An analysis of published trials of interferon monotherapy in children with chronic hepatitis C

Treatment of chronic hepatitis C in children

Since the discovery of hepatitis C virus (HCV) in 1989, significant advances have been made in our understanding of this important viral pathogen. Children at risk for HCV infection include recipients of potentially contaminated blood products and organ transplants, and infants born to HCV-infected mothers. Chronic HCV infection is usually asymptomatic in children but active hepatitis, cirrhosis and hepatocellular carcinoma can occur. The development of treatment strategies for chronic hepatitis C in children has directly evolved from clinical trials in adults. Sustained virologic response, defined by undetectable HCV RNA in serum 24 wk after completion of treatment, occurs in approximately 36% of children treated with conventional interferon alone and in about 50% of those given conventional interferon in combination with ribavirin. Pegylated interferon-based treatment regimens are better than those based on conventional interferon in adults but little is known about pegylated interferon in children. Factors associated with a favorable response to antiviral therapy in children are similar to those in adults and include infection with HCV genotype 2 or 3 and low pretreatment serum HCV RNA levels. Treatment related adverse events in children include 'flu-like' syndrome, fatigue, anorexia, weight loss, depression, anemia, leukopenia and thrombocytopenia.

Treatment options for hepatitis C infection in children

Multiple factors support treatment of hepatitis C virus (HCV) infection in children. These factors include the anticipated long duration of infection after early acquisition, relatively good tolerance of antiviral medications, and avoidance of social stigmatization. Nevertheless, careful selection of appropriate candidates for therapy is important. If a contraindication to current therapeutic agents is present, treatment should be withheld until this has resolved or until new agents are available. Children without contraindications to the medications used for HCV should undergo liver biopsy to determine the presence and degree of fibrosis. In the absence of fibrosis, treatment may be deferred. If any degree of hepatic fibrosis is present, antiviral therapy for HCV should be considered. At present, in the United States, the only therapy approved for children by the Food and Drug Administration (FDA) is a combination of interferon (IFN) alfa-2b and ribavirin. No safe therapies have been established for children younger than 3 years of age. Pegylated interferon in combination with ribavirin may be considered in adolescents older than 16 years of age who are post-pubertal, or in younger children in the context of clinical trials. Multicenter trials are currently underway to determine the safety and effectiveness of other forms of therapy for HCV infection in children.

Virus genotype 1b and long-term response to interferon alpha monotherapy in children with chronic hepatitis C

Interferon alpha (IFN-alpha) remains the basic modality in the treatment of chronic hepatitis C in children, but the effects of therapy are still unsatisfactory. The aim of this study was to evaluate parameters linked to IFN-alpha response within a 2-year period. Human C virus (HCV) infected children (n=34) were subdivided into IFN-treated (n=20) and IFN-untreated (n=14 control) groups. The IFN-treated group received a dosage 3 MU of IFN-alpha three times a week for 24 weeks. Liver biopsy was performed in all IFN-treated children and the HCV genotype was determined before the start of the study. Patients were sequentially screened for alanine transaminase (ALT) activity and tested for the presence of HCV-RNA in serum. All patients had either mild persistent or moderate active hepatitis, which was diagnosed from the liver biopsy. In the IFN-treated group ALT normalisation was observed by the end of treatment in 9/20 patients, but after 6 months 10 patients (50%) had sustained ALT normalisation and in 4 of them the virus was eliminated. They continued to show these features up to the end of the observation period (2 years). Eighteen out of 24 children tested had 1b genotype of virus. Out of 10 responders, all patients who were clear of HCV had the 1b genotype. The median age of responders (6.0, range 3.8-16) was significantly lower than non-responders (14.0, range 4-15) In the control group none of the children were clear of HCV-RNA.

CONCLUSION

The negative predictive effect of HCV genotype 1b in the course of IFN-alpha treatment may be not valid in children and other features have to be taken into account in the assessment of the efficacy of therapy.

The effect of early treatment in children with chronic hepatitis

BACKGROUND

The aim of this study was to compare the efficacy of interferon alpha (IFN) or IFN and ribavirin (IFN+RIB) combination therapy in children with chronic hepatitis C (CHC). Most children were infected during treatment for pediatric malignancies.

