Randomized controlled trial of recombinant alpha-2a-interferon for chronic hepatitis C. Comparison of alanine aminotransferase normalization versus loss of HCV RNA and anti-HCV IgM

Glycosylation shapes the efficacy and safety of diverse protein, gene and cell therapies

Over recent decades, therapeutic proteins have had widespread success in treating a myriad of diseases. Glycosylation, a near universal feature of this class of drugs, is a critical quality attribute that significantly influences the physical properties, safety profile and biological activity of therapeutic proteins. Optimizing protein glycosylation, therefore, offers an important avenue to developing more efficacious therapies. In this review, we discuss specific examples of how variations in glycan structure and glycoengineering impacts the stability, safety, and clinical efficacy of protein-based drugs that are already in the market as well as those that are still in preclinical development. We also highlight the impact of glycosylation on next generation biologics such as T cell-based cancer therapy and gene therapy.

Treatment of yellow fever virus with an adenovirus-vectored interferon, DEF201, in a hamster model

Interferon (IFN) is an innate immune response protein that is involved in the antiviral response during viral infection. Treatment of acute viral infections with exogenous interferon may be effective but is generally not feasible for clinical use due to many factors, including cost, stability, and availability. To overcome these limitations, an adenovirus type 5-vectored consensus alpha IFN, termed DEF201, was constructed as a potential way to deliver sustained therapeutic levels of systemic IFN. To demonstrate the efficacy of DEF201 against acute flaviviral disease, various concentrations of the construct were administered as a single intranasal dose prior to virus infection, which resulted in a dose-responsive, protective effect in a hamster model of yellow fever virus (YFV) disease. A DEF201 dose of 5×10(7) PFU/animal administered intranasally just prior to YFV challenge protected 100% of the animals, while a 10-fold lower DEF201 dose exhibited lower, although significant, levels of protection. Virus titers in the liver and serum and levels of serum alanine aminotransferase were all significantly reduced as a result of DEF201 administration at all doses tested. No toxicity, as indicated by weight loss or gross morbidity, was observed in non-YFV-infected animals treated with DEF201. Protection of YFV-infected animals was observed when DEF201 was delivered as early as 7 days prior to virus challenge and as late as 2 days after virus challenge, demonstrating effective prophylaxis and therapy in a hamster model of disease. Overall, it appears that DEF201 is effective in the treatment of YFV in a hamster model.

Clinical trials of treatment for hepatitis C virus infection in HIV-infected patients: past, present, and future

Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) type 1 is common. Rates of liver-related morbidity and mortality have been increasing in the coinfected population, and treatment for HCV infection in this group remains a challenge. The HCV-monoinfected population, especially patients infected with HCV genotype 2 or 3, has benefited dramatically from the advent of treatment with pegylated interferon plus ribavirin; rates of sustained virological response approach 55%. Coinfected patients lag behind, with rates of sustained virological response ranging between 26% and 40%; rates of sustained virological response are even lower among patients infected with HCV genotype 1. It is encouraging, however, that therapies known to be safe for treating monoinfected patients have been proven to be generally safe and well tolerated in patients coinfected with HIV and HCV, as well. Future therapies, some of which are currently in development, will likely include new targets, such as helicase and polymerase. It is hoped that, as more-effective agents are discovered, the disparity in treatment response will diminish.

A decade of trials of interferon-alpha for chronic hepatitis C. A meta-regression analysis

The most relevant randomized controlled trials of interferon-alpha (IFN) for naive patients with chronic hepatitis C (CHC) published in a decade, just before appearance of pegylated IFN trials in 2000, were included in this paper. Its purpose is to review the relationship between sustained biochemical response in active versus control group versus usual clinical variables as IFN regimens, cirrhosis, genotype and versus less frequently addressed variables as funding, methodological quality or location of principal author. Meta-analysis estimates of global treatment effect varied according to trial design: group 1=IFN versus placebo/no treatment, 32 RCTs, 2499 pts, OR 9.5 (6.3-14.2); group 2a=comparison of IFN schedules, 43 RCTs, 7454 pts, OR 1.6 (1.4-1.9); group 2b=IFN+other drugs versus standard IFN, 30 RCTs, 4737 pts, OR 2.0 (1.6-2.6). Fixed effects (arm-level) meta-regression on the complete data set (171 arms, 10,580 pts) revealed that sustained response was most likely in experimental arms of IFN+ribavirin or other drugs (OR 2.4), arms using yearly schedule (OR 2.0), trial principal author from Asia (OR 1.7), trial sample size >200 (OR 1.4) and arms enrolling less than 50% of cirrhotics (OR 1.3). Moreover, focus was on some significant interactions too, as the effect of trial's quality interacting to the recorded funding (more benefit if no-profit, less if for-profit) and the effect of trial funding interacting to the location of first author (more benefit if from Asia). Three main effects (experimental arm, cirrhosis, funding) and one interaction (funding*location of principal author) explained 31% of between study variability in a random-effect meta-regression. In a subgroup analysis on a data set including available information on HCV genotype (93 arms, around 7000 pts), meta-regression revealed that genotype 1 or 4 less than 50% per arm and specialistic journal were significant predictors of either biochemical (transaminases) or virological (HCV-RNA) sustained response, in a model including the same main effects identified in the complete data set analysis. Finally, although mostly captured by different IFN regimens along time, heterogeneity of effect in a large set of (not-pegylated) IFN trials was also explained by HCV genotype and variables of quality and reporting, such as trial's principal author from Asia.

