACKGROUND

Hepatitis C virus (HCV) infection is associated with an increase in proinflammatory cytokine levels. Similar changes are seen in maintenance hemodialysis patients with malnutrition-inflammation-cachexia syndrome (MICS), which is associated with poor clinical outcomes in this population. We hypothesized that HCV transcription-mediated amplification (TMA), a sensitive qualitative molecular test for HCV RNA, may identify maintenance hemodialysis patients with HCV infection not detected by means of antibody enzyme immunoassay (EIA), particularly in those with MICS.

METHODS

We evaluated HCV status in 314 maintenance hemodialysis patients by using HCV antibody EIA (version 2.0; Abbott Laboratories, Abbott Park, IL) and HCV TMA (Bayer Diagnostics Laboratories, Berkeley, CA).

RESULTS

Twenty-five patients (8%) were EIA positive (EIA+)/TMA+; 4 patients (1%), EIA+/TMA negative (TMA-), and 22 patients (7%), EIA-/TMA+. In the 47 TMA+ patients, the sensitivity of EIA for HCV infection was only 53%. TMA+ patients had lower albumin levels and higher tumor necrosis factor alpha and serum glutamic oxaloacetic transaminase levels than TMA- patients. EIA+/TMA+ patients were more likely than EIA-/TMA+ or EIA-/TMA- patients to have hypoalbuminemia and higher iron and transaminase levels. Of all TMA+ patients, EIA- patients were more likely to have diabetes, be on dialysis therapy longer, and have lower liver enzyme levels and higher proinflammatory cytokine levels, including tumor necrosis factor alpha and interleukin 6.

CONCLUSION

Maintenance hemodialysis patients infected with HCV according to TMA have clinical features suggestive of MICS. In this population, HCV EIA appears to have a low sensitivity for the identification of HCV infection, which may be caused by the confounding effect of MICS or other demographic or clinical factors. These apparently false-negative HCV antibody test results are seen in persons with a longer time on hemodialysis therapy, mirroring observations in other populations with serious progressive conditions, such as human immunodeficiency virus infection.

Management and treatment of hepatitis C virus infection in HIV-infected adults: recommendations from the Veterans Affairs Hepatitis C Resource Center Program and National Hepatitis C Program Office

Nearly 40% of human immunodeficiency virus- (HIV-) infected veterans on highly active antiretroviral therapy (HAART) in the United States are coinfected with hepatitis C virus (HCV). With the increased survival due to declining opportunistic infections as a result of HAART, HCV-associated liver disease has become a leading cause of death in HIV-infected individuals. HCV infection has been shown to lead to rapid progression of HCV-related liver disease in HIV infection. Results from recent clinical trials in HIV/HCV-coinfected patients show improved response rates using pegylated formulations of interferon plus ribavirin when compared to standard interferon plus ribavirin. However, the treatment of HCV in HIV/HCV-coinfected patients can be complicated by the hepatotoxic and myelosuppressive effects of HIV therapy and HIV infection itself. Prior to initiating HCV therapy, HIV therapy should be optimized by improving immune suppression and avoiding specific antiretroviral drugs that may cause hepatotoxicity and myelosuppression. In the event of treatment-related neutropenia or anemia during HCV therapy, the use of growth factors should be considered to maximize sustained virologic response to HCV therapy. In HIV/HCV-coinfected patients with end-stage liver disease, liver transplantation is being investigated and shows promise as a potential therapeutic option. With the recent advances in the treatment of HCV in HIV/HCV-coinfected individuals, all HIV/HCV-coinfected patients eligible for HCV treatment should be evaluated for HCV combination therapy with careful consideration of their HIV disease.

Prevalence of hepatitis C in an ethnically diverse HIV-1-infected cohort in south London

OBJECTIVES

There is limited information on the prevalence of and risk factors for hepatitis C virus (HCV) infection among HIV-1-infected patients in the UK. Our objective was to determine the prevalence of HCV infection among an ethnically diverse cohort of HIV-infected patients in south London, and to extrapolate from these data the number of co-infected patients in the UK.

METHODS

A total of 1017 HIV-1-infected patients who had attended King's College Hospital HIV clinic between September 2000 and August 2002 were screened for HCV antibody using a commercial enzyme-linked immunosorbent assay (ELISA). Positive results were confirmed by polymerase chain reaction (PCR) or recombinant immunoblot assay. Demographic, clinical and laboratory data were obtained from the local computerized database and medical records. We applied our HCV prevalence rates in the different HIV transmission groups to the estimated number of HIV-infected persons in these groups in the UK, to obtain a national estimate of the level of HIV-HCV co-infection.

