Risk factors for symptomatic mitochondrial toxicity in HIV/hepatitis C virus-coinfected patients during interferon plus ribavirin-based therapy

Drug-drug interactions with candidate medications used for COVID-19 treatment: An overview

Drug-drug interaction (DDI) is a common clinical problem that has occurred as a result of the concomitant use of multiple drugs. DDI may occur in patients under treatment with medications used for coronavirus disease 2019 (COVID-19; i.e., chloroquine, lopinavir/ritonavir, ribavirin, tocilizumab, and remdesivir) and increase the risk of serious adverse reactions such as QT-prolongation, retinopathy, increased risk of infection, and hepatotoxicity. This review focuses on summarizing DDIs for candidate medications used for COVID-19 in order to minimize the adverse reactions.

Peg-interferon Plus Ribavirin Combination Therapy in HCV Mono-infected and HCV/HIV Co-infected Patients in Iran

Background: Hepatitis C virus (HCV) infection is a cause of major liver complications, particularly in patients infected with human immunodeficiency virus (HIV). This study aimed to evaluate the efficacy of pegylated interferon (Peg-IFN) and a fixed dose of ribavirin treatment among Iranian HCV mono-infected and HCV/HIV-co-infected patients.

Methods: A total of 214 HCV mono-infected and HCV/HIV co-infected patients attending Liver Disease Center in Tehran were assigned to receive treatment with Peg-IFN-α2a or -α2b plus ribavirin for 24-48 weeks. Sustained virologic response (SVR) was used as the primary efficacy endpoint of Peg-IFN and ribavirin therapy.

Results: Treatment with Peg-IFN and ribavirin has been associated with a considerably higher rate of SVR (24 weeks for HCV genotype 3 and 48 weeks for HCV/HIV co-infected and HCV genotype 1 patients). Overall, the clearance of HCV-RNA at the end of therapy occurred in 48.6% of patients. Adverse events leading to treatment discontinuation were seen in 14% of patients.

Conclusion: This retrospective study revealed a relatively well-tolerated response in both HCV mono-infected and HCV/HIV coinfected patients during treatment with Peg-IFN and ribavirin. However, the recent revolutionized interferon-free therapies for chronic HCV infection should be taken into account for achieving a greater response and minimal adverse events.

Daily cannabis and reduced risk of steatosis in human immunodeficiency virus and hepatitis C virus-co-infected patients (ANRS CO13-HEPAVIH)

Liver steatosis is common in human immunodeficiency virus (HIV)-hepatitis C virus (HCV)-co-infected patients. Some recent studies have found that cannabis use is negatively associated with insulin resistance in the general population and in HIV-HCV-co-infected patients. Given the causal link between insulin resistance and steatosis, we hypothesized that cannabis use has a positive impact on steatosis. Therefore, we aimed to study whether cannabis use in this population was associated with a reduced risk of steatosis, measured by ultrasound examination. ANRS CO13-HEPAVIH is a French nationwide multicentre cohort of HIV-HCV-co-infected patients. Medical and socio-behavioural data from clinical follow-up visits and annual self-administered questionnaires were prospectively collected. A cross-sectional analysis was conducted using data from the first visit where both ultrasound examination data for steatosis (positive or negative diagnosis) and data on cannabis use were available. A logistic regression model was used to evaluate the association between cannabis use and steatosis. Among study sample patients (n = 838), 40.1% had steatosis. Fourteen per cent reported daily cannabis use, 11.7% regular use and 74.7% no use or occasional use ("never or sometimes"). Daily cannabis use was independently associated with a reduced prevalence of steatosis (adjusted odds ratio [95% CI] = 0.64 [0.42;0.99]; P = .046), after adjusting for body mass index, hazardous alcohol consumption and current or lifetime use of lamivudine/zidovudine. Daily cannabis use may be a protective factor against steatosis in HIV-HCV-co-infected patients. These findings confirm the need for a clinical evaluation of cannabis-based pharmacotherapies in this population. Eudract.ema.europa.eu number, DGS050367.

Regimens for Patients Coinfected with Human Immunodeficiency Virus

Hepatitis C virus (HCV) coinfection is prevalent in patients with human immunodeficiency virus (HIV) and has an accelerated disease course. Direct-acting antiviral (DAA) therapies that do not require interferon increase response rates to levels identical to those seen in HCV monoinfection. However, drug-drug interaction between antiretrovirals and HCV medication is the major consideration in deciding on the appropriate HCV therapeutic approach in patients with HIV. This article summarizes the currently available data with HCV DAAs in patients with HIV, and focuses on predicting and managing drug interaction to facilitate successful DAA-based HCV therapy in those with HIV.

HCV and HIV co-infection: mechanisms and management

HCV and HIV co-infection is associated with accelerated hepatic fibrosis progression and higher rates of liver decompensation and death compared to HCV monoinfection, and liver disease is a leading cause of non-AIDS-related mortality among HIV-infected patients. New insights have revealed multiple mechanisms by which HCV and HIV lead to accelerated disease progression, specifically that HIV infection increases HCV replication, augments HCV-induced hepatic inflammation, increases hepatocyte apoptosis, increases microbial translocation from the gut and leads to an impairment of HCV-specific immune responses. Treatment of HIV with antiretroviral therapy and treatment of HCV have independently been shown to delay the progression of fibrosis and reduce complications from end-stage liver disease among co-infected patients. However, rates of sustained virologic response with PEG-IFN and ribavirin have been significantly inferior among co-infected patients compared with HCV-monoinfected patients, and treatment uptake has remained low given the limited efficacy and tolerability of current HCV regimens. With multiple direct-acting antiviral agents in development to treat HCV, a unique opportunity exists to redefine the treatment paradigm for co-infected patients, which incorporates data on fibrosis stage as well as potential drug interactions with antiretroviral therapy.

Update on Hepatitis C Virus and HIV Coinfection

Chronic hepatitis C virus (HCV) infection has historically been difficult to treat in the HIV-infected population, owing to generally poor responses to interferon-based therapies. The recent rapid development of directly acting antiviral agents (DAAs) against HCV has the potential to revolutionize treatment of this infection in the HIV population by improving tolerability and outcome, and, ultimately, reducing the significant burden of liver-related morbidity and mortality in this population. Clinical trials to address the safety and efficacy of novel DAAs in the HCV/HIV coinfected population are ongoing, and show much promise. The rapidity of current drug discovery in the field of HCV is both impressive and daunting for clinicians who will have to master these drugs. Going forward, the inclusion of individuals from this large and growing patient population in clinical trials will be of paramount importance.

