Inflammatory markers neopterin and alanine aminotransferase in HCV patients treated with HCV NS3.4A protease inhibitor telaprevir (VX-950) and/or peginterferon alfa-2a

Disentangling the lifespans of hepatitis C virus-infected cells and intracellular vRNA replication-complexes during direct-acting anti-viral therapy

The decay rate of hepatitis C virus (HCV)-infected cells during therapy has been used to determine the duration of treatment needed to attain a sustained virologic response, but with direct-acting anti-virals (DAA), this rate has been difficult to estimate. Here, we show that it is possible to estimate it, by simultaneously analysing the viral load and alanine aminotransferase (ALT) kinetics during combination DAA therapy. We modelled the HCV RNA and ALT serum kinetics in 26 patients with chronic HCV genotype 1b infection, under four different sofosbuvir-based combination treatments. In all patients, ALT decayed exponentially to a set point in the normal range by 1-3 weeks after initiation of therapy. The model indicates that the ALT decay rate during the first few weeks after initiation of therapy reflects the death rate of infected cells, with an estimated median half-life of 2.5 days in this patient population. This information allows independent estimation of the rate of loss of intracellular replication complexes during therapy. Our model also predicts that the final ALT set point is not related to the release of ALT by dying HCV-infected cells. Using ALT data, one can separately obtain information about the rate of 'cure' of HCV-infected cells versus their rate of death, something not possible when analysing only HCV RNA data. This information can be used to compare the effects of different DAA combinations and to rationally evaluate their anti-viral effects.

Improvement of ALT decay kinetics by all-oral HCV treatment: Role of NS5A inhibitors and differences with IFN-based regimens

BACKGROUND

Intracellular HCV-RNA reduction is a proposed mechanism of action of direct-acting antivirals (DAAs), alternative to hepatocytes elimination by pegylated-interferon plus ribavirin (PR). We modeled ALT and HCV-RNA kinetics in cirrhotic patients treated with currently-used all-DAA combinations to evaluate their mode of action and cytotoxicity compared with telaprevir (TVR)+PR.

STUDY DESIGN

Mathematical modeling of ALT and HCV-RNA kinetics was performed in 111 HCV-1 cirrhotic patients, 81 treated with all-DAA regimens and 30 with TVR+PR. Kinetic-models and Cox-analysis were used to assess determinants of ALT-decay and normalization.

RESULTS

HCV-RNA kinetics was biphasic, reflecting a mean effectiveness in blocking viral production >99.8%. The first-phase of viral-decline was faster in patients receiving NS5A-inhibitors compared to TVR+PR or sofosbuvir+simeprevir (p<0.001), reflecting higher efficacy in blocking assembly/secretion. The second-phase, noted δ and attributed to infected-cell loss, was faster in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.27 vs 0.21 d-1, respectively, p = 0.0012). In contrast the rate of ALT-normalization, noted λ, was slower in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.17 vs 0.27 d-1, respectively, p<0.001). There was no significant association between the second-phase of viral-decline and ALT normalization rate and, for a given level of viral reduction, ALT-normalization was more profound in patients receiving DAA, and NS5A in particular, than TVR+PR.

CONCLUSIONS

Our data support a process of HCV-clearance by all-DAA regimens potentiated by NS5A-inhibitor, and less relying upon hepatocyte death than IFN-containing regimens. This may underline a process of "cell-cure" by DAAs, leading to a fast improvement of liver homeostasis.

Serum Neopterin Levels Among Hepatitis C-Positive Living-Donor Renal Transplant Recipients

BACKGROUND

The role of neopterin as a marker of cell-mediated immunity for immunological monitoring after transplantation is of great potential interest. Neopterin levels among hepatitis C virus (HCV)-positive recipients of living-donor renal transplantation (LDRT) have not been previously described.

METHODS

Twenty-two HCV-positive (group I) and 10 HCV-negative (group II) recipients of LDRT were serially monitored for serum neopterin levels by enzyme-linked immunosorbent assay (ELISA). Group I patients were monitored thrice, ie, before transplantation, day 10, and 6 months post transplantation, while group II patients were monitored twice (day 10 and 6 months post transplantation). Peripheral blood T-lymphocyte subsets (CD3, CD4, CD8, CD4⁺CD25⁺, CD₁₆₊₅₆) and Th1/Th2 cytokines were monitored concomitantly by flow cytometry.

RESULTS

Ten days post transplantation, there was a significant increase in neopterin and neopterin/creatnine levels among group I patients. There was a positive correlation between activated T-lymphocyte (CD4⁺CD25⁺) and neopterin early post transplantation (day 10). Th2 cytokines IL-10 and IL-5 showed a positive correlation with neopterin levels on day 10 and 6 months post transplantation, respectively. Neopterin levels did not show association with either HCV viral load or allograft rejection among our study cohort.

