The impact of co-infection with hepatitis C virus and HIV on the tolerability of antiretroviral therapy

Liver Fibrosis during Antiretroviral Treatment in HIV-Infected Individuals. Truth or Tale?

After the introduction of antiretroviral treatment (ART) back in 1996, the lifespan of people living with HIV (PLWH) has been substantially increased, while the major causes of morbidity and mortality have switched from opportunistic infections and AIDS-related neoplasms to cardiovascular and liver diseases. HIV itself may lead to liver damage and subsequent liver fibrosis (LF) through multiple pathways. Apart from HIV, viral hepatitis, alcoholic and especially non-alcoholic liver diseases have been implicated in liver involvement among PLWH. Another well known cause of hepatotoxicity is ART, raising clinically significant concerns about LF in long-term treatment. In this review we present the existing data and analyze the association of LF with all ART drug classes. Published data derived from many studies are to some extent controversial and therefore remain inconclusive. Among all the antiretroviral drugs, nucleoside reverse transcriptase inhibitors, especially didanosine and zidovudine, seem to carry the greatest risk for LF, with integrase strand transfer inhibitors and entry inhibitors having minimal risk. Surprisingly, even though protease inhibitors often lead to insulin resistance, they do not seem to be associated with a significant risk of LF. In conclusion, most ART drugs are safe in long-term treatment and seldom lead to severe LF when no liver-related co-morbidities exist.

HIV treatment as prevention among people who inject drugs - a re-evaluation of the evidence

Background

Population-level associations between community measures of HIV viral load and HIV incidence have been interpreted as evidence for HIV anti-retroviral treatment (ART) as prevention among people who inject drugs (PWID). However, investigation of concurrent HCV and HIV incidence trends allows examination of alternative explanations for the fall in HIV incidence. We estimate the contribution of ART and reductions in injecting risk for reducing HIV incidence in Vancouver between 1996 and 2007.

Methods

A deterministic model of HIV and HCV transmission among PWID was calibrated to the baseline (1996) HIV and HCV epidemic among PWID in Vancouver. While incorporating parameter uncertainty, the model projected what levels of ART protection and decreases in injecting risk could reproduce the observed reduction in HIV and HCV incidence for 1996-2007, and so what impact would have been achieved with just ART or just reductions in injecting risk.

Results

Model predictions suggest the estimated reduction (84%) in HCV incidence for 1996-2007 required a 59% (2.5-97.5 percentile range 49-76%) reduction in injecting risk, which accounted for nine-tenths of the observed decrease in HIV incidence; the remainder was achieved with a moderate ART efficacy for reducing sexual HIV infectivity (70%, 51-89%) and an uncertain ART efficacy for reducing injection-related HIV infectivity (44%, 0-96%). Despite this uncertainty, projections suggest that the decrease in injecting risk reduced HIV incidence by 76% (63-85%) and ART further reduced HIV incidence by 8% (2-19%), or on its own by 3% (-34-37%).

Conclusions

Observed declines in HIV incidence in Vancouver between 1996 and 2007 should be seen as a success for intensive harm reduction, whereas ART probably played a small role.

Differential predictors of ART adherence among HIV-monoinfected versus HIV/HCV-coinfected individuals

Although adherence is an important key to the efficacy of antiretroviral therapy (ART), many people living with HIV (PLWH) fail to maintain optimal levels of ART adherence over time. PLWH with the added burden of Hepatitis C virus (HCV) coinfection possess unique challenges that potentially impact their motivation and ability to adhere to ART. The present investigation sought to (1) compare ART adherence levels among a sample of HIV/HCV-coinfected versus HIV-monoinfected patients, and (2) identify whether ART-related clinical and psychosocial correlates differ by HCV status. PLWH receiving ART (N = 215: 105 HIV/HCV-coinfected, 110 HIV-monoinfected) completed a comprehensive survey assessing ART adherence and its potential correlates. Medical chart extraction identified clinical factors, including liver enzymes. Results demonstrated that ART adherence did not differ by HCV status, with 83.7% of coinfected patients and 82.4% of monoinfected patients reporting optimal (i.e., ≥95%) adherence during a four-day recall period (p = .809). Multivariable logistic regression demonstrated that regardless of HCV status, optimal ART adherence was associated with experiencing fewer adherence-related behavioral skills barriers (AOR = 0.56; 95%CI = 0.43-0.73), lower likelihood of problematic drinking (AOR = 0.15; 95%CI = 0.04-0.67), and lower likelihood of methamphetamine use (AOR = 0.14; 95%CI = 0.03-0.69). However, among HIV/HCV-coinfected patients, optimal adherence was additionally associated with experiencing fewer ART adherence-related motivational barriers (AOR = 0.23; 95%CI = 0.08-0.62) and lower likelihood of depression (AOR = 0.06; 95%CI = 0.00-0.84). Findings suggest that although HIV/HCV-coinfected patients may face additional, distinct barriers to ART adherence, levels of adherence commensurate with those demonstrated by HIV-monoinfected patients might be achievable if these barriers are addressed.