Human immune response to recombinant human proteins

Delivery of pharmacological doses of proteins to people has raised concerns of inducing immune responses, especially when the protein is provided in multiple doses over an extended period of time. Immune responses could impact the therapeutic exposure and efficacy of the protein itself. In addition, there have been fears of anaphylaxis or autoimmunity. This review summarizes the available literature regarding the measurement and evaluation of immune responses observed during clinical assessment of recombinant human proteins. Immune responses have ranged from none at all to inactivation and/or accelerated clearance. Presence of antibodies does not necessarily impact therapeutic viability. While responses are related to frequency and route of delivery, there is no clear relationship that enables one to predict the clinical experience.

Chronic hepatitis C and interferon alpha: conventional and cumulative meta-analyses of randomized controlled trials

OBJECTIVE

The purpose of this study was to evaluate the clinical usefulness of surrogate markers of the interferon effect (i.e., alanine aminotransferase levels and serum HCV-RNA status) as predictors of long term response, and to identify the optimal schedule of treatment for patients with chronic hepatitis C by means of meta-analysis.

METHODS

Pertinent randomized clinical trials and prospective studies were selected using MEDLINE (1986-1996), a reference list from published articles or reviews. Twenty-six prospective studies reporting data on surrogate markers of interferon response were selected. Thirty-nine trials comparing interferon alpha to no treatment and 25 trials comparing different schedules of interferon were reviewed. Conventional meta-analysis according to the DerSimonian and Laird method was used for the pooling of results.

RESULTS

The pooled probability of late relapse among sustained responders with negative serum HCV-RNA 6 months after treatment was very low (8.7%; 95% confidence interval 5.8-11.6%). The overall risk difference between treated and control groups was 16.63% (95% confidence interval 11.95-21.31%) for sustained aminotransferase normalization. Therapy with higher interferon dose compared with standard dose significantly improves the rate of sustained response (pooled risk difference 10.56%, 95% CI 5.47-15.65%). Cumulative meta-analyses suggest that a clear dose-response relationship exists across a wide range of interferon dosages. The multivariate meta-regression model confirms that the total interferon dose is an independent predictor of sustained response and that it seems more important than the length of treatment.

CONCLUSIONS

Testing for serum HCV-RNA, 6 months after interferon therapy in sustained biochemical responders, is useful for predicting long term response. The current standard total interferon dose of 234 mega-units is suboptimal. Further trials that directly compare different schedules of treatment are needed.

Combination therapy with thymosin alpha1 and interferon for the treatment of chronic hepatitis C infection: a randomized, placebo-controlled double-blind trial

Hepatitis C is a major cause of liver disease leading to cirrhosis. Although interferon (IFN) is the only approved therapy, treatment is characterized by low response rates and dose-limiting side effects. We evaluated the addition of thymosin alpha1 (TA1), an immunomodulatory peptide, to the standard treatment regimen for hepatitis C to determine if combination therapy shows biological activity using outcome measures including normalization of alanine aminotransferase levels, histological activity, and viral load during treatment. We performed a randomized, double-blind, placebo-controlled trial to compare the biological activity of a combination TA1 and IFN with that seen for IFN alone in patients with chronic hepatitis C infection. One hundred nine patients were randomized for intention to treat and received 1.6 mg of TA1 subcutaneously twice weekly and 3 MU of IFN three times weekly; 3 MU of IFN three times weekly and placebo TA1; or placebo for both agents. All patients had chronic HCV infection with confirmation of chronic hepatitis on liver biopsy. Biochemical responders were followed up until alanine aminotransferase (ALT) levels became abnormal or for 26 weeks, and relapsers were retreated for 26 weeks in the same treatment arm. One hundred three patients completed treatment for 26 weeks, and six patients dropped out. The groups were similar with regard to sex, gender distribution, baseline histological activity index (HAI) score, risk factors, and viral titers. End-of-treatment biochemical response was seen in 37.1% of patients treated with combination therapy, 16.2% of patients treated with IFN alone, and 2.7% of untreated controls by intent-to-treat analysis (IFN/TA1 vs. IFN, chi2 = 4.05, P = .04). HCV RNA clearance was seen in 37.1% of IFN/TA1-treated patients and 18.9% of IFN-treated subjects. Mean HCV RNA titers were significantly lower than baseline at weeks 8, 16, and 24 after drug initiation among patients treated with IFN/TA1 but not in the other treatment arms. Histological improvement, as evidenced by a decrease in HAI of more than two points, occurred in the combination therapy arm more frequently than in comparison groups. Cumulative sustained biochemical responses were 14.2% and 8.1% in the IFN/TA1 and IFN arms, respectively, based on an intention-to-treat model. The combination of TA1 and standard IFN treatment for chronic hepatitis C showed evidence of biological activity at the completion of treatment by biochemical, histological, and virological outcome measures. Further research involving longer duration and varied dosing is needed.