Antiretroviral and anti-hepatitis C virus direct-acting antiviral-related hepatotoxicity

Antiretroviral-related hepatotoxicity occurs commonly in patients with human immunodeficiency virus (HIV). Liver injury ranges from unconjugated hyperbilirubinemia and nodular regenerative hyperplasia to lactic acidosis and toxic hepatitis. Effective antiretroviral therapy has changed coinfected patients' primary morbidities and mortality to chronic liver disease rather than complications from HIV. Treatment for hepatitis C virus (HCV) is strongly encouraged early in all coinfected patients. However, drug-drug interactions must be considered to ensure safe and tolerable use alone or in combination with antiretroviral therapies. The first-generation and newer HCV direct-acting antivirals are promising in coinfected patients, with minimal side effects and hepatotoxicity.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

Short communication: Interferon/ribavirin treatment for HCV is associated with the development of hypophosphatemia in HIV/hepatitis C virus-coinfected patients

One-third of all HIV-infected individuals in the United States are estimated to be coinfected with the hepatitis C virus (HCV). Treatment of chronic hepatitis C in patients coinfected with HIV is a complex problem associated with toxicities and drug interactions between HIV antiretrovirals and interferon and ribavirin. In recent HCV treatment studies, we observed a previously unreported development of hypophosphatemia in HIV/HCV-coinfected patients treated with interferon/ribavirin (IFN/RBV). To further investigate this observation, we retrospectively reviewed 61 HIV/HCV-coinfected patients on antiretrovirals (ARVs) during treatment with IFN/RBV as well as 154 HIV-infected patients treated with ARVs alone. We found that HIV/HCV-coinfected patients on IFN/RBV therapy were more likely to develop frequent (57% vs. 13%, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)=0.001) and higher-grade hypophosphatemia (67.0% Grade 2, 33.3% Grade 3 vs. 94.7% Grade 2, 5.3% Grade 3, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)<0.001) than untreated patients. In addition, we found that the new onset of hypophosphatemia after IFN/RBV treatment initiation was followed by a diminished frequency of this toxicity upon cessation of IFN/RBV, supporting the idea that a drug-drug interaction may increase the risk of this toxicity. To understand the risks of developing this toxicity, we evaluated the association between individual ARV use and hypophosphatemia incidence. Our data suggest that concomitant tenofovir (TDF) use may be a risk factor for the development of hypophosphatemia in HIV/HCV-coinfected patients treated with IFN/RBV. Although the etiology of this abnormality is likely multifactorial, clinicians should be aware of hypophosphatemia as a potential marker of renal toxicity in HIV/HCV-coinfected patients being treated with IFN/RBV regimens.

What the infectious disease physician needs to know about pegylated interferon and ribavirin

The treatment of chronic hepatitis C is rapidly evolving from triple therapy to regimens that do not require interferon or even ribavirin. However, pegylated interferon and ribavirin will remain the backbone of hepatitis C therapy for the time being. This review summarizes the pharmacokinetics of peginterferon and ribavirin with a particular emphasis on their side-effect profile and management. Finally, the continued role of peginterferon and ribavirin in future therapies will be discussed.

The treatment of chronic hepatitis C virus infection in HIV co-infection

Chronic HCV co-infection is present in up to one third of HIV-positive patients in Europe. In recent years, apart from the traditional transmission route of intravenous drug abuse, outbreaks of sexually transmitted acute HCV infections, mainly among HIV-positive men who have sex with men, have contributed to the overall disease burden.

Because the natural course of HCV infection is substantially accelerated in HIV-co-infection, end-stage liver disease has become the most frequent cause of non-AIDS related death in this population. Therefore every HIV/HCV co-infected patient should be evaluated for possible anti-HCV therapy with the goal of reaching a sustained virological response and thus cure of hepatitis C infection. The standard of care for the treatment of chronic HCV infection in HIV-infected remains a pegylated interferon in combination with weight-adapted ribavirin.

HAART should not be withheld from HCV co-infected patients due to concerns of drug related hepatotoxicity and in patients with reduced CD4-cell counts HAART should be started first. Under pegylated interferon and ribavirin combination therapy drug to drug interactions and cumulated toxicity between nucleoside analogues and anti-HCV therapy may be observed and concomitant didanosine use is contraindicated and zidovudine and stavudine should be avoided if possible.

The development of new drugs for the treatment of chronic hepatitis C represents a promising perspective also for HIV positive patients. However, these substances will probably reach clinical routine for HIV patients later than HCV monoinfected patients. Therefore at present waiting for new drugs is not an alternative to a modern pegylated interferon/ribavirin therapy.

Inhibition of HCV by the serpin antithrombin III

Background

Although there have been dramatic strides made recently in the treatment of chronic hepatitis C virus infection, interferon-α based therapy remains challenging for certain populations, including those with unfavorable IL28B genotypes, psychiatric co-morbidity, HIV co-infection, and decompensated liver disease. We have recently shown that ATIII, a serine protease inhibitor (serpin), has broad antiviral properties.

Results

We now show that ATIII is capable of inhibiting HCV in the OR6 replicon model at micromolar concentrations. At a mechanistic level using gene-expression arrays, we found that ATIII treatment down-regulated multiple host cell signal transduction factors involved in the pathogenesis of cirrhosis and hepatocellular carcinoma, including Jun, Myc and BMP2. Using a protein interactive network analysis we found that changes in gene-expression caused by ATIII were dependent on three nodes previously implicated in HCV disease progression or HCV replication: NFκB, P38 MAPK, and ERK1/2.

Conclusions

Our findings suggest that ATIII stimulates a novel innate antiviral host cell defense different from current treatment options.

HIV-HCV co-infection facing HCV protease inhibitor licensing: implications for clinicians

With the licensing of the first hepatitis C (HCV) protease inhibitors (PI), telaprevir (TVR) and boceprevir (BOC), cure rates for chronic HCV infection will substantially improve. Human immunodeficiency virus- chronic hepatitis C (HIV-HCV) co-infected patients are in urgent need for these new drugs, because they are facing both severe liver disease and lower response rates than HCV monoinfected patients. The currently available efficacy data are however, limited to two phase II trials. Fortunately, TVR and BOC appear to be able to improve cure rates in co-infected patients. A major challenge for clinicians will be the management of drug-drug interactions of antiretroviral drugs and new PI. As HCV PI are also metabolized by the cytochrome P450 3A4 system interactions are probable as well with non-nucleoside reverse transcriptase inhibitors as with HIV PI. To our knowledge, TVR can only be safely used with one protease inhibitor, boosted atazanavir, and also with efavirenz (EFV), although this combination requires TVR dose adjustments. Boceprevir should not be combined with HIV PI and should not be combined with EFV. The approval of TVR and BOC will create new chances of cure also for HIV-HCV co-infected patients. However, the decision who to treat or not has to be taken carefully on the basis of fibrosis stage and previous treatment outcomes. In addition, HIV therapy needs to be optimized according to the available drug-drug interaction data.

