Efficacy and safety of combination therapy with interferon-alpha2b and ribavirin for chronic hepatitis C in HIV-infected patients

OBJECTIVES: To evaluate the efficacy and safety of a combination therapy of interferon-alpha2b (IFN) and ribavirin for the treatment of chronic hepatitis C in HIV-seropositive patients. DESIGN: Open prospective trial. METHODS: Twenty patients co-infected with hepatitis C virus (HCV) and HIV, with a mean CD4 cell count of 350 +/- 153 x 10(6)/l were treated with IFN (3 MU three times per week) in combination with ribavirin (500 mg or 600 mg twice a day) for 6 months. Tolerance and efficacy were monitored at weeks 12 (month 3) and 24 (month 6). The primary endpoint was a complete virological response, as defined by the lack of detectable HCV RNA in serum. RESULTS: Baseline values of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were 121 +/- 72 IU/l and 75 +/- 67 IU/l, respectively. The total Knodell score was 10.4 +/- 2.4, with nine patients showing histological evidence of active cirrhosis (45%). All patients exhibited circulating HCV RNA. The treatment was well tolerated, with no impact on the course of HIV infection. After 6 months of combination therapy with IFN and ribavirin, 10 patients (50%) exhibited no further detectable HCV RNA viraemia, seven of whom achieved undetectable viraemia at month 3. Levels of ALT and AST decreased after 6 months of treatment from a mean of 121 +/- 72 to 51 +/- 40 IU/l and from a mean of 129 +/- 58 IU/l to 68 +/- 61 IU/l, respectively (P < 0.0002 and P < 0.0001). CONCLUSION: Our results indicate that combination therapy with IFN and ribavirin is effective in 50% of cases in clearing serum HCV RNA and may thus provide effective means of therapy in HIV-HCV-coinfected patients as initial treatment or in patients who have previously failed IFN monotherapy.     

Mutagenic effect of ribavirin on hepatitis C nonstructural 5B quasispecies in vitro and during antiviral therapy

BACKGROUND AND AIMS: Addition of ribavirin to interferon alfa treatment has substantially increased sustained virologic response rates in patients with chronic hepatitis C (CHC). Ribavirin acts as an RNA virus mutagen in vitro, thereby leading to error catastrophe. However, data in CHC are controversial. METHODS: The nonstructural (NS) 5B quasi-species heterogeneity was analyzed in Huh7 cells harboring a subgenomic hepatitis C virus (HCV) replicon system treated with ribavirin or levovirin. Accordingly, NS5B quasi-species were studied in 14 patients with CHC who received ribavirin alone or combined with pegylated interferon alfa both at baseline and during the first weeks of therapy. Analysis of NS3 quasi-species served as control. RESULTS: Cultivation of HCV replicon cells with ribavirin led to higher NS5B mutational frequencies compared with levovirin-treated or untreated cells (P < .05). Patients receiving ribavirin monotherapy showed higher overall mutational frequencies within NS3 and NS5B during therapy as compared with baseline (P < .01). Proportions of ribavirin-specific G-to-A and C-to-T transitions increased (P < .01). Paired analysis confirmed significant mean increases of mutational frequencies of approximately 5%. Ribavirin serum concentrations were positively correlated with mutational frequency changes (P < .05). In patients receiving combination therapy, a decrease of NS5B mutational frequencies ( approximately 10%) and lower proportions of G-to-A and T-to-C mutations (P < .01) were detectable. CONCLUSIONS: Ribavirin, but not its L-enantiomer levovirin, is a mutagen in HCV replicon cells. In patients with CHC, ribavirin monotherapy exhibits a moderate mutagenic effect early during therapy that is not detectable in combination with pegylated interferon alfa.     

