Early HCV dynamics on Peg-interferon and ribavirin in HIV/HCV co-infection: indications for the investigation of new treatment approaches

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.

Hepatitis C virus NS3/4A quasispecies diversity in acute hepatitis C infection in HIV-1 co-infected patients

The growing number of cases of acute hepatitis C (AHC) infections among human immunodeficiency virus type 1 (HIV-1)-positive men who have sex with men (MSM) in the last 10 years has promoted the search for predictors of AHC clearance as well as for epidemiological networks of viral transmission. We characterized the diversity and catalytic efficiency of HCV NS3/4A protease quasispecies in AHC patients coinfected with HIV-1. Plasma samples obtained at HCV diagnosis from 18 MSM HIV-coinfected patients with AHC were studied. Five HCV monoinfected patient samples with AHC were also investigated. An average of 39 clones from each sample was analysed. The catalytic efficiency of the dominant quasispecies (i.e. the most abundant) from each quasispecies was also assayed for mitochondrial antiviral signalling protein (MAVS) cleavage. Phylogenetic analysis identified two clusters of patients with highly related viruses, suggesting a common source of HCV infection. None of the 18 MSM HIV-coinfected patients spontaneously cleared HCV, although 78% of the treated patients achieved a sustained virological response after early treatment with pegylated interferon (pegIFN) plus ribavirin (RBV). The synonymous-nonsynonymous (ds/dn) mutation ratio, a marker of selective pressure, was higher in AHC compared to 26 HIV-1-infected men with genotype 1a chronic hepatitis C (CHC) (P < 0.0001). NS3/4A proteases from AHC patients also exhibited higher catalytic efficiency compared to CHC patients (P < 0.0001). No differences were found when ds/dn mutation ratios and NS3/4A protease catalytic efficiencies from AHC HIV-coinfected patients were compared with AHC monoinfected patients. The presence of epidemiological networks of HCV transmission was confirmed among HIV-1-positive MSM. In addition, substantial genetic diversity was demonstrated in AHC. NS3/4A protease efficiency cleaving MAVS may be associated with virus transmission and response to pegIFN/RBV treatment.

Meta-analysis: IL-28B genotype and sustained viral clearance in HCV genotype 1 patients

BACKGROUND

Polymorphisms in the IL-28B region are a strong predictor of sustained virologic response (SVR) in individual studies of HCV genotype 1 patients receiving peginterferon (pegIFN) and ribavirin.

AIM

To obtain a pooled odds ratio (OR) of SVR in patients of varying race with the favourable IL-28B genotype compared to those with the unfavourable genotype.

METHODS

A literature search was conducted using online databases and a review of conference abstracts. A random effects meta-analysis was performed and study heterogeneity and publication bias were assessed.

RESULTS

There were 21 individual studies of HCV genotype 1 patients of varying ethnicity treated with pegIFN and ribavirin. The pooled prevalence of the favourable IL-28B genotype varied by race (73% vs. 41% vs. 13% in 2612 Asians, 3110 Caucasians and 452 African-Americans, respectively, P < 0.001). However, the strength of association of the IL-28B genotype with SVR was similar in all three racial groups (Caucasians: odds ratio (OR) 3.88, 2.75-5.49, African-Americans: OR 4.63, 2.52-8.50 and Asians OR 5.66, 3.99-8.02, all P < 0.001). The IL-28B genotype was also associated with SVR in 263 HIV/HCV co-infected Caucasians (OR 5.49, 3.02-9.96, P < 0.001). Study quality score and anti-viral treatment regimen did not impact the strength of the association in patient subgroups nor in the pooled population.

CONCLUSIONS

IL-28B genotype is significantly associated with SVR in HCV genotype 1 patients of varying race, as well as in HIV co-infected patients, receiving pegIFN and ribavirin. IL-28B testing in conjunction with other pre-treatment parameters may prove useful in counselling HCV patients.

Effect of an induction period of pegylated interferon-α2a and ribavirin on early virological response in HIV-HCV-coinfected patients: results from the CORAL-2 study

BACKGROUND

It is uncertain whether a 4-week induction period of pegylated interferon and ribavirin increases early virological response (EVR) in HIV-HCV-coinfected patients.

METHODS

HIV and HCV genotype 1- and 4-coinfected subjects were randomized to receive pegylated interferon-α2a 270 μg/week plus ribavirin 1,600 mg daily and epoetin-β for 4 weeks, followed by pegylated interferon-α2a at standard dosages plus weight-based ribavirin (WBR) dosage for 8 weeks (induction arm [IA]), or pegylated interferon-α2a plus WBR for 12 weeks (standard therapy arm [SA]). HCV RNA was determined at weeks 0, 1, 2, 3, 4, 8 and 12. Ribavirin plasma trough concentrations were determined at weeks 4 (RBV-C(4)) and 12 (RBV-C(12)).

RESULTS

A total of 67 patients were included; 33 in the SA and 34 in the IA. Overall, 25% received nucleoside reverse transcriptase inhibitor (NRTI)-sparing regimens. More patients achieved an HCV RNA decrease ≥1 log(10) at week 4 in the IA than in the SA (62% versus 38%; P=0.017), but EVR rates were similar in the two groups (74% versus 59% in the IA and SA, respectively; P=0.15). Independent predictors of faster HCV RNA decrease at 12 weeks were higher RBV-C(4) and younger age. RBV-C(4) were higher in patients allocated in the IA and in those receiving NRTIs (P=0.039).

CONCLUSIONS

A 4-week induction with pegylated interferon-α2a plus ribavirin was associated with a greater decrease in HCV RNA at week 4; however, this did not translate into higher EVR rates. Higher RBV doses and avoidance of NRTI-sparing antiretroviral regimens might improve HCV treatment efficacy.

