Influence of viral genotype and level of viremia on the severity of liver injury and the response to interferon therapy in Spanish patients with chronic C infection

Nutrition status and intestinal permeability in patients eligible for liver transplantation

BACKGROUND

Increased intestinal permeability has been reported in multiple studies of cirrhotic patients, although specific factors associated with this finding have not been fully elucidated. Thus, the aim of this study was to investigate whether there was an association between nutrition status measured by different methods and intestinal permeability in cirrhotic patients who were candidates for liver transplantation.

MATERIALS AND METHODS

The study group comprised 18 cirrhotic patients and 15 healthy controls. Patients' nutrition status was evaluated by Subjective Global Assessment (SGA), anthropometry, dynamometry, and phase angle, which was determined by bioelectrical impedance analysis. Intestinal permeability was assessed by the lactulose/mannitol test.

RESULTS

The prevalence of malnutrition showed wide variance between different assessment methods (5.5%-77.8%). Intestinal permeability was significantly higher in cirrhotic patients than in healthy controls. In relation to nutrition status, intestinal permeability and phase angle did not differ significantly between patients who were considered well nourished (median intestinal permeability, 0.010 [range, 0.001-0.198]; median phase angle, 6.0 [range, 4.2-6.9]) and malnourished patients (intestinal permeability, 0.032 [range, 0.002-0.079]; phase angle, 4.8 [range, 2.2-6.1]) by SGA. In addition, no correlation was found between nutrition diagnosis as assessed by different methods, patient age, liver disease severity scores, and laboratory measurements with intestinal permeability.

CONCLUSION

Although intestinal permeability was increased in cirrhotic patients, this finding was not associated with nutrition status.

Hepatitis C virus genotype 1b as a risk factor for hepatocellular carcinoma development: a meta-analysis

BACKGROUND/AIMS

Hepatitis C virus (HCV) is a known risk factor for hepatocellular carcinoma (HCC), but whether the risk varies among patients infected with different HCV genotypes is still controversial. We performed a meta-analysis to clarify whether the genotype 1b is associated with a higher risk of HCC than other genotypes.

METHODS

We identified 57 relevant papers through a literature search to December 2007 but, since age could represent a major confounder, we focused the meta-analysis on the 21 studies presenting age-adjusted risk estimates for HCV genotype 1b vs. other genotypes. We used random-effects models with the DerSimonian-Laird method and assessed heterogeneity between studies and publication bias.

RESULTS

Patients infected with HCV genotype 1b have almost double the risk to develop HCC than those infected with other genotypes (Relative Risk (95% Confidence Intervals) = 1.78(1.36-2.32)). The pooled risk estimate was somewhat lower when we restricted the analysis to the eight studies conducted in patients with liver cirrhosis (1.60;1.07-2.39) or considering the 36 studies presenting only crude data (1.63;1.30-2.06). In seven studies excluding patients with liver cirrhosis, the RR (95% CI) increased to 2.46(1.69-3.59).

CONCLUSIONS

This meta-analysis suggests that HCV genotype 1b plays an important role in HCC development, especially in patients with early stage liver disease.

An evaluation of the cyclophilin inhibitor Debio 025 and its potential as a treatment for chronic hepatitis C

Debio 025 is a cyclophilin (Cyp) inhibitor without calcineurin-binding properties. The drug inhibits viral replication of genotype 1b and 2a replicons in nanomolar concentrations and shows an additive to synergistic antiviral effect with interferon, ribavirin, and specifically targeted antiviral therapy for hepatitis C (STAT-C) drugs. There is no cross-resistance with protease and polymerase inhibitors. In humans, Debio 025 has shown activity against genotypes 1, 2, 3, and 4, and displays an additive antiviral effect with pegylated interferon (peg-IFN)alpha2a in genotype 1 and 4 patients. The most prominent side effect is reversible hyperbilirubinaemia caused by inhibition of biliary transporters. Debio 025 is a potent anti-HCV drug, with a novel mechanism of action and an efficacy profile that makes it an attractive candidate for combination with current and future HCV treatments.

Gastrointestinal permeability in ovarian cancer and breast cancer patients treated with paclitaxel and platinum

Background

Combination of platinum derivatives with paclitaxel is currently the standard front line regimen for patients with epithelial ovarian carcinoma, and represents also an active regimen in patients with metastatic breast or unknown primary carcinomas. Measurement of intestinal permeability represents one of the potential methods of noninvasive laboratory assessment of gastrointestinal mucositis induced by chemotherapy, but little is known about intestinal permeability in patients treated with paclitaxel or platinum.