New Hopes for HIV and HCV Coinfection in 2004

An increase in liver-related causes of death in HIV-positive patients who are coinfected with the hepatitis C virus (HCV) has been acknowledged over the last few years, particularly since the mid 1990s, when the natural history of HIV infection started to improve with the use of highly active antiretroviral therapy (HAART). Chronic hepatitis C is very common among HIV-infected patients who were infected through intravenous drugs use or contaminated blood products (e.g., hemophiliacs). The bidirectional interferences between HIV and HCV modify the natural history of both infections. Moreover, interactions between anti-HIV and anti-HCV drugs are of concern, and a lower response to anti-HCV therapy limits its benefit in HIV-coinfected patients. Although a slower HCV RNA decay is seen in coinfected patients after standard therapy is initiated with pegylated interferon plus ribavirin, the stopping rule at week 12 that is recommended for HCV-monoinfected individuals seems to be equally valid in HIV-positive patients. This finding is of great value, because it allows treatment to be offered in the absence of contraindication (e.g., low CD4 count, alcohol abuse, etc.) but discontinued as early as 12 weeks when no chances of cure are predicted, which saves costs and deleterious side effects. HAART therapy seems to temper somehow the negative impact exerted by HIV infection over HCV-related liver fibrosis. Liver transplantation is currently the best option for HIV-infected patients with end-stage liver disease. However, the management of patients on the waiting list and after transplantation carries significant new challenges. New anti-HCV drugs are urgently needed and new strategies with the currently available drugs need to be assessed to reduce the negative impact of hepatitis C in HIV-coinfected individuals.

Modeling the impact of early antiretroviral therapy for adults coinfected with HIV and hepatitis B or C in South Africa

OBJECTIVE

There has been discussion about whether individuals coinfected with HIV and hepatitis C virus (HCV) or hepatitis B virus (HBV) (∼30% of all people living with HIV) should be prioritized for early HIV antiretroviral therapy (ART). We assess the relative benefits of providing ART at CD4 count below 500  cells/μl or immediate ART to HCV/HIV or HBV/HIV-coinfected adults compared with HIV-monoinfected adults. We evaluate individual outcomes (HIV/liver disease progression) and preventive benefits in a generalized HIV epidemic setting.

METHODS

We modeled disease progression for HIV-monoinfected, HBV/HIV-coinfected, and HCV/HIV-coinfected adults for differing ART eligibility thresholds (CD4 <350  cells/μl, CD4 <500  cells/μl, immediate ART eligibility upon infection). We report disability-adjusted life-years averted per 100 person-years on ART (DALYaverted/100PYonART) as a measure of the health benefits generated from incremental changes in ART eligibility. Sensitivity analyses explored impact on sexual HIV and vertical HIV, HCV, and HBV transmission.

RESULTS

For HBV/HIV-coinfected adults, a switch to ART initiation at CD4 count below 500  cells/μl from CD4 below 350  cells/μl generates 9% greater health benefits per year on ART (48 DALYaverted/100PYonART) than for HIV-monoinfected adults (44 DALYaverted/100PYonART). Additionally, ART at CD4 below 500  cells/μl could prevent 25% and 32% of vertical transmissions of HIV and HBV, respectively. For HCV/HIV-coinfected adults, ART at CD4 below 500  cells/μl generates 10% fewer health benefits (40 DALYaverted/100PYonART) than for HIV monoinfection, unless ART reduces progression to cirrhosis by more than 70% (33% in base-case).

CONCLUSIONS

The additional therapeutic benefits of ART for HBV-related liver disease results in ART generating more health benefits among HBV/HIV-coinfected adults than HIV-monoinfected individuals, whereas less health benefits are generated amongst HCV/HIV coinfection in a generalized HIV epidemic setting.

Relationship of chronic hepatitis C infection to rates of AIDS-defining illnesses in a Canadian cohort of HIV seropositive individuals receiving highly active antiretroviral therapy

BACKGROUND

The influence of chronic hepatitis C virus (HCV) infection on the risk, timing, and type of AIDS-defining illnesses (ADIs) is not well described. To this end, rates of ADIs were evaluated in a Canadian cohort of HIV seropositive individuals receiving highly active antiretroviral therapy (HAART).

METHODS

ADIs were classified into 6 Centers for Disease Control and Prevention (CDC)-defined etiological subgroups: non-Hodgkin lymphoma, viral infection, bacterial infection, HIV-related disease, protozoal infection, and mycotic infection. Generalized estimating equation (GEE) Poisson regression models were used to estimate the effect of HCV on rates of ADIs after adjusting for covariates.

RESULTS

Among 2,706 HAART recipients, 768 (28%) were HCV coinfected. Rates of all ADIs combined and of bacterial infection, HIV-related disease, and mycotic infection were increased in HCV-coinfected persons and among those with CD4 counts <200 cells/mm3 HCV was associated with an increased risk of ADIs (rate ratio [RR], 1.38; 95% CI, 1.01-1.88) and a 2-fold increased risk of mycotic infections (RR, 2.21; 95% CI, 1.35-3.62) in univariate analyses and after adjusting for age, baseline viral load, baseline CD4 count, and region of Canada. However, after further adjustment for HAART interruptions, HCV was no longer associated with an increased rate of ADIs overall (RR, 1.13; 95% CI, 0.80-1.59), but remained associated with an increased rate of mycotic infections (RR, 1.97, 95% CI, 1.08-3.61).

