Interferon-alpha treatment of chronic hepatitis B in childhood: a consensus advice based on experience in European children

Liver biopsy in children: position paper of the ESPGHAN Hepatology Committee

Liver biopsy (LB) is still the criterion standard procedure for obtaining liver tissue for histopathological examination and a valuable tool in the diagnosis, prognosis, and management of many parenchymal liver diseases. The aim of this position paper is to summarise the present practice of paediatric LB and make recommendations about its performance. Although histological evaluation of the liver is important in assessing prognosis and exploring treatment, noninvasive techniques (ie, imaging, laboratory markers) may replace use of liver histology. The indications for LB are changing as present knowledge of aetiologies, pathomechanism, and therapeutic options in paediatric liver disease is evolving. Adult and paediatric literature was reviewed to assess the existing clinical practice of LB with focus on the technique, indications, risk of complications, and contraindications in paediatrics. This position paper presents types of LB, indications, complications, contraindications, and an essential checklist for paediatric LB.

Assessment of Growth and Development in Children With Hepatitis B Positivity

Background

Chronic infections and liver diseases may influence the growth and development of children by leading to malnutrition. In this study, demographic characteristics, anthropometric measurements and laboratory findings for children with hepatitis B positivity were analyzed.

Methods

A total of 43 cases were admitted to our clinic between January 2012 and February 2013 and detected to have HBsAg positivity.

Results

Malnutrition was detected in 11 cases (25.6%) and obesity in three cases (6.9%). Aspartate aminotransferase (AST) levels were significantly higher in malnourished patients compared to those without malnutrition. The weight to height was significantly higher in patients with positive HBeAg compared to children with negative HBeAg. We found that the weight standard deviation scores (SDS) ratios dropped as alanine aminotransferase (ALT) and AST levels increased and height SDS ratios decreased. In addition, body mass index (BMI) decreased as AST and alpha feto protein (AFP) values increased. While a significant relationship was not detected between insulin-like growth factor binding protein-3 (IGFBP-3) and insulin-like growth factor-1 (IGF-1) and ALT, a significantly negative correlation was detected between IGFBP-3 and IGF-1 and AST. We found a malnutrition rate of 25.6% in children with HBsAg positivity. We also found that weight and height SDS rates decreased as ALT and AST levels increased. In addition, we detected that BMI decreased as AST and AFP values increased.

Conclusion

We consider that hepatic inflammation is the factor that affects growth. Monitoring of growth and development during follow-up of children who are detected to have HBsAg positivity would be beneficial to determine the mechanism and causes of growth retardation.

Chronic hepatitis B in children and adolescents: epidemiology and management

Hepatitis B virus (HBV) infection is a worldwide health problem, which can cause acute liver failure, acute hepatitis, chronic hepatitis, liver cirrhosis, and liver cancer. It is most prevalent in Asia, Africa, Southern Europe, and Latin America. Approximately 2 billion people in the world have been infected by HBV, with more than 350 million as chronic carriers. Implementation of the HBV vaccine led to a significant reduction in viral transmission in many areas of the world; however, it remains highly endemic in many developing countries. The main source of infection in childhood is via perinatal transmission or horizontal transmission during preschool years. The majority of children with chronic hepatitis B (CHB) infection are asymptomatic; however, they may develop progressive disease and are at increased risk of advanced liver disease or liver cancer before their third decade. All children with chronic HBV infection should be regularly monitored for disease progression. The goal of therapy for children with CHB is to arrest disease progression and reduce the risk of developing cirrhosis and cancer. The available medications have a low success rate because of immunotolerance in the child and the development of viral resistance to standard therapy. Therefore, case selection and determination of the best time to commence treatment are essential to increase treatment efficacy and reduce the risk of viral resistance.

Cure for immune-tolerant hepatitis B in children: is it an achievable target with sequential combo therapy with lamivudine and interferon?

We prospectively studied the HBsAg seroconversion with sequential combination therapy of lamivudine (LAM) and interferon (IFN) in hitherto untreatable 'immune-tolerant' chronic hepatitis B in children. In this case-control study, 28 children with immune-tolerant hepatitis B [HBsAg positive for >6 months with near normal aminotransferase level, minimal/no inflammation in liver histology and high viral load (HBV DNA>10(7) copies/mL)] were treated with LAM alone at 3 mg/kg/day for 8 weeks followed by LAM plus IFN alpha (5 MU/m(2) three times a week) for another 44 weeks. They were compared with 34 untreated children. HBV markers (HBsAg, HBeAg, anti-HBe, quantitative HBV DNA) were carried out at baseline, at the end of therapy and 6 monthly thereafter. The mean age was 5.9 ± 3.2 years and 24 were boys. End therapy response: HBe seroconversion was achieved in 11, and of these, five had complete response (HBsAg clearance), 11 did not respond and six had virologic response (DNA undetectable but no HBe seroconversion). Six months after therapy, 10 of the 11 (91%) originally seroconverted children remained seroconverted while one seroreverted. Six of the 28 (21.4%) children lost HBsAg and they remained HBsAg negative and anti-HBs positive on follow-up. After a mean follow-up of 21.1 ± 11.9 months, the status remained same in the responders but one of the nonresponders HBe seroconverted (39.3%). There were no serious side effects of therapy. It is possible to achieve a cure in more than one-fifth of immune-tolerant children with hepatitis B with the sequential combination of LAM and IFN.