Mutation rate of the hepatitis C virus NS5B in patients undergoing treatment with ribavirin monotherapy

BACKGROUND & AIMS: Error catastrophe from an increase in mutation rate may be a possible mechanism of action of ribavirin in chronic hepatitis C (CHC). We sought to evaluate the mutagenic potential of ribavirin in vivo and to determine if conserved regions of hepatitis C virus (HCV) NS5B are mutated during ribavirin therapy. METHODS: Thirty-one patients with CHC genotype 1 who participated in a randomized, placebo-controlled trial of ribavirin for 48 weeks were studied. After 48 weeks, patients on placebo were crossed-over to open-label ribavirin for 48 weeks. Viral RNA was extracted from paired, stored sera at day 0 and week 24 during the randomized phase and weeks 48, 52, and 72 during the cross-over phase. The entire NS5B region was sequenced and the mutation rates were calculated. RESULTS: An increase in mutation rate was observed after 4 weeks (4.4 x 10(-2) vs 2.1 x 10(-3) per site/y, P = .02) but not after 24 weeks (4.0 x 10(-3) vs. 5.5 x 10(-3) per site/y, P = .1) in patients who crossed over to ribavirin. Similarly, during the randomized phase no increase in the number of mutations or the mutation rate was observed at week 24 between the ribavirin- and placebo-treated patients 6.6 vs 4.3 x 10(-3) per site/y, respectively (P = .4). No mutations were observed in conserved regions of NS5B. CONCLUSIONS: Ribavirin therapy is associated with an early, transient increase in the mutation rate of HCV. Lethal mutagenesis and error catastrophe is unlikely to be the sole mechanism of action of ribavirin during therapy for CHC.     

Clinical trial results of peginterferons in combination with ribavirin

Of the large number of patients chronically infected with hepatitis C virus (HCV), only about one third have progressive liver disease, and will eventually develop cirrhosis and hepatocellular carcinoma. These are the patients for whom effective antiviral treatment is most needed. Therapy is currently recommended for patients with chronic hepatitis C who have abnormal alanine aminotransferase (ALT) levels, detectable hepatitis C virus ribonucleic acid (HCV RNA) in the blood, and significant necroinflammatory changes and/or fibrosis on liver biopsy. The current gold standard in terms of treatment efficacy is the combination of peginterferon (PEG-IFN) and ribavirin. The overall sustained virological response rate (SVR) with these regimens is 54 to 61% following 48 weeks of therapy. Patients with genotype 1 infection have a 42 to 51% likelihood of response to 48 weeks of therapy. Those with genotypes 2 or 3 infection will respond to 24 weeks of therapy in 78 to 82% of cases. These SVR rates are 5 to 10 percentage points higher in all patient groups than in those obtained with standard doses of interferon (IFN) and ribavirin. Retreatment of nonresponders to standard IFN monotherapy using PEG-IFN and ribavirin has achieved SVR rates of 34 to 40%. Retreatment of patients who relapsed after IFN monotherapy has resulted in an SVR rate of about 60%. A SVR after retreatment of relapsers and nonresponders with PEG-IFN and ribavirin is more likely in patients previously treated with IFN monotherapy, those with HCV genotypes 2 or 3, patients with low viral load (<2 million copies/mL), and individuals who had a significant decrease in HCV RNA levels during the initial treatment. The potential benefits of long-term anti-HCV suppressive therapy in nonresponders are currently under investigation.     

A randomized, controlled trial to determine whether continued ribavirin monotherapy in hepatitis C virus-infected patients who responded to interferon-ribavirin combination therapy will enhance sustained virologic response

This study assessed the use of ribavirin monotherapy to enhance sustained virologic response in hepatitis C virus (HCV)-infected patients who achieved virologic response to interferon (IFN)-ribavirin combination therapy. Patients who had chronic HCV infection and prior relapse were retreated with IFN-ribavirin for 6 months. Patients with an end-of-treatment virologic response were assigned randomly to either stop use of both IFN and ribavirin or to continue use of ribavirin as monotherapy for an additional 6 months. HCV RNA became undetectable during treatment in 46 patients, who then entered the randomized trial. Sustained virologic response was observed in 13 of 26 patients who continued ribavirin monotherapy and in 15 of 20 patients who stopped use of both IFN and ribavirin (P, not significant). Sustained virologic response was significantly more common in patients with HCV genotype non-1 (75% vs. 56%) and in patients with a virus titer < 2 x 10(6) copies/mL (93% vs. 43%). The results indicate that continuing ribavirin monotherapy after achieving a virologic response does not improve sustained virologic response.     