Complexity and catalytic efficiency of hepatitis C virus (HCV) NS3 and NS4A protease quasispecies influence responsiveness to treatment with pegylated interferon plus ribavirin in HCV/HIV-coinfected patients

The role of the hepatitis C virus (HCV) NS3/4A protease in ablating the signaling pathway involved in the production of alpha/beta interferon (IFN-α/β) suggests a relationship between NS3/4A proteolytic activity and a patient's response to IFN-based therapy. To identify viral factors associated with the HCV treatment response, we analyzed the pretreatment NS3/4A protease gene quasispecies composition of 56 HCV genotype 1-HIV-1-coinfected patients treated in our clinic with pegylated IFN (pegIFN) plus ribavirin (RBV). The catalytic efficiency of the dominant (i.e., the most abundant) quasispecies was also assayed for Cardif cleavage and correlated with treatment outcome. A total of 1,745 clones were isolated and sequenced. Significantly less nucleotide quasispecies heterogeneity and lower Shannon entropy values were detected within the responder group (P < 0.05). A correlation was also found between the efficiency of NS3/4A protease Cardif cleavage and therapy outcome. Proteases from sustained responder patients were more efficient at processing Cardif (mean ± standard error of the mean [SEM], 0.8960 ± 0.05568; n = 19) than proteases from nonresponders (mean ± SEM, 0.7269 ± 0.05306; n = 37; P < 0.05). Finally, the amino acid p distance (the proportion [p] of nucleotide sites at which two sequences being compared are different) was significantly shorter in patients with an interleukin-28B (IL-28B) risk allele (P < 0.01), suggesting that IL-28B risk allele carriers exert a lower positive selection pressure on the NS3/4A protease. NS3/4A protease efficiency in cleaving Cardif may be associated with the pegIFN-RBV treatment response, as shown in our cohort of HIV-HCV-coinfected patients. Greater NS3/4A nucleotide heterogeneity and higher Shannon entropy values in nonresponders suggest that less HCV quasispecies complexity may favor a better response to pegIFN-RBV.

Very early prediction of response to HCV treatment with PEG-IFN-alfa-2a and ribavirin in HIV/HCV-coinfected patients

The objective of this study was to find very early viral kinetic markers to predict nonresponse to hepatitis C virus (HCV) therapy in a group of human immunodeficiency virus (HIV)/HCV-coinfected patients. Twenty-six patients (15 HCV genotype-1 and 11 genotype-3) were treated with a 48-week regimen of peginterferon-alfa-2a (PEG-IFN) (180 μg/week) and weight-based ribavirin (11 mg/kg/day). Samples were collected at baseline; 4, 8, 12, 18, 24, 30, 36 and 42 h; days 2, 3, 4, 7, 8, 15, 22, 29, 43 and 57 then weekly and monthly. Five patients discontinued treatment. Seven patients (27%) achieved a sustained virological response (SVR). Nadir HCV RNA levels were observed 1.6 ± 0.3 days after initiation of therapy, followed by a 0.3- to 12.9-fold viral rebound until the administration of the second dose of PEG-IFN, which were not associated with SVR or HCV genotype. A viral decline <1.19 log for genotype-1 and <0.97 log for genotype-3, 2 days after starting therapy, had a negative predictive value (NPV) of 100% for SVR. The day 2 virological response had a similar positive predictive value for SVR as a rapid virological response at week 4. In addition, a second-phase viral decline slope (i.e., measured from day 2 to 29) <0.3 log/week had a NPV = 100% for SVR. We conclude that first-phase viral decline at day 2 and second-phase viral decline slope (<0.3 log/week) are excellent predictors of nonresponse. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of nonresponse in patients with HCV and HIV.

Pharmacodynamics of PEG-IFN-[alpha]-2a and HCV response as a function of IL28B polymorphism in HIV/HCV-coinfected patients

We examined the association between IL28B single-nucleotide polymorphism rs12979860, hepatitis C virus (HCV) kinetic, and pegylated interferon alpha-2a pharmacodynamic parameters in HIV/HCV-coinfected patients from South America. Twenty-six subjects received pegylated interferon alpha-2a + ribavirin. Serum HCV-RNA and interferon concentrations were measured frequently during the first 12 weeks of therapy and analyzed using mathematical models. African Americans and whites had a similar distribution of IL28B genotypes (P = 0.5). The IL28B CC genotype was overrepresented (P = 0.015) in patients infected with HCV genotype-3 compared with genotype-1. In both genotype-1 and genotype-3, the first-phase viral decline and the average pegylated interferon-alpha-2a effectiveness during the first week of therapy were larger (trend P <= 0.12) in genotype-CC compared with genotypes-TC/TT. In genotype-1 patients, the second slower phase of viral decline (days 2-29) and infected cells loss rate, [delta], were larger (P = 0.02 and 0.11, respectively) in genotype-CC than in genotypes-TC/TT. These associations were not observed in genotype-3 patients.

IL28B SNP rs8099917 is strongly associated with pegylated interferon-α and ribavirin therapy treatment failure in HCV/HIV-1 coinfected patients

Recent genome-wide association studies report that the SNP rs8099917, located 8.9 kb upstream of the start codon of IL28B, is associated with both disease chronicity and therapeutic response to pegIFN-α and RBV in patients infected with genotype 1 HCV. To determine the effect of rs8099917 variation on the response of HCV to therapy, we genotyped this variant in a cohort of 160 HCV/HIV-1 coinfected patients in our clinic unit who received combined peg-IFN-α/RBV therapy. The rs8099917 T/G or G/G genotypes were observed in 56 patients (35%). Treatment failure occurred in 80% of G-allele carriers versus 48% of non-carriers (P<0.0001). This result reveals that the G allele was strongly associated with treatment failure in this patient cohort. Importantly, a highly significant association was found between the G-allele and response to therapy in HCV genotype 1-infected patients (P<0.0001) but not in HCV genotype 3-infected patients. Multivariate analysis (odds ratio; 95% confidence interval; P value) indicated that the rs8099917 TT genotype was a strong predictor of treatment success (5.83; 1.26-26.92; P = 0.021), independent of baseline plasma HCV-RNA load less than 500 000 IU/ml (4.85; 1.18-19.95; P = 0.025) and absence of advanced liver fibrosis (5.24; 1.20-22.91; P = 0.025). These results reveal the high prevalence of the rs8099917 G allele in HCV/HIV-1 coinfected patients as well as its strong association with treatment failure in HCV genotype 1-infected patients. rs8099917 SNP genotyping may be a valid pre-treatment predictor of which patients are likely to respond to treatment in this group of difficult-to-treat HCV/HIV-infected patients.

Pharmacodynamics of PEG-IFN-alpha-2a in HIV/HCV co-infected patients: implications for treatment outcomes

BACKGROUND & AIMS

The pharmacokinetics and pharmacodynamics of pegylated-interferon-alpha-2a (PEG-IFN) have not been described in HCV/HIV co-infected patients. We sought to estimate the pharmacokinetics and pharmacodynamics of PEG-IFN and determine whether these parameters predict treatment outcome.

