Thrice weekly lymphoblastoid interferon is effective in inhibiting hepatitis B virus replication

Alpha-interferon treatment in hepatitis B

Pegylated interferon-α (PEG-IFN-α) is a first line option in the treatment of chronic hepatitis B. Compared with nucleos(t)ide analogues (NAs), therapy with PEG-IFN-α has the advantages of finite treatment duration and higher rates of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) seroconversion, but the disadvantage of greater adverse effects. Choosing PEG-IFN-α requires careful evaluation of the likelihood of achieving a sustained off-treatment response. Sustained off-treatment response with PEG-IFN-α can be predicted by baseline factors in HBeAg positive disease. These include genotype A or B, low viral load, high alanine aminotransferase (ALT), older age and female gender. On the other hand, no pre-treatment factors have been identified that can reliably predict response in HBeAg negative disease. Using on-treatment quantitative HBsAg levels, failure of a long term response can be identified with high negative predictive value (NPV). However, no combination of on treatment parameters have been identified so far that can precisely forecast successful treatment. Up until recently, there was little evidence supporting the use of combining PEG-IFN with NAs. The addition of PEG-IFN in patients who already have viral suppression with NAs therapy appears superior to continuing NAs alone in achieving a sustained response. Also, tenofovir disoproxil fumarate (TDF) in combination with PEG-IFN has been reported to enable significantly higher HBsAg loss than with either monotherapy alone. This occurred in both HBeAg positive and negative patients across all genotypes. In spite of recent developments, rates of HBsAg loss are still only in the order of 10% and so cure remains elusive. Further research is required to identify the optimal combination or sequential therapy regimen, and the subgroups with the highest rates of response so that they can be targeted.

Hepatitis B: 50 years after the discovery of Australia antigen

It is an honour to be invited to recount the progress in our understanding and management of hepatitis B 50 years after the discovery of Australia antigen (Au Ag). During this half century, we have gone from identifying the causative agent--hepatitis B virus (HBV), understanding its biology and the disease it causes, to having vaccines that can prevent HBV infection and antiviral therapy that can suppress HBV replication and prevent progression of HBV-related liver disease. As a result of the progress, prevalence of HBV infection and morbidity and mortality from chronic HBV infection has declined.

New pharmacologic therapies in chronic hepatitis B

Approximately 350 million persons worldwide are chronically infected with hepatitis B, which can result in cirrhosis, liver failure, and hepatocellular carcinoma. Currently, 2 interferons and 5 nucleos(t)ide analogues have been approved for the treatment of chronic hepatitis B (CHB). This article discusses the mechanisms of action, pharmacokinetics, optimal dose, clinical efficacy, and side effects of medications used for the treatment of CHB.

Interferons as Therapy for Viral and Neoplastic Diseases: From Panacea to Pariah to Paragon

For more than 20 years after the excitement engendered by their discovery in 1957 as antiviral agents, there were no significant clinical uses of interferons; however, following their cloning they have been employed as effective treatment for several viral, autoimmune, and neoplastic diseases.

Chronic Hepatitis B Infection: Principles of Therapy

Chronic hepatitis B is a global health concern in many resource-limited settings due to perinatal or pediatric hepatitis B virus transmission. In the United States, pediatric infection has been virtually eliminated due to maternal screening during pregnancy and the availability of an effective vaccine. However, young adults remain an at-risk group for hepatitis B virus infection due to sexual transmission and injection drug use. The frequency of progression from acute hepatitis B virus infection to chronic hepatitis B infection depends on multiple factors, including host immune function and age at time of hepatitis B virus infection. Fortunately, there are 7 currently approved therapies for chronic hepatitis B infection, and several emerging therapies that show promise. Despite the availability of these agents, many clinical questions still surround chronic hepatitis B therapy including when to start therapy, which agent is ideal for first and second line therapy, the appropriate duration of therapy, and the role of combination antiviral therapy. This review focuses on agents available for chronic hepatitis B management, including pharmacology, safety and efficacy data, monitoring parameters, and the role for each in chronic hepatitis B therapy in adult patients.