Predicting sustained virological responses in chronic hepatitis C patients treated with peginterferon alfa-2a (40 KD)/ribavirin

BACKGROUND/AIMS: Prediction of sustained virological response (SVR) during treatment would allow clinicians to identify patients most likely to benefit from therapy. METHODS: Retrospective analysis of data from 1121 adults with chronic hepatitis C treated for 48 weeks with peginterferon alfa-2a (40 KD) 180 microg/week plus placebo or ribavirin (1000/1200 mg/day), or interferon alfa-2b 3 MIU three times/week plus ribavirin in a randomized, multinational, study. RESULTS: 67% of patients treated with peginterferon alfa-2a (40 KD)/ribavirin with early virological responses (HCV RNA negative or > or = 2 log10 decrease) at week 12 had SVRs at week 72 (HCV RNA < 50 IU/mL). The negative predictive value (NPV) was 97%. The probability of an SVR increased with the rapidity of HCV RNA suppression. The highest SVR rates were achieved in patients with rapid virological responses at week 4, but the corresponding NPV (74%) is too low for a decision criterion. In patients with early virological responses by week 12, the SVR rate was approximately 20% lower in those who received <80% compared with patients who received > or = 80% of the planned ribavirin dose. CONCLUSIONS: Early, sustained suppression of HCV replication portends an SVR. Cessation of treatment may be contemplated in patients without a > or = 2 log10 reduction in HCV RNA after 12 weeks.     

Hepatitis C virus-specific T-cell reactivity during interferon and ribavirin treatment in chronic hepatitis C

BACKGROUND & AIMS: The role of virus-specific T-helper lymphocyte reactivity in determining the therapeutic response in chronic hepatitis C virus (HCV) infection is not fully understood. METHODS: We studied CD4(+) T lymphocyte proliferation together with interferon (IFN)-gamma and interleukin (IL)-10 production from peripheral blood mononuclear cells in response to 4 HCV antigens (core, NS3, NS4, and NS5) in 25 patients with chronic hepatitis C undergoing antiviral therapy with IFN alone or in combination with ribavirin, prospectively, before, during, and after treatment. RESULTS: HCV-specific T-cell reactivity was uncommon at baseline but increased markedly during antiviral therapy, peaking around treatment weeks 4-8. Resolution of hepatitis C viremia was significantly more likely in patients who developed HCV-specific T-cell proliferation with increased IFN-gamma production. The main difference in T-cell reactivity of patients treated with IFN plus ribavirin was a significantly lower production of IL-10, whereas lymphocyte proliferation was similar to that in patients receiving IFN monotherapy. CONCLUSIONS: Treatment-induced control of hepatitis C viremia is associated with the development of HCV-specific T-cell responses with enhanced IFN-gamma and low IL-10 production. The greater efficacy of combination therapy with IFN-alpha plus ribavirin may be related to its ability to suppress HCV-specific IL-10 production.     

Hepatitis C virus free-virion and immune-complex dynamics during interferon therapy with and without ribavirin in genotype-1b chronic hepatitis C patients

The Synergistic effect of interferon (IFN) and ribavirin for patients with chronic hepatitis C has been demonstrated, but ribavirin has no apparent direct antiviral effect against hepatitis C virus (HCV) when used as monotherapy. To elucidate the mechanism of ribavirin on enhanced HCV eradication when used in combination therapy, we investigated the serum HCV dynamics of free-virions (FV) and immune-complexes (IC) in genotype-1b infected patients treated with IFN-alpha2b alone (n = 11) or in combination with ribavirin (n = 15). Serum FV- and IC-HCV RNA were separated by immunoprecipitation using anti-human immunoglobulin and quantified serially using real-time detection polymerase chain reaction. At the first phase (day 0-2), the decline of FV- and IC-HCV RNA was similar between the two treatment groups. At the second phase (day 2-28), the decline of IC was significantly faster in patients treated with IFN plus ribavirin compared with IFN alone [exponential decay slope = 0.079 +/- 0.036 vs 0.048 +/- 0.027 log10/day, P = 0.0248; half-life = 81.1 +/- 21.4 vs 135.1 +/- 61.4 h, P = 0.0053], although the second phase FV-decline was not significantly different between the two treatment groups. The fast second phase decline of IC was associated with sustained virological response to therapy. These results suggest that ribavirin may modulate the humoral immune response against HCV and trigger a favourable response to IFN. In conclusion, analysis of early IC-HCV dynamics is useful for predicting the response to therapy and for understanding the mechanism of action of antiviral drugs in chronic hepatitis C patients.     