CONCLUSION

Increased monocyte/macrophage activation with elevated serum neopterin was detected among group I patients on day 10 post transplantation, but it could not predict rejection. It appears that IL-10 either from a regulatory or nonregulatory source helps in the maintenance of stable graft early post transplantation. Further, it would be of interest to assess the role of neopterin in chronic allograft nephropathy and long-term graft outcome.

Hyperbaric oxygen treatment and N-acetylcysteine ameliorate acetaminophen-induced liver injury in a rat model

An overdose of acetaminophen (APAP) produces centrilobular hepatocellular necrosis. We aimed to investigate the hepatoprotective effects of N-acetylcysteine (NAC) only and hyperbaric oxygen (O(2)) treatment (HBOT) combined with NAC, and their anti-inflammatory properties in liver tissue. In the current study, a total of 32 male Sprague Dawley rats were divided into 4 groups: sham, APAP, NAC, and NAC + HBOT. In the APAP, NAC, and NAC + HBOT groups, liver injury was induced by oral administration of 1 g/kg APAP. The NAC group received 100 mg/kg NAC per day. NAC + HBOT group received intraperitoneal injection of 100 mg/kg/day NAC and were given HBOT at 2.8 ATA pressure with 100% O(2) inhalation for 90 min every 12 h for 5 days. Rats in the sham group received distilled water only by gastric tube. All animals were killed on day 6 after APAP or distilled water administration. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, hepatic neopterin, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) levels were measured. There was a significant increase in serum AST and ALT activities in the APAP group compared with the sham group (in both p = 0.001). NAC and NAC + HBOT groups had significant decreases in hepatic neopterin, TNF-α, and IL-6 levels compared with the APAP group. APAP administration caused extensive hepatic necrosis. NAC and NAC + HBO treatments significantly reduced APAP-induced liver injury. Our results showed that the liver damage in APAP toxicity was attenuated by NAC and NAC + HBO treatments. NAC + HBOT exhibit hepatoprotective activity against APAP-induced liver injury in rats.

Sustained virologic response after therapy with the HCV protease inhibitor narlaprevir in combination with peginterferon and ribavirin is durable through long-term follow-up

Achievement of a sustained virologic response (SVR) after peginterferon (PEG-IFN) and ribavirin (RBV) treatment is considered to be a marker for the cure of chronic hepatitis C virus (HCV) infection. Long-term follow-up of patients with SVR after treatment with a direct acting antiviral has not yet been described. We used a randomized placebo-controlled, double-blind, two-period phase 1b trial that was conducted in 40 HCV genotype 1 (treatment-naïve and treatment-experienced)-infected patients. Nineteen patients achieved SVR after treatment with the HCV protease inhibitor narlaprevir followed by PEG-IFN/RBV. In these patients, HCV-RNA tests were scheduled at 3, 6, 12 and 24 months after end of treatment. Patients were followed for a median of 27 months (range 15-32) after end of treatment with a median number of follow-up visits of 4 (range 3-8). All patients remained HCV-RNA negative over time. SVR achieved following narlaprevir and PEG-IFN/RBV-therapy was durable up to 32 months after the end of treatment.

Direct-acting antiviral therapies for hepatitis C genotype 1 infection: a multiple treatment comparison meta-analysis

BACKGROUND

New direct-acting antiviral agents for hepatitis C genotype 1 infection, boceprevir and telaprevir, offer enhanced sustained virologic response (SVR) among both treatment-naïve and treatment-experienced patients.

AIM

To determine the relative efficacy of the new direct-acting antiviral agents by applying a multiple treatment comparison meta-analysis.

DESIGN

We included published Phase II and III randomized controlled trials evaluating head-to-head comparisons between boceprevir, telaprevir, peg-interferon alpha-2a with ribavirin and peg-interferon alpha-2b with ribavirin in hepatitis C genotype 1 patients. We applied Bayesian multiple treatment comparison meta-analysis.

RESULTS

We included data from four boceprevir, three telaprevir and six peg-interferon alpha-2a plus ribavirin vs. peg-interferon alpha-2b plus ribavirin randomized controlled trials. Both boceprevir and telaprevir offer statistically superior outcomes for SVR, relapse and discontinuation due to adverse events than either peg-interferons among both treatment-naïve and treatment-experienced patients. Among treatment-naïve patients, clinical outcomes were similar for boceprevir and telaprevir, for SVR [odds ratio (OR) 0.90, 95% credible interval (95% CrI) 0.41-1.91] and for relapse (OR 1.09, 95% CrI 0.19-4.84). Similarly, among treatment-experienced patients, clinical outcomes were similar for boceprevir and telaprevir and for SVR (OR 1.45, 95% CrI 0.70-3.08) and for relapse (OR 0.35, 95% CrI 0.13-1.02). For treatment-naïve patients receiving standard-duration therapy, telaprevir yielded lower rates of anemia and neutropenia, but higher rates of rash and pruritus. For treatment-experience patients, all adverse event rates were higher with telaprevir.

