Efficacy and tolerance of HCV treatment in HIV-HCV coinfected patients: the potential interaction of PI treatment

Treatment outcomes of treatment-naïve Hepatitis C patients co-infected with HIV: a systematic review and meta-analysis of observational cohorts

Introduction

Co-infection with Hepatitis C (HCV) and HIV is common and HIV accelerates hepatic disease progression due to HCV. However, access to HCV treatment is limited and success rates are generally poor.

Methods

We conducted a systematic review and meta-analysis to assess HCV treatment outcomes in observational cohorts. Two databases (Medline and EMBASE) were searched using a compound search strategy for cohort studies reporting HCV treatment outcomes (as determined by a sustained virological response, SVR) in HIV-positive patients initiating HCV treatment for the first time.

Results

40 studies were included for review, providing outcomes on 5339 patients from 17 countries. The pooled proportion of patients achieving SVR was 38%. Significantly poorer outcomes were observed for patients infected with HCV genotypes 1 or 4 (pooled SVR 24.5%), compared to genotypes 2 or 3 (pooled SVR 59.8%). The pooled proportion of patients who discontinued treatment due to drug toxicities (reported by 33 studies) was low, at 4.3% (3.3–5.3%). Defaulting from treatment, reported by 33 studies, was also low (5.1%, 3.5–6.6%), as was on-treatment mortality (35 studies, 0.1% (0–0.2%)).

Conclusions

These results, reported under programmatic conditions, are comparable to those reported in randomised clinical trials, and show that although HCV treatment outcomes are generally poor in HIV co-infected patients, those infected with HCV genotypes 2 or 3 have outcomes comparable to HIV-negative patients.

Effect of interferon-α2b on the expression of various drug-metabolizing enzymes and transporters in co-cultures of freshly prepared human primary hepatocytes

The purpose of this study was to assess the impact of interferon-α2b (IFN-α2b) on the expression of various drug-metabolizing enzymes and transporters in freshly prepared co-cultures (parenchymal and non-parenchymal cells) of human primary hepatocytes. At therapeutically relevant concentrations (from 1000 to 3000 IU/mL), IFN-α2b up-regulated STAT1 (signal transducer and activator of transcription factor 1) mRNA expression. Conversely, three cytochrome P450s (CYP1A2, CYP2B6, CYP2E1), a UDP-glucuronosyltransferase (UGT2B7), a sulphotransferase (SULT1A1) and organic anion transporter (OAT2) were significantly down-regulated (~50%; P < 0.05). Western blot analysis of CYP1A2, UGT2B7 and OAT2 protein supported the mRNA data. Two peroxisome proliferator activator receptor alpha (PPARα)-controlled genes (pyruvate dehydrogenase kinase 4 and adipose differentiation-related protein), CYP3A4 and multidrug resistance-associated protein 2 were significantly up-regulated (up to 223%; P < 0.05). On the other hand, SULT2A1, carboxylesterase 2, organic anion transporting peptide (OATP1B1, OATP1B3, OATP2B1), organic cation transporter 1, P-glycoprotein and breast cancer resistance protein mRNA expression was not significantly affected. Western blot analysis of CYP3A4 supported the mRNA data also. The present results demonstrated complex interactions between IFN-α2b and hepatocytes and the observed down-regulation of CYP1A2, OAT2 and UGT2B7 is consistent with reports of drug interactions between IFN-α2b and drugs such as theophylline, clozapine and gemfibrozil.

[Role of tenofovir in HIV and hepatitis C virus coinfection]

Chronic hepatitis C virus (HCV) infection is common in HIV-infected individuals, especially if the route of infection is intravenous (e.g. intravenous drug use or blood transfusion). Prognosis is poorer in patients with HCV and HIV coinfection than in those with HCV monoinfection, mainly due to the immunodepression caused by HIV infection and probably also to a direct effect of HIV on the liver. Moreover, although antiretroviral therapy can cause liver damage, there is little doubt about the net benefits obtained with triple therapy in coinfected individuals, since suppression of HIV replication and immune recovery help to halt liver damage. However, not all antiretroviral agents are equal and those with the lowest hepatotoxicity and best metabolic profile should be used in coinfected patients, since hepatic steatosis accelerates progression of hepatic fibrosis and insulin resistance hampers the success of treatment with interferon and ribavirin. Tenofovir is currently one of the safest nucleos(t)ide analogues, due to its low hepatotoxicity and its lack of negative interference on treatment of HCV infection.

