Usefulness of a new immuno-radiometric assay to detect hepatitis C core antigen in a community-based population

Simeprevir-Based Triple Therapy with Reduced Doses of Pegylated Interferon α-2a Plus Ribavirin for Interferon Ineligible Patients with Genotype 1b Hepatitis C Virus

Background/Aims

The present study aimed to evaluate the safety and efficacy of simeprevir-based triple therapy with reduced doses of pegylated interferon (PEG-IFN) and ribavirin for interferon (IFN) ineligible patients, such as elderly and/or cirrhotic patients, and to elucidate the factors contributing to a sustained virologic response (SVR).

Methods

One hundred IFN ineligible patients infected with genotype 1b hepatitis C virus (HCV) were treated. Simeprevir (100 mg) was given orally together with reduced doses of PEG-IFN-α 2a (90 μg), and ribavirin (200 mg less than the recommended dose).

Results

The patients’ median age was 70 years, and 70 patients were cirrhotic. Three patients (3%) discontinued treatment due to adverse events. The SVR rate was 64%. Factors that significantly contributed to the SVR included the γ-glutamyl transferase and α-fetoprotein levels, interleukin-28B (IL28B) polymorphism status, and the level and reduction of HCV RNA at weeks 2 and 4. The multivariate analysis showed that the IL28B polymorphism status was the only independent factor that predicted the SVR, with a positive predictive value of 77%.

Conclusions

Simeprevir-based triple therapy with reduced doses of PEG-IFN and ribavirin was safe and effective for IFN ineligible patients infected with genotype 1b HCV. IL28B polymorphism status was a useful predictor of the SVR.

Low-Dose Pegylated Interferon α-2b Plus Ribavirin for Elderly and/or Cirrhotic Patients with Genotype 2 Hepatitis C Virus

Background/Aims

This study aimed to predict sustained viral response (SVR) to low-dose pegylated interferon (PEG-IFN) plus ribavirin of elderly and/or cirrhotic patients with genotype 2 hepatitis C virus (HCV) using viral response within 2 weeks.

Methods

Low-dose PEG-IFN-α-2b plus ribavirin was administered to 50 elderly and/or cirrhotic patients with genotype 2 HCV for 24 weeks. The dynamics of HCV RNA and HCV core antigen levels within 2 weeks were measured.

Results

The patients’ median age was 66 years. There were 21 male and 29 female patients. The median baseline HCV RNA level was 5.7 log IU/mL. Rapid viral response was achieved in 17 patients (34%), SVR in 28 (56%), and two (4%) discontinued treatment. Univariate analysis of factors contributing to SVR showed significant differences for sex, baseline virus level, and response within 4 weeks. When 40 fmol/L was set as the cutoff value for the core antigen level at 1 week, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for predicting SVR were 93%, 75%, 84%, 88%, and 85%, respectively.

Conclusions

Low-dose PEG-IFN plus ribavirin was a safe and cost-effective treatment for elderly and/or cirrhotic patients with genotype 2 HCV, and the viral response within 2 weeks was a useful predictor of SVR.

Can Hepatitis C Virus Antigen Testing Replace Ribonucleic Acid Polymearse Chain Reaction Analysis for Detecting Hepatitis C Virus? A Systematic Review

The complexity and cost of current diagnostics for hepatitis C virus (HCV) may act as a prevention to the scale-up of treatment in the developing world. Currently, ribonucleic acid (RNA)-polymerase chain reaction tests are the gold standard. However, there is potential for the use of simpler and cheaper antigen tests to confirm HCV infection in different clinical settings. We evaluated the sensitivity and specificity of antigen assays. This was compared with the reference-standard RNA assays. A subanalysis also assessed Architect core antigen test, which is the only commercially available antigen test on the market. In 24 datasets, evaluating HCV-antigen assays in 8136 samples, the percentage of HCV-antigen positive, HCV-RNA negative was 0.57%. The percentage HCV-antigen negative, HCV-RNA positive was 3.52%. There is strong evidence that antigen detection performs as well as RNA-based assays for HCV management. The use of antigen tests could improve access to HCV care in underresourced healthcare settings.