Liver biopsy in modern clinical practice: a pediatric point-of-view

Liver biopsy remains the foundation of evaluation and management of liver disease in children, although the role of the liver biopsy is changing with development of alternative methods of diagnosis and advancement of hepatic imaging techniques. The indications for liver biopsy are evolving as current knowledge of etiologies, noninvasive biomarker alternatives, and treatment options in pediatric liver disease are expanding. The procedure can often be complicated in children by technical difficulties, cost, and smaller specimen size. Communication and partnership of clinicians with pathologists experienced in pediatric liver diseases are essential. DNA sequencing, novel imaging modalities, noninvasive biomarkers of fibrosis and apoptosis, proteomics, and genome-wide association studies offer potential alternative methods for evaluation of liver disease in children. This review presents specific indications, considerations, methods, complications, contraindications, and alternatives for pediatric liver biopsy.

Predictive factors and virological response to interferon treatment in children with chronic hepatitis B

Further knowledge about factors predicting response to interferon treatment for chronic hepatitis B in children is required, in particular as the benefits of therapy are uncertain. In the present study, baseline characteristics were related to virological and histological responses in 27 children given interferon-alpha for 24 weeks after steroid priming. HBe seroconversion was seen in 8 of 27 HBeAg positive patients and was accompanied by a sustained virological response (SR), with a median 4.1 log HBV DNA reduction. Pretreatment viraemia level was the only baseline parameter associated with SR. After 12 weeks of IFN (mid-treatment), viraemia was significantly reduced in all patients, with a median of 3.0 (range 0.6-5.2) log decline in SR compared with 0.6 (range -0.5-3.6) log decline in non-sustained responders (NSR). HBV DNA levels below 1 million copies/ml at week 12 predicted sustained response with a positive predictive value of 75% and a negative predictive value of 89%. During the latter half of the IFN treatment HBV DNA tended to increase by a mean of 0.4-0.5 log for all patient groups. Flares during IFN treatment were rare or mild as measured by ALT. Pretreatment anti-HBc IgM was associated with liver damage but not with response. Histological inflammation scores were improved in SR. Thus, pretreatment HBV DNA levels were associated with IFN response, and the virological response at week 12 predicts SR and may be useful in the decision to continue or modify therapy.

Management of chronic hepatitis B in children

Hepatitis B virus (HBV) infection is a worldwide problem and can cause acute liver failure, acute hepatitis, chronic hepatitis, liver cirrhosis, and liver cancer. In areas of high prevalence such as in Asia, Africa, southern Europe, and Latin America, the hepatitis B surface antigen positive rate ranges from 2% to 20%.In endemic areas, HBV infection occurs mainly during infancy and early childhood. Mother-to-infant transmission accounts for approximately half of the chronic HBV infections. In contrast to infection in adults, HBV infection during early childhood results in a much higher rate of persistent infection and long-term serious complications such as liver cirrhosis and HCC.Three phases of chronic hepatitis B have been identified: the immune-tolerant phase, the immune-active phase, and the inactive hepatitis B phase. These phases of infection are characterized by variations in viral replication, hepatic inflammation, spontaneous clearance, and response to antiviral therapy.The optimal goal of antiviral therapy for chronic HBV infection is to eradicate HBV and to prevent its related liver complications. However, due to the limited effect of available therapies in viral eradication, the goal of treatment is to reduce viral replication, to minimize liver injury, and to reduce infectivity. In this review the current recommendations for monitoring and treating chronic HBV infection in children are reviewed.