CONCLUSION

Although HCV coin-fected individuals are at increased risk of developing ADIs overall, our analysis suggests that behavioral variables associated with HCV (including rates of retention on HAART), and not biological interactions with HCV itself, are primarily responsible.

Metabolic changes associated with antiretroviral therapy in HIV-positive patients

OBJECTIVE: To evaluate metabolic changes associated with highly active antiretroviral therapy (HAART) in HIV-positive patients, and to identify risk factors associated. METHODS: Retrospective study that included 110 HIV-positive patients who where on HAART in the city of Porto Alegre (Southern Brazil) between January 2003 and March 2004. Data on demographic variables, cigarette smoking, diabetes mellitus, cholesterol and triglyceride levels, stage of HIV infection, antiretroviral therapy and HCV coinfection were collected. General linear models procedure for repeated measures was used to test the interaction between HAART and HCV coinfection or protease inhibitor treatment. RESULTS: Total cholesterol, triglycerides, and glucose levels significantly increased after receiving HAART (p<0.001 for all variables), but no interaction with protease inhibitors was seen for total cholesterol, glucose and triglyceride levels (interaction treatment*protease inhibitors p=0.741, p=0.784, and p=0.081, respectively). An association between total cholesterol levels and HCV coinfection was found both at baseline and follow-up (effect of HCV coinfection, p=0.011). Glucose levels were increased by HAART (treatment effect, p=0.036), but the effect was associated to HCV coinfection (treatment*HCV effect, p=0.018). Gender, smoking habit, intravenous drug use and age were not significantly associated with cholesterol, triglyceride and glucose changes. CONCLUSIONS: HCV-infected patients at baseline were significantly less likely to develop hypercholesterolemia. The results provide further evidence of the role of HAART for the development of metabolic disturbances.

Cellular and molecular interactions in coinfection with hepatitis C virus and human immunodeficiency virus

Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is associated with increased HCV replication and a more rapid progression to severe liver disease, including the development of cirrhosis and hepatocellular carcinoma. In this review, we discuss the current understanding of the pathogenesis of HCV/HIV coinfection and the cellular and molecular mechanisms associated with the accelerated course of liver disease. The strength and breadth of HCV-specific T-cell responses are reduced in HCV/HIV-coinfected patients compared with those infected with HCV alone, suggesting that the immunosuppression induced by HIV compromises immune responses to HCV. HCV is not directly cytopathic, but many of the pathological changes observed in the liver of infected patients are a direct result of the intrahepatic antiviral immune responses. Apoptosis also has a role in HCV-mediated liver damage through the induction of apoptotic pathways involving the host immune response and HCV viral proteins. This review summarises the evidence correlating the role of cell-mediated immune responses and apoptosis with liver disease progression in HCV/HIV-coinfected patients.

Management complexities of HIV/hepatitis C virus coinfection in the twenty-first century

Because of shared routes of transmission, hepatitis C virus (HCV) coinfection is common among HIV-infected persons. Because of the effectiveness of antiretroviral therapy, chronic HCV has now emerged as a major cause of morbidity and mortality in this population. Because chronic HCV is highly prevalent among HIV-infected patients and has a rapid disease progression, antiviral therapy with pegylated interferon plus ribavirin is critical for the long-term survival of HIV/HCV-coinfected patients. In this article, the authors review the (1) epidemiology of HCV among HIV-infected individuals, (2) effect of HIV on the natural history of chronic HCV, (3) impact of antiretroviral therapy on HCV coinfection, and (4) management of chronic HCV in the HIV-infected person.

New paradigms in the management of hepatitis C virus co-infections

Liver disease has emerged as a major contributor to morbidity and mortality in patients with HIV infection. Hepatitis C virus (HCV) infection is a key element in the etiology of liver-associated injury in this population. Increased rates of fibrotic progression have been described and are mediated by alcohol use, the severity of immunosuppression, the use of antiretroviral therapy, and other factors. Large clinical trials have demonstrated the efficacy of treatment with pegylated interferon plus ribavirin and highlighted issues related to management of patients with HIV/HCV co-infection. Although treatment for HCV infection in this group remains a challenge, achievement of a sustained virologic response is feasible in approximately 35% of patients. Treatment must be individualized and attention must be paid to the potential for drug-drug interactions.

[HIV and HCV coinfection]

Chronic hepatitis due to hepatitis C virus (HCV) infection is now one of the leading causes of morbidity and mortality among HIV-infected individuals. Coinfected patients present an accelerated course toward cirrhosis and an enhanced risk of liver toxicity associated with the use of antiretroviral agents. Treatment of chronic hepatitis C in HIV1 patients is less efficacious than in HCV-monoinfected individuals and requires particular expertise.