Telaprevir: a hepatitis C NS3/4A protease inhibitor

BACKGROUND

Telaprevir is a hepatitis C NS3/4A protease inhibitor approved by the US Food and Drug Administration as part of combination therapy for the management of chronic hepatitis C virus (HCV) genotype 1 infection.

OBJECTIVE

The article reviews published literature on telaprevir, including its chemistry, mechanism of action, resistance, pharmacodynamic and pharmacokinetic properties, drug interactions, therapeutic efficacy, HIV/HCV coinfection, pharmacogenomics, adverse events, pharmacoeconomics, and dosing and administration.

METHODS

English-language literature was included. Searches of MEDLINE and BIOSIS databases from 1975 through January 2012 were performed. Emphasis was placed on reference citations involving clinical trials, randomized controlled trials, and research in humans. Additional publications were found by searching the reference lists of identified articles and reviewing abstracts from recent scientific meetings. Search terms included, but were not limited to, telaprevir, VX-950, hepatitis C virus genotype 1, resistance, pharmacology, pharmacokinetics, pharmacodynamics, drug interactions, pharmacogenomics, adverse events, and therapeutic use.

RESULTS

Review of the databases revealed 471 publications/abstracts on this subject. Of these, 85 were chosen based on the review criteria. Two Phase III studies investigated the efficacy and tolerability of telaprevir administered for 12 weeks (T12) when used with peginterferon alfa and ribavirin (PR) in treatment-naive subjects. The ADVANCE study reported that patients who had an extended rapid virologic response (eRVR; an undetectable HCV RNA level at both 4 and 12 weeks of treatment) with triple therapy could be treated with PR for a total of 24 weeks (T12PR24 group) versus standard PR treatment for 48 weeks (PR48 group [control]). The proportions of patients who achieved sustained virologic response (SVR; undetectable HCV RNA concentration at 24 weeks after the completion of therapy) in the T12PR24 and PR48 groups were 89% and 44%, respectively. The ILLUMINATE study reported T12PR24 was noninferior to T12PR48 in patients with an eRVR to combination therapy. In the REALIZE study, patients with a history of relapse responded well to T12PR48 compared with PR48 (SVR, 83% vs 24%). Telaprevir is a substrate/inhibitor of cytochrome P450 (CYP3A4) and a substrate/inhibitor of P-glycoprotein and poses an important risk for drug interactions. Adverse drug events (ADEs) reported most commonly with triple therapy compared with the T or PR regimen alone were rash, pruritus, nausea, diarrhea, and anemia. The serious AEs most commonly reported during T + PR therapy were anemia, rash, and pruritus. Two reports concluded that T combined with PR was not cost-effective due to the high cost of telaprevir. One study reported that the combination of T + PR would be cost-effective if the treatment rate of HCV genotype 1 infected patients reached 50%.

CONCLUSION

Including telaprevir as part of triple therapy for the management of chronic HCV genotype 1 infection significantly increases the likelihood of achieving an SVR over standard dual drug therapy (PR) in both treatment-naive and -experienced patients. However, due to the high cost, the use of triple therapy with telaprevir will likely be limited to patient groups known to respond poorly to dual therapy.

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.

Directly acting antivirals for hepatitis C and antiretrovirals: potential for drug-drug interactions

PURPOSE OF REVIEW

Boceprevir and telaprevir are directly acting antivirals (DAAs) that have recently been licensed for treatment of hepatitis C virus (HCV) infection. Data in both untreated and previously treated patients indicate a significantly increased sustained virological response (SVR) compared with that observed with conventional therapy. However, the advent of DAA therapy poses specific challenges for HCV treatment in terms of managing drug-drug interactions (DDIs). This review aims to provide a comprehensive summary of DDI with the recently licensed DAAs, including pharmacokinetic data and current recommendations made by the manufacturers and with particular reference to antiretrovirals. Potential for DDIs with the DAAs in clinical development and the mechanisms of interaction are also discussed.

RECENT FINDINGS

Targeted pharmacokinetic drug interaction studies have demonstrated that both boceprevir and telaprevir are potent inhibitors of the metabolic enzyme cytochrome P4503A4, making them perpetrators of interactions with co-administered medications which are metabolized by this enzyme. In addition, co-administered medications may affect plasma levels of boceprevir and telaprevir via various mechanisms, some of which remain to be fully elucidated.

SUMMARY

As a result of DDIs, the concomitant use of some medicines with DAA will be contraindicated, whereas other combinations may require caution, monitoring, or dose modification of the co-administered drug. Management of DDIs with these novel agents will pose a new challenge, and prescriber awareness of the potential for DDIs is fundamental for safe prescribing. Online resources are likely to play a key role in prescriber education and clinical decision-making.

Iatrogenic mitochondriopathies: a recent lesson from nucleoside/nucleotide reverse transcriptase inhibitors

The use of nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) has revolutionized the treatment of infection by human immunodeficiency virus (HIV) and hepatitis-B virus. NRTIs can suppress viral replication in the long-term, but possess significant toxicity that can seriously compromise treatment effectiveness. The major toxicity of NRTIs is mitochondrial toxicity. This manifests as serious side effects such as myopathy, peripheral neuropathy and lactic acidosis. In general, it is believed that the mitochondrial pathogenesis is closely related to the effect of NRTIs on mitochondrial DNA polymerase-γ. Depletion and mutation of mitochondrial DNA during chronic NRTI therapy may lead to cellular respiratory dysfunction and release of reactive oxidative species, resulting in cellular damage. It is now apparent that the etiology is far more complex than originally thought. It appears to involve multiple mechanisms as well as host factors such as HIV per se, inborn mitochondrial mutation, and sex. Management of mitochondrial toxicity during NRTI therapy remains a challenge. Interruption of NRTI therapy and substitution of the causative agents with alternative better-tolerated NRTIs represents the mainstay of management for mitochondrial toxicity and its clinical manifestations. A range of pharmacological approaches has been proposed as treatments and prophylaxes.