Interferon-alpha 2b therapy in low-activity hepatitis C: a pilot study

BACKGROUND

Many patients with chronic hepatitis C have long periods of normal or near-normal liver enzyme levels, even though histologic alterations have been confirmed. The recommendation today is not to treat this patient group.

METHODS

In a pilot study 23 hepatitis C virus (HCV) RNA-positive patients with alanine aminotransferase (ALAT) levels less than 1.5 times upper normal limits for at least 6 months on more than three occasions and with histologic liver abnormalities compatible with chronic hepatitis C were treated with 3 MU of interferon-alpha 2b three times a week for 6 months.

RESULTS

Nine patients (39%) became HCV RNA-negative in serum during treatment, but only two (8.7%) remained so after 6 months' follow-up. Significantly more patients with genotype other than type 1 became HCV RNA-negative than patients with genotype 1 during treatment (P = 0.005).

CONCLUSIONS

Patients with low-activity chronic hepatitis C have a response to interferon-alpha treatment similar to that of patients with increased ALAT levels. Genotype seems to influence the rate of response.

The effect of interferon on the liver in chronic hepatitis C: a quantitative evaluation of histology by meta-analysis

BACKGROUND/AIMS

Several randomized clinical trials of interferon in chronic hepatitis C have examined the histological changes in paired biopsy specimens. We have attempted a quantitative evaluation by meta-analysis.

METHODS

Randomized Clinical Trials found by MEDLINE search were included if: a) they compared different IFN regimens with non-active treatment or with each other, b) they obtained biopsies before starting and at the time of stopping IFN in a sizable proportion of the treated and control patients, and c) they assessed the biopsy-specimens semi-quantitatively according to Scheuer's numerical scoring system or Knodell's Histological Activity Index, with quantitation of fibrosis and of lobular, portal and periportal necroinflammation.

RESULTS

Seventeen trials were identified, in which 1223 adult patients had been studied. All trials homogeneously pointed towards a favorable interferon effect. The pooled data show a statistically significant histological improvement in treated patients as compared with controls for each of the four Histological Activity Index components and for the total Histological Activity Index score (overall improvement was -0.82 in favor of interferon, p<0.0001, 95% Confidence Interval -1.25 to -0.40). In the ten trials reporting histological changes separately in biochemical responders (primary and sustained responders) and non-responders, histological improvement was confined to the subset of biochemical responders. No change or very little change occurred in non-responders.

CONCLUSIONS

Interferon treatment in chronic hepatitis C significantly improves liver histology. The effect of interferon is closely related to biochemical response. Studies assessing histological outcome 1 year or more after interferon treatment in long-term responders and comparatively in non-responders or relapsers would be important to confirm the regression of the necroinflammatory process in the former, as suggested by the normal serum alanine aminotransferase levels.

Quantitative detection of hepatitis C virus RNA in the serum of patients with chronic hepatitis C treated with interferon: a pilot study

BACKGROUND

It is not known whether the measurement of serum hepatitis C virus (HCV) RNA by reverse transcription polymerase chain reaction (RT-PCR) could improve the management of patients with chronic hepatitis C being treated with interferon.

OBJECTIVES

We analysed, in a pilot study, the relations between the variations of HCV-RNA and alanine aminotransferase (ALT) serum levels in 18 anti-HCV positive patients treated with interferon.

STUDY DESIGN

Serum HCV-RNA was measured, using a non competitive coamplification assay (Amplicor HCV Monitor), before (at 3, 2 and 1 months and baseline), during (first, third and sixth month) and after treatment for at least 8 months (range 8-17 months). HCV-RNA levels fluctuations were correlated with those of ALT and treatment outcome. According to the ALT pattern, four patients were non responders, seven partial responders, four relapsers and two long term responders.