Effect of hepatitis C coinfection on discontinuation and modification of initial HAART in primary HIV care

OBJECTIVES

To estimate the effect of hepatitis C (HCV) coinfection on time to first occurrence of either discontinuation or modification of initial HAART among previously antiretroviral therapy-naive HIV-infected patients.

METHODS

The analysis included antiretroviral therapy-naive patients who initiated HAART prior to November 2003 and were participating in the University of North Carolina Center for AIDS Research, HIV/AIDS observational clinical cohort. The effect of HCV status on time to first occurrence of either HAART discontinuation or modification was assessed using Kaplan-Meier survival estimates and multivariable proportional hazards regression was used to estimate hazard ratios.

RESULTS

Of 296 patients initiating HAART, 22% were coinfected with HCV. During a median follow-up of 473 days [interquartile range (IQR), 167-940] from HAART initiation, 104 (35%) patients discontinued and 91 (31%) modified their first regimen. Reasons for discontinuation and modification were comparable by HCV serostatus and included treatment failure (12%), toxicity (41%), and barriers to adherence (47%). The median time to first occurrence of either discontinuation or modification among HCV-infected patients was 401 days (IQR, 128-821), and among HCV-uninfected patients was 493 days (IQR, 204-952) (P = 0.22). After adjustment for baseline demographic and clinical characteristics, the hazard ratio contrasting HCV-infected with HCV-uninfected patients was 1.39 (95% confidence interval, 0.95-2.03; P = 0.09).

CONCLUSION

HCV coinfection was only marginally associated with a shorter duration of an initial HAART regimen, suggesting optimization of a first HAART regimen may not appreciably depend on HCV serostatus.

Hepatitis C coinfection is independently associated with decreased adherence to antiretroviral therapy in a population-based HIV cohort

OBJECTIVE

To characterize the impact of hepatitis C (HCV) serostatus on adherence to antiretroviral treatment (ART) among HIV-infected adults initiating ART.

METHODS

The British Columbia HIV/AIDS Drug Treatment Program distributes, at no cost, all ART in this Canadian province. Eligible individuals used triple combination ART as their first HIV therapy and had documented HCV serology. Statistical analyses used parametric and non-parametric methods, including multivariate logistic regression. The primary outcome was > or = 95% adherence, defined as receiving > or = 95% of prescription refills during the first year of antiretroviral therapy.

RESULTS

There were 1186 patients eligible for analysis, including 606 (51%) positive for HCV antibody and 580 (49%) who were negative. In adjusted analyses, adherence was independently associated with HCV seropositivity [adjusted odds ratio (AOR), 0.48; 95% confidence interval (CI), 0.23-0.97; P = 0.003], higher plasma albumin levels (AOR, 1.07; 95% CI, 1.01-1.12; P = 0.002) and male gender (AOR, 2.53; 95% CI, 1.04-6.15; P = 0.017), but not with injection drug use (IDU), age or other markers of liver injury. There was no evidence of an interaction between HCV and liver injury in adjusted analyses; comparing different strata of HCV and IDU confirmed that HCV was associated with poor adherence independent of IDU.

CONCLUSIONS

HCV-coinfected individuals and those with lower albumin are less likely to be adherent to their ART.

Eligibility for and Outcome of Hepatitis C Treatment of HIV-Coinfected Individuals in Clinical Practice: The Swiss HIV Cohort Study

Background

Morbidity and mortality of individuals co-infected with HIV and hepatitis C virus (HCV) is often determined by the course of their HCV infection. Only a selected proportion of those in need of HCV treatment are studied in randomized controlled trials (RCTs). We analysed the prevalence of HCV infection in a large cohort, the number of individuals requiring treatment, the eligibility for HCV treatment, and the outcome of the combination therapy with pegylated interferon-α and ribavirin in routine practice.

Methods

We analysed prescription patterns of HCV treatment and treatment outcomes among participants from the Swiss HIV Cohort Study with detectable hepatitis C viraemia (between January 2001 and October 2004). Efficacy was measured by the number of patients with undetectable HCV RNA at the end of therapy (EOTR) and at 6 months after treatment termination (SVR). Intention-to-continue-treatment principles were used.

Results

A total of 2,150 of 7,048 (30.5%) participants were coinfected with HCV; HCV RNA was detected in 60%, and not assessed in 26% of HCV-antibody-positive individuals. One hundred and sixty (12.5%) of HCV-RNA-positive patients started treatment. In patients infected with HCV genotypes 1/4 or 2/3, EOTR was achieved in 43.3% and 81.2% of patients, respectively, and SVR rates were 28.4% and 51.8%, respectively. More than 50% of the HCV-treated patients would have been excluded from two large published RCTs due to demographic, clinical and laboratory criteria.

Conclusions

Despite clinical and psychosocial obstacles encountered in clinical practice, HCV treatment in HIV-coinfected individuals is feasible with results similar to those obtained in RCTs.

New paradigms in the management of HIV and hepatitis C virus coinfection

PURPOSE OF REVIEW

Chronic hepatitis C virus infection is currently one of the leading causes of morbidity and mortality in HIV-infected individuals, mainly in hemophiliacs and intravenous drug users. The bidirectional interferences between hepatitis C virus and HIV have clinical consequences and complicate the management of coinfected individuals.

