Treatment with interferon of chronic hepatitis B associated with antibody to hepatitis B e antigen

Long-term results of interferon alpha monotherapy in patients with HBeAg-negative chronic hepatitis B

We sought to evaluate the long-term results of interferon-alpha (IFN-alpha) therapy in patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B. Eighty HBeAg-negative naive patients (62 men; mean age, 39.9 years) who received IFN-alpha for 6 months were studied. Alanine aminotransferase normalization with undetectable HBV-DNA by molecular hybridization was accepted as response. All patients but 1 were precirrhotic stage. At the end of treatment, 44 (55%) patients responded, and they were followed for a mean of 59.5 months (range, 18-132). Twenty-seven patients (61.4%) showed recurrence (63% in first year). Responses at 6 months and at the end of the follow-up period 42.5% and 30% (including 7 patients without end treatment response), respectively. Recurrence of HBV replication was not detected after the 2-years follow-up period. Histologic improvement was observed in 83.3% patients with end-of-follow-up response. HBsAg became negative in 4 patients (5%). On multivariate analysis, younger age (P = .04) and lower GGT level (P = .037) were independent factors for prediction of end-of-follow-up response. Nearly half of the patients with HBeAg-negative chronic hepatitis B responds to IFN-alpha at the end of therapy. Despite the high recurrence rates, response continues in about one third of patients after a mean of 59.5 months.

The "return" of hepatitis B

There has been a significant advance in the treatment of chronic Hepatitis B virus (HBV) infection and the following drugs were approved for therapy: Conventional interferon (IFN), pegylated interferon alfa-2a (PEG IFN alpha2a), lamivudine, adefovir and entecavir. Compared to nucleoside analogues IFN induces higher rates of sustained remission and HBsAg loss. Conventional IFN in lower doses (1, 5-3 MIU) tiw for 4-6 mo has similar efficacy in comparison to "standard IFN therapy". Longer IFN treatment is a significant factor for long-term remission in HBeAg-negative CHB, but the higher actual IFN dose is not such a factor. PEG IFN is superior to conventional IFN. There is no significant difference between PEG IFN alpha2a at doses 90 mcg/wk and 180 mcg/wk in HBeAg-positive patients. These results provide a rational for further clinical trials with lower doses PEG IFN alpha2a given in prolonged course as maintenance or intermittent treatment. Serious new problems arose after the introduction of nucleoside/nucleotide analogues in clinical practice. The most important ones are drug-resistance and the high rates of relapse after treatment discontinuation. Therapy should only be recommended if the expected benefit exceeds significantly the abstain from treatment. The choice of therapy should take into account the patient's age, co-morbidity, severity of liver disease and the risk of drug-resistance. New antivirals significantly suppress HBV-replication, but have no effect on cccDNA in hepatocytes, and after the treatment discontinuation viral relapses occurs. At the present level of knowledge it is impossible "to eradicate the virus" The realistic treatment goal is to achieve durable response by clearance of HBeAg, sustained decrease of serum HBV DNA levels, normalization of ALT, improvement of liver histology and stopping of liver fibrogenesis. The competition between IFN based therapy and nucleoside or nucleotide analogues still remains. IFN can cure the liver disease while nucleotide analogues only suppress the viral replication during therapy and can reduce the liver fibrosis. Treatment should be prolonged for 24-mo or longer by using maintenance or intermittent treatment course with the lowest effective IFN and PEG IFN doses. Nucleoside/nucleotide analogues are a promising treatment option, but additional data for treatment duration and long-term post-treatment outcome are necessary.

Adefovir dipivoxil for the treatment of hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND

Adefovir dipivoxil, a nucleotide analogue, demonstrated clinically significant antiviral activity in patients with chronic hepatitis B in phase 1 and 2 clinical trials.

METHODS

We randomly assigned 185 patients with chronic hepatitis B who were negative for hepatitis B e antigen (HBeAg) to receive either 10 mg of adefovir dipivoxil or placebo once daily for 48 weeks in a 2:1 ratio and a double-blind manner. The primary end point was histologic improvement.