Interferon lowers tumor recurrence rate after surgical resection or ablation of hepatocellular carcinoma: a pilot study of patients with hepatitis B virus-related cirrhosis

BACKGROUND

Hepatocellular carcinoma (HCC) caused by hepatitis B virus (HBV) often recurs after surgical or medical treatment.

METHODS

Eighty consecutive patients with HBV-positive cirrhosis and HCC who underwent potentially curative ablation for HCC were analyzed. Eleven patients received long-term interferon (IFN) therapy. HBV DNA was quantified at the time of HCC treatment. A DNA value of <6.0 log copies/ml was considered low.

RESULTS

Initial DNA was low in 39 and high in 41 patients. HCC recurrence rates in the low DNA group and high DNA group were 46.9% and 82.6% at the fifth year, and 73.5% and 91.3% at the tenth year, respectively (P = 0.0103). Similarly, recurrence rates after treatment of HCC in the normal aspartate aminotransferase (AST) group (<38 IU/l, n = 42) and abnormal AST group (n = 38) were 50.6% and 84.0% at the fifth year, and 71.3% and 100% at the tenth year, respectively (P = 0.0003). Six of the 38 patients with abnormal AST, and 5 of 42 patients with normal AST, received IFN after confirmation of tumor ablation. In the subgroup of abnormal AST, tumor recurrence rates in the IFN and untreated groups were 16.7% and 37.9% at the end of the first year, 16.7% and 60.1% at the second year, and 16.7% and 83.4% at the third year, respectively (P = 0.0139). Multivariate analysis revealed that IFN significantly reduced the recurrence rate (hazard ratio = 0.21, P = 0.037) even after adjusting for background characteristics.

CONCLUSIONS

IFN was inferred to decrease tumor recurrence after treatment of HCC in patients with HBV-related cirrhosis, especially in the subgroup with high AST.

Hepatitis B virus-related hepatocellular carcinogenesis and its prevention

To elucidate the influence of serum hepatitis B virus (HBV) load on hepatocellular carcinogenesis in cirrhotic patients, HBV-DNA was sequentially measured. In a nested, case-control study using 96 patients without antiviral therapy, high HBV-DNA (> or =10(3.7) copies/ml) in the last 3 years was significantly associated with carcinogenesis (a patient group without hepatocellular carcinoma (HCC) development; 0/48 vs. a patient group with eventual HCC development; 22/48, p < 0.0001). No patient with a continuously low HBV-DNA for the last 3 years developed HCC. Persistence of high HBV-DNA concentration suggested an increased risk of carcinogenesis. In a retrospective cohort study using 57 patients with interferon therapy, HCC developed in 2 (8.0%) of the 25 patients with HBV-DNA loss, while carcinogenesis was found in 11 (34.4%) of 32 patients without HBV-DNA loss (Fisher's exact test, p = 0.026). A significant decrease or loss of serum HBV-DNA stops HCC development, and its sequential analysis could be very useful both in the prediction and early detection of small HCC.

Significance of hepatitis B virus DNA clearance and early prediction of hepatocellular carcinogenesis in patients with cirrhosis undergoing interferon therapy: long-term follow up of a pilot study

BACKGROUND AND AIM

Because the anti-carcinogenic effect and mechanism of interferon (IFN) in patients with hepatitis B virus (HBV)-related cirrhosis have not been elucidated, quantitative analysis of HBV-DNA concentration was carried out sequentially.

METHOD

Of 60 consecutive patients with cirrhosis who began IFN therapy between 1986 and 1990, 57 patients were completely observed for the appearance of hepatocellular carcinoma (HCC). All patients underwent intermittent administration of IFN for a median period of 18 months. HBV-DNA was quantified using transcription mediated amplification and hybridization protection assay. A HBV-DNA count <3.7 log-genome equivalent (LGE)/mL (equivalent to 10(3.7) or 5000 copies/mL) was considered to be a negative value.