Baseline CD4 cell count and outcome of pegylated interferon plus ribavirin therapy in HIV/hepatitis C virus-coinfected patients

OBJECTIVE

When to start hepatitis C treatment in HIV/hepatitis C virus (HCV)-coinfected patients remains unresolved. Our objective was to determine if a baseline CD4 count >/=350 cells/mm predicts a sustained HCV response to pegylated interferon plus ribavirin.

METHODS

We conducted a multicenter cohort study of HIV/HCV-coinfected patients treated for HIV in hospitals in Nice, Tourcoing, and Marseille (France). Sustained viral response (SVR) was defined as undetectable HCV RNA 24 weeks after treatment. The relation between CD4 cell count and SVR was examined separately for patients with HCV genotype 1 or non-1.

RESULTS

One hundred seventy-five patients were included. In patients with HCV genotype 1, the rate of SVR was 13% and was not related to baseline CD4 cell count (odds ratio [OR] = 1.0, 95% confidence interval [CI]: 0.1 to 9.3). In patients with HCV genotype non-1, the rate of SVR was 46% and was not significantly increased by a baseline CD4 count >/=350 cells/mm (OR = 1.8, 95% CI: 0.6 to 5.9).

CONCLUSIONS

Higher CD4 cell count at treatment initiation with pegylated interferon plus ribavirin did not improve treatment success probability, regardless of HCV genotype.

Therapeutic issues in HIV/HCV-coinfected patients

The importance of treating hepatitis C virus (HCV)-associated morbidities in a growing population of patients coinfected with human immunodeficiency virus (HIV) has increased since the introduction of highly active antiretroviral therapy. As a result, investigative attention is turning to HCV-related liver disease and treatment-associated issues in coinfection. HIV/HCV-coinfected patients have higher HCV RNA loads and show more rapid progression of fibrosis than do monoinfected patients. Combination therapy with pegylated interferon plus ribavirin (RBV) is the standard of care for HCV in coinfected patients. Therapy slows fibrosis progression, but toxicity prevents identification of the most effective RBV dose. Coinfected patients have about a threefold greater risk of antiretroviral therapy-associated hepatotoxicity than patients with HIV only. Other challenges include anaemia, mitochondrial toxicity, drug-drug interactions and leucopenia. Thus, chronic hepatitis C should be treated in HIV/HCV-coinfected patients, but steps must be taken to prevent and treat potential toxicities. The first European Consensus Conference on the Treatment of Chronic Hepatitis B and C in HIV Co-infected Patients was held March 2005 in Paris to address these issues. This article reviews the peer-reviewed literature and expert opinion published from 1990 to 2005, and compares results with presentations and recommendations from the Consensus Conference to best present current issues in coinfection.

Liver enzyme elevation in hepatitis C virus (HCV)-HIV-coinfected patients prior to and after initiating HAART: role of HCV genotypes

Transaminase elevation is frequently seen in hepatitis C virus (HCV)-HIV-coinfected patients receiving antiretroviral therapy (ART), representing an increase in the immune response against HCV and being one of the mechanisms proposed to be involved. There is a report claiming that HCV genotype 3 is an independent risk factor. Our objectives were to assess the incidence of liver toxicity in an HIV-HCV-coinfected population with relatively preserved cellular immunity, and the role of HCV genotypes in the elevation of liver enzymes, both at baseline and after initiating ART. All HIV(+) patients with positive anti-HCV serology and CD4(+) cell counts above 100/mm(3) who began triple ART were identified, and their HCV-RNA levels and HCV genotype were determined. Liver enzymes were determined at baseline and bimonthly during follow-up. Of anti-HCV patients 147 were included, 128 (87.1%) of whom had detectable plasma HCV-RNA. HCV-1 and HCV-4 genotypes were found to confer an increased probability of having at baseline transaminases within normal limits over the other genotypes. Severe transaminase elevations (grades 3 and 4) occurred in 5/124 patients (4.0%), all with high pre-HAART ALT and positive HCV-RNA levels. Multivariate analysis showed that patients with genotype HCV-3 had a 3.27 times higher risk of developing HAART-related transaminase elevations of any grade. In conclusion, subjects with the HCV-1 genotype more often had transaminases within normal limits at baseline. The incidence of severe transaminase elevation after initiating ART was very low (4%) in this HIV(+) population with relatively preserved cellular immunity. HCV genotype 3 was identified as a risk factor for the development of transaminase elevation of any grade.