RECENT FINDINGS

There is an increased rate of liver complications among coinfected patients due to the decrease in opportunistic infections resulting from the use of potent antiretroviral therapy and accelerated progression to liver cirrhosis in the HIV setting. Conversely, the risk of hepatotoxicity of antiretrovirals is higher in the presence of chronic hepatitis C. While the standard therapy for hepatitis C in HIV is the combination of pegylated interferon plus ribavirin, overall treatment responses are lower in HIV-coinfected than in hepatitis C virus-monoinfected patients. Moreover, interactions between ribavirin and HIV drugs (i.e. didanosine, zidovudine) are associated with higher risks of side effects.

SUMMARY

Given the accelerated progression to end-stage liver disease in coinfected patients, treatment of hepatitis C should be a priority. While hepatitis C therapy should not be denied in the absence of contraindication, it should be re-assessed at week 12 and therapy continued only in patients showing more than 2 log drops in viremia, to avoid side effects. Most recent data suggest that adequate selection of candidates, expert management of side effects, and prescription of appropriate ribavirin doses (in genotypes 1-4) and extending treatment (in genotypes 2-3) all might allow response rates in coinfected patients to approach those seen in hepatitis C virus-monoinfected individuals.

Effect of serostatus for hepatitis C virus on mortality among antiretrovirally naive HIV-positive patients

BACKGROUND

We examined the effect of hepatitis C virus (HCV) seropositivity on risk of death among people receiving their first antiretroviral treatment (ART) for HIV infection.

METHODS

In British Columbia, the HIV/ AIDS Drug Treatment Program is the only source of free ART. Patients who initiated a triple-drug ART regimen between July 31, 1996, and July 31, 2000, were included if they were ART-naive and had baseline HCV serological data. Outcomes of interest for survival analysis were deaths from natural and HIV-related causes, with a data cutoff of June 30, 2003.

RESULTS

Of 1186 eligible subjects, 606 (51%) were HCV positive and 580, negative. Fewer HCV-positive people were male (78% v. 93%, p < 0.001) and had an AIDS diagnosis at baseline (11% v. 15%, p = 0.028). Their CD4 fraction was significantly higher at baseline (19% v. 16% of T lymphocytes, p < 0.001) but their absolute CD4 counts, log HIV viral load and the type of ART initiated were similar to those of HCV negative people. Of 163 deaths (from natural causes only) during the study period, 118 (19%) were in HCV positive and 45 (8%) in HCV negative patients (p < 0.001); of the 114 deaths attributed to HIV infection, these proportions were 79 (13%) versus 35 (6%; p < 0.001). After adjustment for potential confounders, HCV seropositivity remained predictive of death (adjusted hazard ratio [HR] 2.20, 95% confidence interval [CI] 1.50- 3.21, p < 0.001), especially HIV-related death (adjusted HR 1.75, 95% CI 1.13- 2.72, p = 0.012).

INTERPRETATION

In this population-based HIV treatment program, we found HCV seropositivity to be an independent predictor of mortality, especially death related to HIV infection.

Hepatitis C virus treatment decision-making in the context of HIV co-infection: the role of medical, behavioral and mental health factors in assessing treatment readiness

Hepatitis C virus (HCV)-related liver disease is among the leading causes of mortality among HIV patients, yet very few co-infected patients receive pegylated-interferon and ribavirin combination therapy, the standard of care for chronic HCV. Whereas factors related to the provider, patient and clinic setting all contribute to HCV treatment decision-making, the decision of the provider to recommend or defer treatment is perhaps the most critical determinant of whether a patient receives treatment. This paper reviews the literature related to the medical, behavioral and mental health variables that contribute to providers' assessment of treatment readiness, and associations with treatment response, adherence and retention. A greater understanding of the multilevel factors contributing to HCV treatment decision-making, as well as patient characteristics that predict treatment outcome and adherence, can inform the development of interventions aimed at improving HCV care for HIV patients.

Pegylated interferon alpha-2a with or without ribavirin in HCV/HIV coinfection: partially blinded, randomized multicenter trial

We evaluated the safety and efficacy of peginterferon alpha-2a (pegIFNalpha-2a), with or without ribavirin, in 154 HCV/HIV coinfected patients. All received pegIFNalpha-2a (180 microg/week) for 12 weeks, with those achieving an early virologic response (EVR) continued on monotherapy through week 48. Patients without an EVR were randomized at week 14 to also receive ribavirin (800 mg/day) or placebo through week 48. Patients with detectable HCV RNA at week 24 were discontinued. An EVR occurred in 59 of 154 patients on monotherapy, and a sustained virologic response (SVR) occurred in 19 of 55 of those achieving an EVR and continuing monotherapy through week 48. One week 12 nonresponder receiving pegIFNalpha-2a plus ribavirin, and none receiving pegIFNalpha-2a plus placebo, achieved a SVR. Discontinuations for adverse events occurred in 10 of 154 patients before, and 16 of 131 after, week 14. HIV RNA and CD4 counts did not change significantly during treatment. PegIFNalpha-2a was therefore at least as effective as standard interferon and ribavirin combination therapy and was well tolerated, without a negative impact on HIV parameters.