Reviews for APASL guidelines: immunomodulator therapy of chronic hepatitis B

The primary aim of immunomodulator therapy is to help the natural human immune system to mount a defense against hepatitis B virus. IFN-alpha has been used for the treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B for over two decades and has been shown to be effective in suppressing HBV replication and in inducing serological response leading to long-term clinical benefits. IFN-alpha has been used in patients with well-compensated cirrhosis with comparable or better response to that in non-cirrhotic patients. IFN-alpha therapy in patients with cirrhosis has a similar side effect profile as in those without cirrhosis. However, IFN-alpha is contraindicated in patients with overt or decompensated cirrhosis. Pegylated IFN-alpha has been shown to be effective in treatment of chronic hepatitis B with sustained response rate in about one-third of the treated patients. Peg IFN-alpha treatment in non-responders to lamivudine or adefovir dipivoxil showed similar response rate to that seen in naïve patients. Thymosin alpha(1) is effective in treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B with a significantly increasing virological response over time after therapy.

Therapeutic efficacy of sequential and simultaneous treatments with interferon-alpha and lamivudine in children with chronic hepatitis B

BACKGROUND

Interferon (IFN)-alpha and lamivudine (LAM), a nucleoside analog, are frequently used drugs for the treatment of chronic hepatitis B (CHB), and their combined therapy has been shown to be effective. The purpose of the present study was to examine the therapeutic efficacy of sequential and simultaneous combination therapies of IFN-alpha and LAM in children with CHB.

METHODS

A total of 45 children with CHB, whose antibody status was positive for hepatitis B surface antigen (HBsAg), hepatitis B envelope antigen (HBeAg), and HBV-DNA at least for 6 months; who had alanine aminotransferase (ALT) levels 1.5-fold higher than normal and hepatic activity index scores higher than 6, were allocated to two groups. The first group included 24 children who were given standard dose IFN-alpha (5 MU/m(2) s.c., thrice weekly) for 6 months, followed by LAM (4 mg/kg per day per oral, maximum 100 mg/day) for an additional 6 months (sequential therapy group). The second group included 21 children who were given IFN-alpha and LAM therapy simultaneously for 6 months and who continued with LAM alone for another 6 months (simultaneous therapy group). Partial response was defined as normalization of ALT and eradication of HBV-DNA. Complete response was defined as normalization of ALT, eradication of HBV-DNA and e seroconversion. Non-responders were defined as having positive HBV-DNA and abnormal ALT levels. Sustained response was defined as absence of HBsAg and presence of hepatitis B surface antibody (anti-HBs).

RESULTS

The mean age of the sequential therapy group was 12.7 +/- 4.1 years, and 16 (66.7%) of the patients were male. The mean age of the simultaneous therapy group was 14.8 +/- 4.6 years, and 15 (71.4%) were male. In the first group, 13 patients (54.2%) were non-responders; partial response was observed in five patients (20.8%), and complete response was seen in six patients (25%). Despite the occurrence of e seroconversion, normalization of ALT was not achieved in one case. In the second group, which consisted of 21 patients, 11 subjects (52.4%) were non-responders; partial response was observed in one case (4.8%), and complete response was seen in seven (33.3%). Sustained response was found in two patients (9.5%). There were no significant differences between the groups (P > 0.05).

CONCLUSION

When the therapeutic efficiency of two different treatment regimens applied for 1 year was evaluated in childhood CHB therapy, it was remarkable that there was a sustained response and a higher complete response in group 2, although there was no considerable difference between the therapy results of both groups.

Treatment of Viral Hepatitis in Children

Hepatitis B and hepatitis C are important causes of chronic liver disease in children and adolescents, and later on for potential cirrhosis and primary hepatocellular carcinoma. The risk of developing chronic hepatitis B (HB) infection ranges from 90% in neonates to <5% in adults. Hepatitis C induces chronic infection in at least 85% of affected persons. HBV and HCV associated liver damage appears to be less severe in children than in adults. At the present time, lamivudine and a combination of interferon and lamivudine seem to be the best options for HB infection treatment in the pediatric population, even though they induce the presence of drug-resistant mutations, and new therapies have to be developed to improve reduction and cessation of viral replication and decrease the emergence of mutations. Therapy with interferon and ribavirin seems to offer the best results for children and adolescents. Results from a study on pegylated interferon in a pediatric population might lead to better therapeutic responses. Cost of treatment for chronic viral hepatitis is very high and efforts have to continue to extend hepatitis B vaccination to the general population worldwide to reduce vertical and horizontal transmission of hepatitis C.

Virus-specific T cell immune response in children and adolescents with chronic hepatitis B virus infection

OBJECTIVES

To study the hepatitis B-specific T cell-mediated immune response in chronically infected children and adolescents.

PATIENTS AND METHODS

In all, 36 HBsAg-positive patients, 2 to 19 years old, were included. There were 9 HBeAg-positive patients with normal levels of alanine aminotransferase (ALT) (group 1), 18 HBeAg-positive patients with elevated ALT (group 2), and 9 HBeAg-negative, anti-HBe-positive patients (group 3). Four patients in group 2 were treated with interferon during the study. In all patients, HBcAg-specific T cell proliferation and ALT levels were prospectively studied in repeated samples for a mean follow-up time of 1.6 years. The baseline HBV-DNA and plasma cytokine levels were determined, and genotypes were analyzed.