PATIENTS AND METHODS

We reviewed the charts of 20 patients (11 boys and 9 girls) aged 10.6 +/- 3.7 years with CHC who were treated between 1995 and 2001. Seven patients diagnosed with CHC before 1998 were treated with 3 million units of IFN three times weekly for 6 to 12 months. Thirteen children diagnosed after 1998 were treated with 3 million units of IFN three times weekly plus 15 mg/kg of ribavirin daily for 6 months (IFN+RIB).

RESULTS

Demographic and clinical characteristics were not different between the two treatment groups. A sustained complete response defined as serum alanine aminotransferase normalization and hepatitis C virus RNA clearance at 6 and 12 months after termination of treatment occurred in three of seven children (43%) treated with IFN monotherapy compared with 7 of 12 children (54%) in the group treated with IFN+RIB combination therapy (not significant). The only difference between responders and nonresponders was the duration of infection before the initiation of therapy, which was significantly shorter in responders (1 +/- 0.3 vs. 5.6 +/- 2.2; P = 0.001).

CONCLUSIONS

In this small cohort of children with CHC, early initiation of antiviral treatment was associated with a sustained response rate independent of treatment type. Regular follow-up of children at risk of acquiring hepatitis C virus infection should assist in the early diagnosis. Early initiation of antiviral treatment may improve the rate of sustained response.

Pediatric issues in new therapies for hepatitis B and C

Two antiviral treatments have been approved for hepatitis B virus (HBV) infection by the US Food and Drug Administration (FDA) for use in children: interferon (IFN)-alpha, 6 MU/m(2) three times a week subcutaneously for 6 months, and lamivudine, 3 mg/kg/d orally for 12 months. Twenty-six percent to 58% of children treated with IFN become HBV DNA negative, and up to 38% become negative to hepatitis B e antigen (HBeAg). Lamivudine, a nucleoside analogue that blocks viral replication by inhibition of the HBV polymerase, has been associated with comparable rates of seroconversion of HBeAg to anti-HBe. Loss of surface antigen occurs in less than 5% of patients treated with lamivudine, compared with 3% to 33% in those treated with IFN-alpha. Fifty percent to 65% of children treated with lamivudine clear HBV DNA after 12 months of therapy, but relapse rates have not been clarified. Patients treated with lamivudine develop drug-resistant (YMDD) mutants in the HBV polymerase at the rate of 16% to 32% per year. No treatments for children with hepatitis C virus (HCV) have been approved by the FDA. However, published reports describe treatment with IFN monotherapy and combination therapy with IFN and ribavirin. Trials of PEG-IFN alone or in combination with ribavirin are in progress. Given the lack of data regarding treatment of HCV in children, it is generally agreed among pediatric hepatologists that the optimal treatment is within the context of randomized, controlled trials.

Interferon alpha in the treatment of chronic hepatitis C in children: a meta-analysis [correction of metanalysis]

Children with chronic hepatitis C may be ideal candidates for treatment with interferon alpha (IFNalpha) as they have liver disease at an early stage. However, adverse drug reactions need to be considered. The aim of this study was to conduct a systematic review of literature on interferon therapy of chronic hepatitis C in children, and to perform a meta-analysis of pooled data. A computerized search gave 18 articles on IFNalpha therapy in children with chronic hepatitis C; after exclusion of uncontrolled trials and of trials including patients with comorbidities, data from two studies could be pooled (48 patients). The outcomes assessed were biochemical, defined as normalization of alanine transaminase, and virologic, defined as HCV-RNA loss, both sustained at 24 months after enrollment. Results of the studies were homogenous. Risk difference was 37% (95%CI: 12.9-61) in favour of IFNalpha treated children for sustained biochemical response, and 36.8% (95%CI: 14.3-59.3) in favour of treated children for sustained HCV clearance, respectively. The differences were highly significant (P = 0.007 and P = 0.004, respectively). The histological end-point, as well as side-effects, could not be analysed, due to lack of data. This review identifies the poor methodology of the majority of the published trials. The study provides support for the efficacy of IFNalpha in improving both biochemical and virologic outcomes in chronic hepatitis C in children, but evidence is confined to these surrogate end-points.