METHODS

Twenty-six HCV/human immunodeficiency virus (HIV)-co-infected patients were treated with a 48-week regimen of PEG-IFN (180 microg/week) plus ribavirin (11 mg/kg/day). HCV RNA and PEG-IFN concentrations were obtained from samples collected until week 12. A modeling framework that includes pharmacokinetic and pharmacodynamic parameters was developed.

RESULTS

Five patients discontinued treatment. Seven patients achieved a sustained virological response (SVR). PEG-IFN concentrations at day 8 were similar to steady-state levels (p=0.15) and overall pharmacokinetic parameters were similar in SVRs and non-SVRs. The maximum PEG-IFN effectiveness during the first PEG-IFN dose and the HCV-infected cell loss rate (delta), were significantly higher in SVRs compared to non-SVRs (median 95% vs. 86% [p=0.013], 0.27 vs. 0.11 day(-1) [p=0.006], respectively). Patients infected with HCV genotype 1 had a significantly lower average first-week PEG-IFN effectiveness (median 70% vs. 88% [p=0.043]), however, 4- to 12-week PEG-IFN effectiveness was not significantly different compared to those with genotype 3 (p=0.114). Genotype 1 had a significantly lower delta compared to genotype 3 (median 0.14 vs. 0.23 day(-1) [p=0.021]). The PEG-IFN concentration that decreased HCV production by 50% (EC(50)) was lower in genotype 3 compared to genotype 1 (median 1.3 vs. 3.4 [p=0.034]).

CONCLUSIONS

Both the HCV-infected cell loss rate (delta) and the maximum effectiveness of the first dose of PEG-IFN-alpha-2a characterised HIV co-infected patients and were highly predictive of SVR. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of response in patients with HCV and HIV.

The importance of steatosis in chronic hepatitis C infection and its management: A review

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease with approximately 180 million people infected worldwide. Hepatic steatosis is a frequent histological finding in chronic hepatitis C (CHC) infection and is 2- to 3-fold more common than would be expected by chance alone. A high body mass index with excess visceral fat distribution is associated with steatosis in patients infected with HCV genotype 1 but not genotype 3, re-enforcing the concept that in patients with CHC, some have "metabolic steatosis", predominantly HCV genotype 1, and others "viral steatosis", mainly HCV genotype 3. Accumulating evidence suggests that steatosis may contribute to progression of fibrosis in CHC. Hepatic insulin resistance appears to play a role through the pro-fibrogenic effects of compensatory hyperinsulinemia. The aim of this review was to assess the effect host and viral factors play in steatosis development in patients with CHC infection and its possible relationship with hepatocellular carcinoma. The review examines the mechanisms by which CHC infection causes hepatic steatosis, the impact hepatic steatosis has on the natural history of the disease and finally, explores if treatments leading to a reduction in the amount of steatosis might lead to improved treatment outcomes. The basic medical science of steatosis in CHC will be discussed including proposed models of steatogenesis and the influence of viral and metabolic factors at the molecular level and how these might impact on current and future therapies.

Plasma HCV-RNA decline in the first 48 h identifies hepatitis C virus mono-infected but not HCV/HIV-coinfected patients with an undetectable HCV viral load at week 4 of peginterferon-alfa-2a/ribavirin therapy

During peginterferon-alfa-2a/ribavirin therapy, plasma hepatitis C virus (HCV)-RNA decreases with a rapid first phase and a slower second phase. We compared the viral load decrease and slope in the first 48 h in patients with a rapid viral response (RVR, i.e. HCV-RNA < 50 IU/mL at week 4) with patients not achieving an RVR. From 23 HCV-infected (14 mono-infected and nine HCV/HIV-coinfected) genotype 1 or 4 positive peginterferon-alfa-2a/ribavirin-treated patients, plasma HCV-RNA was determined at baseline, 48 h, weeks 1, 2, 4, 8, 12, 48 and 72. The HCV viral load decrease (Delta0-48), the slope (lambda(1)) and the efficiency factor (epsilon) were determined in the first 48 h after the start of therapy. Five (36%) HCV mono-infected patients and three (33%) HIV/HCV-coinfected patients achieved an RVR whereas six (43%) HCV mono-infected patients and five (56%) HIV/HCV-coinfected patients reached a sustained viral response (SVR). In contrast to HIV/HCV-coinfected patients, five HCV mono-infected patients with an RVR showed both a larger Delta0-48 and steeper lambda(1) (-1.77log(10) IU/mL +/- 0.66 and -2.04/day +/- 0.76) compared to nine non-RVR patients (-0.66log(10) IU/mL +/- 0.39; P = 0.019 and -0.76/day +/- 0.41; P = 0.019). When divided by SVR, a greater Delta0-48 and steeper lambda(1) were also seen in both HCV mono-infected and HIV/HCV-coinfected patients. Thus, in the first 48 h after the start of therapy, HCV mono-infected patients with an RVR have a larger viral load decrease, steeper viral slope and a higher efficiency factor as compared with non-RVR patients.

Factors affecting early viral load decline of Asian chronic hepatitis C patients receiving pegylated interferon plus ribavirin therapy

Background

Early viral load decline following pegylated interferon-α2a and ribavirin therapy is an important predictor of the treatment responses in chronic hepatitis C (CHC) patients, thus, it is essential to evaluate the influence of host and viral factors on early viral load decline.

Methods

Clinical and serial virological data were collected from 145 consecutive Asian CHC patients with pegylated interferon-α2a plus ribavirin therapy. A dose of pegylated interferon-α2a was administered at week 1 and then weekly with daily oral ribavirin for 24 or 48 weeks. Genotyping and quantification of hepatitis C virus (HCV) RNA were done using molecular methods.

Results

A total of 81 patients were infected with HCV genotype 1, 61 with genotype 2 and 3 with both genotypes 1 and 2. At the end of follow-up, 110 patients attained sustained virological response (SVR). In multivariate analyses, body mass index (BMI) and genotype were related to viral load decline at day 2, baseline viral load and high-density lipoprotein (HDL) cholesterol levels were correlated with viral load decline between days 2 and 28. Genotype, baseline viral load, alanine aminotransferase (ALT) levels and BMI independently predicted rapid virological response, whereas only genotype 2, lower baseline viral load and more substantial viral load decline at day 28 predicted a higher SVR.