RESULTS

The percent of patients with at least 1 sample indicating T cell proliferation was 55% in group 1 and 89% in groups 2 and 3, respectively (P = 0.07 group 1 vs group 2, P = 0.013 group 1 vs the combined groups 2 and 3). Tendencies for positive correlations between the degree of T cell proliferation and ALT levels were noted in groups 1 and 3 and for negative correlations in HBeAg seroconverting patients of group 2. In patients with successful interferon treatment, a pattern of more vigorous T cell proliferation than in patients with spontaneous seroconversion was noted.

CONCLUSIONS

A majority of patients showed signs of ongoing T cell proliferation. The continuation of the T cell-mediated immune response seems to be of importance in maintaining the HBeAg seroconversion over time.

The influence of interferon-alpha and combination interferon-alpha and lamivudine therapy on height and weight in children with chronic hepatitis B infection

AIM

To evaluate the height and weight patterns of children with chronic hepatitis B (CHB) with and without treatment.

METHODS

Thirty-four patients with immunoactive CHB randomly assigned to receive interferon-alpha2a (IFN) (5 mIU/m2, 6 months, group I) or IFN (same dose and duration) plus lamivudine (4 mg/kg/day, 24 months) (group II). Fifteen immunotolerant patients (group III) were followed without any treatment. Height (Ht-SDS), weight (Wt-SDS) and growth velocity (GV-SDS) standard deviation scores were monitored for a total of 36 months.

RESULTS

Ht-SDS was significantly lower in group II than in group I one year after completion of IFN treatment (p < 0.05). Wt-SDS was significantly higher in group I than the other groups two years after completion of IFN treatment (p < 0.05). In groups I and II, the percentage of children showing abnormal GV-SDS decreased once treatment was completed (p < 0.05).

CONCLUSION

CHB does not have deleterious effects on height and weight. Although IFN treatment temporarily compromises weight gain and growth velocity, lamivudine does not have any additional adverse effect.

The incidence and evolution of thyroid dysfunction during interferon-alpha therapy in children with chronic hepatitis B infection

AIM

To assess the effect of interferon-alpha (IFN-alpha) therapy on thyroid functions in children with chronic hepatitis B infection (CHB).

METHODS

Sixty-eight children (7.8 +/- 3.6 years) were treated with 5 (n = 37, group I) or 10 MU/m2 (n = 31, group II) IFN for 6 months. Thyroid hormones, thyrotropin, thyrotropin-releasing hormone stimulation test, thyroid peroxidase and thyroglobulin autoantibodies were evaluated.

RESULTS

Baseline features were not different in the two groups. After therapy, thyroid dysfunction was 27% and 41.9% in groups I and II (n.s.). Subclinical hypothyroidism was 17.9%/ 29%, subclinical hyperthyroidism 5.4%/12.9%, hypothyroidism 2.7%/-, and thyroid antibody positivity 2.7%/- in groups I and II (n.s.). Thyroid dysfunction was 33.8% in the whole group (p = 0.001). Predictors of IFN induced-thyroid dysfunction were female sex and age < 6 years. Thyroid dysfunction resolved within median 6 months in all but three children.

CONCLUSION

Although IFN-induced thyroid dysfunction is mostly subclinical and reversible, this side effect should be kept in mind.

Combined lamivudine/interferon-alpha treatment in "immunotolerant" children perinatally infected with hepatitis B: a pilot study

OBJECTIVE

To investigate whether combining the antiviral effect of lamivudine with the immune-boosting action of interferon-alpha (IFN-alpha) is effective in treating hepatitis B virus (HBV) "immunotolerant" children.

STUDY DESIGN

Twenty-three children (8 boys; mean age, 10 years) infected during the first year of life (17 Asian, 21 with normal aminotransferase levels, 15 with HBV-DNA >1000 pg/mL by hybridization and all with mild histologic changes) were treated with lamivudine (3 mg/kg) for 8 weeks alone and then lamivudine (3 mg/kg) and IFN-alpha (5 MU/m(2), 3 times weekly) in combination for 10 months.

RESULTS

Seventy-eight percent became HBV-DNA negative at the end of treatment, 5 (22%) seroconverted to anti-HBe, 4 (17%) of whom achieved complete viral control, becoming persistently HBsAg negative and anti-HBs positive. None had YMDD mutations. The viral status of the patients has not changed after a median follow-up of 40 months (range, 36 to 48).