Hepatitis C virus infection in children coinfected with HIV: epidemiology and management

Mothers with hepatitis C virus (HCV) and HIV coinfection are the major source of HCV/HIV coinfection in infancy and childhood. There is no known intervention capable of interrupting HCV spread from mother to child, while the majority of infant HIV infections occurring in the developed world can be prevented by antiretroviral prophylaxis in the mother and child, elective caesarean section, and formula-feeding. In the era preceding treatment of HIV infection with highly active antiretroviral therapy, HCV coinfection was of little concern because the short-term survival of patients with HIV infection prevented the slowly developing consequences of chronic hepatitis C. As the life expectancy of patients with HIV infection increased with therapy, HCV has emerged as a significant pathogen. Several lines of evidence in adult patients suggest that liver disease may be more severe in patients coinfected with HIV and that progression of HIV disease may be accelerated by HCV coinfection. Whether coinfected children may share these clinical patterns remains a matter of speculation. Chronic hepatitis C in otherwise healthy children is usually a mild disease; liver damage may be sustained and fibrosis may increase over the years, suggesting slow progression of the disease. Interferon-alpha has been the only drug used in the past decade to treat hepatitis C in children and adolescents, with average response rates of 20%. Preliminary results of treatment with interferon-alpha and ribavirin suggest that the efficacy would be greater with combined therapy. These treatment protocols have not yet been applied to children coinfected with HIV, but the increasing number of long-term survivors will probably prompt further investigation in the near future. At present, treating HIV disease and monitoring HCV infection and hepatotoxicity induced by antiretroviral drugs seem to be the more reasonable approach to HCV/HIV coinfection in childhood.

Chronic hepatitis C virus infection in childhood: clinical patterns and evolution in 224 white children

The characteristics and evolution of hepatitis C virus (HCV) infection were retrospectively investigated in a study of 224 HCV RNA-seropositive white children who were consecutively recruited at 7 European centers in 1980-1998. At presentation, all patients were positive for antibodies to hepatitis C virus, 87% were asymptomatic, and 48% had alanine aminotransferase (ALT) levels that were < or =2 times the upper limit of the range considered to be normal. Of 200 children followed for 1-17.5 years (mean follow-up +/- standard deviation [SD], 6.2+/-4.7 years), only 12 (6%) achieved sustained viremia clearance and normalization of the ALT level. In 92 revised liver biopsy specimen analyses, the mean fibrosis score (+/-SD) was 1.5+/-1.3 for children <15 years of age and 2.3+/-1.2 for children > or =15 years of age (range, 0-6 years; P<.01). Pediatric HCV infection is usually mild, but few patients, especially those who are perinatally infected, clear viremia in the medium-term follow-up. Conversely, the higher rates of fibrosis observed in older patients suggest the possibility of an insidious progression of HCV-associated liver disease.

Recombinant alfa-interferon plus ribavirin therapy in children and adolescents with chronic hepatitis C

Treatment with alfa-interferon alone yielded poor results in children with chronic hepatitis C and was not generally recommended. Owing to limited experience with combination therapy in children, the aim of the study was to evaluate the efficacy and tolerability of alfa-interferon 2b in combination with ribavirin in these patients with different routes of viral transmission. In an uncontrolled pilot study, 41 children and adolescents ranging from 3 to 16 years were treated with alfa-interferon at a dose of 3 or 5 MU/m(2) 3 times weekly in combination with oral ribavirin (15 mg/kg/d) for 12 months. The mode of infection was unknown in 4, parenterally transmitted in 16, and vertically transmitted in 21 children. Forty patients completed the study. Eleven children, who remained hepatitis C virus (HCV)-RNA positive 6 months after the beginning, discontinued therapy. One boy stopped treatment because of side effects. At the end of treatment 25 patients were HCV-RNA negative (61%). All individuals remained HCV-RNA negative during the 6-month follow-up period. Nine of 15 children with parenteral (56.3%), 14 of 21 with vertical (66.6%), and 2 of 4 with unknown route of infection responded. Side effects included minor clinical signs such as fever, flu-like symptoms, anorexia, and more severe signs (21.4%) such as the development of thyroid autoantibodies and impairment of thyroid function. In conclusion, combination of alfa-interferon with ribavirin seems to be an important advance in the treatment of chronic hepatitis C in children and adolescents. This also is true for both vertically infected patients and for individuals with normal transaminase levels before therapy.