Conclusions

HCV genotype, baseline viral load, pretreatment BMI, HDL and ALT levels have a significant effect on early viral load decline of Asian CHC patients with interferon-based therapy. Only HCV genotype, baseline viral load and viral load decline at day 28 can independently predict SVR.

Differences in Virological Response to Pegylated Interferon and Ribavirin between Hepatitis C Virus (Hcv)-Monoinfected and HCV–Hiv-Coinfected Patients

Background

Suboptimal doses of ribavirin have been suggested to explain the diminished efficacy of pegylated interferon (PEG-IFN) plus ribavirin in hepatitis C virus (HCV)–HIV-coinfected patients.

Methods

A cohort of 104 coinfected patients and an age-, sex- and genotype-matched cohort of HCV-monoinfected patients ( n=104) were compared. All patients received PEG-IFN-α2a 180 μg/week plus ribavirin 800–1,200 mg daily (HCV genotype 2/3 patients received 800 mg daily and those with genotype 1/4 received 1,000–1,200 mg daily) for 48 weeks (24 weeks for monoinfected patients with genotypes 2/3). HCV RNA levels were determined qualitatively at weeks 4, 12, 24, 48 and 72 and quantified monthly until week 12.

Results

The coinfected cohort had more advanced liver disease and lower body weight. HCV genotype 1 patients coinfected with HIV showed higher levels of HCV RNA than monoinfected patients. A significantly higher proportion of coinfected patients interrupted the prescribed treatment period prematurely (84% versus 98%). During the first 12 weeks, smaller decreases in HCV RNA levels were observed in coinfected patients. Among patients with HCV genotype 1, coinfected patients achieved lower rates of early virological response (64% versus 87%), end-of-treatment response (47.3% versus 80%) and sustained virological response (SVR; 27.3% versus 56.4%), but not rapid virological response (RVR). HCV–HIV-coinfected patients with HCV genotype 2/3 achieved significantly lower rates of RVR (52% versus 88%). Multivariate analysis identified RVR, gender and liver fibrosis as independent predictors of SVR.

Conclusions

Differences in efficacy of PEG-IFN-α2a plus ribavirin treatment between HCV–HIV-coinfected and HCV-monoinfected patients were maintained despite optimized ribavirin dose.

Pegylated IFN-alpha2b plus ribavirin for treatment-naive patients coinfected with HCV and HIV

Since 1995, after the generalization of highly active antiretroviral therapy (HAART), HCV coinfection in patients with HIV has become a clinical problem of first magnitude. In fact, currently, HCV coinfection is the primary cause of morbi-mortality of AIDS patients in many hospitals. As a consequence, a significant number of clinical trials have been carried out during the past 8-10 years on HCV/HIV-coinfected patients, and have been coincident that the use of pegylated interferon (PEG-IFN) plus ribavirin should be now the gold standard for treating these patients. Various prospective, randomized studies have reached the conclusion that PEG-IFN-alpha(2b) plus ribavirin achieves HCV cure rates in approximately 50% of all patients, together with important clinical consequences, since hepatic illness progression stops or even reverts. Although adverse events are extremely common with this combined treatment, it is also true that their handling by experts means that only 10-15% of patients must abandon treatment.

Peginterferon vs. interferon in the treatment of different HCV genotype infections in HIV patients

It remains difficult to achieve high sustained response rates (SVRs) in chronic hepatitis patients coinfected with human immunodeficiency virus (HIV). The aim of this study was to perform a meta-analysis of randomized controlled trials (RCTs) comparing peginterferon with interferon in the treatment of patients carrying different genotypes of hepatitis C virus (HCV) and coinfected with HIV. A Medline literature search was conducted to identify RCTs evaluating SVRs to peginterferon and interferon in HCV/HIV-coinfected patients. Six studies matched the selection criteria, and the HCV genotype of 1,717 coinfected patients was reported. For genotypes 1 or 4 HCV and HIV-coinfected patients, both types of peginterferon, alpha-2a and alpha-2b, achieved higher SVRs compared with the respective types of interferon. The SVRs achieved in patients infected with HCV genotypes 1 or 4 treated with peginterferon and ribavirin was not satisfactory in comparison with those of patients infected with HCV genotypes 2 or 3 (26% vs. 55%). The probability of achieving higher SVRs in patients when treated with peginterferon plus ribavirin increased compared with other therapies, especially for patients coinfected with HCV genotypes 1 or 4 and HIV. The likelihoods of serious adverse effects and withdrawal rates were similar.

Significant effect of hepatitis C virus specific CTLs on viral clearance in patients with type C chronic hepatitis treated with antiviral agents

AIM

To evaluate the correlation between hepatitis C virus (HCV) specific cytotoxic T lymphocytes (CTLs) and viral clearance in antiviral treated patients, we examined the number and function of HCV epitope-specific CTLs and the viral load in 12 HLA-A2-positive patients with chronic hepatitis C, after undergoing interferon therapy.

METHODS

Peripheral blood mononuclear cells (PBMC) were analyzed on days 0, 3, 7, 14 and 28 of undergoing antiviral therapies. To investigate the quantity of the antigen specific CTLs, CD8-positive T cells were isolated using microbeads and were stained for HLA-A*0201 tetramers. To investigate the function of CTLs, PBMC were stimulated with the same synthetic epitope peptides and analyzed to determine their interferon (IFN)-gamma expression.

RESULTS

In seven patients, HCV-RNA became undetectable 4 weeks after antiviral therapies (EVR), but five patients were non-responders (NR). In peptide NS3 1406 on day 3 and day 7 of therapy and in NS3 1073 on day 3 of therapy, the level of IFN-gamma expression on CD8+ T cells was significantly higher in the EVR group than in the NR group. In other peptides, the number of and cytokine production from the CTLs in the EVR group were also higher than in the NR group, but not significantly.

CONCLUSION

After antiviral therapy, analysis of the number and function of antigen-specific CTLs in the early phase was thus found to be useful for predicting viral clearance in chronic hepatitis C patients.