CONCLUSIONS

This pilot study suggests that lamivudine pretreatment followed by a combination of lamivudine and IFN-alpha can induce complete viral control in HBV immunotolerant children, hitherto considered poor responders.

Comparison of Two Different Regimens of Combined Interferon-α2A and Lamivudine Therapy in Children with Chronic Hepatitis B Infection

Aim

To evaluate the efficacy of two regimens of combined interferon-α2a (IFN-α2a) and lamivudine (3TC) therapy in childhood chronic hepatitis B.

Methods

A total of 177 patients received IFN-α2a, 9 million units (MU)/m2 for 6 months. In group I (112 patients, 8.7±3.5 years), 3TC (4 mg/kg/day, max 100 mg) was started simultaneously with IFN-α2a, in group II (65 patients, 9.6±3.8 years) 3TC was started 2 months prior to IFN-α2a. 3TC was continued for 6 months after antiHBe seroconversion or stopped at 24 months in non-responders.

Results

Baseline alanine aminotransferase (ALT) was 134.2 ±34.1 and 147.0 ±45.3; histological activity index (HAI) was 7.4 ±2.7 and 7.1 ±2.3; and HBV DNA levels were above 2,000 pg/ml in 76% and 66% of patients in groups I and II, respectively ( P>0.005). Complete response was 55.3% and 27.6% in groups I and II, respectively ( P<0.01). AntiHBe seroconversion was higher and earlier, and HBV DNA clearance was earlier in group I ( P<0.05). HBsAg clearance was 12.5% and 4.6% and antiHBs seroconversion was 9.8% and 6.2% in groups I and II, respectively ( P>0.05). Breakthrough occurred in 17.9% and 24.6%; breakthrough times were 15.9 ±4.6 and 14.1 ±5.1 months; and relapse rates were 6.8% and none in groups I and II, respectively ( P>0.05, P>0.05, P>0.05). Responders had higher HAI (HAI>6) and higher pre-treatment ALT than non-responders.

Conclusion

Simultaneous 3TC+IFN-α2a yields a higher response and earlier antiHBe seroconversion and viral clearance than consecutive combined therapy. Relapse rate is low. Predictors of response are high basal ALT and high HAI scores. 3TC can be administered for 24 months without any side effect and breakthrough rate is comparable with previous studies.

Long-term follow-up of hepatitis B carrier children treated with interferon and prednisolone

The long-term outcome of treatment with Interferon Alpha 2B with and without Prednisolone priming in children infected perinatally with hepatitis B was reviewed. The group studied included 48 children (aged 2-16 years), who were HBe antigen and hepatitis B DNA positive between 1991 and 1993. Twenty children were randomized to a therapeutic trial at that time, and received Prednisolone in reducing doses for 6 weeks and Interferon for 16 weeks while 22 children were monitored without treatment for 12 months. Fourteen of the untreated group and 6 additional children later received treatment with Interferon alone (n = 20). Eight children for whom treatment was declined were followed long term. Median follow-up was 7.5 years (range 1.5-10.6). There was no significant effect of Interferon therapy on seroconversion with or without Prednisolone at 12 months post-treatment compared to untreated children. On longer term follow-up, the 5-year HBeAg to anti-HBe seroconversion percentages, estimated from Kaplan-Meier curves, were 54% for Prednisolone plus Interferon, 22% for Interferon alone, and 12% for untreated children. The median time to seroconversion was 3.9 years (range 0.4-8.2) and was shortest in those treated with Prednisolone plus Interferon. Children who had elevated hepatic transaminase enzymes prior to treatment or during Prednisolone priming had a better response. In contrast to many European studies, no child cleared HBsAg and produced anti-HBs. Treatment with Prednisolone priming and Interferon, improved both the time and rate of seroconversion compared to no treatment or Interferon alone, suggesting that this combination of drugs might have an immunomodulatory effect.

Three-phase sequential combined treatment with lamivudine and interferon in young patients with chronic hepatitis B

Alpha-interferon (IFN) or lamivudine monotherapy are ineffective in treating chronic HBeAg positive patients with high viral load and low alanine aminotransferase (ALT) levels. We investigated whether priming lamivudine treatment might enhance the antiviral and immunostimulant action of lamivudine/IFN combination in young tolerant patients. Eleven chronic HBeAg positive patients received: 100 mg/day lamivudine for 3 months followed by IFN 5 MU/m2/tiw with lamivudine 100 mg/day for 6 months and then lamivudine alone 100 mg/day for 9 months. Quantitative hepatitis B virus (HBV)-DNA was evaluated during treatment and core-promoter, precore and polymerase HBV mutants were detected by direct sequencing at the end of therapy. Serum HBV-DNA levels dropped during lamivudine monotherapy and in combination with IFN. After IFN withdrawal, viraemia transiently increased to high levels in five of 11 (45%) patients who showed rt M204V/I lamivudine mutant resistant. Two patients cleared HBeAg without anti-HBe seroconversion. One patient presented core-promoter (A1762T/G1764A) and precore stop codon mutations. Hence, three-phase sequential combined lamivudine/IFN treatment reduced HBV-DNA serum level, but did not lead to HBeAg and HBV-DNA clearance in these highly viraemic, normal ALT patients. Lamivudine/IFN combination did not prevent the emergence of YMDD lamivudine resistance. New schedules of antiviral treatments must be evaluated in this population at risk of disease progression.