Clinical Utility of a New Automated Hepatitis C Virus Core Antigen Assay for Prediction of Treatment Response in Patients with Chronic Hepatitis C

Hepatitis C virus core antigen (HCV Ag) is a recently developed marker of hepatitis C virus (HCV) infection. We investigated the clinical utility of the new HCV Ag assay for prediction of treatment response in HCV infection. We analyzed serum from 92 patients with HCV infection who had been treated with pegylated interferon and ribavirin. HCV Ag levels were determined at baseline in all enrolled patients and at week 4 in 15 patients. Baseline HCV Ag levels showed good correlations with HCV RNA (r = 0.79, P < 0.001). Mean HCV Ag levels at baseline were significantly lower in patients with a sustained virologic response (SVR) than in those with a non SVR (relapse plus non responder) based on HCV RNA analysis (2.8 log₁₀fmol/L vs. 3.27 log₁₀fmol/L, P = 0.023). Monitoring of the viral kinetics by determination of HCV RNA and HCV Ag levels resulted in similarly shaped curves. Patients with undetectable HCV Ag levels at week 4 had a 92.3% probability of achieving SVR based on HCV RNA assay results. The HCV Ag assay may be used as a supplement for predicting treatment response in HCV infection, but not as an alternative to the HCV RNA assay.

Prediction of a null response to pegylated interferon α-2b plus ribavirin in patients with high viral load genotype 1b hepatitis C

Background/Aims

The present study aimed to clarify whether virological response within 2 weeks after therapy initiation can predict a null response to pegylated interferon α-2b plus ribavirin therapy in patients with high viral load genotype 1b hepatitis C.

Methods

The participants consisted of 72 patients with high viral load genotype 1b. The dynamics of viral load within 2 weeks were measured.

Results

Significant differences between null responders and nonnull responders were noted for interleukin (IL)-28B genotype, amino acid 70 substitution, α-fetoprotein, low-density lipoprotein cholesterol, hyaluronic acid, and viral response. The area under the curve (AUC) for the receiver operating characteristic curve of the hepatitis C virus (HCV) RNA level decline at 2 weeks (AUC=0.993) was the highest among the factors predicting the null response. When the cutoff value for the HCV RNA level decline at 2 weeks was set at 0.80 log, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in predicting a null response were 82%, 96%, 82%, 96%, and 94%, respectively. In comparison, values for the non-TT and mutant type of amino acid 70 substitution were similar to those for HCV RNA level decline at 2 weeks.

Conclusions

Virological response at 2 weeks or the combination of IL-28B and amino acid 70 substitution are accurate predictors of a null response.

Diagnostic performances of hepatitis C virus-NS4 antigen in patients with different liver pathologies

BACKGROUND AND AIMS

Hepatitis C virus (HCV) has emerged as the major pathogen of liver disease worldwide. The aim of this study was to quantitate and evaluate the performance of HCV-NS4 antigen as an alternative approach for confirmation of viremia.

METHODS

Detection of HCV-NS4 was assessed in 883 patients with chronic hepatitis C. Areas under the ROC curves (AUC) were used to assess and compare diagnostic accuracy of ELISA for HCV-NS4 with quantitative HCV-RNA as a gold standard.

RESULTS

HCV-NS4 was identified at 27 kDa using Western blot. AUC for HCV-NS4 detection was 0.95 for all patients with different liver pathologies: 0.93 for liver fibrosis (LF), 0.95 for liver cirrhosis (LC) and 0.98 for hepatocellular carcinoma (HCC). The mean ± SD (μg/mL) of HCV-NS4 in LF was 94.2 ± 55.6; in LC was 99.3 ± 64.8 and in HCC was 124.9 ± 70.3.