Synergistic inhibition of intracellular hepatitis C virus replication by combination of ribavirin and interferon- alpha

Treatment of hepatitis C virus (HCV) infection with interferon (IFN)- alpha and ribavirin combination therapy results in superior clinical antiviral responses than does monotherapy with IFN. To explore the virological basis of the effects of combination therapy, we analyzed the effects of IFN- alpha and ribavirin, singly and in combination, on intracellular HCV replication by use of an HCV replicon system. A new replicon that expressed a selectable chimeric reporter protein comprising firefly luciferase and neomycin phosphotransferase was constructed. The replicon was highly sensitive to IFN-alpha (50% inhibitory concentration [IC(50)], 0.5 U/mL). Therapy with ribavirin showed weak suppression of HCV replication at a lower concentration (IC(50), 126 mu mol/L). The nucleotide sequence diversity of the replicon was increased significantly by therapy with ribavirin, suggesting that error-prone HCV replication was induced by the drug. Importantly, use of a clinically achievable concentration of ribavirin (approximately 10 mu mol/L) in combination with IFN showed strong synergistic inhibitory effects on HCV replication. Our results suggest that the direct effects of ribavirin on the genetic stability of the HCV subgenome and its synergistic action combined, with IFN-alpha, may explain the improved clinical responses to combination therapy.     

Effect of combined interferon-alpha induction therapy and ribavirin on chronic hepatitis C virus infection: a randomized multicentre study

BACKGROUND: The efficacy of interferon-alpha (IFN) induction in combination with ribavirin for chronic hepatitis C virus (HCV) infection is not known. METHODS: A total of 256 treatment-naive HCV RNA-positive patients with biopsy-confirmed chronic hepatitis were enrolled in a randomized multicentre study. The patients received either standard combination therapy with 3 MIU interferon-alpha2b thrice weekly for 26 weeks or 6 MIU interferon-alpha2b daily for 4 weeks and 3 MIU 3/7 days for 22 weeks. All patients received ribavirin 1000 mg or 1200 mg (weight dependent) daily during the 26-week treatment period. Patients were monitored for HCV RNA during and following treatment. RESULTS: The sustained virological response rates (26 weeks after end of treatment) were 54% and 47% for patients receiving IFN induction/ribavirin and standard IFN/ribavirin, respectively (P = 0.35). Among patients infected with genotype 1a/1b, the sustained response rates were 32% and 35%. In patients infected with genotype 2b/3a IFN induction/ribavirin led to a sustained response rate of 80% as compared to 65% in the standard combination therapy group (P = 0.073). Steatosis was more frequently seen in liver biopsies from patients infected with genotype 3a as compared to genotypes la/lb. Among genotype 1a/1b infected patients. steatosis was a highly significant predictor of failure to achieve sustained virological response. Logistic regression analysis (multivariate analysis) showed that independent predictors of sustained virological response were low age, female gender, genotype 2b/3a and HCV RNA negativity at 2 weeks. CONCLUSIONS: IFN induction in combination with ribavirin does not increase the sustained virological response rate among patients infected with HCV. Absence of steatosis is an independent predictor of sustained virological response in patients infected with genotypes 1a/1b.     