Hepatitis infection in the treatment of opioid dependence and abuse

Many new and existing cases of viral hepatitis infections are related to injection drug use. Transmission of these infections can result directly from the use of injection equipment that is contaminated with blood containing the hepatitis B or C virus or through sexual contact with an infected individual. In the latter case, drug use can indirectly contribute to hepatitis transmission through the dis-inhibited at-risk behavior, that is, unprotected sex with an infected partner. Individuals who inject drugs are at-risk for infection from different hepatitis viruses, hepatitis A, B, or C. Those with chronic hepatitis B virus infection also face additional risk should they become co-infected with hepatitis D virus. Protection from the transmission of hepatitis viruses A and B is best achieved by vaccination. For those with a history of or who currently inject drugs, the medical management of viral hepatitis infection comprising screening, testing, counseling and providing care and treatment is evolving. Components of the medical management of hepatitis infection, for persons considering, initiating, or receiving pharmacologic therapy for opioid addiction include: testing for hepatitis B and C infections; education and counseling regarding at-risk behavior and hepatitis transmission, acute and chronic hepatitis infection, liver disease and its care and treatment; vaccination against hepatitis A and B infection; and integrative primary care as part of the comprehensive treatment approach for recovery from opioid abuse and dependence. In addition, participation in a peer support group as part of integrated medical care enhances treatment outcomes. Liver disease is highly prevalent in patient populations seeking recovery from opioid addiction or who are currently receiving pharmacotherapy for opioid addiction. Pharmacotherapy for opioid addiction is not a contraindication to evaluation, care, or treatment of liver disease due to hepatitis virus infection. Successful pharmacotherapy for opioid addiction stabilizes patients and improves patient compliance to care and treatment regimens as well as promotes good patient outcomes. Implementation and integration of effective hepatitis prevention programs, care programs, and treatment regimens in concert with the pharmacological therapy of opioid addiction can reduce the public health burdens of hepatitis and injection drug use.

Hepatitis C viral kinetics during treatment of hepatitis C virus/HIV coinfected patients

PURPOSE OF REVIEW

Studies of hepatitis C virus and HIV kinetics during treatment have been instrumental in elucidating the viral lifecycle and mechanisms of action of antiviral therapies. We sought to review data on hepatitis C virus kinetics in hepatitis C virus/HIV coinfected patients and to illustrate how viral kinetics might direct therapeutic decisions in these patients.

RECENT FINDINGS

Few studies have so far analysed the dynamic changes in hepatitis C virus RNA after treatment initiation in hepatitis C virus/HIV coinfected patients. These studies applied mathematical models previously developed in hepatitis C virus mono-infected patients, and the results obtained did not reveal major differences in viral kinetics between the two patient groups. Similar to mono-infected patients, early measurements of hepatitis C virus RNA levels after treatment initiation have been shown to have utility in predicting treatment response in coinfected patients.

SUMMARY

Confirmatory studies are required to determine definitively whether differences exist between hepatitis C virus kinetics in mono compared with coinfected patients. With additional data, these methods have the potential to direct decisions in hepatitis C virus/HIV coinfection.

Safety and efficacy of an induction dose of pegylated interferon alpha-2a on early hepatitis C virus kinetics in HIV/HCV co-infected patients: the CORAL-1 multicentre pilot study

To evaluate the safety and efficacy of an induction dose of pegylated interferon alpha 2a (IFN-alpha2a) on the 12-week hepatitis C virus (HCV) kinetics in human immunodeficiency virus (HIV) patients co-infected with HCV. One hundred sixteen HIV/HCV co-infected patients from nine hospitals in Spain were randomized to receive 270 microg/week of pegylated IFN-alpha2a for 4 weeks followed by 180 microg/week for 8 weeks or 180 microg/week for 12 weeks. Ribavirin was given at a daily dose of 1000 or 1200 mg. The main outcome measure was the percentage of patients achieving an HCV-RNA below 50 IU/mL or a decrease of 2 or more log(10) at week 12 (early virologic response, EVR). HCV-RNA was measured at baseline, weekly, for the first 4 weeks and monthly thereafter. We observed no difference in the percentage of patients achieving an EVR between arms (on-treatment, 74% in both arms; intention-to-treat, 70% in the induction arm and 67% in the control arm), nor were there differences in the percentage achieving an undetectable HCV qualitative polymerase chain reaction at any time points or in the decrease in HCV-RNA from baseline. No differences were found between arms in the percentage of dropouts (8% in the whole study population). Our study failed to find a benefit of an induction dose of 270 microg/week of pegylated IFN-alpha2a for 4 weeks on the EVR in co-infected patients who are treatment naive. Despite the lack of benefit with this regimen, induction therapy with this schedule was safe and well tolerated in co-infected patients.

Early ribavirin pharmacokinetics, HCV RNA and alanine aminotransferase kinetics in HIV/HCV co-infected patients during treatment with pegylated interferon and ribavirin

BACKGROUND/AIMS

We evaluated whether early ribavirin pharmacokinetics differ comparing hepatitis C/human immunodeficiency virus coinfected sustained virological responders and nonresponders.

METHODS

Twenty-four treatment-naive coinfected patients received pegylated-interferon alfa-2b (12 kDa) (1.5 microg/kg) once weekly plus daily ribavirin (13.6 mg/kg/d) for up to 48 weeks. Serum HCV RNA, serum alanine aminotransferase, and plasma ribavirin levels were measured frequently during the first 16 days of therapy and monthly thereafter.

RESULTS

Six patients were sustained responders. During the first 4 weeks of treatment, median plasma ribavirin levels and area under the ribavirin curve were significantly lower (p<0.0001 and p<0.01, respectively) in sustained responders compared with nonresponders. Compared to ribavirin levels at weeks 2 and 4, ribavirin levels in sustained responders continued to increase significantly until week 8 (p<0.02). At week 4, hemoglobin declines were significantly (p=0.002) greater in sustained responders than nonresponders. At week 1, serum HCV RNA levels and changes in alanine aminotransferase levels relative to baseline could identify likely responders better than plasma ribavirin levels.

CONCLUSIONS

We conjecture that intracellular ribavirin accumulation may be enhanced early in treatment in coinfected sustained responders, although this hypothesis should be investigated further. At week 1, serum HCV RNA and changes in alanine aminotransferase levels relative to baseline might identify likely responders.

Rapid virological response at week 4 predicts response to pegylated interferon plus ribavirin among HIV/HCV-coinfected patients

Introduction

The clinical applicability of early viral kinetics at week 4 in predicting sustained virological response (SVR) of pegylated interferon (peg-IFN) plus ribavirin (RBV) in HIV/HCV-coinfected patients is unclear. Our objective was to determine if rapid virological response (RVR) at week 4 of therapy with peg-IFN and RBV could predict SVR among HIV/HCV-coinfected patients.