CONCLUSIONS

HCV-NS4 antigen detection using ELISA is a reliable test in the confirmation of HCV infection.

Is hepatitis C virus core antigen an adequate marker for community screening?

A new hepatitis C virus (HCV) core antigen (HCV Ag) assay was thought to have a good correlation with HCV RNA. The aim was to elucidate the usefulness of this HCV Ag assay in community screening. In a township where HCV is endemic, 405 residents aged 58 years or older responded to a follow-up community screening. All subjects were tested for anti-HCV (AxSYM, version 3.0; Abbott Diagnostics) and HCV Ag (Architect HCV Ag test; Abbott Diagnostics). For subjects with anti-HCV signal-to-cutoff ratios (S/CO) > 10 and/or HCV Ag > 3 fmol/liter, HCV RNA data (Taqman HCV RNA; Roche Diagnostics) were further checked. A total of 115 (28.4%) subjects had their serum HCV RNA levels measured, and 93 were HCV RNA positive. The other 290 subjects were supposed to be HCV RNA negative. HCV Ag was significantly correlated with HCV RNA according to the following equation: (log HCV RNA) = 2.08 + 1.03 (log HCV Ag) (R(2) = 0.94; P < 0.001). As determined using a combination of the values for anti-HCV (S/CO > 40) and HCV Ag (>3 fmol/liter) as a cutoff to predict viremia, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 96.8%, 100%, 99.3%, 100%, and 99%, respectively. In conclusion, for a community study, HCV Ag showed good correlation with HCV RNA. In addition, anti-HCV or HCV Ag can predict HCV viremia well, while a combination of anti-HCV (>40 S/CO) and HCV Ag (>3 fmol/liter) can provide the best result validity.

Association of HCV core antigen seropositivity with long-term mortality in patients on regular hemodialysis

Anti-hepatitis C virus (HCV) antibody seropositivity is independently associated with poor prognosis in hemodialysis (HD) patients. However, anti-HCV antibody cannot distinguish between patients with active infection and those who have recovered from infection. We therefore aimed in this study to examine the association of HCV core antigen (HCVcAg) seropositivity with mortality in HD patients. We first measured serum HCVcAg using an immunoradiometric assay and anti-HCV antibody in 405 patients on regular HD, and followed them for 104 months. There were 82 patients (20.2%) who had been positive for anti-HCV antibodies; 57 (69.5%) of these were positive for HCVcAg. During the follow-up, 29 patients were excluded, so we tested the association of HCVcAg seropositivity with all-cause, cardiovascular (CV) and non-CV mortalities in 376 patients. A total of 209 patients (55.6%) had expired during the observational period, 92 out of them due to CV causes. After adjusting for comorbid parameters, HCVcAg was independently associated with overall mortality (HR 1.61, 95% CI 1.05–2.47, p < 0.05). HCV infection was significantly related to liver disease-related mortality. Past HCV infection also contributed to CV mortality (HR 2.63, 95% CI 1.27–5.45, p < 0.01). In contrast, anti-HCV antibody and HCVcAg seropositivities did not associate with infectious disease-related and cancer-related (expect for hepatocellular carcinoma) mortality. It follows from these findings that HCVcAg serology is associated with all-cause and CV mortality in HD patients.

New automated hepatitis C virus (HCV) core antigen assay as an alternative to real-time PCR for HCV RNA quantification

An automated hepatitis C virus (HCV) antigen (Ag) assay was evaluated with clinical samples. Determination of HCV Ag and RNA levels in 282 subjects using Abbott HCV Ag and Roche Cobas TaqMan assays revealed that these two tests were highly correlated (r = 0.9464). Thus, the HCV Ag assay could be an alternative test to quantitative reverse transcription-PCR.