RESULTS

At week 48, 64 percent of patients who had base-line liver-biopsy specimens available in the adefovir dipivoxil group had improvement in histologic liver abnormalities (77 of 121), as compared with 33 percent of patients in the placebo group (19 of 57, P<0.001). Serum hepatitis B virus (HBV) DNA levels were reduced to fewer than 400 copies per milliliter in 51 percent of patients in the adefovir dipivoxil group (63 of 123) and in 0 percent of those in the placebo group (0 of 61, P<0.001). The median decrease in log-transformed HBV DNA levels was greater with adefovir dipivoxil treatment than with placebo (3.91 vs. 1.35 log copies per milliliter, P<0.001). Alanine aminotransferase levels had normalized at week 48 in 72 percent of patients receiving adefovir dipivoxil (84 of 116), as compared with 29 percent of those receiving placebo (17 of 59, P<0.001). No HBV polymerase mutations associated with resistance to adefovir were identified. The safety profile of adefovir dipivoxil was similar to that of placebo.

CONCLUSIONS

In patients with HBeAg-negative chronic hepatitis B, 48 weeks of adefovir dipivoxil treatment resulted in significant histologic, virologic, and biochemical improvement, with an adverse-event profile similar to that of placebo. There was no evidence of the emergence of adefovir-resistant HBV polymerase mutations.

Molecular, immunological and clinical properties of mutated hepatitis B viruses

Hepatitis B virus (HBV) is at the origin of severe liver diseases like chronic active hepatitis, liver cirrhosis and hepatocellular carcinoma. There are some groups of patients with high risk of generation of HBV mutants: infected infants, immunosuppressed individuals (including hemodialysis patients), patients treated with interferon and lamivudine for chronic HBV infection. These groups are the target for molecular investigations reviewed in this paper. The emergence of lamivudine- or other antiviral-resistant variants, rises concern regarding long term use of these drugs. Infection or immunization with one HBV subtype confers immunity to all subtypes. However, reinfection or reactivation of latent HBV infection with HBV mutants have been reported in patients undergoing transplant and those infected with HIV. Mutations of the viral genome which are not replicative incompetent can be selected in further course of infection or under prolonged antiviral treatment and might maintain the liver disease. Four open reading frames (ORF) which are called S-gene, C-gene, X-gene and P-gene were identified within the HBV genome. Mutations may affect each of the ORFs. Mutated S-genes were described to be responsible for HBV-infections in successfully vaccinated persons, mutated C-genes were found to provoke severe chronic liver diseases, mutated X-genes could cause serious medical problems in blood donors by escaping the conventional test systems and mutated P-genes were considered to be the reason for chemotherapeutic drug resistance. This paper reviews molecular, immunological and clinical aspects of the HBV mutants.

Interferon monotherapy in chronic hepatitis B

Interferon-alpha (IFN-alpha) has been the only approved agent for the treatment of chronic hepatitis B in most countries, but this is rapidly changing. It is expensive, associated with frequent and unpleasant side effects, has limited efficacy and is ineffective in subjects with no/mild liver necro-inflammation. Loss of HBsAg and viral replication markers occur 6% and 20%, more often in IFN-treated subjects than controls. The most important factors that will predict favourable response to IFN-alpha therapy are elevated ALT and low serum HBV DNA levels. Chinese patients and children with active liver have similar response rates as Caucasian adults with equivalent ALT levels. Patients with HBeAg negative disease fare less well. Long-term follow up has shown that most IFN responders maintained their response although very few people have complete eradication of HBV.

Core variability does not affect response to interferon alpha in HBeAg negative chronic hepatitis B

BACKGROUND/AIMS

The pre-core stop codon variant (A 1896) of hepatitis B virus (HBV) has been associated with chronic active liver disease with acute exacerbations and a high relapse rate after an initial response to alpha-interferon (IFN-alpha) therapy. Poor sustained response has been correlated with a high prevalence of mutations in the core region, potentially enabling escape from the immune system. The aim of this study was to analyse the predictive factors of response to IFN-alpha in such patients.

METHODS

We studied the baseline clinical, biochemical, histological, serological and virological parameters in 30 hepatitis B s antigen positive (HBsAg-positive)/hepatitis B e antigen negative (HBeAg-negative) Greek patients with chronic liver disease. The patients were selected from a cohort who received IFN-alpha for 24 weeks. These were divided into three groups of ten sequential patients: those with no response to IFN-alpha treatment, those who relapsed after an initial response, and those with a sustained response. Serum HBV DNA was measured by a liquid hybridisation method, and the anti-HBc IgM was quantitated by the IMx analyser. The amino-acid sequence of core protein residues 40-89, a region where a clustering of mutations has been detected previously in severe hepatitis, was compared with a sequence from an HBeAg positive patient with chronic liver disease.