Evaluation of long-term efficacy of interferon alpha-2b and ribavirin in combination in naive patients with chronic hepatitis C: an Italian multicenter experience. Ribavirin-Interferon in Chronic Hepatitis Italian Group Investigators

BACKGROUND/AIMS: A combination of interferon alpha and ribavirin has been suggested to reach a higher rate of sustained virological response in patients with chronic hepatitis C than monotherapy. In this study we assessed the long-term efficacy of this combination therapy in the treatment of selected Italian naive chronic hepatitis C patients compared to interferon alpha monotherapy. METHODS: We enrolled 428 naive patients who were randomly assigned to receive either recombinant interferon alpha-2b and ribavirin for 24 weeks or interferon alpha-2b alone for 48 weeks. The primary end-point of the study was the rate of sustained virological response. Serum HCV RNA levels were determined before treatment; during treatment at weeks 12 and 24 in the patients receiving the combination therapy; at weeks 12, 24, 36 and 48 in the patients receiving monotherapy; and after therapy at weeks 12, 24 and 48 in the patients in both study groups. RESULTS: Sustained virological response was observed in 43% of the patients treated with combination therapy and in 14% of the patients treated with monotherapy. Logistic regression analysis showed that sustained response was associated with the combination therapy, with HCV genotype other than 1b, with an HCV viral load of 3x10(6) copies/ml or less, with an inflammation score of 7 or less, and with an estimated duration of disease of 10 years or less. CONCLUSIONS: A 24-week treatment course with interferon alpha-2b and ribavirin offers a greater chance of sustained virological response compared to treatment with interferon alpha-2b alone for 48 weeks, and may be indicated as initial therapy in such patients.     

Relationships between cellular immune responses and treatment outcomes with interferon and ribavirin in HIV/hepatitis C virus co-infection

OBJECTIVE: To test the hypothesis that hepatitis C virus (HCV)-specific interferon (IFN)gamma immune responses are correlated with HCV virological response following treatment in subjects with HIV-1 and HCV co-infection. DESIGN: Immune responses were studied in a treatment trial comparing standard interferon alfa (IFN) to pegylated interferon alfa (PEG-IFN), each with ribavirin (R). METHODS: Using HCV antigens core, NS3 and NS5, and Candida, enzyme-linked immunosorbent spots on peripheral blood mononuclear cells measured IFNgamma and interleukin (IL)-10 production. Immunologic, virologic and clinical variables were modeled using recursive partitioning (CART) to identify factors associated with HCV virological response at week 24 (VR) and week 72 (SVR) in 108 patients. RESULTS: There were no significant differences in baseline IFNgamma immune responses and higher IL-10 to NS3 in subjects with VR versus non-responders. Subjects who had significant decreases in IL-10 responses at week 24 compared to baseline for NS3, NS5, or summed HCV responses were more likely to be VR. Using baseline immunological responses and clinical data in CART models, patients who were randomized to PEG-IFN/R and had high IL-10 responses to summed HCV proteins were more likely to be VR (73%), whereas those on IFN/R who had low IFNgamma responses to Candida were less likely to be VR (5%). The main correlate of SVR for genotype-1 subjects was maintenance of HCV-specific IFNgamma responses from baseline to week 72. CONCLUSIONS: In this cohort of subjects with HIV and HCV, a decrease in HCV-specific IL-10 responses and maintenance of IFNgamma responses during treatment with IFN were associated with week 24 or 72 virological response.     

Triple therapy of initial high-dose interferon with ribavirin and amantadine for patients with chronic hepatitis C

Aims: We previously reported the potential effect of combination therapy of an initial high‐dose interferon (IFN) and amantadine on the eradication of HCV‐RNA in patients with chronic hepatitis C. The additive effects of amantadine on interferon and ribavirin combination therapy remain controversial. In this study we investigated the efficacy of initial high‐dose IFN with ribavirin and amantadine on the virological response in patients with chronic hepatitis C with a high viral load of genotype 1b. Methods: Twenty‐two patients with high viral loads of genotype 1b hepatitis C virus were enrolled in this pilot study. Patients were administered IFN‐beta for four weeks and then IFN‐alpha2b for 22 weeks with daily oral administration of ribavirin and amantadine. Results: A sustained virological response (SVR) was shown in 31.8% (seven of 22 patients). With the naïve patients, the SVR rate was 21.4% (three of 14 patients). In patients who could not eradicate HCV‐RNA by previous IFN monotherapy, the SVR rate was 50% (four of eight patients). Conclusion: Triple therapy with an initial high dose of IFN with ribavirin and amantadine may be effective, especially for chronic hepatitis C IFN‐retreatment patients with a high viral load of genotype 1b.     