Management of Hepatitis C in HIV-infected Patients

As the survival of HIV-infected patients has been lengthening over the past 10 years as a consequence of effective antiretroviral therapy, hepatitis C virus (HCV) coinfection has emerged as a major cause of morbidity and mortality in this population. HCV/HIV coinfection is associated with accelerated progression of liver disease, untoward effects on the immunologic and virologic response to antiretroviral medications, and possibly with a more aggressive course of HIV disease. The results of major trials of combination therapy for HCV in coinfected patients have clearly established the combination of pegylated interferon-alpha with ribavirin as the treatment of choice in this population. However, the effectiveness and tolerability of this regimen remains suboptimal, particularly in patients with genotype 1 HCV infection. This paper reviews the impact of HCV coinfection in HIV-infected patients, outlines current concepts on management and antiviral treatment, and discusses some of the newer agents, currently in the therapeutic pipeline, that are directed against novel molecular targets.

Special considerations in the initiation and management of antiretroviral therapy in individuals coinfected with HIV and hepatitis C

BACKGROUND

Although hepatitis C (HCV) treatment efficacy has improved in recent years, the majority of HIV/HCV-coinfected individuals may not enjoy the full benefits of these treatments and appropriate HIV management is crucial. Evidence is accumulating regarding the impact of HIV/HCV coinfection on the response to, and safety and tolerability of, antiretroviral therapy (ART) in this population.

METHODS

Computerized, English-language literature searches of MEDLINE and PubMed databases (January 1985 to May 2004) for studies of HIV and HCV infection in humans to examine critically (a) the impact of HCV on the HIV virologic and immunologic response to ART; (b) the safety and tolerability of ART in coinfected individuals; and (c) the relationship between immune suppression and immune restoration on hepatic injury.

RESULTS

Three key messages emerged regarding the use of ART in HIV/HCV-coinfected individuals: (a) although HCV appeared to have no impact on HIV virologic response, the data are equivocal regarding immunologic response; (b) morbidities associated with HCV infection, such as insulin resistance, diabetes, mitochondrial dysfunction, and liver inflammation, are also associated toxicities of ART, and (c) both immune suppression and restoration can contribute to the onset and acceleration of HCV-related liver disease.

CONCLUSIONS

The CD4 cell count threshold for initiating ART in HIV/HCV-coinfected patients may be higher because of the impact of immune suppression and restoration on the onset of HCV-associated liver disease and the possibility of a blunted immune response to ART at lower CD4 cell counts. Further, overlapping morbidity between HCV-related mitochondrial and metabolic disease manifestations and ART toxicities warrant careful attention by clinicians.

Hepatitis C infection increases the risk of the modification of first highly active antiretroviral therapy in HIV-infected patients

We assessed predictors of discontinuation or change of the first regimen of highly active antiretroviral therapy in 465 HIV-infected adults, in the first year. A total of 187 patients modified their regimen: 45 discontinuing and 142 changing because of clinical/virological failure, intolerance/toxicity or non-adherence. Predictors of modification of the regimen were hepatitis C seropositivity, liver cirrhosis, higher baseline viral load, sex (women had a lower risk) and calendar year (lower risk staring in 2000).

Acute liver enzyme elevations in HIV-1-infected patients

BACKGROUND

Acute liver enzyme elevations (ALEE) have been associated with a first-line highly active antiretroviral therapy (HAART) and/or viral hepatitis coinfections in HIV-infected patients. By comparison, the frequency and the risk factors of ALEE in untreated patients and in patients treated with several antiretroviral regimens need to be assessed.

PURPOSE

To describe the long-term frequency and the characteristics of ALEE in antiretroviral treated and untreated patients and to define risk factors for ALEE in a retrospective cohort of HIV-1-infected patients.

METHOD

An HIV-infected cohort was retrospectively examined. ALEE was defined as levels of alanine amino transferase and/or alkaline phosphatase rising to at least 2.5 times above baseline values. Hazard ratios (HR) for ALEE were estimated using an extension of the Cox proportional model taking into account recurrent events.

RESULTS

Out of 239 assessable patients, 12 (5%) were coinfected with hepatitis B virus (HBV) and 34 (14.2%) with hepatitis C virus (HCV). The incidence rate of ALEE was 9.9/100 patients-year and the cumulative incidence was 20.9%. HCV genotype 3 tended to give a higher risk of ALEE. Independent factors for developing ALEE in multivariate logistic regression were HBV (HR = 4.0) and HCV (HR = 3.4) coinfections, antiretroviral therapy (HR = 2.6), CDC stage C (HR = 2.5), and high alkaline phosphatase baseline values (HR = 1.7).

CONCLUSION

The occurrence of ALEE is influenced more by the past medical history and the clinical background of the patients than by antiretroviral therapy. These patient-linked variables must be taken into account to avoid unwarranted treatment withdrawal.