The HIV/HCV-coinfected patient and new treatment options

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

Impact of HAART exposure and associated lipodystrophy on advanced liver fibrosis in HIV/HCV-coinfected patients

The impact of antiretroviral drug exposure and associated lipodystrophy and/or insulin resistance (IR) on advanced liver fibrosis in HIV/HCV-coinfected patients is not fully documented. We determined the prevalence of advanced liver fibrosis (defined by hepatic stiffness ≥9.5 kPa) and associated factors, focusing on the impact of highly active antiretroviral therapy and its major adverse effects (lipodystrophy and IR), in 671 HIV/HCV-coinfected patients included in the ANRS CO13 HEPAVIH cohort. One hundred ninety patients (28.3%) had advanced liver fibrosis. In univariate analysis, advanced liver fibrosis was significantly associated with male sex, higher body mass index, HCV infection through intravenous drug use, a lower absolute CD4 cell count, a longer history of antiretroviral treatment, longer durations of protease inhibitors, non-nucleoside reverse transcriptase inhibitors and NRTI exposure, lipodystrophy, diabetes, and a high homeostasis model assessment method (HOMA) value. The only antiretroviral drugs associated with advanced liver fibrosis were efavirenz, stavudine and didanosine. In multivariate analysis, male sex (OR 2.0, 95% CI 1.1-3.5; P = 0.018), HCV infection through intravenous drug use (OR 2.0, 95% CI 1.1-3.6; P = 0.018), lipodystrophy (OR 2.0, 95% CI 1.2-3.3; P = 0.01), median didanosine exposure longer than 5 months (OR 1.7, 95% CI 1.0-2.8; P = 0.04) and a high HOMA value (OR 1.1, 95% CI 1.0-1.2; P = 0.005) remained significantly associated with advanced liver fibrosis. Mitochondrial toxicity and IR thus appear to play a key role in liver damage associated with HIV/HCV-coinfection, and this should be taken into account when selecting and optimizing antiretroviral therapy. Antiretroviral drugs with strong mitochondrial toxicity (e.g. didanosine) or a major effect on glucose metabolism should be avoided.

[Treatment of chronic hepatitis B: adherence and safety]

Second generation nucleos (t) idic analogues result in a complete viral suppression after 48 to 96 weeks of therapy in most patients, regardless of the virus (HBV genotype, wild type or pre-C mutant), the underlying liver disease (cirrhosis or not) or the immune status (mono- or HIV/HBV co-infection). This antiviral efficacy may result in HBe or HBs seroconversion. Its clinical impact is important since inactivation of necroinflammation allows, in the absence of liver comorbidities, a stabilisation then a reversal of fibrosis and cirrhosis, and consequently a decrease in the occurrence of carcinomatous or non-carcinomatous complications. The future issues for long-term anti-HBV therapy will be adherence on the one hand and safety on the other hand. Therapeutic failures are mainly related to poor adherence more than to viral resistance. Adherence of patients has to be optimized by therapeutic education and education of physicians. Long-term safety has to be systematically evaluated. More than the neuromuscular or metabolic side effects (lactic acidosis), the renal and bone-related adverse events have to be monitored, followed-up and anticipated by good clinical practices.

Evaluation of Lassa antiviral compound ST-193 in a guinea pig model

Lassa virus (LASV), a member of the Arenaviridae family, causes a viral hemorrhagic fever endemic to West Africa, where as many as 300,000 infections occur per year. Presently, there are no FDA-approved LASV-specific vaccines or antiviral agents, although the antiviral drug ribavirin has shown some efficacy. A recently identified small-molecule inhibitor of arenavirus entry, ST-193, exhibits submicromolar antiviral activity in vitro. To determine the antiviral utility of ST-193 in vivo, we tested the efficacy of this compound in the LASV guinea pig model. Four groups of strain 13 guinea pigs were administered 25 or 80 mg/kg ST-193, 25 mg/kg of ribavirin, or the vehicle by the intraperitoneal (i.p.) route before infection with a lethal dose of LASV, strain Josiah, and continuing once daily for 14 days. Control animals exhibited severe disease, becoming moribund between days 10 and 15 postinfection. ST-193-treated animals exhibited fewer signs of disease and enhanced survival when compared to the ribavirin or vehicle groups. Body temperatures in all groups were elevated by day 9, but returned to normal by day 19 postinfection in the majority of ST-193-treated animals. ST-193 treatment mediated a 2-3-log reduction in viremia relative to vehicle-treated controls. The overall survival rate for the ST-193-treated guinea pigs was 62.5% (10/16) compared with 0% in the ribavirin (0/8) and vehicle (0/7) groups. These data suggest that ST-193 may serve as an improved candidate for the treatment of Lassa fever.

HIV infection and the liver: the importance of HCV-HIV coinfection and drug-induced liver injury

Hepatitis C virus-Human immunodeficiency virus (HCV-HIV) coinfections are identified in up to 30% of patients infected with HIV and in 8% of patients infected with HCV. Now that progression of HIV and deaths due to AIDS can be prevented by highly active antiretroviral therapy (HAART), it is clear that HCV coinfection is associated with accelerated progression to cirrhosis and increased liver-related morbidity and mortality. Antiviral therapy with pegylated interferon and ribavirin for HCV in HCV-HIV coinfected patients is less successful than in patients with HCV monoinfection, and HAART can cause drug-induced liver injury. Multiple barriers limit the number of HCV-HIV coinfected patients who receive antiviral therapy for HCV, and the role of orthotopic liver transplantation (OLT) in HIV monoinfected and HCV-HIV coinfected patients remains controversial. Clinical trials of HCV-specific protease or polymerase inhibitors combined with pegylated interferon and ribavirin are needed urgently in coinfected patients, both before and after OLT.

Clinical syndromes and consequences of antiretroviral-related hepatotoxicity

Highly active antiretroviral therapy (HAART)-related hepatotoxicity complicates the management of patients infected with human immunodeficiency virus (HIV), increases medical costs, alters the prescription patterns, and affects the guideline recommendations. Among the clinical consequences derived from HAART-related liver toxicity, hypersensitivity reactions and lactic acidosis are recognized as acute events with potential to evolve into fatal cases, whereas there seems to be other syndromes not as well characterized but of equal concern as possible long-term liver complications. Belonging to the latter category of syndrome, HAART-related nonalcoholic steatohepatitis, liver fibrosis, portal hypertension, and nodular regenerative hyperplasia are discussed in this review. Updated information on liver toxicity of current antiretroviral drugs, including the most recently licensed, is provided. Management and prevention of liver toxicity among HIV-infected patients treated with HAART are reviewed as well.