Simple formula to predict response to peginterferon alpha2b and ribavirin combination therapy in genotype 1 chronic hepatitis C patients with high viral loads

Aim: We advocate a simple formula which can conveniently predict the outcome of Peg‐interferon (IFN) alpha2b and ribavirin (RBV) combination therapy for genotype 1 chronic hepatitis C (CH‐C) with high viral load. Methods: A total of 338 (group A: 230, Group B: 108) genotype 1 CH‐C patients treated with Peg‐IFN alfa‐2b and RBV were enrolled. Clinical parameters differing significantly between sustained virological responders (SVRs) and non‐SVRs in group A were categorized, then a simple formula to predict SVR was constructed and re‐evaluated in group B. Another formula containing hepatitis C virus amino acid mutations/substitutions also was constructed. Results: In group A, gender and HCV RNA load <1000 KIU were significant predictors of SVR by multivariate logistic regression analysis. A simple formula was constructed (formula A): male gender (point 2) + HCV RNA load <1000 KIU (3) + platelet counts ≥15 × 10⁴ /mm³ (1) + age <60 (1). In group A, score (0–1) predicted SVR rate 23.8% (2–4): 48.1% and (5–7): 70.2%. According to this formula, score (0–1) predicted SVR rate 7.1% (2–4): 38.6%, and (5–7): 70.3% in group B. Information on HCV amino acid mutations/substitutions seemed to add some accuracy. Conclusions: This simple formula can be used to roughly determine, at the patients' first/second visit, the probability of response to Peg‐IFN alpha2b and RBV combination therapy for genotype 1 CH‐C with high viral load.     

Impact of ribavirin priming on viral kinetics and treatment response in chronic hepatitis C genotype 1 infection

Ribavirin amplifies the interferon‐alpha (IFN) signalling cascade. As ribavirin needs 4 weeks to reach steady state, ribavirin priming may optimize hepatic IFN sensitivity before starting a pegylated (PEG)‐IFN/ribavirin combination therapy. This study investigated potential benefits of ribavirin priming prior to PEG‐IFN2a/ribavirin combination therapy on viral kinetics, on‐treatment and sustained virological response (SVR) in chronic hepatitis C virus (HCV) genotype 1 infection. Sixty‐eight treatment naive patients were randomized 2:2:1 to ribavirin (ribavirin arm) or placebo (placebo arm) or PEG‐IFN2a (PEG‐IFN2a arm) for 6 weeks prior to 12 weeks of PEG‐IFN2a/ribavirin combination therapy within a double‐blind, placebo‐controlled trial. Then, standard PEG‐IFN2a/ribavirin combination therapy according to the German guidelines was continued under the responsibility of the investigators. Ribavirin was given according to body weight and PEG‐IFN2a at a dose of 180 μg subcutaneously once/week. During ribavirin priming, HCV RNA showed a decline of −0.58 log₁₀ IU/mL (P < 0.001) that was unrelated to the IL28B rs12979860 genotype (CC vs CT/TT, P = 0.244). Ribavirin priming did neither increase the PEG‐IFN2a‐induced first‐ or second‐phase viral decline (P values >0.100) nor on‐treatment response or SVR (HCV RNA undetectable at week 12 of combination therapy: ribavirin arm 56%, placebo arm 38%, PEG‐IFN2a arm 50%; SVR: ribavirin arm 41%, placebo arm 54%, PEG‐IFN2a arm 50%; P values >0.300). In conclusion, ribavirin monotherapy showed a significant antiviral activity that was not influenced by the IL28B genotype. Ribavirin priming prior to PEG‐IFN2a/ribavirin combination therapy did neither increase the first‐ or second‐phase viral decline nor on‐treatment response or SVR.     