RESULTS

Multiple logistic regression analysis showed that the initial response to IFN-alpha could be predicted by pre-treatment absence of HBcAg staining in the liver and high ALT values, but no parameter could predict sustained response. The pre-treatment extent and pattern of aminoacid substitutions in the core region sequenced was similar in all groups studied and was not associated with IFN-alpha response.

CONCLUSIONS

In HBsAg-positive/HBeAg-negative patients with chronic liver disease, response to IFN-alpha therapy was not correlated with genomic variability of the core region. Other parameters such as pre-treatment HBcAg positivity in the liver and alanine aminotransferase values indicative of disease activity before treatment were associated with initial IFN-alpha response.

Low-dose recombinant interferon therapy in anti-HBe-positive chronic hepatitis B in Asian Indians

Approximately 15% of Indian patients with hepatitis B virus (HBV)-related chronic liver disease (CLD) have infection with precore mutant forms. These patients are likely to have an aggressive course. There are equivocal reports of success with interferon therapy of mutant infection in the West. This therapy has not been evaluated in precore mutant-related CLD in Asian Indians. Eighteen patients (mean age 38.2 +/- 12 years, M:F: 17:1) with biopsy proven CLD and precore mutant HBV infection (hepatitis B surface antige (HBsAg) positive, hepatitis B e antigen (HBeAg) negative, anti-HBe positive, HBV-DNA positive) were included. Interferon alpha 2b was given at 3 mIU on alternate days for 4 months. Serology, determination of HBV-DNA (both by dot-blot hybridization and polymerase chain reaction) and liver biopsy were repeated after completion of the therapy. Response to interferon therapy was defined as loss of HBV-DNA by dot-blot hybridization. Thirteen (72.2%) patients responded to the treatment (responders). Mean alanine aminotransferase levels (83 +/- 12 vs 55 +/- 29 IU/L, P < 0.01) and the histological activity index (15 +/- 1.4 vs 12 +/- 1.3, P < 0.01) significantly decreased in the responders compared with initial values. Serum albumin levels also improved at the end of the therapy (3.5 +/- 0.4 g/dL vs 3.8 +/- 0.4 g/dL, P = 0.07). During follow up, seven of the 13 (54%) responders relapsed; cirrhotics relapsed more often than chronic hepatitis patients (P < 0.05). All 18 patients, however, continued to be HBV-DNA positive at the end of follow up. This study concluded that: 1. Interferon therapy is beneficial, albeit to a limited extent, in HBV precore mutant-related chronic liver disease in Asian Indians. 2. It is ineffective in eliminating the mutant HBV infection, which explains the high relapse rate. 3. Prolonged low-dose interferon therapy alone or in combination with newer nucleoside analogues should be evaluated in these patients.

Interferon treatment in hepatitis B surface antigen-positive hepatitis B e antibody-positive chronic hepatitis B: role of hepatitis B core antibody IgM titre in patient selection and treatment monitoring

Chronic hepatitis B infection with the hepatitis B e antigen (HBeAg)-negative variant is associated with a severe clinical course and a low response rate to interferon (IFN). In an attempt to improve the chances of sustained response to interferon we designed a pilot study, using titres of IgM antibodies to hepatitis B core antigen (HBcAb IgM) to guide treatment initiation. Eighteen adults who were HBeAg-negative with biopsy-proven chronic active hepatitis (seven with cirrhosis) entered the study. They were followed-up bimonthly with routine liver function tests, and HBcAb IgM titres were also determined. Treatment (lymphoblastoid IFN 5 million units (MU) m(-2) three times weekly for 6 months) was started when the HBcAb IgM titre was increasing. Fifteen (83.3%) patients had normal alanine aminotransferase (ALT) levels and undetectable HBV DNA at the end of treatment. HBcAb IgM decreased in all responders. We observed a relapse in four patients (three with cirrhosis), in the first year after treatment, with an increase in ALT, HBV DNA and titre of HBcAb IgM. Eleven patients (61.1%) had a sustained response and eight of these 11 patients were followed-up for more than 18 months; two responders cleared hepatitis B surface antigen (HBsAg). Hence, the rate of sustained response to IFN in HBeAb-positive patients with chronic hepatitis is improved if treatment is started when HBcAb IgM levels are increasing.