RESULTS

The median and mean baseline HCV-RNA levels were significantly different in patients infected by HCV type 1, 2 and 3, being 248,449, 235,506; 4170, 17,866 and 22,315, 79,273 molecules per ml, respectively (P < 0.0001). We did not find any significant difference between median and mean baseline viremia of responders and non responders. After 1 month of treatment viremia was below the sensitivity levels of the assay in 77.7% (14/18) of the patients who normalized ALT, at least temporarily. On the contrary, HCV-RNA remained detectable in non responders.

CONCLUSIONS

Our data suggest that HCV-RNA detection using Amplicor Monitor at the first month of treatment can be useful to identify non responders, avoiding three additional months of treatment as would be required by ALT monitoring alone. During the post-treatment follow-up, persistence of undetectable HCV-RNA and normal ALT levels helps to identify long term responders from patients with the risk of relapse in spite of biochemical remission.

Incidence of hepatocellular carcinoma after interferon therapy in patients with chronic hepatitis C

We examined the effect of interferon (IFN) therapy for chronic active hepatitis (CAH) C in 207 patients by estimating the incidence of hepatocellular carcinoma (HCC) after IFN therapy using the person-years method. Statistical analysis was performed using the Mantel-Haenszel chi-square test. No HCC was detected in patients with normal serum alanine aminotransferase (ALT) levels after IFN therapy (response-effect group), and in patients with both normal serum ALT levels and hepatitis C virus (HCV)-RNA clearance after IFN therapy (complete-responder group). The incidence per 100,000 person-years in the patients with elevated serum ALT level after IFN therapy (other-effects group) were 1968 and 1624, respectively. The incidence in control patients who did not achieve IFN therapy was 901. No statistically significant differences were observed between the other-effects group, non-responder group, and the control group. Our results so far suggest that normalization of the serum ALT levels and/or HCV clearance might reduce the incidence of HCC.

Relationship between pretreatment viremia level and response to interferon-alpha therapy in chronic hepatitis C differs in viral type 1 and 2 infections

To determine the contribution of virus-related factors to long-term remission of chronic hepatitis C infection, we analyzed viral type and viremia level in 185 patients who had undergone a six-month course of interferon-alpha therapy. These virus-related factors were measured by an enzyme-linked immunosorbent assay with use of viral type-specific antigens and the branched DNA (bDNA) signal amplification assay, respectively. Sustained and long-term sustained responses were achieved in 55% and 50% of the patients, respectively. Transient or no responses were observed in 30% and 15% of the patients, respectively. Thirty-five percent of viral type 1 patients and 82% of viral type 2 patients had long-term sustained responses. Forty-two percent of bDNA-positive and 71% of bDNA-negative patients experienced long-term sustained responses. On multivariate analysis, viral type, Knodell's intralobular score, and viremia level were strong independent predictors of long-term sustained response (P < 0.0001, = 0.0060, and 0.037, respectively). Viremia level, however, was a significant predictor only in viral type 1, not type 2, patients. The relation between pretreatment viremia level and response to interferon-alpha therapy in chronic hepatitis C differs in viral type 1 and 2 infections.

The quantitative humoral immune response to the hepatitis C virus is correlated with disease activity and response to interferon-alpha

BACKGROUND/AIM

Virus-host interactions may have pathogenetic significance in chronic hepatitis. Thus the humoral immune response was evaluated during the clinical course of HCV-infected patients.

METHODS

Eighteen selected chronic HCV patients received three doses of 3 or 6 MU interferon-alpha 2a weekly for 6 to 12 months and were followed up for 6 to 60 months. Anti-HCV antibody levels were serially measured either in end-point diluted sera with the Matrix-Assay or with quantitative anti-HC34-IgG and -IgM ELISA. Circulating immune complexes were assessed by flow cytometry and the results were correlated with histology, quantitative HCV-RNA levels and genotypes.

RESULTS

Nine complete responders (CR; genotypes 1a n = 4; 1b n = 1; 2a n = 1; 3a n = 3) showing sustained virus elimination and ALT normalisation had low HCV-RNA pretreatment levels (mean 14 x 10(3) copies/ml) compared to six nonresponders and three partial responders (NR/PR; genotypes 1a n = 2; 1b n = 7) who had significantly higher HCV-RNA pretreatment levels (mean 254 x 10(3) copies/ml; p < 0.01). In untreated NR/PR the HC34 core-antigen was most immunogenic, in CR the NS3-derived HC29-antigen. Pre-treatment levels of anti-HC 34-IgG and -IgM antibody levels in NR/PR were higher than in CR (IgM/IgG p = 0.05, n.s.) and these differences became significant during or after therapy (3 months therapy: IgM p < 0.02/IgG p < 0.07; end of therapy: IgM 0.006/IgG p < 0.04; 6 months post-therapy: IgM p < 0.002/IgG p < 0.004). The PR patients showed recurrent anti-HC34 antibody levels that preceded disease reactivation and detectable HCV-RNA in serum. Immune complex formation increased in some patients during treatment but did not correlate with disease activity, quantitative viraemia, antibody levels or therapy outcome.