Children with hepatitis C

An estimated 240,000 children in the United States have antibody to hepatitis C virus (HCV) and 68,000 to 100,000 are chronically infected with HCV. Acute HCV infection is rarely recognized in children outside of special circumstances such as a known exposure from an HCV-infected mother or after blood transfusion. Most chronically infected children are asymptomatic and have normal or only mildly abnormal alanine aminotransferase levels. Although the natural history of HCV infection acquired in childhood seems benign in the majority of instances, the infection takes an aggressive course in a proportion of cases leading to cirrhosis and end-stage liver disease during childhood; the factors responsible for a more aggressive course are unidentified. An optimal approach to management of hepatitis C in children would be prevention, particularly of perinatal transmission, which is now the major cause of new cases of hepatitis C in children. Obstetrical factors may be important determinants of transmission, which, if confirmed, should lead to changes in the care of infected women. Therapy of HCV infection in children is also not well defined. There have been no large randomized, controlled trials of therapy in children with chronic hepatitis C. Small heterogeneous studies of interferon monotherapy have reported sustained virological response rates of 35% to 40%. There are few data regarding the use of combination therapy with interferon and ribavirin in children and no information on the use of peginterferon. Clearly, there are important needs for future epidemiologic and clinical research on hepatitis C in childhood.

[Role of interferons in the treatment of hepatitis B and hepatitis C virus infections]

BACKGROUND

Since the discovery of hepatitis C (HCV), the efficacy of treatment has significantly progressed using standard mono-therapy: with Interferon alpha (IFN) during six months we obtained approximately 10% sustained response and currently with the association of pegylated IFN and Ribavirin a 55% sustained response was achieved.

CURRENT POSITION AND MAJOR POINTS

HCV infection continues to present therapeutic problems which have not entirely been solved, mainly related to clinical and biological tolerance, and non-responders. Moreover, the care of patients with extra-hepatic localization, cirrhotic patients, as well as therapeutic problems of co-infected HIV-HCV patients. As regards hepatitis B (HBV) new effective treatments against this virus have appeared, IFN then nucleoside analogs, some of which are available in France (i.e. lamivudine, adefovir, dipovoxil). The main objective of chronic hepatitis B treatment is to obtain the complete inhibition of the HBV virus by Hbe-antigen antibody seroconversion which would therefore significantly increase patient survival. In this article the advantages and disadvantages of the different treatments are assessed.

FUTURE PERSPECTIVES

Despite the considerable and rapid progress obtained in the therapeutic treatment of infection due to HCV and HBV a number of unknown factors remain, which warrants further trials, in particular to evaluate the efficacy as well as the tolerance of the antiviral agent association.

Children with hepatitis C

An estimated 240,000 children in the United States have antibody to hepatitis C virus (HCV) and 68,000 to 100,000 are chronically infected with HCV. Acute HCV infection is rarely recognized in children outside of special circumstances such as a known exposure from an HCV-infected mother or after blood transfusion. Most chronically infected children are asymptomatic and have normal or only mildly abnormal alanine aminotransferase levels. Although the natural history of HCV infection acquired in childhood seems benign in the majority of instances, the infection takes an aggressive course in a proportion of cases leading to cirrhosis and end-stage liver disease during childhood; the factors responsible for a more aggressive course are unidentified. An optimal approach to management of hepatitis C in children would be prevention, particularly of perinatal transmission, which is now the major cause of new cases of hepatitis C in children. Obstetrical factors may be important determinants of transmission, which, if confirmed, should lead to changes in the care of infected women. Therapy of HCV infection in children is also not well defined. There have been no large randomized, controlled trials of therapy in children with chronic hepatitis C. Small heterogeneous studies of interferon monotherapy have reported sustained virological response rates of 35% to 40%. There are few data regarding the use of combination therapy with interferon and ribavirin in children and no information on the use of peginterferon. Clearly, there are important needs for future epidemiologic and clinical research on hepatitis C in childhood.