Tolerance of interferon-alpha therapy in children with chronic hepatitis B

OBJECTIVE

To assess the side-effects of interferon-alpha (IFN-alpha) therapy in children with chronic hepatitis B.

METHODS

This prospective study was performed on one hundred children by interviewing the patients and their parents; clinical examinations and laboratory investigations were performed during and after therapy.

RESULTS

The most frequent side-effects of IFN-alpha therapy were fever, flu-like symptoms, and headaches. Lowering of the mean haemoglobin level, leukocyte and platelet count was significant, but transient during INF-alpha treatment. No increase in autoantibody titres or significant alterations in thyroid function was observed. Twelve months after treatment, hepatitis Be antigen (HBeAg) elimination and alanine aminotransferase (ALT) normalization was achieved in 46% of the children; HBeAg and hepatatis B surface antigen (HBsAg) elimination, together with ALT normalization, was achieved in 14% of the cases.

CONCLUSION

The side-effects of the IFN-alpha therapy in children such as fever, flu-like symptoms and bone marrow suppression are common, but transient and mild.

Short- and long-term effects of treatment of chronic hepatitis B and delta virus by IFN

Chronic hepatitis B virus (HBV) infection is a common infectious disease in the world. Two percent of the patients with chronic HBV infection will develop cirrhosis each year, and will die prematurely from cirrhosis or hepatocellular carcinoma. So far interferon alfa and lamivudine are the only effective drugs. Interferon alfa can be used at the dosage of 9-10 million units thrice a week for 4-6 months either intramuscularly or subcutaneously for standard treatment. Interferon provides sustained response in 1/3 of the patients when HBe Ag is (+). Response rate to interferon therapy in HBe Ag(-) patients was similar to that reported in HBe Ag(+) ones. However the responses were not sustained in many patients, serum HBV-DNA reappear in most after stopping the treatment. Extension of therapy to 1 year may be needed in patients who are unresponsive to therapy and having HBV-DNA levels <10 pg/ml and ALT >100 IU. Establishment of unresponsiveness in early phases of the therapy is important and careful follow up of serum HBe Ag may be helpful. Interferon alfa treatment of chronic HDV infection may result in temporary normalization of ALT values. Disappearance of HBV-DNA and HBs Ag from the serum upon completion of therapy dictates sustained response in chronic HDV infection. The long term effect of interferon with respect to virological and histopathological responses is poor in HDV infection and longer periods of therapy in higher doses may be beneficial.

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.

Lamivudine treatment for chronic hepatitis B infection in children unresponsive to interferon

BACKGROUND/AIMS

Lamivudine is a potent inhibitor of hepatitis B virus (HBV) replication. This prospective open study reports the results of lamivudine treatment in children with chronic hepatitis B infection who did not respond to previous interferon treatment.

PATIENTS AND METHODS

Lamivudine, 3 mg/kg/day (maximum, 100 mg/day), was given for 52 weeks to 20 children and adolescents, ages 8.5 to 19 years, with chronic hepatitis B infection who had been treated with interferon 2 to 5 years earlier. We evaluated virologic and biochemical responses, the occurrence of YMDD mutants and adverse effects.

RESULTS

All children were HBV DNA+, hepatitis B e antigen (HBeAg) /anti-hepatitis B e antibody- at start of treatment. At the end of 1 year, HBV DNA declined by 95% in all patients, and 8 of 18 (44%) had sustained undetectable HBV DNA by hybridization assay. Median pretreatment alanine aminotransferase (ALT) x1.5 upper limit of normal decreased to ALT x0.9 upper limit of normal after 1 year. One child became HBeAg-negative. YMDD mutants were detected in 11 of 17 (65%) children after 1 year of lamivudine treatment. Among children with YMDD mutant variants, 54% maintained normal ALT values and 45% had undetectable HBV DNA by hybridization assay. No adverse effects were observed.