Methods

Intestinal permeability was assessed in 36 breast and ovarian cancer patients treated with paclitaxel/platinum combination by measuring, using capillary gas chromatography, urinary sucrose, lactulose, xylose and mannitol after oral challenge. The significance of differences during the therapy compared to pre-treatment values was studied by Wilcoxon paired test. The differences between groups of patient were studied by Mann-Whitney U test. Fisher exact test was used to compare the frequency in different subgroups.

Results

After administration of the first dose, a significant (p < 0.05) decrease in xylose absorption and increased lactulose/mannitol, sucrose/mannitol, lactulose/xylose and sucrose/xylose ratios were observed, but these parameters returned subsequently to pre-treatment levels. Patients who experienced serious (grade 3 or 4) toxicity had at baseline significantly lower percentages of xylose, mannitol and sucrose, and higher lactulose/mannitol ratio. Nine of 13 (69%) patients with baseline lactulose/mannitol ratio 0.070 or above experienced serious toxicity compared to 4 out of 23 patients (17%) with the ratio below 0.070 (p = 0.002). Post-treatment lactulose, lactulose/mannitol, sucrose/mannitol and lactulose/xylose ratios were significantly increased in patients with serious toxicity.

Conclusion

A transient significant increase in lactulose/monosaccharide and sucrose/monosaccharide ratios was observed in ovarian and breast cancer patients treated with paclitaxel and platinum. Increased lactulose absorption, lactulose/mannitol, sucrose/mannitol and lactulose/xylose ratios were evident in patients with grade 3 or 4 toxicity, and increased baseline lactulose/mannitol ratio predicted serious toxicity.

Influence of age and body size on intestinal permeability and absorption in healthy dogs

OBJECTIVE

To evaluate effects of age and body size of dogs on intestinal permeability (unmediated diffusion) as measured by the ratio of urinary lactulose to L-rhamnose (L:R) and absorption (carrier-mediated transport) as measured by the ratio of urinary D-xylose to 3-O-methyl-D-glucose (X:MG) and to determine whether these variables correlated with fecal quality.

ANIMALS

6 Miniature Poodles, 6 Standard Schnauzers, 6 Giant Schnauzers, and 6 Great Danes.

PROCEDURE

A solution that contained lactulose and rhamnose or xylose and 3-O-methyl-D-glucose was administered orally to dogs that were 12, 22, 36, and 60 weeks old. Urine was collected 6 hours later, and urinary L:R and X:MG were calculated. Fecal moisture and scoring were recorded during the same periods.

RESULTS

Age and breed did not affect intestinal absorption, and we did not detect a relationship between X:MG and fecal variables. In contrast, we detected significant effects of age and body size on intestinal permeability. Puppies (12 weeks old) and large dogs had higher intestinal permeability than adult (60 weeks old) and small dogs. The increased intestinal permeability in large dogs was associated with lower fecal quality as indicated by the significant positive correlations between L:R and fecal moisture (r, 0.61) and L:R and fecal scores (r, 0.86) in adult dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

These results indicate that age and body size should be considered when assessing intestinal permeability by use of the L:R urinary excretion test in dogs. High intestinal permeability could be a possible cause of poor fecal quality in large dogs.

(51)CrEDTA colonic permeability and therapy response in patients with ulcerative colitis

Orally administered (51)Cr-labelled ethylenediaminetetraacetic acid ((51)CrEDTA) has been used to evaluate intestinal permeability in inflammatory bowel disease, especially Crohn's disease. However, information about colonic permeability in ulcerative colitis (UC) is relatively scarce. The aim of this study was to investigate the urinary excretion of orally administered (51)CrEDTA, its relation to disease activity and its response to medical therapy in patients with UC. Forty-three patients with UC and 19 controls were examined. Disease activity was evaluated by endoscopy. In 19 patients with active UC, the (51)CrEDTA permeability test was repeated after medical therapy. (51)CrEDTA (95 microCi; 26 MBq) was given orally after an overnight fast and urine was collected over a 24 h period. The first urine samples were taken 5 h and the second 24 h after the oral administration of (51)CrEDTA. Urine samples were counted in a gamma counter. In controls, the median 5 h and 24 h excretions were 0.10% and 0.93%, respectively. Patients with UC showed significantly increased urine (51)CrEDTA excretion at both time intervals (5 h: 2.41%, P<0.0002; 24 h: 6.72%, P<0.0001). There was also a significant correlation between intestinal permeability and disease activity (5 h: r=0.45, P=0.0025; 24 h: r=0.51 P=0.0006). After medical therapy, (51)CrEDTA urinary excretion was significantly decreased (pre-treatment UC: 7.87%; post-treatment UC: 2.50%; P<0.0002). Briefly, the (51)CrEDTA test reflected colonic permeability in UC and might be useful as an indicator of disease severity. Moreover, this study suggested that, in patients with UC, medical therapy not only leads to the recovery of acute inflammation but also restores mucosal barrier integrity and function.