Pharmacological significance of triazole scaffold

The triazole nucleus is one of the most important and well known heterocycles which is a common and integral feature of a variety of natural products and medicinal agents. Triazole nucleus is present as a core structural component in an array of drug categories such as antimicrobial, anti-inflammatory, analgesic, antiepileptic, antiviral, antineoplastic, antihypertensive, antimalarial, local anaesthetic, antianxiety, antidepressant, antihistaminic, antioxidant, antitubercular, anti-Parkinson's, antidiabetic, antiobesity and immunomodulatory agents, etc. The broad and potent activity of triazole and their derivatives has established them as pharmacologically significant scaffolds. The basic heterocyclic rings present in the various medicinal agents are 1,2,3-triazole and 1,2,4-triazole. A large volume of research has been carried out on triazole and their derivatives, which has proved the pharmacological importance of this heterocyclic nucleus. The present paper is an attempt to review the pharmacological activities reported for triazole derivatives in the current literature with an update of recent research findings on this nuclei.

The influence of HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV-positive Individuals

Objective

This study was performed to investigate the impact of HAART versus no HAART and nucleoside free versus nucleoside containing HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV/HCV co-infected patients. In addition a control group of HCV mono-infected patients undergoing anti-HCV therapy was evaluated.

Methods

Multicenter, partially randomized, controlled clinical trial. HIV-negative and -positive patients with chronic HCV infection were treated with pegylated interferon alfa-2a and ribavirin (800 - 1200 mg/day) for 24 - 48 weeks in one of four treatment arms: HIV-negative (A), HIV-positive without HAART (B) and HIV-positive on HAART (C). Patients within arm C were randomized to receive open label either a nucleoside containing (C1) or a nucleoside free HAART (C2).

Results

168 patients were available for analysis. By intent-to-treat analysis similar sustained virological response rates (SVR, negative HCV-RNA 24 weeks after the end of therapy) were observed comparing HIV-negative and -positive patients (54% vs. 54%, p = 1.000). Among HIV-positive patients SVR rates were similar between patients off and on HAART (57% vs. 52%, p = 0.708). Higher SVR rates were observed in patients on a nucleoside free HAART compared to patients on a nucleoside containing HAART, though confounding could not be ruled out and in the intent-to-treat analysis the difference was not statistically significant (64% vs. 46%, p = 0.209).

Conclusions

Similar response rates for HCV therapy can be achieved in HIV-positive and -negative patients. Patients on nucleoside free HAART reached at least equal rates of sustained virological response compared to patients on standard HAART.

Ability of treatment week 12 viral response to predict long-term outcome in genotype 1 hepatitis C virus/HIV coinfected patients

OBJECTIVE

Guidelines recommendation to extend treatment duration in genotype 1 hepatitis C virus (HCV)/HIV-coinfected patients who clear the virus later than treatment week 4 is not evidence-based. Our main objective was to study the ability of week 12 viral response [early virologic response (EVR)] to predict long-term outcome in patients treated for 48 weeks.

DESIGN

Multicenter retrospective cohort analysis.

METHODS

Genotype 1 HCV treatment-naive, HIV-coinfected adult patients with compensated liver disease who started combination therapy with fixed-dose pegylated-interferon (pegIFN) alfa-2a or weight-based pegIFN alfa-2b plus ribavirin were included. Univariate and forward stepwise logistic regression analysis were used to identify predictors of sustained viral response (SVR) and relapse.

RESULTS

By intention-to-treat analysis, 31.3% (87/278) of patients achieved an SVR. SVR rate was more than three-fold higher in patients who cleared the virus by week 12 of treatment compared with late responders. Among 123 end-of-treatment responders, 36 (29.3%) relapsed. Relapse risk increased in patients with cirrhosis, in those with ribavirin dose reductions and in late responders: more than 65% of patients who cleared the virus between weeks 12 and 24 relapsed following 48 weeks of treatment compared with 10% of those attaining a complete EVR (<15 IU/ml) at treatment week 12 (risk ratio 6.4, 95% confidence interval 2.9-14.4).

CONCLUSION

Viral response at treatment week 12 is a strong predictor of long-term outcome. Genotype 1 HCV/HIV-coinfected patients who achieve a complete EVR (<15 IU/ml) are at low risk of viral relapse after completing the standard 48 weeks of therapy.

HIV/HCV-coinfection: which role can new antiretrovirals such as integrase inhibitors play?

End-stage liver disease has become one of the most frequent causes of death in HIV/HCV-coinfected patients. The role of new antiretrovirals in the progression of liver fibrosis has yet to be defined. However with significant toxicities and drug-to-drug interactions of nucleoside reverse transcriptase inhibitors in combination with ribavirin, with drug to drug interaction of HIV protease inhibitors with HCV protease inhibitors and calcineurin-inhibitors, new antiretrovirals lacking these interactions represent attractive alternatives in the setting of anti-HCV therapy or post liver transplantation. In the following review we want to focus on the new class of HIV integrase inhibitors and discuss present data with regard to special issues of HIV and HCV co-infection.

Nanomedicine for respiratory diseases

Treatment of respiratory diseases and infections has proved to be a challenging task, with the incidence of these ailments increasing worldwide. Nanotechnology-based drug and gene delivery systems offer a possible solution to some of the shortfalls of the current treatment regimen. Nanobased drug delivery systems have revolutionised the field of pharmacotherapy by presenting the ability to alter the pharmacokinetics of the conventional drugs to extend the drug retention time, reduce the toxicity and increase the half-life of the drugs. Delivery of exogenous genes to the airway epithelium in vivo has been limited by several physiological barriers, resulting in the low success rate of these systems. With the advent of nanotechnology, DNA compacted with cationic polymers to produce nanoparticles has exhibited a significant increase in the transfection efficiencies. With nanoparticulate drug/gene delivery systems, specific cells can be targeted by functionalising the polymeric nanoparticles with ligands that allow the particles to dock at a specific site of the cell. In addition, polymeric systems allow for the cargo to be released in a controlled and stimuli-responsive manner. The advantages that nanoparticulate delivery systems present in the treatment of respiratory diseases and infections are summarised in this review.