RESULTS

Of the 1017 HIV-1-infected patients, 407 (40%) were white men, 158 (15.5%) were black African men, 268 (26.3%) were black African women, and 61 (6%) and 26 (2.6%) were black Caribbean men and women, respectively. Heterosexual exposure was the most common route of HIV acquisition (53.5%), followed by men having sex with men (36.9%), and current or previous injecting drug use (IDU) (7.2%). The overall prevalence of HCV co-infection was 90/1017 (8.9%), but this varied substantially according to route of transmission, from 82.2% among those with a history of IDU (which accounted for 67% of all HCV infections), to 31.8% in those who had received blood products, to 3.5% and 1.8% in those with homosexually and heterosexually acquired infection, respectively. Multivariate logistic regression analysis identified several independent risk factors for HCV infection: a history of IDU [odds ratio (OR) = 107.2; 95% confidence interval (CI) = 38.5-298.4], having received blood products (OR = 16.5; 95% CI = 5.1-53.7), and either being from a white ethnic group (OR = 4.3; 95% CI = 1.5-12.0) or being born in Southern Europe (OR = 6.7; 95% CI = 1.5-30.7). Based on the 35,473 known HIV-1-infected persons in the UK and the 10 997 estimated to be unaware of their status, we projected that there are at least 4136 HIV-HCV co-infected individuals in the UK and 979 who are unaware of their status.

CONCLUSIONS

Overall, 9% of our cohort was HIV-HCV co-infected. The prevalence was highest among intravenous drug users (82%), who accounted for most of our HCV cases, and lowest among heterosexual men and women from sub-Saharan Africa and the Caribbean [< 2%]. Our estimate that a significant number of co-infected persons may be unaware of their HIV and HCV status, highlights an urgent need to increase the uptake of HCV and HIV testing, particularly among injecting drug users, to reduce the risk of onward transmission.

Integrating Care for Hepatitis C Virus (HCV) and Primary Care for HIV for Injection Drug Users Coinfected with HIV and HCV

Injection drug use accounts for most of the incident infections with hepatitis C virus (HCV) and for at least one-third of new human immunodeficiency virus (HIV) infections. Coinfection with HCV and HIV presents complex and challenging medical conditions. Ensuring access to and maintaining care for HIV and HCV for drug users presents special challenges to the health care team that require a nonjudgmental attitude, experience, and patience. Care for HCV infection, however, can be used as an instrument to engage drug-using persons in ongoing primary care relationships. Common elements to both care for HCV infection and primary care for HIV infection are testing for and counseling about HCV and HIV, substance abuse and mental health services, social support, and subspecialty referral. These elements, in particular treatment for substance abuse, can be focal points for model care systems that provide integrative care for both HCV and HIV infections.

Association of hypocholesterolaemia with hepatitis C virus infection in HIV-infected people

OBJECTIVE

To study the impact of hepatitis C virus (HCV) status on serum cholesterol levels in HIV-infected patients.

METHODS

We retrospectively analysed data from the 881 participants of the Veterans Ageing Cohort 3 Site Study. Four different models were constructed using total cholesterol, low-density lipid (LDL) cholesterol, high-density lipid (HDL) cholesterol and triglycerides as dependent variables. The relevant covariates included HCV antibody status, HIV medication class, CD4 count, HIV viral load, glucose level, lipid-lowering drug use, gender, race, age, liver function test results, ethanol use, drug use, and HIV exposure category. Variables excluded from the final model included niacin use, gender, race, age, current ethanol use, and HIV exposure category.

RESULTS

Of the 881 HIV-positive patients enrolled in the study, 700 (79%) were screened for HCV antibody, with 300 (42.8%) HCV antibody positive and 400 (57.2%) HCV antibody negative. A positive HCV antibody status was independently associated with lower total cholesterol levels (P=0.001) and LDL cholesterol levels (P<0.001) but not with lower HDL cholesterol or triglyceride levels. HCV-positive patients had predicted LDL levels 19 mg/dL lower than those of HCV-negative subjects. HCV infection was also associated with a decreased use of lipid-lowering medication, and protease inhibitor use was associated with increased LDL and total cholesterol levels.

CONCLUSIONS

HCV infection has been associated with lower cholesterol levels in HIV-negative individuals, and the same appears to be true with HIV-infected patients. This is an interesting finding given that HCV particles bind to LDL receptors in vitro and also because HCV-lipid interactions appear to be important in the HCV replication cycle.