CONCLUSION

Anti-HC34 antibodies, i.e. of the IgM-subtype, correlated quantitatively with viraemia and disease activity. Monitoring the antibody levels may predict the long-term therapy outcome during interferon-alpha treatment.

Interferon-alpha for viral hepatitis

IFN-alpha has emerged as a promising treatment of chronic viral hepatitis. Although therapeutic response to IFN is far from universal, efficacy has been demonstrated; and studies combining IFN-alpha with other agents, as well as trials with new preparations of IFN-alpha, are under way. Children do not represent a large part of the identified population with chronic viral hepatitis. Yet children, by simple virtue of age, are more recently infected. In addition, longer life expectancies can be expected to be associated with greater morbidity from chronic viral hepatitis. Children seem to tolerate therapy with IFN-alpha well. Treatment of children with chronic viral hepatitis should be strongly considered, with protocols designed to ascertain specific pediatric safety and efficacy.

Virus and host factors are both important determinants of response to interferon treatment among patients with chronic hepatitis C

Virus and host factors have both been linked to the response to interferon treatment among patients with chronic hepatitis C but their relative importance and potential interactions are unclear. Hepatitis C virus genotype and level of viraemia were determined in pretreatment sera from 65 Australian patients treated with interferon-alpha 2b (IFN-alpha 2b), 3 MU tiw for 6 months. Hepatitis C viraemia was quantitated by a competitive reverse transcription-polymerase chain reaction (RT-PCR) method and genotype was determined by a line probe assay. By univariate analysis, there were positive associations between initial (short-term) responses to IFN treatment and younger age (P = 0.004), absence of cirrhosis (P = 0.01), and injecting drug use as risk factor for infection (P = 0.05) but not gender, duration of infection, or level of viraemia. Genotype appeared to be important (P = 0.06) but failed to reach statistical significance. By multivariate analysis, absence of cirrhosis was the only significant independent predictor of treatment response (P = 0.01). Among initial responders, the factors associated with long-term response were the pretreatment HCV RNA titre and the duration of infection. There was a close association between viral genotype, but not viral load, and the severity of liver disease. An interplay of factors determines the outcome of a 6-month course of interferon treatment for hepatitis C. Severity of liver disease, but not the viral load, is the most crucial determinant of initial response to interferon, and histological severity appeared to be influenced by the viral genotype. The level of hepatitis C virus (HCV) viraemia and the duration of infection are independent determinants of long-term response by affecting the relapse rate after interferon treatment.

Quantitative assessment of hepatitis C virus RNA and IgM antibodies to hepatitis C core in chronic hepatitis C

BACKGROUND/AIMS

IgM antibodies to hepatitis C virus have been found in a variable proportion of patients with chronic hepatitis C. We have evaluated whether IgM anti-core antibodies correlate with viraemia or hepatic injury in chronic hepatitis C.

METHODS

Serum from 106 patients with chronic hepatitis C with varying stages of disease were tested for IgM anti-core hepatitis C virus by immunoassay. All patients were seropositive for IgG antibody to hepatitis C virus by second-generation ELISA; 25 had histologic cirrhosis and 57 chronic hepatitis. IgM anti-core was detected in 84/106 (79.2%) patients. HCV-RNA was tested by branched (bDNA) signal amplification assay or by polymerase chain reaction in 92 patients.

RESULTS

All IgM-anti-HCV positive patients had detectable HCV-RNA. Seventy of 87 (80.5%) HCV-RNA-positive patients were IgM anti-core positive. Levels of IgM anti-HCV were significantly higher in patients with HCV-RNA detected by bDNA than in those who were bDNA negative, but there was no correlation between HCV-RNA concentrations and IgM anti-HCV levels. Of the 84 patients with positive results for IgM anti-core hepatitis C virus, 59 (70.2%) had abnormal alanine aminotransferase levels. The levels of IgM anti-core hepatitis C virus were likewise significantly higher in those with abnormal alanine aminotransferase levels. There was no difference in the percentage of patients with a positive IgM anti-HCV, or in levels of IgM anti-core hepatitis C virus in those with chronic hepatitis versus cirrhosis.

CONCLUSIONS

These data suggest that the majority of patients with chronic hepatitis C virus infection are IgM anti-core hepatitis C virus positive, and the detection seems to be associated with viral replication and biochemical evidence of hepatic necrosis. IgM anti-core hepatitis testing may prove useful as an adjunct in the clinical assessment of patients with chronic hepatitis C.

Hepatitis C virus-specific B cell activation: IgG and IgM detection in acute and chronic hepatitis C

BACKGROUND/AIMS/METHODS

Immunological responses to hepatitis C virus infection have not been fully studied. In an attempt to clarify some immunopathogenetic aspects of B cell activation during acute and chronic hepatitis C virus infection and to identify markers of chronicity or of recovery, the humoral response in hepatitis C virus-infected patients was studied.