Increased rate of death related to presence of viremia among hepatitis C virus antibody-positive subjects in a community-based cohort study

The overall mortality of patients infected with hepatitis C virus (HCV) has not been fully elucidated. This study analyzed mortality in subjects positive for antibody to HCV (anti-HCV) in a community-based, prospective cohort study conducted in an HCV hyperendemic area of Japan. During a 10-year period beginning in 1995, 1125 anti-HCV-seropositive residents of Town C were enrolled into the study and were followed for mortality through 2005. Cause of death was assessed by death certificates. Subjects with detectable HCV core antigen (HCVcAg) or HCV RNA were considered as having hepatitis C viremia and were classified as HCV carriers; subjects who were negative for both HCVcAg and HCV RNA (i.e., viremia-negative) were considered as having had a prior HCV infection and were classified as HCV noncarriers. Among the anti-HCV-positive subjects included in the analysis, 758 (67.4%) were HCV carriers, and 367 were noncarriers. A total of 231 deaths occurred in these subjects over a mean follow-up of 8.2 years: 176 deaths in the HCV carrier group and 55 in the noncarrier group. The overall mortality rate was higher in HCV carriers than in noncarriers, adjusted for age and sex (hazard ratio, 1.53; 95% confidence interval, 1.13-2.07). Although liver-related deaths occurred more frequently among the HCV carriers (hazard ratio, 5.94; 95% confidence interval, 2.58-13.7), the rates of other causes of death did not differ between HCV carriers and noncarriers. Among HCV carriers, a higher level of HCVcAg (>or=100 pg/mL) and persistently elevated alanine aminotransferase levels were important predictors of liver-related mortality.

CONCLUSION

The presence of viremia increases the rate of mortality, primarily due to liver-related death, among anti-HCV-seropositive persons in Japan.

A new sensitive and automated chemiluminescent microparticle immunoassay for quantitative determination of hepatitis C virus core antigen

A new sensitive and automated chemiluminescent assay was developed for the quantitative determination of hepatitis C virus (HCV) core antigen (Ag) in human sera or plasma: the Abbott ARCHITECT HCV Ag test. The assay sensitivity was determined by testing 10 commercial HCV seroconversion panels. Without exception, a positive result for HCV core Ag was observed before anti-HCV detection, resulting in an average reduction in the period between exposure and detection of 35.8 days. Both HCV core Ag and HCV RNA were detected in the panels at the same time, indicating equivalent sensitivity and detectability. A total of 197 HCV specimens comprising genotypes 1a, 1b, 2a, 2b, 3a, 3k, 4a, 5a and 6a were evaluated. Among these, 196 (99.5%), 191 (97%) and 193 (98%) were reactive using the HCV Ag, the immunoradiometric HCV Ag and the Amplicor HCV Monitor 2 assays, respectively. A comparison with the Amplicor HCV Monitor 2 showed a correlation coefficient (r) of 0.74. The specificity of the assay was established at 99.8% by testing 5403 specimens from US volunteer blood donors, hospitalized patients and individuals with medical conditions unrelated to HCV infection, in addition to specimens containing potentially interfering substances.

Association of a genetic polymorphism in ectonucleotide pyrophosphatase/phosphodiesterase 1 with hepatitis C virus infection and hepatitis C virus core antigen levels in subjects in a hyperendemic area of Japan

BACKGROUND

The clinical course of chronic hepatitis C virus (HCV) infection is strongly associated with insulin resistance and obesity. The K121Q polymorphism in the ectonucleotide pyrophosphatase/phosphodiesterase (ENPP)-1 gene and the rs7566605 genotype located near insulin-induced gene 2 have been shown to be associated with insulin resistance and obesity. This study examined whether the K121Q polymorphism in ENPP1 or the rs7566605 genotype is associated with the clinical course of HCV infection.

METHODS

The relationships between the clinical characteristics of 469 anti-HCV antibody-seropositive subjects (353 were positive for HCV core antigen or RNA, whereas 116 were negative for HCV RNA) and the polymorphisms were analyzed.