Update on chronic hepatitis C in HIV/HCV-coinfected patients: viral interactions and therapy

With highly active antiretroviral therapy (HAART), HIV-infected patients can now live longer and healthier lives, and other comorbid diseases, such as chronic hepatitis C, have emerged as a significant health concern. Coinfection with the hepatitis C virus (HCV) may limit life expectancy because it can lead to serious liver disease including decompensated liver cirrhosis and hepatocellular carcinoma. HCV-induced fibrosis progresses faster in HIV/HCV-coinfected persons, although HAART may be able to decrease this disease acceleration. Combination therapy for HCV with interferon and ribavirin can achieve a sustained viral response, although at a lower rate than in HCV-monoinfected patients. Combination treatment with pegylated interferon and ribavirin will probably emerge as the next HCV therapy of choice for HIV/HCV-coinfected patients. HCV combination therapy is generally safe, but serious adverse reactions, like lactic acidosis, may occur. Cytopenia may present a problem leading to dose reductions, but the role of growth factors is under study. All HIV/HCV-coinfected patients should be evaluated for therapy against the hepatitis C virus. A sustained viral load will probably lead to regression of liver disease, and even interferon-based treatment without viral clearance may slow down progression of liver disease. HIV/HCV-coinfected patients who have progressed to end-stage liver disease have few therapeutic options other than palliative care, since liver transplants are generally unavailable. The mortality post-transplant may be higher than in HCV-monoinfected patients. We are entering an era where safe and effective HCV therapy is being defined for HIV/HCV-coinfected patients, and all eligible patients should be offered treatment.

Managing antiretroviral-associated liver disease

The use of all potent drugs is associated with toxicities and antiretroviral (ARV) drugs are no exception. Antiretroviral therapy-associated hepatic toxicity is of increasing concern in the management of patients with HIV/AIDS. Liver toxicity has been reported in some HIV-infected patients being treated with drugs from all of these classes of ARV drugs: protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Although the majority of cases involve asymptomatic elevations of liver enzymes (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]), severe, and, in a minority of cases, life threatening, liver disease has been reported in patients treated with ARV drugs. The exact causes of elevated plasma levels of AST and ALT are complex and, in many cases, obscure. The combination of viral hepatic disease, drugs that act adversely directly on the liver and drugs that act on other systems of the body which in turn, adversely affect the liver, can result in hepatic toxicity. Such toxicity may be inappropriately attributed solely to the direct effect of a drug. Knowledge of the possible causes of liver toxicity, and ways to avoid it, should reduce the risk of developing hepatotoxicity. The physician's task is to prevent the development of liver toxicity, e.g., by choosing appropriate therapeutic regimens and by careful management of the patient. This involves frequent monitoring of the patient, both clinically and by utilizing liver function tests on a regular basis. If signs and symptoms of liver disease do develop, prompt and expert management is essential. This review discusses the influence of a number of factors on hepatic toxicity including viral hepatitis, insulin resistance and the specific ARV drugs used in the treatment of patients with HIV/AIDS.

The clinical spectrum of hepatitis C virus in HIV coinfection

The biochemical, virologic, and histologic spectrum of hepatitis C virus (HCV) in 66 consecutive patients with HIV-HCV coinfection and 119 HCV controls was compared: 86% of coinfected patients had CD4 counts >200 cells/mm3, 51% had a normal alanine aminotransferase (ALT) value, the mean HCV RNA titer was 5.7 log IU/mL, 92% of coinfected patients were of genotype 1, and the mean histologic activity index was 6.86 with advanced fibrosis in 32% of patients. The biochemical, virologic, and histologic findings of HCV in coinfected patients were similar to those observed in HCV controls. For both groups of patients, no clinical, biochemical, or virologic factors could reliably identify patients with advanced fibrosis or cirrhosis, underscoring the importance of liver biopsy in the evaluation of these patients. The spectrum of liver disease in coinfection includes a significant proportion of patients with normal ALT values, and excluding these patients from previous studies has led to an overestimation of HCV disease severity.

Immune recovery is associated with persistent rise in hepatitis C virus RNA, infrequent liver test flares, and is not impaired by hepatitis C virus in co-infected subjects

OBJECTIVES

The impact of highly active antiretroviral therapy (HAART) on hepatitis C virus (HCV) is unknown. We analysed changes in HCV RNA and the frequency of hepatotoxicity in co-infected patient enrolling in AIDS Clinical Trials Group trials, and determined whether HCV impairs successful immune reconstitution in these populations.

DESIGN/METHODS

In a prospective analysis of co-infected patients completing at least 16 weeks of HAART in four trials, and co-infected patients with available stored plasma from two other completed HAART trials, HCV RNA was measured at baseline and to week 48. A retrospective analysis of immune recovery in 40 HCV-RNA-positive and 129 HCV-RNA-negative patients from a single trial was performed.

RESULTS

Prospective analysis: 60 patients completed at least 16 weeks of HAART. The mean HCV-RNA level increased 0.35 log IU/ml at week 16 and 0.43 log IU/ml at week 48. When stratified by baseline CD4 cell count, subjects' HCV-RNA levels increased 0.43 and 0.59 log IU/ml at weeks 16 and 48 for entry CD4 cell counts < 350 cells/mm, but only 0.26 and 0.1 log IU/ml at weeks 16 and 48 for entry CD4 cell counts > 350 cells/mm. Severe alanine aminotransferase elevations occurred in only 3.3%. Retrospective analysis: HCV co-infection had no effect on the overall mean CD4 cell increase at weeks 16 or 48 compared with uninfected controls.