Analysis of hepatitis B virus precore variants in hepatitis B e antibody-positive patients treated with prednisone plus interferon

To assess the effects of prednisone and interferon on the distribution of hepatitis B virus (HBV) precore mutants, nine hepatitis B e antibody (HBeAb)-positive patients with HBV chronic infection were studied. Patients were treated with prednisone (30 mg day-1 for 4 weeks, followed by 20 mg day-1 for 2 weeks and by 10 mg day-1 for 1 week), followed by recombinant interferon-alpha (15 MU thrice per week) for 6 months, without a clearance period. The HBV precore region was amplified by polymerase chain reaction (PCR) and distribution of the precore mutants was determined by hybridization of PCR products. Moreover, the glucocorticoid-responsive element (GRE) was sequenced to determine whether changes in the sequence were produced at the end of prednisone treatment. During prednisone treatment, changes in alanine transaminase (ALT) were observed in only two patients, in who ALT decreased to nearly normal values. In three patients ALT normalized at the end of interferon treatment. At baseline, wild-type HBV alone was detected in one patient, while seven patients were infected by a mixture of wild-type and precore mutants, predominantly wild type. At the end of prednisone treatment, two patients were infected by only wild-type HBV. The proportion of precore mutants decreased in three cases, while no changes were observed in three. At the end of interferon treatment, the precore mutant proportion decreased in the three responders, while tending to increase or remain unchanged in the rest. No significant changes in GRE sequence were found as a result of prednisone treatment. Our results would appear to confirm the role of the immune system in the selection of precore mutants.

Nucleotide sequence analysis of precore and proximal core regions in patients with chronic hepatitis B treated with interferon

The aim of the study was to estimate the prevalence of HBeAg defective mutants among patients with chronic hepatitis B (CHB) in the United States and to study the effect of interferon-alpha (IFN-alpha) on determining the occurrence of mutations in the HBV precore and proximal core regions. Twenty CHB patients who were treated with IFN-alpha were studied. Initially, all were HBV DNA positive by dot-blot hybridization; 17/20 were HBeAg positive, and 3/20 were anti-HBe positive. The precore (87 nt) and proximal core (81 nt) regions were sequenced after PCR amplification by the dideoxy chain termination method. In pretreatment sera, 15/20 patients harbored wild-type HBV only, while in 5/20 at least one nucleotide substitution was found. Mutations that prevent HBeAg synthesis were found in three patients, all of whom had G-to-A substitution at nt 1896 and two of them were anti-HBe positive. Follow-up sera were available in 18 patients. With respect to pretreatment specimen, 15/18 patients had no changes in the sequenced regions after therapy. Sequence changes were observed in the remaining three patients: In one an HBeAg defective strain was replaced by a wild-type strain; in the second a wild-type strain was replaced by an HBeAg defective strain; and in the third two mutations changing the deduced amino acid sequence of the core protein developed in the wild-type strain. In conclusion, most of our patients (85%) were initially infected by HBV strains having no mutations that prevented HBeAg synthesis. IFN-alpha therapy infrequently resulted in the appearance of mutations in the precore and proximal core regions.

Comparison of anti-HBe-positive and HBe-antigen-positive chronic hepatitis B in France. French Multicentre Group

Two groups of patients with HBV DNA-positive chronic active hepatitis B, from 20 French hospitals, separated according to HBe status, were prospectively subjected to a comparative analysis of various epidemiological, clinical, biochemical, serologic and histologic features. There were 61 patients with anti-HBe and 215 patients with HBeAg. At diagnosis, 25 variables were compared between the two groups. Some of the patients were followed up for 1 year. Anti-HBe chronic hepatitis B occurred with a prevalence of 22.1%. In the anti-HBe-chronic hepatitis B group, the patients were older, and more often of Southern European origin; the source of infection was more frequently unknown, hepatitis B markers were more frequently observed within the family, and the estimated duration of liver disease was longer. Serum HBV DNA levels were lower in the anti-HBe-positive group. No difference was observed in ALT levels at diagnosis and during follow up in the patients studied. Cirrhosis was more frequent in the anti-HBe-positive group. There was no difference in histological activity score between the two groups. These results suggest that anti-HBe-positive, chronic active hepatitis B is not rare in France, and that the higher occurrence of cirrhosis in this group may be related to a longer duration of the disease.