RESULTS

No significant differences in body mass index, plasma glucose level, serum insulin level, and other biochemical markers were observed between subgroups of subjects with different genotypes at the K121Q polymorphism or rs7566605. The frequency of the homozygous wild-type genotype at K121Q in HCV carriers, however, was significantly higher than that in subjects who were negative for HCV RNA (84.5% vs. 75.9%; P < 0.05). Moreover, in HCV carriers, HCV core antigen levels in subjects homozygous for the wild-type genotype at K121Q were significantly higher than in heterozygous carriers of K121Q (5358 fmol/l vs. 4002 fmol/l; P = 0.04). In contrast, the rs7566605 genotype was not associated with hepatitis C viremia or with the HCV core antigen level.

CONCLUSIONS

The K121Q variant of ENPP1 may be associated with hepatitis C viremia and core antigen levels in HCV carriers.

Alanine aminotransferase flare-up in hepatitis C virus carriers with persistently normal alanine aminotransferase levels in a hyperendemic area of Japan

BACKGROUND

The clinical features of hepatitis C virus (HCV) carriers with persistently normal alanine aminotransferase (PNALT) levels (ALT < or = 34 IU/l) have not been fully elucidated. We investigated clinical factors associated with ALT flare-up in PNALT individuals in a HCV hyperendemic area of Japan.

METHODS

We analyzed 101 HCV carriers who had PNALT between 1993 and 2000. The first occurrence of ALT flare-up (ALT > or = 35 IU/l) between 2001 and 2005 was evaluated by the Kaplan-Meier method. Multivariate analysis of factors predicting ALT flare-up were conducted using Cox proportional hazards models.

RESULTS

The mean follow-up period was 2.8 years, and the 5-year cumulative incidence of ALT flare-up was estimated to be 31.8%. In multivariate analysis, an ALT level of 20-34 IU/l and a high serum ferritin level (> or =90 ng/ml) in the most recently available data up to the year 2000, as well as H63D heterozygosity in the HFE gene, were independently and strongly associated with the incidence of ALT flare-up (Hazard ratios = 5.6, 3.1, and 4.8, respectively). In addition, HFE H63D heterozygosity was significantly associated with higher serum ferritin levels in subjects with PNALT (153.8 + or - 73.3 ng/ml in subjects with the 63HD genotype vs. 89.4 + or - 51.3 ng/ml in subjects with the 63HH genotype, P = 0.043).

CONCLUSIONS

HCV carriers with PNALT in this population were at risk for ALT flare-up. Basal ALT levels, serum ferritin levels, and HFE polymorphism are potentially important predictors of ALT flare-up.

Host immune status and incidence of hepatocellular carcinoma among subjects infected with hepatitis C virus: a nested case-control study in Japan

A nested case-control study was conducted to examine the association between host immune status, as characterized by serum immune marker levels, and the development of hepatocellular carcinoma (HCC) up to 8 years later in persons with chronic hepatitis C virus (HCV) infection. Cases (n = 39) and matched controls (n = 117) were selected from participants of the Town C HCV Study in Japan between 1996 and 2004 and matched on age at first available sample (+/-1 year), gender, and length of follow-up. Separate analyses were done for each of three serum immune markers: soluble tumor necrosis factor-receptor II (sTNF-R2) and soluble intercellular adhesion molecule-1 (sICAM-1), as indicators of type 1, cell-mediated immune response, and soluble CD30 (sCD30), as an indicator of type 2, humoral immune response. The median concentrations of sTNF-R2, sICAM-1, and sCD30 among controls were 3,170 pg/mL, 305 ng/mL, and 3.0 units/mL, respectively, and were higher among cases (3,870 pg/mL, 372 ng/mL, and 3.3 units/mL, respectively). The risk of developing HCC among subjects with immune marker concentrations above the median levels of the controls was >2-fold greater than among subjects with lower concentrations for all three markers [sTNF-R2: odds ratio (OR), 6.9; 95% confidence interval (95% CI), 2.4-20.5; sICAM-1: OR, 2.0; 95% CI, 0.9-4.1; and sCD30: OR, 2.1; 95% CI, 1.0-4.7]. Simultaneous adjustment for all three markers revealed only sTNF-R2 to be associated with HCC risk (OR, 6.4; 95% CI, 2.0-20.6). Adjustment for alcohol consumption and HCV serotype did not materially alter these associations. Results from this prospective, community-based study suggest that a dysregulation in both type 1-related and type 2-related host immunity contributes to the development of HCV-associated HCC.