[Treatment of chronic hepatitis C in HIV-infected patients]

Since the pivotal trials conducted over the last few years which have used the combination of pegylated interferon along with fixed low doses (800 mg/day) of ribavirin and have provided treatment for 12 months, regardless the kinetics of hepatitis C virus (HCV) viral load during therapy, great progress has been made in the treatment of chronic hepatitis C in HIV-infected patients. Results approaching those seen in HCV-monoinfected patients can be obtained with optimal dosages of ribavirin, extension of treatment beyond 48 weeks in the absence of rapid virologic response and/or in patients older than 40 years, with severe fibrosis (METAVIR score F3 or F4) and/or with high HCV viral load and with a better management of HIV treatment in order to avoid a negative interaction between HCV and HIV therapies (interaction between abacavir and ribavirin) and to improve the tolerance of HCV therapy (Didanosine should never be used with ribavirin, Zidovudine and Stavudine should be avoided when possible with ribavirin).

Antiviral treatment for chronic hepatitis C in patients with human immunodeficiency virus

BACKGROUND

Antiviral treatment for chronic hepatitis C may be less effective if patients are co-infected with human immunodeficiency virus (HIV).

OBJECTIVES

To assess the benefits and harms of antiviral treatment for chronic hepatitis C in patients with HIV.

SEARCH STRATEGY

Trials were identified through manual and electronic searches in The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded. The last search was May 2009.

SELECTION CRITERIA

Randomised trials comparing at least 12 weeks of any anti-HCV treatment versus another treatment regimen or no treatment. Included patients had chronic hepatitis C and stable HIV irrespective of previous antiviral therapy.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of risk of bias were done in duplicate. Analysis was by intention-to-treat.

MAIN RESULTS

Fourteen trials were included. None of the included 2269 patients were previously treated for chronic hepatitis C. Peginterferon (either 2a, 180 microgram, or 2b, 1.5 microgram/kg, once weekly) plus ribavirin was more effective in achieving end of treatment and sustained virological response compared with interferon plus ribavirin (5 trials, 1340 patients) or peginterferon (2 trials, 714 patients). The benefit of peginterferon plus ribavirin was seen irrespective of HCV genotype although patients with genotype 1 or 4 had lower response rates (27%) than patients with genotype 2 or 3 (56%). The remaining trials compared different treatment regimens in patients who were treatment naive or had no virological response after three months of treatment, but overall they had not enough power to show any effect of increasing the dose of interferon or adding both amantadine or ribavirin. The overall mortality was 23/2111 patients with no significant differences between treatment regimens. Treatment increased the risk of adverse events including anaemia and flu-like symptoms, and several serious adverse events occurred including fatal lactic acidosis, liver failure, and suicide due to depression.

AUTHORS' CONCLUSIONS

Peginterferon plus ribavirin may be considered a treatment for patients with chronic hepatitis C and stable HIV who have not received treatment for hepatitis C as the intervention may clear the blood of HCV RNA. Supporting evidence comes mainly from the analysis of this non-validated surrogate outcome assessed in comparisons against other antiviral treatments. There is no evidence on treatment of patients who have relapsed or did not respond to previous therapy. Careful monitoring of adverse events is warranted.

Viral hepatitis and HIV co-infection

Chronic hepatitis B virus (HBV) infection is overall recognised in 10% of HIV+ persons worldwide, with large differences according to geographical region. Chronic hepatitis C virus (HCV) infection affects 25% of HIV+ individuals, with greater rates ( approximately 75%) in intravenous drug users and persons infected through contaminated blood or blood products. HIV-hepatitis co-infected individuals show an accelerated course of liver disease, with faster progression to cirrhosis. The number of anti-HBV drugs has increased in the last few years, and some agents (e.g. lamivudine, emtricitabine, tenofovir) also exert significant activity against HIV. Emergence of drug resistance challenges the long-term benefit of anti-HBV monotherapy, mainly with lamivudine. The results using new more potent anti-HBV drugs (e.g. tenofovir) are very promising, with prospects for stopping or even revert HBV-related liver damage in most cases. With respect to chronic hepatitis C, the combination of pegylated interferon plus ribavirin given for 1 year permits to achieve sustained HCV clearance in no more than 40% of HIV-HCV co-infected patients. Thus, new direct anti-HCV drugs are eagerly awaited for this population. Although being a minority, HIV+ patients with delta hepatitis and those with multiple hepatitis show the worst prognosis. Appropriate diagnosis and monitoring of chronic viral hepatitis, including the use of non-invasive tools for assessing liver fibrosis and measurement of viral load, may allow to confront adequately chronic viral hepatitis in HIV+ patients, preventing the development of end-stage liver disease, for which the only option available is liver transplantation. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol 85, issue 1, 2010.

Efficacy of pegylated interferon plus ribavirin treatment in HIV/hepatitis C virus co-infected patients receiving abacavir plus lamivudine or tenofovir plus either lamivudine or emtricitabine as nucleoside analogue backbone

OBJECTIVES

To compare the response to hepatitis C virus (HCV) therapy among human immunodeficiency virus (HIV)/HCV co-infected patients receiving a nucleos(t)ide reverse transcriptase inhibitor [N(t)RTI] backbone consisting of abacavir plus lamivudine with that observed in subjects who receive tenofovir plus lamivudine or emtricitabine.

METHODS

A total of 256 subjects, enrolled in a cohort of 948 HIV-infected patients who received pegylated interferon and ribavirin from October 2001 to January 2006, were included in this study. All patients were taking one protease inhibitor or one non-nucleoside reverse transcriptase inhibitor and abacavir plus lamivudine or tenofovir plus lamivudine or emtricitabine as N(t)RTI backbone during HCV therapy. Sustained virological response (SVR) rates in both backbone groups were compared.

RESULTS

In an intention-to-treat analysis, 20 out of 70 (29%) individuals under abacavir and 83 out of 186 (45%) under tenofovir showed SVR (P = 0.02). N(t)RTI backbone containing tenofovir was an independent predictor of SVR in the multivariate analysis [adjusted odds ratio (95% CI), 2.6 (1.05-6.9); P = 0.03]. The association between abacavir use and lower SVR was chiefly seen in patients with plasma HCV-RNA load higher than 600 000 IU/mL and genotype 1 or 4. Among patients treated with ribavirin dose <13.2 mg/kg/day, 3 (20%) of those under abacavir versus 22 (52%) under tenofovir reached SVR (P = 0.03), whereas the rates were 31% and 38% (P = 0.4), respectively, in those receiving >/=13.2 mg/kg/day.