RESULTS

Of 25 patients who had HBV-DNA loss after IFN therapy, nine lost HBV-DNA during the therapy and 16 lost HBV-DNA after cessation of the therapy. The other nine patients showed a transient loss of HBV-DNA, and the remaining 23 retained persistently positive HBV-DNA during and after therapy. Although HCC developed in two (8.0%) of the 25 patients with HBV-DNA loss, carcinogenesis was found in 11 (34.4%) of 32 patients without HBV-DNA loss (Fisher's exact test, P = 0.026). In the two exceptional patients, HCC was detected at 1.2 and 3.6 years after loss of HBV-DNA, respectively. When the HBV-DNA concentration decreased by 2 LGE/mL (decrease to 1/100) at 6 months after initiation of interferon, HBV-DNA became negative eventually in 15 (60.0%) of 25 patients.

CONCLUSION

A significant decrease or loss of serum HBV-DNA prevents development of HCC, and sequential analysis of HBV-DNA could be very useful in both the prediction and the early detection of small HCC.

Chronic hepatitis B virus infection: treatment strategies for the next millennium

Chronic hepatitis B virus (HBV) infection is a leading cause of cirrhosis and hepatocellular carcinoma worldwide. Its prevalence approaches 10% in hyperendemic areas, such as southeast Asia, China, and Africa. Although chronic HBV infection is seen less frequently in North America and Europe, an estimated 1.25 million persons in the United States are infected. In the past decade, revolutionary strides have been made toward the treatment of chronic HBV infection. Interferon-alpha was once the only available therapy but has recently been joined by the nucleoside analogues, the most extensively studied of which is lamivudine. Interferon therapy continues to have a role in the treatment of a carefully selected group of patients. Lamivudine therapy, which has less stringent selection criteria, suppresses HBV DNA in almost all treated patients: Seventeen percent to 33% experience loss of hepatitis B e antigen, and 53% to 56% have a histologic response. Extended lamivudine treatment leads to the development of a specific lamivudine-resistant virus with base-pair substitutions at the YMDD locus of the DNA polymerase. Newer nucleoside analogues and other immunomodulator therapies are being investigated. In the future, combination therapy with different classes of agents may yield improved response rates and delay the development of resistance.

Interferon decreases hepatocellular carcinogenesis in patients with cirrhosis caused by the hepatitis B virus: a pilot study

BACKGROUND

To elucidate the influence of long term interferon administration on the rate of occurrence of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV)-related cirrhosis, the authors analyzed 313 consecutive patients with cirrhosis.

METHODS

Of the 313 patients, 94 underwent long term intermittent administration of interferon for > or = 6 months, and the remaining 219 patients received no interferon or other antiviral drug.

RESULTS

Cumulative occurrence rates of HCC in the group treated with interferon and the untreated group were 4.5% and 13.3%, respectively, at the end of 3 years; 7.0% and 19.6%, respectively at the end of 5 years; and 17.0% and 30.8%, respectively, at the end of 10 years. The rate of HCC development in the treated group was significantly lower than that of the untreated group (P = 0.0124). The Cox proportional hazard model revealed that interferon treatment was an independent contributing factor in lowering the rate of carcinogenesis (odds ratio = 0.39; P = 0.031) even after correction by significant covariates in multivariate analysis. The virologic study showed that the role of interferon therapy from the viewpoint of cancer prevention was much more significant in patients with a HBV DNA concentration of > or = 10 milliequivalents.

CONCLUSIONS

Interferon therapy for patients with HBV-related cirrhosis significantly decreased the HCC rate, especially in patients with a larger amount of serum HBV DNA. If interferon is administered properly for a selected group of patients, an effective strategy of cancer prevention can be achieved, even in patients with cirrhosis.