Translational control of viral gene expression in eukaryotes

As obligate intracellular parasites, viruses rely exclusively on the translational machinery of the host cell for the synthesis of viral proteins. This relationship has imposed numerous challenges on both the infecting virus and the host cell. Importantly, viruses must compete with the endogenous transcripts of the host cell for the translation of viral mRNA. Eukaryotic viruses have thus evolved diverse mechanisms to ensure translational efficiency of viral mRNA above and beyond that of cellular mRNA. Mechanisms that facilitate the efficient and selective translation of viral mRNA may be inherent in the structure of the viral nucleic acid itself and can involve the recruitment and/or modification of specific host factors. These processes serve to redirect the translation apparatus to favor viral transcripts, and they often come at the expense of the host cell. Accordingly, eukaryotic cells have developed antiviral countermeasures to target the translational machinery and disrupt protein synthesis during the course of virus infection. Not to be outdone, many viruses have answered these countermeasures with their own mechanisms to disrupt cellular antiviral pathways, thereby ensuring the uncompromised translation of virion proteins. Here we review the varied and complex translational programs employed by eukaryotic viruses. We discuss how these translational strategies have been incorporated into the virus life cycle and examine how such programming contributes to the pathogenesis of the host cell.

Methodological issues in papers on IFN therapy: time for reappraisal

We conducted an analytical review of 194 full papers on interferon (IFN) therapy for chronic hepatitis C to evaluate current methodology (i.e. study design, criteria for evaluating the efficacy of therapy and predictors of response). Of the papers evaluated, 64 were randomized controlled trials (RCT), 40 were non-randomized controlled trials (NRCT) and 90 were observational studies (OS). The methodological analysis was focused mainly on clinical trials. The number of patients enrolled in RCT was higher compared with the number enrolled in NRCT. Uniform enrolment criteria were used in less than 50% of the trials. Only 20% of RCT and 2.5% of NRCT used criteria for defining sample size. The response rate was calculated on an intention-to-treat basis in 36 of the RCT and in 14 of the NRCT. The outcome of treatment and the criteria employed to define the response to treatment were found to be far from standardized. In 51.5% of the RCT and 42.5% of the NRCT, normalization of alanine aminotransferase (ALT) level at the end of follow-up was the only marker of response studied. Only 57.6% of the trials considered histological evidence as an important outcome. Among the clinical trials, 71.1% evaluated predictors of good response to IFN therapy. In 51% of the OS, ALT normalization by the end of follow-up was the only criterion for defining response. In conclusion, to ensure a high level of reliability in comparing or combining the results of different studies, some basic general requirements must be followed when planning trials on antiviral therapy.

Neutrophil depletion prevents intestinal mucosal permeability alterations in burn-injured rats

Cutaneous thermal injury increases intestinal mucosal permeability. The mechanisms of this functional disturbance are not fully understood. We investigated whether accumulation of neutrophils in the intestine contributes to the increase in mucosal permeability. Labeled and unlabeled lactulose and mannitol were infused into a segment of rat ileum or jejunum. Blood concentrations of [(3)H]lactulose and [(14)C]mannitol were measured after 30, 60, and 90 min. On day 1 postburn, lactulose permeability increased fourfold in the ileum and twofold in the jejunum compared with sham-burned rats; mannitol permeability increased twofold in the ileum and 1. 5-fold in the jejunum. A greater increase in permeability occurred on day 3 postburn in the ileum, but not in the jejunum. The depletion of neutrophils in burned rats prevented the increase in permeability in both segments on day 1 postburn. Histological studies of intestines from burned, with or without neutrophil depletion, and sham-burned rats showed similar morphology. However, numerous neutrophils were found in the extravascular compartment in day 1 postburn, but not in neutrophil-depleted and sham-burned rats. These findings support the concept that the burn-induced increase in mucosal permeability is produced during the accumulation of neutrophils in the intestine and can be abrogated by the depletion of neutrophils.