The management of chronic hepatitis B

The immediate goals of hepatitis B virus (HBV) therapy are to suppress the histologic progression of the disease and diminish infectivity. Although many drugs have been used in the treatment of this condition, only interferon has proven to be consistently effective. The ideal candidate for interferon therapy is a patient who has a high baseline aminotransferase level and a low HBV DNA level. Responders to interferon therapy usually demonstrate an alanine aminotransferase (ALT) flare to at least twofold the baseline value during the second or third month of therapy, indicating that the patient has become immunologically activated. Low baseline ALT levels before treatment (i.e., < 100 U/liter) are associated with a low response rate. An improvement in response rates occurs when patients with low ALT levels are primed with a short course of prednisone. Piecemeal necrosis markedly improves within a short time after a response is achieved, although residual portal tract inflammation often is demonstrated on biopsy. The loss of HBV DNA and hepatitis B e antigen is generally maintained after interferon therapy, but relapse occurs in approximately 10% of the patients. Further studies with interferon are indicated in multiple patient groups.

Long-term response to interferon therapy in chronic hepatitis B: importance of hepatitis B virus heterogeneity

The long-term therapeutic efficacy of alpha IFN and the influence of preC variants on the type of response were evaluated in 25 patients with chronic hepatitis B, 14 HBeAg and 11 antiHBe positive patients, treated with alpha IFN and monitored for at least four years after discontinuing therapy. In both groups of patients, serum HBV-DNA became frequently undetectable by DNA dot blot during treatment, suggesting that alpha IFN has an antiviral effect both on HBeAg and antiHBe positive chronic carriers. However, long term follow up showed that the loss of viral DNA in antiHBe carriers was only transient, because all responder patients relapsed from 1 to 48 months after IFN withdrawal. In the HBeAg positive carriers, selection for preC mutants was observed at the end of follow up in 2 patients who seroconverted to antiHBe and remained viremic. Both the frequent occurrence of reactivations in antiHBe compared to HBeAg carriers, and the association of IFN therapy with preC mutant virus selection during long term post-treatment follow up observed in this study, indicate that preC variants are more resistant to IFN therapy than preC wild type HBV. Our data suggest therefore, that IFN therapy may be less frequently able to induce a permanent remission in patients infected with preC mutants.

Frequent and rapid emergence of mutated pre-C sequences in HBV from e-antigen positive carriers who seroconvert to anti-HBe during interferon treatment

Hepatitis B virus (HBV) variants which cannot express e-antigen (HBeAg) are characteristic for many viremic anti-HBe positive chronic carriers who often have particularly severe and fluctuating hepatitis. Whether such variants are selected for and are less amenable to interferon treatment is under dispute. Therefore, by DNA amplification and direct sequencing we have investigated the emergence of HBV pre-C sequence variants in nine e-antigen positive chronic carriers, all of whom seroconverted to anti-HBe or lost HBeAg during interferon treatment, and in three of whom no viral DNA was detectable after interferon treatment. In most, but not all of the patients we found newly emerging pre-C sequences in a subpopulation of the viral genomes that included silent point mutations, amino acid changes, start and stop codon and frameshift mutations. The emergence of these mutations was paralleled by a drastic decrease of viremia during treatment. The observed mutations appeared most frequently during interferon treatment. Some of the mutations appeared or disappeared late after interferon treatment concomitant with anti-HBe antibody development. The appearance or lack of mutations in the pre-C region of a subpopulation of HBV of these patients was independent of successful virus elimination. These data indicate that interferon treatment is frequently associated with the simultaneous fall in titer of viral DNA by several orders of magnitude and the emergence of novel pre-C sequences, some of them preventing HBeAg expression. However, the presumably immune-mediated selection for pre-C mutant viruses and decrease in viremia under interferon treatment appears not to be prognostic for successful or unsuccessful virus elimination.

High prevalence and heterogeneity of HBV preC mutants in anti-HBe-positive carriers with chronic liver disease in southern Italy

In this study we have investigated the prevalence and type of preC mutants in anti-HBe/HBV-DNA-positive patients with chronic hepatitis B in an endemic area. HBV-DNA from sera of 42 anti-HBe chronic HBV carriers was amplified by PCR and the preC region was directly sequenced. With one exception, all patients tested were found to be infected with viruses containing mutations in the preC region that predictably prevent precore and e antigen expression. Thirty-one patients were infected with HBV containing a stop codon; two had a mixture of wild-type and preC stop codon mutant; three had preC mutants with mutations in the translation initiation codon and two of them an additional stop codon; four had a frameshift mutation, and one had two stop codons. One patient was infected with a virus showing a mutation creating only an amino acid exchange which could not prevent HBeAg expression. The data obtained indicate a higher prevalence and heterogeneity of preC mutants in our geographical area than recognized so far in anti-HBe-positive carriers with chronic hepatitis B.