Hepatitis C virus infection in San Francisco's HIV-infected urban poor

OBJECTIVE

To measure Hepatitis C Virus (HCV) prevalence, incidence, and initiation of HCV therapy in a representative HIV-infected cohort of the urban poor.

DESIGN

Cohort analysis.

SETTING

The Research and Access to Care for the Homeless (REACH) Cohort is a systematic sample of HIV-infected marginally housed individuals identified from single-room occupancy hotels, homeless shelters, and free lunch programs in San Francisco.

PARTICIPANTS

Two hundred forty-nine participants with 28.9 months (median) of follow-up were studied. Mean age was 44 (range 24 to 75, standard deviation 8.4) years. Eighty-two percent were male, 43% were African-American, 64% were lifetime injection drug users, and 24% had been on the street or in a shelter in the prior month.

INTERVENTIONS

We measured HCV testing and treatment history with structured interviews; additionally, participants were tested for HCV antibodies (EIA-2) with RNA viral load confirmation.

MAIN RESULTS

At baseline, 172 (69.1%) were HCV-positive and 182 (73.1%) were HCV-positive at follow-up, including 155 (62.2%) with viremia. HCV-positive status was associated with having injected drugs, elevated serum alanine aminotransferase, homelessness in the last 1 year, and more severe depressive symptoms. The incidence of new HCV infection was 4.63% per person-year (ppy; 95% confidence interval, 2.31 to 8.13) in the entire cohort and 16.77% ppy among injection drug users. The prevalence of HCV antibody-negative HCV-viremia was 13.2% (10/76). Nonwhites were less likely to receive HCV testing and subspecialty referral, controlled for drug use and other confounders. Sixty-eight percent (123/182) were aware treatment was available; however, only 3.8% (7/182) or 1.16% ppy received HCV treatment.

CONCLUSIONS

While HCV infection is common, HCV treatment is rare in the HIV-HCV coinfected urban poor. Urban poor, nonwhite individuals are less likely to receive HCV testing and subspecialty referral than their white counterparts. Antibody-negative infection may complicate screening and diagnosis in HIV-infected persons. J

Design and construction of novel molecular conjugates for signal amplification (I): conjugation of multiple horseradish peroxidase molecules to immunoglobulin via primary amines on lysine peptide chains

Immunoconjugates are widely used for indirect detection of analytes (such as antibodies or antigens) in a variety of immunoassays. However, the availability of functional groups such as primary amines or free sulfhydryls in an immunoglobulin molecule is the limiting factor for optimal conjugation and, therefore, determines the sensitivity of an assay. In the present study, an N-terminal bromoacetylated 20 amino acid peptide containing 20 lysine residues was conjugated to N-succinimidyl-S-acetylthioacetate (SATA)-modified IgG or free sulfhydryl groups on 2-mercaptoethylamine (2-MEA)-reduced IgG molecules via a thioether (S[bond]CH(2)CONH) linkage to introduce multiple reactive primary amines per IgG. These primary amines were then covalently coupled with maleimide-activated horseradish peroxidase (HRP). The poly-HRP-antibody conjugates thus generated demonstrated greater than 15-fold signal amplification upon reaction with orthophenyldiamine substrate. The poly-HRP-antibody conjugates efficiently detected human immunodeficiency virus (HIV)-1 antibodies in plasma specimens with significantly higher sensitivity than conventionally prepared HRP-antibody conjugates in an HIV-1 solid-phase enzyme immunoassay and Western blot analysis. The signal amplification techniques reported here could have the potential for development of highly sensitive immunodiagnostic assay systems.

Hepatitis C and human immunodeficiency virus infection

In the United States, an estimated 200,000 persons are infected with both hepatitis C virus (HCV) and human immunodeficiency virus (HIV). As the lives of HIV-infected persons have been prolonged by use of highly active antiretroviral therapy, liver disease has emerged as an important, and in some settings, the leading cause of morbidity and mortality. Human immunodeficiency virus infection appears to adversely affect all stages of hepatitis C infection, leading to increased viral persistence and accelerated progression of HCV-related liver disease. In turn, hepatitis C may affect the management of HIV infection, increasing the incidence of liver toxicity caused by antiretroviral medications. The medical management of hepatitis C in HIV-infected persons remains controversial, in part because of the complexity of both infections and potential drug interactions, but chiefly because there is so little published information. Nonetheless, the burden of liver disease is too high to delay management of HIV/HCV-coinfected persons while awaiting better data. Instead, the management of hepatitis C today must be based on data generated on persons without HIV and an understanding of both infections. Properly designed studies of therapy in HIV/HCV-coinfected persons are needed to help guide management of these patients in the future.