Comparison between three quantitative assays in patients with chronic hepatitis C and their relevance in the prediction of response to therapy

To compare three quantitative assays measuring viral load in patients with chronic hepatitis C and to determine their value in predicting response to interferon (IFN) therapy, we analysed serum from 896 patients from eight European Centres using QUANTIPLEXtrade mark bDNA, MONITOR AMPLICORtrade mark and SUPERQUANTtrade mark assays. Analyses were performed on the same sample. Viral genotype was assessed using INNO-LiPA HCV II kits. Intercentre variations were observed that were related to the handling of specimens not processed and stored within 6 h of blood sampling. Among sera with optimal handling, a stronger correlation was observed between bDNA and SUPERQUANT (0.806) than between bDNA and MONITOR (0.677) and between MONITOR and SUPERQUANT (0.632). These discrepancies were greatest with genotype 2 (bDNA/SUPERQUANT= 0.772; bDNA/MONITOR=0. 456; SUPERQUANT/MONITOR= 0.299). This correlation was influenced by viraemia level and was better at lower viral loads. The proportion of sera with undetectable viral load was 15% with bDNA, 9.7% with MONITOR and 7.7% with SUPERQUANT. For the three measurements, the best cut-offs of sustained response to IFN treatment were located at their detection threshold. Among patients with viral load below the detection level, a sustained response was observed in 35% tested with bDNA, 38% with MONITOR and 80% with SUPERQUANT. Hence a stronger correlation was observed between bDNA and SUPERQUANT than between either of these assays and MONITOR. SUPERQUANT was the most sensitive assay and this greater sensitivity was associated with a better predictive value of treatment response.

Low HCV replication levels in end-stage hepatitis C virus-related liver disease

BACKGROUND/AIMS

The relationship between HCV RNA levels and the severity of HCV-related liver disease has been addressed in a few studies, which has led to conflicting results. To clarify this point, we studied serum HCV RNA levels in patients with HCV liver disease at various stages, using a second-generation branched DNA (bDNA) assay.

METHODS

One hundred and forty-eight patients with chronic HCV infection were classified into 3 groups: group A included 92 patients with chronic active hepatitis (CAH) without cirrhosis; group B included 30 patients with CAH and compensated cirrhosis; group C included 26 patients with end-stage cirrhosis. In all patients, serum HCV RNA was sought by qualitative PCR and quantified using second-generation bDNA assay. HCV RNA was also quantified after liver transplantation in 22 patients from group C. HCV genotype was determined in all patients.

RESULTS

HCV RNA was detected by PCR in 100%, l00% and 92% of the patients from groups A, B and C, respectively (NS). The proportion of patients with HCV RNA levels higher than the cut-off of bDNA assay was significantly lower in patients from group C than in patients from groups A and B (50% vs 94% and 93% respectively, p<0.0001). The mean HCV viremia was lower in group C than in groups A and B (1.35+/-0.24 MEq/ml vs 5.00+/-6.04 MEq/ml and 5.85+/-7.70 MEq/ml, respectively, p<0.0001). This difference was independent of HCV genotype. In the patients from group C, post-transplant HCV RNA levels were significantly higher than pretransplant HCV RNA levels (14.90+/-26.40 vs 1.35+/-0.24 MEq/ml, p=0.0065).

CONCLUSIONS

HCV RNA levels do not appear to differ significantly among patients with CAH with or without compensated cirrhosis. In contrast, HCV RNA levels seem to be significantly lower in patients with end-stage HCV-related liver cirrhosis. In these patients, high levels of replication are restored after liver transplantation, suggesting that low pretransplant viral loads are not due to the intrinsic characteristics of the infective viral strains, but rather to the severity of liver disease.

The viral clearance in interferon-treated chronic hepatitis C is associated with increased cytotoxic T cell frequencies

BACKGROUND/AIMS

Cytotoxic T lymphocytes have been demonstrated in peripheral blood and liver tissue of patients with chronic hepatitis C virus infection, but their significance for viral clearance is unknown. Therefore, we analyzed hepatitis C virus-specific cytotoxic T lymphocyte precursor frequencies in chronic hepatitis C virus carriers during interferon-alpha treatment.

