Effects of interferon-alpha on serum hepatitis C virus in patients with chronic hepatitis C

The biology of interferon-alpha and the clinical significance of anti-interferon antibodies

The therapeutic indications for Interferons (IFNs) have dramatically increased in number in recent years to include many different diseases of viral, malignant, angiogenic, allergic, inflammatory and fibrotic origin. In particular, the current pandemic of hepatitis C virus infection has further stimulated the requirement for a comprehensive understanding of both the mechanism of action of IFN and the reasons for therapeutic failure. The role of anti-IFN antibodies as a cause of treatment failure has been a particularly controversial area. In this review we will outline the biology and proposed mechanisms of action of IFN-alpha (IFN-alpha) and discuss the incidence, methods of detection and clinical significance of anti-IFN antibodies.

[Therapy of hepatitis C]

The purpose of this review is an update of the therapy of hepatitis C especially with Interferon-alpha. From the large number of publications on this topic the established facts were worked out. Taking these facts as a base guidelines for the therapy in practical use were defined. In addition the aspects of therapeutic strategies of chronic hepatitis C which until now can not definitely be judged are discussed. In the relatively few patients in whom hepatitis C is diagnosed already in the acute phase, Interferon-alpha-treatment (3 x 3 million units 3 times a week) for 3 to 4 months increases the percentage of patients in whom HCV-RNA in the serum is eliminated. In patients with chronic hepatitis C, after decision finding for treatment, a standard scheme is recommended which consists of a monotherapy with recombinant Interferon-alpha. The dosage of Interferon-alpha is in the first 12 to 16 weeks 5 up to 6 million units given 3 times a week. For the further therapy 3 million units 3 times a week seems to be appropriate. The recommended duration of Interferon-alpha-therapy is 12 months. A long-term benefit of about 20% can be achieved in unselected groups of patients when judged on the permanent normalisation of serum transaminases and elimination of HCV-RNA in the serum. Important factors which may influence the probability of a sustained response, like HCV genotype, virus titer in serum, duration of the disease, high hepatic iron content and the presence of cirrhosis, are discussed. Up to now there exist no reliable guidelines in the case of a "no change" situation and for patients with a flare-up of inflammatory activity during or after therapy. Combination therapy of Interferon-alpha with other drugs like analogous of nucleotides (for example ribavarin), non steroidal antirheumatic drugs and ursodesoxycholic acid (UDCA) have still to be evaluated in controlled clinical trials.

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.

Long-term administration of natural interferon-alpha in patients with chronic hepatitis C: relationship to serum RNA concentration, HCV-RNA genotypes, histological changes and hepatitis C virus

To virologically assess the efficacy of interferon therapy in chronic hepatitis C, either 5 or 10 MU/day natural interferon-alpha (IFN alpha) was administered to 57 patients with chronic hepatitis C for 38 weeks. A complete and sustained response (CR-SR), as evidenced by the absence of serum hepatitis C virus (HCV)-RNA during the administration period and at 6 months after the final administration of IFN alpha and normal GPT level at 6 months after final administration, occurred in 42.6% (23/54) of subjects. Liver tissue was histologically evaluated using the histological activity index (HAI) score before and after the administration period. In CR-SR cases, significant improvements (P < 0.01) occurred in periportal necrosis, intralobular necrosis, portal inflammation and total score. A comparison, by HCV genotypes, revealed that CR-SR occurred in 60% (9/15) of subjects with type 2a and 30.3% (10/33) of subjects with type 1b. A comparison by virus concentration revealed that CR-SR occurred in 71.4% (15/21) of those subjects having a virus concentration of < 10(5) copies/mL, but in only 24.2% (8/33) of those having a virus concentration of > 10(5) copies/mL. Analysis by a multiple logistic model revealed a strong correlation between the therapeutic effect of interferon therapy and the pre-administration virus concentration (P = 0.0061) and genotype (P = 0.0015). These results suggest that the pre-administration virus concentration and genotype are both key factors affecting the therapeutic effect of interferon therapy in chronic hepatitis C and that the therapeutic effect of interferon is satisfactorily high, irrespective of virus concentration, in subjects with type 2a HCV, but varies depending on virus concentration in subjects with type 1b.

Randomized controlled trial of recombinant interferon-alpha 2b in the treatment of Chinese patients with chronic hepatitis C

To evaluate the efficacy of recombinant interferon (IFN) alpha 2b in the treatment of Chinese patients with chronic hepatitis C, a randomized controlled trial was conducted in 50 chronic hepatitis C patients: 25 patients received 3 million units of subcutaneously injected recombinant IFN-alpha 2b three times per week for 6 months, and 25 patients received no specific treatment were used as controls. At the end of the IFN treatment, 19 patients (76%) in the IFN-treated group normalized serum ALT compared with only 6 patients (24%) in the control group (p < 0.01). Relapse within 6 months after the completion of treatment occurred in 13 IFN-treated patients (68%). Normalized serum ALT was seen in 6 patients (24%) in the IFN-treated group and 1 patient (4%) in the control group 6 months after discontinuation of IFN therapy (p = 0.10). The presence of serum hepatitis C virus (HCV) RNA measured by reverse transcription-polymerase chain reaction was detected at the end of the IFN treatment in all 13 patients who relapsed after cessation of therapy. In only 3 of 25 IFN-treated patients (12%) was the presence of serum HCV RNA not detectable at the end of the IFN treatment or 6 months after cessation of therapy. No patient in the control group had undetectable serum HCV RNA during the study period. Using multivariate logistic regression analysis, the low pretreatment levels of HCV RNA, measured by a quantitative branched DNA amplification assay, was the only independent predictor of a sustained response to IFN therapy (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized controlled trial of recombinant interferon alpha-2b in the treatment of Chinese patients with acute post-transfusion hepatitis C

To evaluate the efficacy of recombinant interferon alpha-2b in the treatment of patients with acute post-transfusion hepatitis C, a randomized controlled trial was conducted in 33 acute post-transfusion hepatitis C patients; 16 patients received 3 million units of subcutaneously injected recombinant interferon alpha-2b 3 times a week for 3 months and 17 patients without specific treatment were used as controls. At the end of the interferon treatment, 13 (81%) patients in the interferon-treated group normalized serum alanine aminotransferase compared with only six (35%) patients in the control group (p < 0.01). One year after completion of the interferon treatment, nine (56%) patients in the interferon-treated group and six (38%) patients in the control group normalized serum alanine aminotransferase (p = 0.35). Serum HCV-RNA measured by reverse transcription-polymerase chain reaction was positive in all patients at the time of enrollment and then became undetectable in 13 (81%) patients in the interferon-treated group and two (12%) patients in the control group at the end of interferon treatment (p < 0.001). One year after completion of the interferon treatment, seven (44%) patients in the interferon-treated group and two (13%) patients in the control group had persistent undetectable serum HCV-RNA (p = 0.08). Using a logistic regression model, the lower pretreatment level of serum HCV-RNA measured by quantitative branched DNA signal amplification assay was the only predictor for a favorable response to the interferon treatment in acute hepatitis C patients.(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)