CONCLUSIONS

Children with chronic hepatitis B infection treated with lamivudine after failure of interferon therapy had decreased HBV replication and improved ALT values. However, lamivudine treatment resulted in an exceptionally high rate of lamivudine-resistant mutants and low HBeAg seroconversion rate.

Hepatitis B and C infection in children undergoing chemotherapy or bone marrow transplantation

Despite preventive measures, patients who have cancer or who undergo bone marrow transplantation remain at higher risk of viral infection since they often receive multiple blood products. This category of patients also includes subjects from countries that are highly endemic for hepatitis B virus and hepatitis C virus infection and who travel to developed countries for specialized treatment. This review discusses the current opinions concerning the diagnostic, clinical, and therapeutic aspects of hepatitis B and C virus infection in different groups of patients: children with chronic infection before chemotherapy, children infected during chemotherapy or bone marrow transplantation, and patients with chronic infection after the end of treatment.

Serological and molecular response on combined antiviral treatment in children with chronic hepatitis B after pediatric malignancy

BACKGROUND

Chronic hepatitis B is a serious long-term problem for children surviving malignancy. The annual rate of spontaneous clearance of hepatitis B e antigen (HBeAg) is only 3% in these patients, and the response to monotherapy with interferon (IFN)-alpha is also low.

OBJECTIVE

To monitor the serological and molecular response on combined antiviral treatment in children with chronic hepatitis B after pediatric malignancy.

STUDY DESIGN

Twelve patients with a history of childhood malignancy and chronic hepatitis B were treated with prednisone for 4 weeks (0.6 mg/kg body weight per day orally for 3 weeks followed by 0.3 mg/kg body weight per day for 1 week) followed by IFN-alpha-2a (5 megaunits/m(2) body surface area, three times a week, subcutaneously) at least for 1 year. After 1 year of IFN-alpha monotherapy, treatment was discontinued in patients with HBeAg seroconversion as well as patients without HBeAg seroconversion and a decrease of serum hepatitis B virus (HBV) DNA level less than 0.5 logs of the basal level. Patients who had a decrease of the serum HBV DNA of more than 0.5 logs of the basal level underwent treatment continuation with IFN-alpha combined with famciclovir (FAM) (20 mg/kg body weight per day orally) for another year.

RESULTS

After 1 year of IFN-alpha monotherapy, a decrease of the serum HBV DNA level to less than 0.5 logs was found in eight of 12 patients. Two of them additionally developed HBeAg seroconversion after 3 and 12 months. The remaining six patients received antiviral treatment with IFN-alpha combined with FAM for another year. Two of them showed HBeAg seroconversion after 21 and 24 months from study entry. HBeAg seroconversion was only observed in patients who had a decrease of serum HBV DNA to levels below 1 x 10(6) copies/ml. Treatment-induced toxicity was moderate and reversible in all patients.

CONCLUSION

Combination treatment of chronic hepatitis B with prednisone, IFN-alpha, and FAM seems to be a safe and effective treatment option for children surviving pediatric malignancy.

Drug treatment of pediatric chronic hepatitis B

Children with chronic hepatitis B are at risk of developing long-term complications such as cirrhosis and hepatocarcinoma. It is estimated that half to two-thirds of affected children will clear the hepatitis B e antigen (HBeAg) naturally before reaching adulthood. As in adults, treatments in children accelerate the virological response (DNA negativity and HBeAg loss, with anti-HBe seroconversion), which is associated with normalization of transaminase levels. Treatments also favor subsequent loss of hepatitis B surface antigen (HbsAg), the ultimate goal for minimizing long-term consequences. Interferon-alpha was the first approved treatment for pediatric chronic hepatitis B, and was shown to promote DNA negativity and HBeAg loss in 26% of treated patients (6 MU/m(2) body surface area for 6 months) at 1 year and 33% at 18 months (versus 11% in controls). 10% of treated patients also lost HBsAg. Adverse effects mainly included fever, flu-like symptoms and growth impairment during the treatment phase. Nucleotide analogs have now emerged as promising alternatives for the treatment of chronic hepatitis B. Lamivudine dose-ranging studies showed a higher clearance in children, and the optimal dosage was established to be 3 mg/kg once daily in children up to 12 years of age. Efficacy trials showed complete virological response (HBeAg loss and DNA negativity) in 23% of all treated patients after 1 year, and in 34% of patients with initial transaminase levels >2 x the upper limit of normal. Lamivudine resistance due to mutant/variant viruses is observed in 19% of children after 1 year, a figure that may increase by an average of 20% per year. Other nucleotide analogs, such as adefovir, will soon be tested in children, and have shown promising results in adults without so far demonstrating viral resistance. Finally, therapeutic vaccines aiming to induce a cellular immune response towards hepatitis B antigens are being tested in adults, but no clinical benefit has so far been established.