RESULTS

In children with acute jaundice, with negative markers of acute hepatitis A, B and E, six of 87 (6.9%) had detectable anti-HCV IgM, and only one (1.1%) had detectable anti-HCV IgG. In adults with acute jaundice, with negative markers of acute hepatitis A, B and E, ten of 23 (43.5%) had detectable anti-HCV IgM associated in eight patients with detectable anti-HCV IgG. In chronic hepatitis C virus-infected adult patients, all anti-HCV IgG seropositive, four of 14 (28%) patients had detectable HCV-IgM in serum. In vitro specific antibody production was inducible in a minority of patients. In acute and chronic hepatitis C virus-infection, IgM-HCV serology did not correlate with viremia as detected by polymerase chain reaction.

CONCLUSIONS

Therefore, the polymerase chain reaction remains at the moment the only direct marker to demonstrate hepatitis C virus viral replication in patients with acute and chronic hepatitis while anti-HCV IgM analysis alone has only a limited diagnostic value in hepatitis C virus-infection.

Chronic hepatitis C in patients with normal or near normal alanine aminotransferase levels: the role of interferon alpha 2b therapy

BACKGROUND/AIMS

Interferon is the only approved therapy for chronic hepatitis occurring as a consequence of an infection with the hepatitis C virus. Because interferon is expensive, has a large number of untoward effects and its efficacy is not guaranteed, many physicians limit their use of this therapy to those with histologically advanced but not end-stage cirrhotic disease. Moreover, most cases are biopsied only after 6 months or more of abnormal alanine aminotransferase levels have been documented. The rationale for this approach to patients with hepatitis C virus infection has not been demonstrated.

METHODS

In the present study, a total of 37 patients with alanine aminotransferase levels < 1.5 upper limits of normal (59 IU/l or less) who were HCV-RNA positive by reverse transcriptase polymerase chain reaction, were selected for interferon treatment, having been identified as having hepatitis C virus disease as the result of a screening Ab-HCV test confirmed with a positive radio immune blotting assay. Once identified, each subject underwent a percutaneous liver biopsy and was tested for the presence of HBsAg, Ab-HBs and HBV-DNA. All liver biopsies were read and graded according to the criteria of Knodell et al. Each subject was treated with interferon a2b at a dose of 5 MU administered daily until a response was achieved (a minimum period of 6 months) or until a full year had elapsed. A response was defined as HCV-RNA negativity in serum on three consecutive monthly determinations. The study population consisted of 21 males and 16 females ranging in age from 17 to 72 years (mean 46.7 +/- 2.2 years). Their mean serum alanine aminotransferase level at the initiation of therapy was 37.5 +/- 2.1 IU/l with a range of 10-59 (normal values being 40 IU/l or less). 54% of the subjects were presumed to have acquired their hepatitis C virus infection as a result of a blood transfusion; 32% as a result of prior intravenous drug abuse; and 13% had no identifiable risk factor for hepatitis C virus. Despite having normal or near normal serum alanine aminotransferase levels, 9 subjects had chronic persistent hepatitis, 13 had chronic active hepatitis and 15 had chronic active hepatitis + cirrhosis documented by histopathologic assessment of their liver biopsies.

RESULTS

An interferon response was achieved in 5/9 with chronic persistent hepatitis, 11/13 with chronic active hepatitis and 8/15 with chronic active hepatitis + cirrhosis for an overall response rate of 65%.

CONCLUSIONS

This study has demonstrated that individuals who: 1) are hepatitis C virus positive with serum alanine aminotransferase levels < 1.5 x upper limits of normal can have histologically advanced liver disease; 2) can respond to interferon therapy defined as clearance of detectable HCV-RNA in serum; and, 3) should be considered for interferon treatment.

The long-term efficacy of interferon alfa in chronic hepatitis C patients: a critical review

With current therapeutic regimens, sustained responses occur in no more than 25% of patients with chronic hepatitis C who are treated with interferon. Relapses occur usually within 6 months from therapy suspension, but clinical and virologic recurrencies can be observed as late as after 3 years of follow up. The rate of long-term responses seems to depend on the dosage and the period of administration of interferon, but the best therapeutic protocol remains unknown. As a direct marker of permanent recovery is not available, indirect signs of disease resolution are: (i) continuously normal alanine aminotransferase levels; (ii) clearance of HCV-RNA; (iii) disappearance of anti-C100/NS4; and (iv) significant histological improvements assessed at least 2 years after therapy withdrawal. Known baseline predictive features of long-term response are the absence of cirrhosis, low viraemic levels and infection with HCV of type III or IV genotype (Okamoto's classification). According to recent reports, the lower the heterogeneity of the hypervariable region of the envelope 2 gene of HCV, the higher the chance of a sustained remission. There is not yet any consensus on the efficacy of a second therapeutic course of interferon in inducing a permanent response, and controlled trials are needed to clarify this issue.