Alanine aminotransferase level as a predictor of hepatitis C virus-associated hepatocellular carcinoma incidence in a community-based population in Japan

We evaluated the utility of alanine aminotransferase (ALT) measurements in predicting the incidence of hepatocellular carcinoma (HCC) in a cohort of 667 adults with chronic hepatitis C virus (HCV) infection from a community-based population in Japan, between 1994 and 2003. Cox proportional hazards regression analysis was used to describe the relationship between prediagnostic levels of ALT and the rate of HCC, after adjusting for age and gender; hazard ratios (HRs) and 95% confidence intervals (CIs) were obtained. Over an average of 8 years of follow-up, 52 HCC cases were identified. A significant association between a 20 IU/L difference in higher ALT level and subsequent HCC incidence was observed (HR = 1.2; 95% CI: 1.1, 1.3). An abnormal ALT level (> or =35 IU/L) increased the HCC rate by 4-fold compared to a normal ALT level (HR = 4.1; 95% CI: 2.1, 8.0). Among 551 subjects with at least 4 repeated measurements of ALT, those with persistently abnormal ALT levels (n = 118) had a strong, significantly increased HCC rate compared to those with persistently normal ALT levels (n = 296) (HR = 23.2; 95% CI: 3.0, 178.5). This study demonstrates that elevated ALT levels, measured on an average of 8 years before HCC diagnosis, predict an increased rate of HCV-associated HCC in a community-based population and that utilizing serial measurements to identify persistent ALT abnormality may be useful in determining HCC risk.

Comparison of serum hepatitis C virus (HCV) RNA and core antigen levels in patients coinfected with human immunodeficiency virus and HCV and treated with interferon plus ribavirin

Trak-C (Ortho-Clinical Diagnostics) is an enzyme-linked immunosorbent assay-based method capable of quantifying hepatitis C virus (HCV) core antigen (CA) in serum and could be an alternative to molecular detection and quantification of HCV RNA. We have evaluated the Trak-C assay in comparison with an HCV RNA quantitative assay (Versant HCV v3.0; Bayer Diagnostics) in the follow-up of 348 treated, human immunodeficiency virus (HIV)/HCV-coinfected patients included in the ANRS HC02 RIBAVIC trial. ANRS HC02 RIBAVIC is a therapeutic, multicenter, randomized protocol comparing the efficacy of alpha interferon 2b (IFN-alpha2b) (3 million units three times a week)-ribavirin (800 mg/day) to that of pegylated IFN-alpha2b (1.5 mug/kg of body weight/week)-ribavirin (800 mg/day) during 48 weeks of treatment of HIV/HCV-coinfected patients naïve to HCV treatment. Patients were assessed for virological analysis at day 0 and weeks 4, 12, 24, 48, and 72. Correlation of HCV RNA and HCV CA at the initiation of treatment was excellent (r = 0.92). HCV RNA and CA kinetics were similar during follow-up of HCV treatment from day 0 to week 72 whatever the group of response and genotype. The positive and negative predictive values of response to the treatment at week 4 were 59 and 94%, respectively, for HCV RNA load reduction of >2 log and 54 and 94%, respectively, for HCV CA below the threshold value (4.18 log(10) pg/ml . 10(4)). Trak-C, a new assay able to quantify CA in HIV/HCV-coinfected patients, correlates well with quantitative HCV RNA assays and is cheaper and easier to perform than molecular technology. HCV CA could be a valuable alternative test for therapeutic follow-up of coinfected patients treated with IFN plus ribavirin in developing countries.