Cytokine amplification and inhibition of immune and inflammatory responses

Cytokines are soluble mediators of intercellular communication. They contribute to a chemical signalling language that regulates development, tissue repair, haematopoiesis, inflammation and the immune response. Potent cytokine polypeptides have pleiotropic activities and functional redundancy. They act in a complex network where one cytokine can influence the production of, and response to, many other cytokines. In the past 5 years this bewildering array of 100+ effector molecules and associated cell surface receptors has been simplified by study of three-dimensional cytokine and cytokine receptor structure: elucidation of convergent intracellular signalling pathways; and molecular genetics, especially targeted gene disruption to 'knockout' production of individual cytokines in mice. It is also now clear that much of the pathophysiology of infectious disease can be explained by the induction of cytokines and the subsequent cellular response. Cytokine and cytokine antagonists have also shown therapeutic potential in a number of chronic and acute diseases.

Relation between treatment efficacy and cumulative dose of alpha interferon in chronic hepatitis B. European Concerted Action on Viral Hepatitis (Eurohep)

BACKGROUND/AIMS

Alpha interferon (IFN) is an established treatment of chronic hepatitis B. The effect has been shown to be dose related, recommended dose regimens being associated with a doubling of the spontaneous, baseline HBeAg to anti-HBe seroconversion rate. However, the efficacy of IFN treatment in relation to the dose of IFN actually received remains to be established. The aim of this study was to estimate the relative efficacy of IFN as a function of the cumulative IFN dose. In addition we determined if and when a patient returns to his baseline chance of seroconversion after stopping IFN therapy.

MATERIALS AND METHODS

Individual patient data from 10 clinical controlled trials were available for the present analysis, in all, 746 patients, of whom 491 received IFN and 255 were untreated controls. The data were analyzed performing a time-dependent Cox regression analysis of the relative efficacy of IFN using the cumulative IFN dose administered up to any given time during the observation period and the time after termination of therapy as explanatory variables.

RESULTS

In the proposed model, the chance of HBeAg disappearance for a treated patient relative to no therapy was estimated to 2.1 at a cumulative dose of 100 MU and leveled out at about 2.8 at a cumulative dose of 500 MU. The effect of IFN was shown to decay rapidly after discontinuation and after 3 months a patient could be considered to be back to his baseline chance of HBeAg disappearance. These findings show that IFN administered at a dose of 15-30 MU/week should be considered effective (relative efficacy approximately 2) already after 1-2 months of treatment.

CONCLUSIONS

The present findings do not lend any support to the concept that IFN treatment becomes less effective when a certain total dose of IFN has been administered or that the treatment effect reaches beyond 3 months after stopping IFN.

Alpha interferon treatment may prevent hepatocellular carcinoma in HCV-related liver cirrhosis

BACKGROUND/AIMS

The aims of alpha-interferon treatment for chronic viral liver infections are clearance of the virus and healing of the disease. Hepatocellular carcinoma is a complication of viral cirrhosis; but it is not yet known whether treatment of viral cirrhosis with alpha-interferon prevents this complication.

METHODS

The incidence and the risk (Cox regression analysis) of developing hepatocellular carcinoma were calculated in 347 patients with hepatic cirrhosis; 227 (34 hepatitis B virus and 193 hepatitis C virus related) were treated with alpha-interferon and 120 (28 hepatitis B virus and 92 hepatitis C virus) did not receive this treatment, in order to evaluate the efficacy of alpha-interferon in the prevention of hepatocellular carcinoma. In all patients, the cirrhosis was well compensated (Child A).