DISCUSSION

Boceprevir and telaprevir exhibit similar effects among hepatitis C genotype 1 treatment-naïve and treatment-experienced patients.

Boceprevir and telaprevir for the treatment of chronic hepatitis C genotype 1 infection: an indirect comparison meta-analysis

Background

The aim of this study was to examine the relative efficacy and safety of boceprevir and telaprevir, when used in combination with pegylated interferon alpha and ribavirin, using an indirect comparison meta-analysis.

Methods

Published phase II and phase III randomized placebo-controlled trials examining the efficacy of boceprevir and telaprevir in chronic hepatitis C virus genotype 1 infected adult populations were included. The primary outcomes were sustained virologic response, relapse, and discontinuation of all study drugs. Secondary outcomes included the adverse events of anemia, neutropenia, rash, and pruritus.

Results

Four boceprevir trials and six telaprevir trials were included. No significant differences were observed for sustained virologic response among either naïve (relative risk [RR] 1.14, 95% confidence interval [CI] 0.93–1.37, P = 0.20) or experienced patients (RR 0.81, 95% CI 0.52–1.23, P = 0.30). Similarly, for relapse among naïve (RR 0.80, 95% CI 0.18–3.45, P = 0.77) and experienced patients (RR 1.71, 95% CI 0.90–3.24, P = 0.10), or discontinuation of therapy for naïve (RR 0.80, 95% CI 0.28–2.29, P = 0.72) and experienced patients (RR 0.88, 95% CI 0.69–1.12, P = 0.30). Telaprevir was more likely to be associated with rash and pruritus, and boceprevir was more likely to be associated with neutropenia in certain patient populations.

Conclusion

Boceprevir and telaprevir appear comparable in terms of sustained virologic response, relapse, or discontinuation of therapy for patients treated with standard-dose therapy durations and response-guided therapy durations.

Combined noninvasive imaging and modeling approaches reveal metabolic compartmentation in the barley endosperm

The starchy endosperm of cereals is a priori taken as a metabolically uniform tissue. By applying a noninvasive assay based on (13)C/(1)H-magnetic resonance imaging (MRI) to barley (Hordeum vulgare) grains, we uncovered metabolic compartmentation in the endosperm. (13)C-Suc feeding during grain filling showed that the primary site of Ala synthesis was the central region of the endosperm, the part of the caryopsis experiencing the highest level of hypoxia. Region-specific metabolism in the endosperm was characterized by flux balance analysis (FBA) and metabolite profiling. FBA predicts that in the central region of the endosperm, the tricarboxylic acid cycle shifts to a noncyclic mode, accompanied by elevated glycolytic flux and the accumulation of Ala. The metabolic compartmentation within the endosperm is advantageous for the grain's carbon and energy economy, with a prominent role being played by Ala aminotransferase. An investigation of caryopses with a genetically perturbed tissue pattern demonstrated that Ala accumulation is a consequence of oxygen status, rather than being either tissue specific or dependent on the supply of Suc. Hence the (13)C-Ala gradient can be used as an in vivo marker for hypoxia. The combination of MRI and metabolic modeling offers opportunities for the noninvasive analysis of metabolic compartmentation in plants.

Danoprevir monotherapy decreases inflammatory markers in patients with chronic hepatitis C virus infection

Danoprevir is a potent and selective direct-acting antiviral agent that targets the protease activity of hepatitis C virus (HCV) NS3/4A. This agent results in a significant rapid decline in HCV RNA levels when it is used in monotherapy. The present study evaluated whether plasma concentrations of the inflammatory markers gamma interferon-inducible protein 10 (IP-10) and neopterin or the interferon-stimulated gene product 2'-5'-oligoadenylate synthetase (OAS-1) were correlated with the plasma HCV RNA concentration before or during 14-day danoprevir monotherapy. In contrast to pegylated interferon and ribavirin treatment, a higher baseline IP-10 concentration was positively correlated with a greater first-phase HCV RNA decline upon danoprevir administration. Changes in the IP-10 plasma concentration during danoprevir administration were also associated with categorical changes in HCV RNA concentration at days 7 and 14. The neopterin concentration appeared to be moderately decreased during danoprevir administration, although these changes were not statistically significant. However, changes in neopterin concentration showed a statistically significant correlation with changes in IP-10 concentration. Considerable variation in the OAS-1 concentration was observed before and during treatment, including in patients treated with placebo and/or patients with minimal virologic response. Overall, these results suggest that effective treatment with a direct-acting antiviral agent may reduce hepatic inflammation and that first-phase HCV RNA decline during treatment with an NS3/4A protease inhibitor is more robust in patients with high baseline IP-10 concentrations.