Interferon-alpha-2a. A review of its pharmacological properties and therapeutic use in the management of viral hepatitis

Interferon-alpha-2a is a recombinant interferon with antiviral, antitumour and immunomodulatory properties. Clinical studies have demonstrated that the drug offers therapeutic benefit in patients with some forms of chronic viral hepatitis. Remission, as measured by clearance of viral DNA and hepatitis B 'e' antigen (HBeAg), and normalisation of serum alanine aminotransferase levels, is observed in approximately 30 to 45% of patients with chronic hepatitis B receiving interferon-alpha-2a (2.5 to 18MU administered 3 times/week); about 5 to 15% of untreated controls remit spontaneously every year. Complete recovery [with loss of hepatitis B surface antigen (HBsAg)] is usually noted in < 20% of treated individuals. Similar response rates have been reported in the relatively small number of children evaluated to date. Although numerous studies have shown that interferon-alpha-2a (at various dosages) induces biochemical amelioration of chronic hepatitis C in approximately 50 to 75% of patients, relapse is common. Thus, long term remission may only be observed in about 15 to 30% of treated patients. On the other hand, this disorder remits spontaneously in only a few patients. The role of interferon-alpha-2a in the treatment of chronic hepatitis D remains unclear. Although preliminary data suggest it may be beneficial, cessation of therapy is generally followed by relapse. As with other types of interferons, most patients receiving interferon-alpha-2a experience an 'influenza-like' syndrome, which tends to diminish with continuing therapy. Other effects such as fatigue, lethargy, anorexia and weight loss are usually dose-limiting. Serum neutralising antibodies develop in approximately 10 to 20% of treated patients. Thus, although response rates are less than optimal, interferon-alpha-2a is a drug of first choice amongst the limited therapeutic options available for the management of well-compensated chronic viral hepatitis B or C.

Usefulness of simple assays for serum concentration of hepatitis C virus RNA and HCV genotype in predicting the response of patients with chronic hepatitis C to interferon alpha 2a therapy

The use of two new assays was evaluated for predicting the response to interferon (IFN) therapy in patients with chronic hepatitis C. The genotype of hepatitis C virus (HCV) was established by an enzyme-linked immunosorbent assay based on genotype-specific recombinant peptides of the NS4 region (genotyping ELISA). The concentration of HCV RNA was measured by a branched DNA assay (bDNA assay). Seventy-eight patients received the same regimen of IFN alpha 2a. Of the 74 patients assessed who completed the program, 38 (51.4%) were responders; i.e., their serum aminotransferase levels remained normal for 6 months or longer after stopping IFN, while 36 (48.6%) were nonresponders. The results of the HCV genotype determined by the genotyping ELISA and by the polymerase chain reaction (PCR) assay based on genotype-specific primers were similar. The serum concentrations of HCV RNA as measured by the bDNA assay and by the competitive PCR assay correlated closely and significantly (r = 0.82, P < 0.001). Multiple logistic regression analysis showed that the serum concentration of HCV RNA determined by the bDNA assay, the HCV genotype determined by the genotyping ELISA, and the histology activity index (HAI) of the liver were independently associated with IFN efficacy. By using these three variables in combination, a predictive rate of 82.4% was obtained. A lower level of HCV RNA, genotype 2 and a lower HAI score for liver histology were predictive of a favorable response to IFN. Thus, the genotyping ELSIA and the bDNA assay appear to be useful for clinical management of patients receiving IFN therapy.

Long term follow-up and patterns of response of ALT in patients with chronic hepatitis NANB/C treated with recombinant interferon-alpha

The response to interferon treatment in chronic hepatitis NANB/C has usually been classified as complete, partial or absent, according to the behavior of serum alanine aminotransferase (ALT). However, a more detailed observation of the enzymatic activity has shown that the patterns may be more complex. The aim of this study was to describe the long term follow-up and patterns of ALT response in patients with chronic hepatitis NANB/C treated with recombinant interferon-alpha. A follow-up of 6 months or more after interferon-alpha was achieved in 44 patients. We have classified the serum ALT responses into six patterns and the observed frequencies were as follows: I. Long term response = 9 (20.5%); II. Normalization followed by persistent relapse after IFN = 7 (15.9%); III. Normalization with transient relapse = 5 (11.9%); IV. Temporary normalization and relapse during IFN = 4 (9.1%); V. Partial response (more than 50% of ALT decrease) = 7 (15.9%); VI. No response = 12 (27.3%). In conclusion, ALT patterns vary widely during and after IFN treatment and can be classified in at least 6 types.