Methods

HIV/HCV-coinfected patients in whom an HCV viral load determination had been carried out at week 4 of therapy were included in the study. The positive predictive value (PPV) and the negative predictive value (NPV) of RVR (undetectable serum HCV RNA at 4 week) for SVR were calculated in the study population. Receiver operating characteristic curves were calculated to determine the best cutoff of HCV RNA decrease to predict treatment failure.

Results

A total of 101 HIV/HCV-coinfected patients were included. RVR and SVR were observed in 39 (39%) and in 49 (48%) individuals, respectively. Of patients with RVR, 37/39 patients achieved SVR (PPV: 95%), whereas 50/62 individuals without RVR did not show SVR (NPV: 81%). The highest NPV (96%) was reached by using a cutoff level of HCV RNA decrease of 0.6 log10. By applying this cutoff level, treatment could have been discontinued in 25 (25%) patients.

Conclusions

An undetectable serum HCV RNA determination at week 4 of treatment with peg-IFN plus RBV is a reliable predictor of SVR in HIV/HCV-coinfected patients. In addition, a decrease of HCV RNA less than 0.6 log10 at this point of treatment could identify an appreciable proportion of individuals who will fail to achieve SVR.

Genetic and catalytic efficiency structure of an HCV protease quasispecies

The HCV nonstructural protein (NS)3/4A serine protease is not only involved in viral polyprotein processing but also efficiently blocks the retinoic-acid-inducible gen I and Toll-like receptor 3 signaling pathways and contributes to virus persistence by enabling HCV to escape the interferon antiviral response. Therefore, the NS3/4A protease has emerged as an ideal target for the control of the disease and the development of new anti-HCV agents. Here, we analyzed, at a high resolution (approximately 100 individual clones), the HCV NS3 protease gene quasispecies from three infected individuals. Nucleotide heterogeneity of 49%, 84%, and 91% were identified, respectively, which created a dense net that linked different parts of the viral population. Minority variants having mutations involved in the acquisition of resistance to current NS3/4A protease inhibitors (PIs) were also found. A vast diversity of different catalytic efficiencies could be distinguished. Importantly, 67% of the analyzed enzymes displayed a detectable protease activity. Moreover, 35% of the minority individual variants showed similar or better catalytic efficiency than the master (most abundant) enzyme. Nevertheless, and in contrast to minority variants, master enzymes always displayed a high catalytic efficiency when different viral polyprotein cleavage sites were tested. Finally, genetic and catalytic efficiency differences were observed when the 3 quasispecies were compared, suggesting that different selective forces were acting in different infected individuals.

CONCLUSION

The rugged HCV protease quasispecies landscape should be able to react to environmental changes that may threaten its survival.

Complete nucleotide sequence of genotype 4 hepatitis C viruses isolated from patients co-infected with human immunodeficiency virus type 1

The hepatitis C virus (HCV) genotype 4 is spreading among southern European intravenous drug users, who are frequently co-infected with human immunodeficiency virus type 1 (HIV-1). Response to interferon (IFN) alpha-based therapies in HIV-1 positive patients co-infected with HCV genotype 4 is poor, similar to that obtained for HCV genotype 1 and much lower than for HCV genotypes 2 and 3. The lack of sequence data related to HCV of genotype 4 prompted us to sequence the complete genome of two genotype 4 variants isolated from two HIV-1 co-infected patients (24 and 25). Our aim was to investigate the evolutionary relationships of the former variants with other genotypes and/or genotype 4 subtypes. Sequence alignments and phylogenetic analysis from genomic regions 5'NC, core-E1 and NS5B revealed that the variants isolated from patients 24 and 25 (both subtyped 4c/4d by INNO-LIPA II HCV) belong to subtypes 4d and 4a, respectively. When looking at the complete genome sequence one of the variants showed a new genotype 4 subtype. Interestingly, sequence length differences in the interferon sensitivity determining region coding regions were observed when compared with sequences from other genotypes. Similarly, when the catalytic efficiency of the NS3/4 protease from patients 24 and 25 samples were determined, they displayed 70.6+/-7.7 and 23.5+/-3.4%, respectively, of the activity shown by genotype 1 NS3/4 proteases. Overall, pairwise comparison and phylogenetic analysis of nucleotide sequences of the complete genome or the different protein-encoding regions showed that genotype 4 sequences were more closely related to genotype 1 sequences. The description of new HCV genome variants may help our understanding of the HCV biology as well as the role of different genotypes in HCV treatment and therapy response.

[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.

Results of a Study of Prolonging Treatment with Pegylated Interferon-α2A plus Ribavirin in HIV/HCV-Coinfected Patients with No Early Virological Response

Objective

To assess the efficacy and safety of an extended treatment period in HIV/hepatitis C virus (HCV)-coinfected patients without early virological response (EVR).

Methods

Patients received pegylated interferon (peg-INF)-α2a 180 μg/week plus ribavirin 800 mg/d for 12 weeks. Patients achieving EVR at week 12 continued under therapy for an additional 12 or 36 weeks depending on genotype. Patients without EVR were randomized to complete the standard treatment or treatment lasting 72 weeks (extension arm).

Results

One hundred and ten patients were included (mean age 38.7 years, mean weight 68 kg, 74% males, 74% on highly active antiretroviral therapy, mean CD4+ T-cell count 564 cells/mm3). Fifty-one patients harboured genotype 1, 44 genotype 2/3, and 15 genotype 4. Fifty-three had an HCV load >800,000 IU/ml. Premature interruptions occurred in 32.7%. EVR was achieved in 63.6% (51% in genotype 1, 88.6% in genotype 2/3, 33.3% in genotype 4). End-of-treatment response was 52.7% (47.2% in genotype 1, 68.2% in genotype 2/3, 26.7% in genotype 4). Sustained virological response (SVR) was achieved in 41.8% (37.3% in genotype 1, 54.6% in genotype 2/3, 20% in genotype 4). Only one patient allocated to the extended arm achieved SVR. The rate of drop-outs in the extension arm was 68%. The negative predictive value of EVR was 97.5%.

Conclusions

This study shows no benefit of extending therapy in patients without EVR at week 12. Measures to improve adherence to HCV antiviral therapy should be considered when new approaches based on extended periods of treatment are investigated.