CONCLUSION

In HCV-co-infected patients undergoing HAART, immune recovery is associated with a persistent increase in HCV RNA, especially with baseline CD4 cell counts < 350 cells/mm. HCV co-infection did not antagonize the CD4 cell response to HAART.

Is hepatitis C virus co-infection associated with survival in HIV-infected patients treated by combination antiretroviral therapy?

OBJECTIVE

To study whether hepatitis C virus (HCV) co-infection or the severe elevation of transaminases is associated with survival after the initiation of antiretroviral combination therapy.

DESIGN

Prospective hospital-based cohort (Aquitaine Cohort).

METHODS

HIV-infected adults started on an antiretroviral combination before 30 June 1999. HCV infection was defined as antibody detection or positive HCV RNA. Severe elevation of transaminases was defined as a value of aspartate or alanine aminotransferase (AST, ALT) above five times the upper limit of normal values. Survival was studied using a Cox model, including at least baseline HCV status and transaminases as a time-dependent covariate.

RESULTS

Overall, 995 patients were analysed, including 576 HCV-positive individuals (58%). At baseline, HCV-positive patients were younger, more often injecting drug users and women, and had more frequently elevated transaminases. A shorter survival was associated with AIDS stage [hazard ratio (HR) versus non-AIDS 1.67; 95% confidence interval (CI) 1.03; 2.68], lower CD4 cell count (HR for 50 cells/mm3 lower 1.33; CI 1.17; 1.51), lower haemoglobin (HR for 1 g/dl lower 1.20; CI 1.07; 1.35), lower platelet count (HR for 10 000 cells/mm3 lower 1.04; CI 1.01; 1.07), and AST during follow-up (HR for > or = 200 IU/l 2.30; CI 1.32; 4.03). HCV co-infection (HR 1.20; CI 0.75; 1.92) was not statistically associated with survival.

CONCLUSION

The occurrence of a severe elevation of transaminases was associated with poorer survival, although HCV was not. If liver toxicity may be treatment induced, plasma drug concentrations could guide dosage adjustments of antiretroviral treatments currently prescribed to optimize their use.

Hepatotoxicity associated with antiretroviral therapy containing dual versus single protease inhibitors in individuals coinfected with hepatitis C virus and human immunodeficiency virus

To determine the rates of patients coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) who discontinued therapy as a result of protease inhibitor (PI)-related hepatotoxicity, a retrospective review was conducted. Baseline CD4 counts, plasma HIV RNA levels, and duration of therapy were comparable between single- and dual-PI-treated subjects and between subjects receiving ritonavir-containing therapy and those receiving ritonavir-sparing therapy. The proportions of patients with elevations in alanine aminotransferase level to > or =5 times the upper limit of normal (19% versus 26%) and hyperbilirubinemia (30% versus 38%) were similar between the dual-PI (n=27) and single-PI treatment groups (n=39), respectively. No difference in these characteristics was observed between ritonavir-containing (n=34) and ritonavir-sparing (n=32) treatment arms. Rates of treatment discontinuation due to hepatotoxicity were similar for single-PI and dual-PI therapy and for ritonavir-containing and ritonavir-sparing regimens. Dual-PI therapy and inclusion of ritonavir do not seem to increase the rates of hepatotoxicity in PI-treated, HIV-HCV coinfected subjects.

Characteristics of hepatitis C virus infection in HIV-infected people

Knowledge pertaining to hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co-infection is currently incomplete or conflicting. Several points are well studied, however. Plasma HCV RNA levels are higher in matched HIV-infected people than in HIV-seronegative control subjects and are inversely correlated with CD4(+) T lymphocyte counts. HCV genotype does not appear to influence this value. Co-infected individuals develop histological and clinical features of HCV liver disease more rapidly than HIV-seronegative patients. Co-infected individuals appear to respond to interferon-alpha therapy equally as well as HIV-seronegative HCV-infected adults, but minimal information exists regarding the efficacy and toxicity of combination HCV therapy (interferon-alpha plus ribavirin) in this population. Adverse consequences of highly active antiretroviral therapy in co-infected patients include hepatic toxicity and, in a minority of patients, an 'immune restoration syndrome'. It is unclear whether long term, highly active antiretroviral therapy positively or negatively influences the natural history of HCV infection.

Issues in HIV/Hepatitis C Co-infection

Co-infection of patients with hepatitis C virus (HCV) and HIV is prevalent. HCV disease is clearly exacerbated in the setting of HIV disease, and the long-term effects of HCV have become an increasing concern as patients live longer on highly active antiretroviral therapy. Although treatment for HCV disease is evolving rapidly, its role in the HIV-infected patient is not well delineated. This review will focus on the major issues in the HIV/HCV co-infected patient and discuss therapy for HCV in the era of highly active antiretroviral therapy.