Peginterferon alone or with ribavirin enhances HCV-specific CD4 T-helper 1 responses in patients with chronic hepatitis C

BACKGROUND & AIMS: Pegylated interferons (IFNs) with or without ribavirin were shown in several studies to improve sustained virologic response compared with standard IFN alpha-2 therapy. This study investigated if the greater efficacy of pegylated IFNs might be related to modulation of immunologic responses. METHODS: Hepatitis C virus (HCV)-specific CD4+ T-cell responses and cytokine production to various HCV proteins (Elispot assay) in peripheral blood were prospectively assessed in 42 patients receiving IFN alpha-2a monotherapy, peginterferon (PEG IFN) alpha-2a monotherapy, or PEG IFN alpha-2a plus ribavirin and correlated to the outcome of therapy. RESULTS: The sustained virologic response rate was significantly higher in the PEG IFN groups (42% in PEG IFN alpha-2a monotherapy and 57% in PEG IFN alpha-2a/ribavirin combination) than in the standard IFN alpha-2a group (14%). The sustained response was 48% in HCV genotype 1 patients treated with PEG IFN alpha-2a/ribavirin therapy. Pretreatment HCV-specific CD4+ responses were either weak or absent. PEG IFN alone or combined with ribavirin induced significant increase in the frequency, strength, and breadth of HCV-specific CD4+ T-cell responses with type 1 predominance; whereas interferon alpha-2a monotherapy was associated with lower, fluctuating, short-lived responses. Sustained responders maintained multispecific HCV-specific CD4+ T-cell responses with enhanced IFN-gamma production. Relapsers and partial responders initially displayed significant HCV-specific CD4+ T-cell responses that waned or were lost. CONCLUSIONS: The efficacy of PEG IFN alpha-2a alone or in combination with ribavirin in inducing high rates of sustained virologic response may be owing to the higher efficacy of PEG IFN in induction and maintenance of significant multispecific HCV-specific CD4+ T-helper 1 responses.     

HIV／HCV共感染合并血友病患者利巴韦林联合干扰素治疗前后特异性细胞免疫反应的研究

目的研究HIV／HCV共感染合并血友病患者在利巴韦林联合干扰素治疗过程中的细胞免疫反应,了解此类患者在抗HCV治疗过程中HCV的损伤机制和免疫重建过程。方法收集36例HIV／HCV共感染合并血友病患者,分别在干扰素和利巴韦林治疗前、治疗结束24周后采集外周血单个核细胞（PBMC）,Elispot方法检测在HCV核心抗原、NS3和NS5刺激下,检测IFN-γ、IL-2、IL4和IL-10的分泌情况,分析细胞免疫反应与病毒应答的关系。结果在HIV／HCV共感染患者中,治疗前非应答者IFN-γ,IL-2水平高于应答者,应答者IL-10对NS3的反应增高;治疗结束后24周应答者IL-10对HCV抗原蛋白NS3、NS5的反应显著下降,IL-2轻度下降,IFN-γ持续反应,IL-4几乎检测不到;非应答者IL-2、IFN-γ对核心抗原、NS3的反应下降,但差异无统计学意义。结论在HIV／HCV共感染合并血友病患者中,IL-10、IL-2的下降,IFN-γ的持续反应与HCV病毒学持续应答相关,细胞因子在HCV感染的发病机制中起着重要作用。     

Efficacy of a short‐term ribavirin plus interferon alpha combination therapy followed by interferon alpha alone in previously untreated patients with chronic hepatitis C: a randomized multicenter trial