Efficacy and safety of pegylated interferon-alpha2b plus ribavirin for the treatment of chronic hepatitis C in HIV-infected patients

Low response rates and concerns about safety have limited the implementation of treatment for chronic hepatitis C (CHC) in patients with HIV infection. The efficacy and safety of pegylated interferon (peg-IFN) plus ribavirin in HIV-infected patients with CHC were evaluated in a prospective, open-label, multicenter study. Sixty patients with persistently high transaminases, positive HCV-RNA, CD4 count > or = 300 cells/microl, and HIVRNA <10,000 copies/ml were included. Patients were given peg-IFN 80-150 microg/week plus ribavirin 800-1200 mg/day. Treatment was scheduled for 24 weeks for genotypes 2/3 and 48 weeks for genotypes 1/4. In an intent- to-treat analysis, 16 (26.7%) patients achieved a sustained virological response (SVR). Twenty patients (33.3%) discontinued treatment prematurely, but only in 10 (16.6%) was discontinuation due to adverse events. Negative predictive values for SVR on the basis of HCV-RNA decline between baseline and week 4 were 100% for 1- and 2-log10 fall, and positive predictive values were 40% and 58.3% for 1- and 2-log10 fall, respectively. CD4 fell by a median of 216 cells during treatment, but no HIV-associated complications occurred. In conclusion, treatment with peg-IFN alpha-2b plus ribavirin is safe and clears RNA-HCV in about one-quarter of HIV-infected patients with CHC. Efforts should be focused on optimizing management of side effects and counseling to improve adherence and to keep patients on treatment. Assessment of HCV-RNA at week 4 may help guide early therapeutic decision making.

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.

HCV clearance and treatment outcome in genotype 1 HCV-monoinfected, HIV-coinfected and liver transplanted patients on peg-IFN-alpha-2b/ribavirin

BACKGROUND/AIMS

Differences in HCV-RNA clearance during therapy might explain the lower efficacy of peg-IFN/RBV in HIV/HCV-coinfection. There are limited data on HCV-RNA clearance and treatment outcomes in liver transplanted (LT) patients.

METHODS

To assess the rates of SVR and baseline predictors of failure after 48 weeks of weight-adjusted peg-IFN-alpha-2b/RBV in 120 patients with HCV genotype 1: 61 HCV-monoinfected, 40 HIV-coinfected and 19 LT-patients. Viral clearance was evaluated in patients completing 24 weeks of therapy (n=112, 93%).

RESULTS

SVR was significantly lower in HIV-coinfection than in HCV-monoinfection or LT (18 vs. 39 vs. 42%, P<0.02). By multivariate analysis, HIV-coinfection (OR 3.048, 95% CI 1.133-8.196; P=0.027), baseline HCV-RNA over 800,000 IU/ml (OR 2.800; 95% CI 1.121-6.993, P=0.027) and higher AST values (OR 1.009; 95% CI 1.001-1.018; P=0.028) were significantly associated to failure. Despite similar baseline HCV load (5.67 vs. 5.75 vs. 5.90 log10 IU/ml), HIV-coinfection showed significantly lower HCV-RNA decreases than HCV-monoinfection at weeks 4 (P=0.015), 12 (P=0.015) and 24 (P=0.0003), and than LT at weeks 12 (P=0.003) and 24 (P=0.023). 36/60 subjects (60%) reaching EVR by week 12 obtained SVR vs. 3/60 (5%) who did not.

CONCLUSIONS

HIV-coinfection was independently associated to treatment failure, and led to a significantly slower HCV-RNA clearance.

Impact of Ribavirin Exposure on Early Virological Response to Hepatitis C Therapy in HIV-Infected Patients with Chronic Hepatitis C

Background

The use of pegylated interferon (PEG-IFN) plus ribavirin (RBV) is currently the recommended treatment for chronic hepatitis C virus (HCV) infection. Coinfection with HIV is a negative predictor of response, for reasons not well understood.

Methods

We examined the virological response at weeks 4 and 12 in 198 HCV/HIV-coinfected patients enrolled in a prospective trial in which PEG-IFN alpha 2a (180 μg per week) and RBV (1000-1200 mg daily) were provided.

Results

In an on-treatment analysis, 52.8% of patients achieved undetectable HCV-RNA (<600 IU/ml) at week 4, while 63% and 77.2% of patients had a decline of at least 2 and 1 log10, respectively. At week 12, 73.1% of patients reached undetectable HCV-RNA, and 83.5% and 89% achieved at least a 2- and 1-log10 drop, respectively. More than 85% of HCV genotypes 2/3 cleared HCV-RNA at week 4, a proportion significantly higher when compared with genotypes 1 (33.8%) and 4 (28.6%). Multivariate logistic regression analysis identified genotype 3 and RBV exposure (mg/kg of body weight) as independent predictors of virological response at week 12 of therapy.

Conclusion

Early virological response rates to PEG-IFN plus RBV in HCV/HIV-coinfected patients seem to be similar to those reported for HCV-monoinfected subjects. The use of suboptimal doses of RBV in most earlier trials might account for the low response rates seen in coinfected patients. To our knowledge, this is the first report demonstrating that RBV exerts a significant independent effect on early virological response. Therefore, strategies aimed at optimizing doses and adherence to RBV might help to improve responses to HCV therapy in coinfected patients.

Role of viral kinetics under HCV therapy in HIV/HCV-coinfected patients

Patients coinfected with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are less responsive to anti-HCV therapies and are at a higher risk of toxicity than HCV monoinfected patients. HCV viral kinetics is the basis for the study of response to interferon-based therapy and for predicting sustained virological response (SVR). A lack of early virological response (EVR; undetectable HCV RNA or a decrease of >/=2 log(10) from baseline) after 12 weeks of pegylated interferon (peg-IFN) plus ribavirin (RBV) is an equally reliable predictor of lack of SVR in HIV/HCV-coinfected patients and in the monoinfected HCV population. Early stopping rules are particularly important in coinfected HIV/HCV patients, considering their low chances of response in the more difficult-to-treat HCV genotypes 1 and 4 (<30%). Several factors have been involved in this low efficacy, including higher baseline HCV viraemia, slower viral kinetics decay under interferon pressure and a defective immune substratum. A better understanding of HCV viral kinetics under HCV therapy may be the basis for assaying different peg-IFN plus RBV schedules, such as induction or extending strategies, and may help physicians to make tailored decisions for the management of their patients.