Clinical trial of lamivudine in children with chronic hepatitis B

BACKGROUND

Lamivudine therapy is effective for chronic hepatitis B infection in adults. We evaluated the efficacy and tolerability of lamivudine as a treatment for chronic infection with hepatitis B virus (HBV) in children.

METHODS

Children with chronic hepatitis B were randomly assigned in a 2:1 ratio to receive either oral lamivudine (3 mg per kilogram of body weight; maximum, 100 mg) or placebo once daily for 52 weeks. The primary end point was virologic response (defined by the absence of serum hepatitis B e antigen and serum HBV DNA) at week 52 of treatment.

RESULTS

Of the 403 children screened, 191 were randomly assigned to receive lamivudine and 97 to receive placebo. The rate of virologic response at week 52 was higher among children who received lamivudine than among those who received placebo (23 percent vs. 13 percent, P=0.04). Lamivudine therapy was well tolerated and was also associated with higher rates of seroconversion from hepatitis B e antigen to hepatitis B e antibody, normalization of alanine aminotransferase levels, and suppression of HBV DNA.

CONCLUSIONS

In children with chronic hepatitis B, 52 weeks of treatment with lamivudine was associated with a significantly higher rate of virologic response than was placebo.

Management of chronic hepatitis B and C virus infections

Hepatitis B and C virus (HBV and HCV) infections present an important health problem causing significant morbidity and mortality on a worldwide scale. The younger the subjects infected, the higher the risk predisposing to progression towards chronic infection. Treatment of chronic HBV and HCV infections is aimed at reducing hepatic inflammation and thus improving the symptoms, decreasing the likelihood of long-term sequelae such as hepatocellular carcinoma, and increasing the survival rate. Interferon accelerates the spontaneous course of chronic HBV infection in children with greater disease activity and lower levels of replication. There is limited information on the use of lamivudine and its long-term benefit in children with chronic HBV infection. The response of combination therapy with IFN and ribavirin in children with chronic HCV infection is still under investigation. The long-term clinical and virological effects of various drugs used in chronic HBV and HCV infections on children remain to be evaluated.

Antiviral therapy: respiratory infections, chronic hepatitis

This review focuses on the activity, clinical pharmacology, and clinical indications of antiviral agents used in the management of influenza, respiratory syncytial virus infections, and chronic hepatitis B and C. Two neuraminidase inhibitors, a new class of antiviral agents, were recently approved for the treatment of influenza A and B in children.

Prolonged interferon alpha treatment in children with chronic hepatitis B

Interferon alpha has been used widely to treat hepatitis B virus infection in children. However, the overall initial response rates have been < 50% and several strategies have been attempted to improve this. The aim of this study was to evaluate the safety and efficacy of prolonged interferon alpha treatment in children who did not respond to a previous course of interferon alpha treatment. Twenty-seven children with chronic hepatitis B who had not responded to a 6-month course of interferon alpha 2a (5 MU/m2 body surface) thrice weekly subcutaneously continued to receive interferon alpha at the same dosage for another 6 months without a rest phase. The children were followed for 6 months after completing 12 months of therapy. All of them had HBsAg, HBV-DNA and HBeAg tested on completion of the first course. Six of the 27 (22.2%) cleared both HBV-DNA and HBeAg after completion of therapy and all six had a sustained response. Pre-treatment predictive factors were not significantly associated with treatment response. No adverse effect of interferon was seen during follow-up. We conclude that prolonged interferon treatment is well tolerated and leads to additional benefit.

Impact of chronic hepatitis B and interferon-alpha therapy on growth of children

Interferon-alpha (IFN) has been approved as treatment for children with chronic hepatitis B (CHB). The aims of this study were to assess the impact on children's growth of the disease itself and of IFN treatment. The growth of 142 children with CHB (70 IFN-treated, 72 untreated) was monitored for a minimum of one year. Regression analysis models were used to determine which of the variables most affected children's growth. After adjusting for racial differences, the population of 142 children with CHB had a mean baseline height for age percentile of 39 and a mean baseline weight for age percentile of 38, which were significantly different (P < 0.0001) from the 50th percentiles of their respective reference populations. The height for age Z score of untreated children was inversely correlated with serum hepatitis B virus DNA and aspartate aminotransferase levels, and the weight for age Z score was inversely correlated with serum hepatitis B virus DNA levels. While undergoing IFN therapy, children displayed a "U-shaped" growth pattern, such that height for age and weight for age Z scores at 3 or 6 months were lower than scores at baseline or 12 months. In this study the average child with CHB showed compromised growth even in the absence of IFN therapy. During IFN therapy, children's growth was temporarily disrupted.