Levels of hepatitis C virus (HCV) RNA in serum and their relationship to levels of immunoglobulin M and G antibodies against HCV core protein

The presence and levels of hepatitis C virus (HCV) RNA and immunoglobulin M (IgM) and IgG antibodies against the virus core protein were determined in 449 serum specimens. Despite the fact that a relationship between the presence, but not the levels, of HCV RNA and HCV IgM was observed, the significance of HCV core IgM assays seems limited.

Efficacy of an analysis of lymphocyte subsets in predicting the clinical response to alpha-interferon therapy in thalassaemia patients with chronic infection by hepatitis C virus: a pilot study

alpha-interferon (alpha-IFN) has been used to treat chronic non-A non-B hepatitis in thalassaemic patients with response rates from 45% to 83%. Unfortunately, treatment with alpha-IFN is associated with side-effects which have a negative effect on the quality of life of the patient. Therefore it would be useful if we could distinguish in advance those patients who would benefit from such therapy from those who would not. In the present study we found that the modification of lymphocyte subsets 20 h after the administration of the first dose of alpha-IFN revealed that relative numbers of T helper lymphocytes (CD4+) increased in three non-responding patients and decreased in five responding patients, whereas those of T suppressor lymphocytes (CD8+), and natural killer cells (CD57+, CD16+) decreased in non-responding patients and increased in responding patients. Therefore analysis of the lymphocyte subsets CD4, CD8, CD57 and CD16 before and 20 h after the administration of alpha-IFN can be used to predict the clinical response to treatment with alpha-IFN.

Significance of IgG and IgM HCV antibody secretion in vitro in patients with chronic hepatitis C: correlation with disease activity and response to interferon-alpha

Hepatitis C virus antibodies are found in the serum of most patients with chronic hepatitis C. However, the significance of the humoral response is still uncertain. In this study, in vitro IgG and IgM anti-hepatitis C virus secretion by peripheral blood mononuclear cells of patients with chronic hepatitis C was analyzed. Peripheral-blood mononuclear cells from 21 of 36 patients (58.3%) secreted IgG anti-hepatitis C virus in vitro, as demonstrated with anti-hepatitis C virus-specific enzyme immunoassays and recombinant immunoblot assays. Ten of the 36 patients (27.8%) showed both IgG and IgM anti-hepatitis C virus core in vitro. In 9 of these 10 patients, IgM anti-hepatitis C virus was also detected in serum. Patients with in vitro IgM or IgG anti-hepatitis C virus secretion had higher ALT levels in serum than did patients without such secretion in vitro (99.5 +/- 22.1 and 85.6 +/- 34.4 vs. 38.1 +/- 37.4 U/L; p < 0.0001, p < 0.001). Furthermore, with a histology activity score it was demonstrated that patients with in vitro IgM or IgG HCV antibodies (or both) had more severe chronic active hepatitis than did patients without in vitro hepatitis C virus antibody secretion (p < 0.01). To analyze the therapy outcome, we included in this study 18 patients who had received interferon-alpha previously. Seven of eight in vitro hepatitis C virus antibody-positive patients were nonresponders, whereas the in vitro hepatitis C virus antibody-negative patients were mostly complete therapy responders (8 of 10).(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of chronic sporadic-type non-A, non-B hepatitis with lymphoblastoid interferon: gamma GT levels predictive for response

The aim of this study was to evaluate the efficacy of human lymphoblastoid interferon-alpha treatment in chronic sporadic-type non-A, non-B hepatitis. We also aimed to determine if histological or liver function data could predict either response or relapse. Sixty patients with chronic sporadic-type non-A, non-B hepatitis were randomized in two groups of 30. One group was treated with interferon-alpha (3 MU thrice weekly) for one year; the other group was untreated controls. The treated group was followed for another year after interferon withdrawal. Liver function tests were performed during treatment. Liver biopsy was carried out before and a year after randomization. We evaluated rate of response [normalization of alanine aminotransferase (ALT) levels for at least three consecutive months] and rate of relapse (ALT rebound after therapy suspension). We also looked at possible predictive factors for response and relapse. In the treatment group the rate of response was 55% (16/29). No control patient exhibited ALT normalization. Among the responders, 31% (5/16) relapsed after interferon withdrawal. Low gamma GT and female sex are positive predictive factors of response (P < 0.01 and P < 0.02 respectively). Presence of portal and periportal inflammation at the second liver biopsy was correlated with relapse (P < 0.05). In conclusion, human lymphoblastoid interferon-alpha treatment for one year is beneficial in patients suffering from chronic sporadic-type non-A, non-B hepatitis. Low pretreatment gamma GT levels and female sex are positive predictors of response in this patient population.(ABSTRACT TRUNCATED AT 250 WORDS)