Open, Randomized, Multicentre Italian Trial on Peg-Ifn plus Ribavirin versus Peg-Ifn Monotherapy for Chronic Hepatitis C in HIV-Coinfected Patients on Haart

Background

Chronic hepatitis C is common and aggressive in HIV-positive patients, so the development of a well-tolerated HCV therapy is a priority. We evaluated the efficacy and safety of pegylated interferon α2b (PEG-IFN) plus ribavirin (RBV) versus PEG-IFN monotherapy in HIV/HCV-coinfected patients undergoing highly active antiretroviral therapy (HAART), and analysed the predictive factors of response.

Methods

An Italian, multicentre, open-label trial including 135 coinfected patients, randomized to PEG-IFN 1.5 μg/kg/week plus RBV 400 mg twice daily ( n=69, arm A) or PEG-IFN 1.5 μg/kg/week ( n=66, arm B) for 48 weeks. We assessed the predictive values of early virological response (EVR) at week 8 (HCV-RNA drop >2 log10 compared with baseline or undetectable levels) on sustained virological response (SVR).

Results

Fifty-five patients (28 from arm A and 27 from arm B) completed 48 weeks of therapy. At the end of treatment, 20/28 patients in arm A and 11/27 in arm B had HCV-RNA <50 IU/ml. In a per-protocol analysis, SVR was reached by 54% of patients in arm A (genotype 2–3, 11/16; genotype 1–4, 4/12) and 22% in arm B (genotype 2–3, 3/15; genotype 1–4, 3/12). In an intention-to-treat analysis, the SVR was 22% in arm A (genotype 2–3, 11/32; genotype 1–4, 4/37) versus 9% in arm B (genotype 2–3, 3/32; genotype 1–4, 3/34). The best predictors of SVR were the use of combination therapy, infection with HCV genotype 3 versus genotype 1, and EVR at week 8. Thirty patients (15 from arm A and 15 from arm B) dropped out of the trial prematurely due to side effects. The positive predictive value of EVR at week 8 was 65%, the negative predictive value was 86%.

Conclusions

PEG-IFN plus RBV can be considered a solid option for the treatment of HIV/HCV-coinfected patients. The key to successfully improving efficacy is strong compliance through strict overall patient monitoring, in order to best manage drug toxicity. EVR assessment at week 8 may become a useful stategy in the management of therapy.

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.

Mitochondrial Effects of a 24-Week Course of Pegylated-Interferon plus Ribavirin in Asymptomatic HCV/HIV Co-Infected Patients on Long-Term Treatment with Didanosine, Stavudine or Both

Background

It has been suggested that the addition of ribavirin (RBV) as a part of the treatment for chronic hepatitis C virus (HCV) in HIV co-infected patients on didanosine (ddI) or stavudine (d4T) might increase the nucleoside-induced impairment of mitochondrial function. Design: Comparative study to investigate the impact on mitochondrial function of adding RBV to a long-term treatment with ddI, d4T or both in HCV/HIV non-cirrhotic, asymptomatic patients. We included 26 patients: 16 continued with their current antiretroviral therapy (control group) and 10 patients received a concomitant 24-week course of RBV plus pegylated interferon (PEG-IFN) α-2b therapy (HCV-treated group).

Methods

We assessed peripheral blood mononuclear cells mitochondrial DNA (mtDNA) content and mitochondrial respiratory chain (MRC) function at baseline and at 24 weeks of follow-up. In the HCV-treated group we performed additional determinations at 12 weeks during anti-HCV therapy and 24 weeks after finishing anti-HCV therapy.

Results

Times on ddI or d4T exposure were 194 ±54.9 and 131 ±66.5 weeks in the HCV-treated and control groups, respectively. There were no differences either in mtDNA content, the enzyme activity of MRC complexes or clinical parameters at baseline. Throughout the study, mitochondrial measurements remained stable within groups and without differences when we compared HCV-treated and control groups.

Conclusions

In our study, the addition of RBV and PEG-IFN during a 24-week period in HCV/HIV non-cirrhotic, asymptomatic patients on long-term ddI, d4T or both had no impact on mitochondrial function. These findings could suggest that additional triggers are required to achieve a critical threshold in the degree of mitochondrial damage needed for symptoms to develop.

Hepatitis C Virus-Rna Clearance in HIV-Coinfected Patients with Chronic Hepatitis C Treated with Pegylated Interferon plus Ribavirin

Hepatitis C virus (HCV)-RNA clearance seems to occur more slowly in HIV/HCV-coinfected patients than in HCV-monoinfected subjects treated with pegylated interferon alpha (peg-IFN) plus ribavirin (RBV). As a consequence, concern has arisen over the feasibility of following the treatment rules applied to HIV-negative patients with chronic hepatitis C. A total of 89 HIV/HCV-coinfected patients who had fully completed a course of peg-IFN plus RBV were analysed. Of these, 29 (32.6%) reached sustained virological response (SVR). Reductions >2 logs in plasma HCV-RNA occurred in 52 (58%) patients at week 12 of treatment (early virological response; EVR). None of patients who showed HCV-RNA drops <2 logs at week 12 reached SVR (negative predictive value: 100%). The positive predictive value of EVR was 56%. On the other hand, relapses occurred in 19 (39.6%) out of the 48 patients who had negative HCV-RNA at the end of treatment, and there were no differences noted when comparing patients with HCV genotypes 2/3 and 1/4. In summary, the quantitative assessment of plasma HCV-RNA at week 12 predicts the chance of SVR using peg-IFN plus RBV in HIV-positive patients with chronic hepatitis C, as it does in HIV-negative individuals. Thus, discontinuation of anti-HCV therapy, which is associated with frequent side effects, might be warranted in HIV/HCV-coinfected patients showing HCV-RNA reductions <2 logs at week 12 of treatment. On the other hand, relapses in virological responders were unexpectedly high in HIV/HCV-coinfected patients when treatment was provided following the rules applied to HIV-negative subjects. This is particularly relevant for HCV genotypes 2/3, which only rarely relapse in HIV-negative patients. Therefore, extending therapy (for 12 months in HCV genotypes 2/3 and perhaps for 18 months in HCV genotypes 1/4) might be warranted in HIV/HCV-coinfected patients showing EVR.