Abstract: Background: Combination therapy with interferon alpha (IFNα) plus ribavirin has been shown to improve the sustained response rate in patients with chronic hepatitis C but there is little information regarding the lengths of time for this therapeutic regimen. In this study we therefore tried to evaluate whether the analysis of different virological parameters could provide new clues with respect to the early determination of the efficacy of this form of combination therapy. Furthermore, we also examined whether short‐term induction combination therapy followed by IFNα alone is more effective than monotherapy in mounting an initial as well as a sustained virological response. Methods: 185 patients with histologically proven chronic hepatitis C (mean age 42 years (range 19–65 years); 110 males, 75 females) were enrolled in the study. The patients were randomly assigned to receive, over the first 12 weeks, either interferon alpha 2a 6 million units (MU) three times weekly plus ribavirin 14 mg/kg per day (n=93) or the same dose of IFNα alone (n=92). Patients with a virological response (serum HCV RNA undetectable) after 12 weeks were subsequently treated with 3 MU IFNα alone thrice weekly for a further 40 weeks. Otherwise, treatment was discontinued. After the end of treatment, patients were followed up for 24 weeks. Results: Patient characteristics at baseline were not significantly different in the two treatment groups. An initial virological response at week 12 was seen in 61 (66%) patients receiving IFNα plus ribavirin and in 44 (48%) being treated with IFNα alone (p=0.015) and this improvement in the response rate was mainly restricted to HCV genotype 1‐infected patients (58% vs. 38%). In contrast, end‐of‐treatment (week 52) and sustained virological response rates were similar in both groups (37% vs. 29% and 26% vs. 17% [p=0.1], respectively). Interestingly, patients with HCV genotype 3, however, clearly benefited from short‐term combination therapy. Thus, sustained virological response rates in these patients significantly increased from 25% (IFNα monotherapy) to 59% (combination therapy) (p=0.05). Conclusions: Short‐term combined therapy for 12 weeks is more effective than the monotherapy with respect to the induction of an initial virological response but this effect applies only to genotype 1‐infected patients. However, there is no significant difference between both therapeutic schedules with regard to the induction of sustained response. Although HCV genotype 3‐infected patients seem to benefit from this short‐term combined therapy, prolonged combined therapy may be necessary in HCV genotype 1‐infected patients.     

Mutations in the NS5A and E2-PePHD region of hepatitis C virus type 1b and correlation with the response to combination therapy with interferon and ribavirin

Nonstructural 5A (NS5A) and the second envelope (E2) proteins of hepatitis C virus (HCV) have the potential to block interferon (IFN)-induced RNA-dependent protein kinase (PKR) and may therefore interfere with the response to IFN therapy, but controversy still exists regarding the relevance of this. This study aimed to assess whether mutations in these regions correlated with the response to combination therapy, IFN and ribavirin. Pretreatment parameters were analysed in 57 HCV-1b patients who had received IFN-alpha2b (3 or 5 MU three times weekly) and ribavirin (800-1200 mg per day) for 24 weeks. The amino acid sequences of the NS5A and PKR-eIF2alpha phosphorylation homology domain (E2-PePHD) were deduced from the corresponding coding sequence, which were determinated by direct sequencing of the HCV genome amplified by the polymerase chain reaction. Twenty (36%) patients achieved a sustained virological response (SVR). The mean number of amino acid substitutions in the NS5A-PKR binding domain (2209-2274), interferon sensitivity-determining region (ISDR) (2209-2248), and E2-PePHD sequence (659-670) in patients with and without SVR were 4.53 +/- 3.31 vs 2.83 +/- 1.78 (P = 0.094), 2.45 +/- 2.74 vs 1.03 +/- 1.32 (P = 0.042) and 0.25 +/- 0.70 vs 0.03 +/- 0.17 (P = 0.109), respectively. Patients with a mutant-type (>/= 4) NS5A-ISDR had a higher rate of SVR (six of nine, 67%) than those with wild-type (five of 22, 23%) (P = 0.038). Stepwise multiple logistic regression analysis of the factors (age, gender, viral load, cirrhosis rate, IFN dosage and amino acid substitutions) revealed that the mutation in NS5A-ISDR (>/= 4 vs < 4) was the only independent variable of treatment outcome. Our study showed that NS5A-ISDR mutations were correlated with the SVR to combination therapy in chronic HCV-1b patients in Taiwan.