CONCLUSIONS

HIV-infected patients who receive abacavir plus lamivudine respond worse to pegylated interferon plus ribavirin than those who are given tenofovir plus lamivudine or emtricitabine as N(t)RTI backbone, especially in those receiving lower ribavirin doses.

Longitudinal effects of hepatitis C virus treatment on hepatic mitochondrial dysfunction assessed by C-methionine breath test

BACKGROUND

Hepatitis C virus (HCV) infection is characterized by remarkable levels of oxidative stress induced by virus interactions with hepatic mitochondria.

AIM

To examine hepatic mitochondrial function in HCV-infected patients assessed by a non-invasive (13)C-methionine breath test (MeBT) and to explore longitudinal effects of antiviral treatment.

METHODS

Twenty-one patients with chronic hepatitis C undergoing antiviral treatment with pegIFNalpha and ribavirin and 20 healthy controls were studied. MeBT was performed at baseline, week 12, end-of-treatment and after 24 weeks of follow-up in all patients with early virological response (n = 15).

RESULTS

Twelve patients achieved sustained virological response (SVR); three patients relapsed for HCV-RNA replication. Cumulative percentage 13C-exhalation (cPDR(1.5h)) was significantly decreased in HCV-infected individuals compared to controls irrespective of genotype and fibrosis stage (P < 0.001). Antiviral treatment induced a further decay in cPDR(1.5h) (P < 0.01). After treatment cessation, 13C-exhalation returned at least to baseline values in all patients. SVR was even associated with a mean cPDR(1.5h) increase of 70% compared to baseline.

CONCLUSIONS

Hepatitis C virus infection and antiviral treatment synergistically impair hepatic mitochondrial function, which may return to normal after sustained virus elimination. MeBT may be a valuable diagnostic instrument for monitoring hepatic mitochondrial function in particular in patients with mitochondrial comorbidities.

Pegylated interferon 2a and 2b in combination with ribavirin for the treatment of chronic hepatitis C in HIV infected patients

Coinfection with hepatitis C virus (HCV) and HIV is an increasingly recognized clinical dilemma, particularly since the advent of highly active antiretroviral therapy. Several studies of this population have demonstrated both more rapid progression of liver disease and poorer overall prognosis compared to HCV monoinfected patients. Consensus guidelines, based primarily on the results of 4 major randomized trials, recommend treatment with peginterferon and ribavirin for 48 weeks in coinfected patients. However, this current standard of care is associated with lower response rates to therapy than those seen in monoinfected patients. Important predictors of response include HCV genotype, pretreatment HCV RNA level, and presence of rapid virologic response (RVR) and early virologic response (EVR). Use of weight-based ribavirin dosing appears to be safe and enhances the likelihood of sustained virologic response (SVR). Adverse effects most commonly encountered are anemia and weight loss. Mitochondrial toxicity can occur in the setting of concomitant nucleoside reverse transcriptase inhibitor use, especially didanosine, abacavir, and zidovudine, and these should be discontinued before initiation of ribavirin therapy. Discontinuation of therapy should be considered in patients failing to demonstrate EVR, though ongoing trials are investigating a potential role for maintenance therapy in these patients. Peginterferon combined with weight-based ribavirin is appropriate and safe for treatment of HCV in HIV - HCV coinfected patients. This review summarizes the data supporting these recommendations.

Low Response to Pegylated Interferon plus Ribavirin in HIV-Infected Patients with Chronic Hepatitis C Treated with Abacavir

Background

There is little information about the influence of antiretroviral drugs on the antiviral activity of pegylated interferon (PEG-IFN) plus ribavirin (RBV) against hepatitis C virus (HCV).

Methods

All HIV-infected patients with chronic hepatitis C who received first-line PEG-IFN plus RBV were retrospectively analyzed. Only patients in whom virological stopping rules were applied and who did not change their antiretrovirals were chosen. Plasma RBV concentrations were measured at week 4.

Results

A total of 493 patients (78% males, mean age 41 years, 78% on antiretroviral therapy, mean CD4+ T-cell count 561 cells/μl) fit the study inclusion criteria. Mean baseline serum HCV RNA was 5.89 log10 IU/ml, 65% were infected by genotypes 1 or 4 and 40% had advanced liver fibrosis (Metavir F3F4). The overall rate of sustained virological response (SVR) was 38%. Factors associated with lack of SVR in the multivariate analyses (odds ratio [95% confidence interval], P-value) were higher baseline serum HCV RNA (2.42 per log10 IU/ml [1.31–4.46], 0.005), HCV genotypes 1 or 4 (5.95 [2.50–14.29], <0.001) and lower RBV plasma trough concentrations (1.74 per μg/ml [1.15–2.63], 0.009). Interestingly, a trend was noticed for abacavir use (2.22 [0.91–5.40], 0.08), which become significant when only considering the subset of patients with RBV plasma levels <2.3 μg/ml (7.63 [1.39–41.67], 0.02).

Conclusions

The use of abacavir might interfere with the anti-HCV activity of PEG-IFN plus RBV. As both antivirals are guanosine analogues, an inhibitory competition between abacavir and RBV might explain this observation, which is more prominent in patients with lower RBV exposure.

Severe weight loss in HIV / HCV-coinfected patients treated with interferon plus ribavirin: incidence and risk factors