METHODS

Blood mononuclear cells or CD8+ T cells from HLA-A2 positive and negative patients and controls were analyzed in chromium-release assays using a panel of 18 synthetic peptides from the HCV core, E1 and NS4 antigens bearing HLA-A2 binding motifs. Specific cytotoxic T lymphocyte precursor frequencies were studied within CD8+ T cells derived from interferon-alpha-treated patients using a TNF-alpha-based ELISPOT assay and compared to viremia levels.

RESULTS

T cells from 16 of 24 HLA-A2+ but none of the six HLA-A2- patients with chronic hepatitis C and six HLA-A2+ healthy controls lysed targets pulsed with peptide cocktails. Fine specificity revealed four very immunogenic epitopes in the core (C36-44, C132-140) and the envelope regions (E332-340, E363-372). Cytotoxic T lymphocyte precursor frequencies were prospectively analyzed in 11 interferon-alpha-treated HLA-A2+ hepatitis C virus patients. Four sustained and two transient therapy responders showed lower pretreatment viremia levels and significantly higher specific cytotoxic T lymphocyte precursor frequencies during viral clearance compared to five therapy non-responders and untreated controls.

CONCLUSIONS

The quantitative induction of HLA-class I restricted responses by interferon-alpha could contribute to a beneficial outcome of hepatitis C virus infections. Furthermore, it appears that the balance between viral load and specific cellular immune responses is critical for successful viral clearance.

The cellular immune responses induced in the follow-up of interferon-alpha treated patients with chronic hepatitis C may determine the therapy outcome

BACKGROUND/AIMS

To study whether the host's immune response determines viral clearance in chronic hepatitis C, virological markers and antigen-specific T cell reactions were analysed in 30 chronic HCV carriers followed up during interferon-alpha therapy, 11 untreated anti-HCV positive individuals and 10 healthy controls.

METHODS

Proliferative T helper cell responses to recombinant HCV core and non-structural antigens were monitored by 3H-thymidine uptake assay and compared to quantitative viraemia levels and HCV genotypes.

RESULTS

Of the 30 treated patients, six had sustained complete responses (20%), another six were transient therapy responders (20%) and 18 were non-responders (60%). Viral clearance was associated with the HCV genotype 3 and low pretreatment viral load. In a substantial proportion of complete and transient therapy responders, increased NS3-, helicase- and NS4-antigen-specific T cell responses were observed during interferon-alpha therapy. In non-responders and in the later clinical courses of transient therapy responders, core and NS5-specific T cell responses dominated. In addition, 11 untreated anti-HCV antibody positive individuals were studied. Two HCV-RNA negative patients who might have recovered from HCV infection showed strong persistent lymphoproliferative responses to NS3, helicase and NS4 antigens, whereas seven of the nine viraemic patients reacted with HCV core or NS5 antigens.

CONCLUSIONS

Interferon-alpha treatment enhances NS3-, helicase- and NS4-antigen-specific T helper cell responses in patients with viral clearance, whereas viral persistence was associated with increased T cell reactivities against core and NS5 antigens. Immunogenetical, immunological and virological factors that may influence differential T cell induction in chronic hepatitis C are discussed.

Comparative responses to three different types of interferon-alpha in patients with chronic hepatitis C

We investigated the efficacy and tolerability of three different types of interferon-alpha, administered with the same schedule to naive patients with chronic hepatitis C. One hundred and seven patients with histologically proven chronic hepatitis C were enrolled during a period of three years and randomly divided into three groups, to receive (a) leukocyte-interferon-alpha, 6 MU three times a week for 4 months, followed by 3 MU three times a week for 8 months (Group I); (b) recombinant-IFN-alpha-2a, with the same schedule (Group II); and (c) lymphoblastoid-IFN-alpha-N1, with the same schedule (Group III). All patients were followed-up for 6 months to evaluate the long-term response. The 'Complete Response' rates at the end of treatment were: 50%, 46.1% and 41.6%, in Groups I, II and III, respectively; most patients relapsed after the end of therapy, so that the 'sustained responders' were, after 6 months of follow-up, 18.7%, 23.1% and 19.4%, respectively. Analysis of pre-treatment variables showed that age, ALT and gamma GT serum levels, as well as the prevalence of liver cirrhosis, were lower in the 'sustained responder' group. Four patients were eliminated from the study because of severe adverse events: 1, 2 and 1, in Groups I, II and III, respectively. Our results indicate a similar response rate with the three different types of interferon-alpha, although at baseline, age, serum levels of gamma globulins and the number of patients with cirrhosis-possible negative-risk factors, were higher in Group I.