Weight loss is reported by more than 20% of hepatitis C virus (HCV)-monoinfected patients treated with the peg-interferon (peg-IFN) and ribavirin combination. The aim of this study was to determine the incidence and risk factors of severe weight loss (> or =10%) in human immunodeficiency virus (HIV) / HCV-coinfected patients participating in a randomized, controlled 48-week trial comparing peg-IFN alpha 2b plus ribavirin with IFN alpha-2b plus ribavirin. Univariate and multivariate analyses were used to identify links with antiretroviral treatments, anti-HCV therapy and clinical and laboratory findings. One hundred eleven (28.9%) of 383 patients who received at least one dose of anti-HCV treatment subsequently had severe weight loss. Among patients who took at least 80% of the planned total dose, severe weight loss occurred in 74 patients (32.7%). In multivariate analysis, age >40 years [hazard ratio (HR), 1.59; 95% CI 1.09 to 2.31; P = 0.016], body mass index (BMI) >22 (HR, 1.72; 95% CI, 1.16 to 2.55; P = 0.0069), peg-IFN alpha-2b (HR, 1.82; 95% CI, 1.24 to 2.69; P = 0.0022) and female sex (HR, 1.60; 95% CI, 1.05 to 2.43; P = 0.027) were associated with severe weight loss. In contrast, patients taking non-nucleoside reverse transcriptase inhibitors (NNRTI)-containing antiretroviral regimens were less likely to lose weight (HR, 0.62; 95% CI, 0.39 to 0.96; P = 0.034). Lipodystrophy tended to occur more frequently in patients who had severe weight loss than in the other patients (26.1%vs 17.6%; P = 0.0682) and patients whose weight loss >5% persisted 24 weeks after the completion of anti-HCV therapy (n = 58 / 111) were more likely to be receiving stavudine-based antiretroviral therapy, suggesting that mitochondrial toxicity plays some role in weight loss. These findings show that severe weight loss is a frequent side effect of anti-HCV therapy in HIV / HCV-coinfected patients. The underlying mechanisms remain to be identified.

Management and therapy of chronic hepatitis C in HIV

PURPOSE OF REVIEW

Chronic hepatitis C is currently one of the leading causes of hospitalization and death in HIV+ persons. Treatment is particularly challenging in coinfected patients due to lower efficacy and more side effects.

RECENT FINDINGS

The combination of pegylated interferon plus ribavirin is the current treatment of choice. In the absence of contraindications, treatment should be provided with no restrictions up front (e.g., asking unnecessarily for a liver biopsy) and revisited at weeks 4 and 12. Treatment should only be continued in early virological responders. The use of standard ribavirin doses (1000-1200 mg/day) and for at least 12 months is crucial to maximize the effect of therapy. In patients with rapid virological response (undetectable viraemia at week 4), shorter periods of therapy (24 weeks) may be advisable for hepatitis C virus genotypes 2 and 3. Patients with low CD4 percentages should defer treatment and prioritize highly active antiretroviral therapy. Didanosine should never be co-administered with ribavirin due to potential life-threatening complications. When possible, zidovudine, stavudine and abacavir should be replaced by other agents having no deleterious interactions with ribavirin.

SUMMARY

The treatment of chronic hepatitis C has become a priority in hepatitis C virus/HIV-coinfected patients, and the best results are obtained by tailoring therapy to the individual patient's characteristics.

Predictors of Severe Haematological Toxicity Secondary to Pegylated Interferon plus Ribavirin Treatment in HIV-HCV-Coinfected Patients

Background

Haematological adverse events related to pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy could affect the patients’ quality of life; however, the risk factors for severe haematological toxicity associated with this therapy in patients coinfected with hepatitis C virus (HCV) and HIV are unclear. The objective of this study was to identify predictors of severe haematological toxicity among HIV-HCV-coinfected patients treated with PEG-IFN plus RBV.

Methods

This retrospective multicentric study included 237 HIV-HCV-coinfected patients on PEG-IFN plus RBV. Predictors of severe anaemia, neutropenia, thrombocytopenia and overall haematological toxicity were analyzed.

Results

Eighty (34%) individuals showed an episode of severe haematological toxicity. Severe anaemia, neutropenia and thrombocytopenia occurred in 32 (13%), 42 (18%) and 26 (11%) patients, respectively. In the multivariate analysis, zidovudine use (adjusted odds ratio [AOR] 3.3; 95% confidence interval [CI] 1.6–10; P=0.001), baseline body weight <65 kg (AOR 2.5; 95% CI 1.1–5; P=0.024), cirrhosis (AOR 5; 95% CI 1.6–16.6; P=0.006), PEG-IFN-α2a (AOR 2.7; 95% CI 1.1–6.6; P=0.029) and pretreatment haemoglobin level <14 g/dl (AOR 2.7; 95% CI 1.3–5.5; P=0.005) were associated with any kind of severe haematological toxicity. Likewise, haemoglobin level <13 g/dl, neutrophil counts <2,500 cells/mm3 and platelet counts <175,000 cells/mm3 were independent predictors of severe anaemia, neutropenia and thrombocytopenia, respectively.

Conclusions

Zidovudine treatment, cirrhosis, baseline low body weight, use of PEG-IFN-α2a, and baseline haemoglobin level <14 g/dl are predictors of overall severe haematological toxicity secondary to PEG-IFN plus RBV in HIV-infected individuals. Low pretreatment levels of each haematological series predict a significant decrease of their values during therapy.

Premature Treatment Discontinuation in HIV/HCV-Coinfected Patients Receiving Pegylated Interferon plus Weight-Based Ribavirin

Background

Chronic hepatitis C therapy in HIV patients is often penalized by more frequent premature treatment discontinuations. It is unclear what the relative contribution of more adverse events and/or early virological failures are.

Methods

PRESCO was a prospective, multicentre, comparative trial, in which 389 HIV/HCV-coinfected patients with CD4+ T-cell counts >300 cells/ml and elevated aminotransferases received pegylated interferon-α2a (peg IFN-α2a) 180 mg per week plus ribavirin (RBV) 1,000–1,200 mg daily. Patients with HCV genotypes 1 or 4 were treated for 48 or 72 weeks while HCV genotypes 2 or 3 carriers were treated for 24 or 48 weeks. Use of didanosine was not allowed.

Results

Sustained virological response (SVR) was achieved by 193 (49.6%), and was significantly greater in HCV-2/3 than in HCV-1/4 patients (72.4% versus 35%; P<0.0001). Premature treatment discontinuations occurred in 174 patients (44.7%). This was due to early virological failure in 66 (17%), serious adverse events in 32 (8.2%), loss-to-follow-up in 12 (3.1%) and voluntary withdrawal in 64 (16.4%). Only 10 patients (2.6%) stopped HCV therapy due to severe anaemia. Two patients stopped HCV medication due to symptomatic mitochondrial toxicity. There were no episodes of hepatic decompensation.

Conclusions

Treatment with RBV 1,000–1,200 mg/day plus peg IFN-α2a is relatively safe and provided SVR in nearly half of the HIV/HCV-coinfected patients, twice as many amongst the HCV-2/3 than HCV-1/4 carriers. Avoidance of didanosine, limited use of zidovudine and therapy restricted to patients with CD4+ T-cell counts >300 cells/ml most probably explains the lower and different spectrum of serious adverse events in PRESCO compared with prior trials conducted in coinfected patients.