RESULTS

Over mean follow-up periods of 49 months for hepatitis B virus and 32 months for hepatitis C virus, 20/347 patients (6/62 hepatitis B virus and 14/285 hepatitis C virus) developed hepatocellular carcinoma. The risk of developing this tumor was significantly greater in males (p < 0.007) and in patients not treated with alpha-interferon (p < 0.01). The Relative Risk of developing hepatocellular carcinoma increased significantly (p < 0.0002) with each passing year. In patients with hepatic cirrhosis secondary to hepatitis B virus infections, the risk did not seem to be modified by alpha-interferon treatment, even though a greater, but not significant risk (Relative Risk = 4.9; p = 0.3) was calculated for untreated patients; in contrast, in hepatitis C virus-related cirrhosis, this risk was reduced by a factor of 4.0 (p = 0.04). The tumor developed only in non-responder patients regardless of virus type. After adjustment for confounding factors (sex, age, alcohol consumption, cigarette smoking), a statistically significant (p < 0.025) effect of interferon treatment in preventing hepatocellular carcinoma was still demonstrated when responders were matched with controls, but not when responders were compared with non-responders.

CONCLUSIONS

These results show that, in addition to its ability to halt the progression of viral-induced liver disease, alpha-interferon is also of benefit in patients with hepatitis C virus cirrhosis who respond to this treatment by lowering their risk of developing hepatocellular carcinoma.

The treatment effect of alpha interferon in chronic hepatitis B is independent of pre-treatment variables. Results based on individual patient data from 10 clinical controlled trials. European Concerted Action on Viral Hepatitis (Eurohep)

Alpha interferon induces HBeAg seroconversion in about one third of treated patients and has become an established treatment of chronic hepatitis B. A number of smaller studies have suggested that response to treatment is more likely to occur in patients with higher levels of transaminases, with recent (adult) onset, a history of acute hepatitis, low levels of HBV DNA and in heterosexual males. The aim of this European co-operative study was to estimate the effect of alpha interferon more accurately and to evaluate the influence of host pre-treatment variables on the effect of interferon. Individual data were collected from 751 patients from 10 controlled clinical trials on alpha interferon (lymphoblastoid or recombinant) treatment for chronic hepatitis B. Alpha interferon was administered to 496 patients, while 255 were untreated controls. Individual patient data were analysed by survival analysis (log rank test and Cox regression analysis), stratified by trial, with the disappearance of HBeAg as the major endpoint. The results showed that the HBeAg disappearance rate with or without interferon treatment was higher in patients with high aminotransferase levels, with a history of acute hepatitis and in male heterosexual patients disregarding HIV status. If HIV-positive patients were excluded, the effect of sexual orientation was not significant. Therapy with alpha interferon increased the a priori HBeAg disappearance rate by a factor of 1.76; the relative treatment effect of alpha interferon was independent of the tested pretreatment host variables, but dependent on the total (intended) interferon dose (low dose < or = 200 MU/m2 increased HBeAg disappearance by a factor 1.37; medium/high dose > or = 200 MU/m2 increased HBeAg disappearance by a factor 2.05). In conclusion, this meta-analysis suggests that the effect of alpha interferon is less than previously assumed and independent of pretreatment host variables tested. It confirms the higher therapeutic benefit of a total dose exceeding 200 MU/m2 and of selection of patients based on disease activity and immune reactivity. Although all patient seem to have the same relative benefit, the absolute benefit of alpha interferon treatment seems to be greatest in patients with high transaminase levels and with a history of acute hepatitis.

Liver transplantation in chronic viral B and C hepatitis

Liver transplantation is a valid treatment in chronic viral B and C hepatitis. But disease recurrence is very frequent in HBV hepatitis after the procedure, and its prevention and treatment are unresolved problems. Hepatitis C recurrence in the graft seems also to be common, and further studies of its pathobiology are needed.

Histological behaviour of chronic hepatitis in patients treated with alpha interferon

To evaluate the histological effects of alpha Interferon (IFN) therapy, serial liver biopsy specimens from 30 patients with chronic hepatitis were studied. The biopsies were examined using a scoring system. After 12 mths of IFN therapy responders were 8 out of 11 HBV infected patients, 10 out of 12 HCV infected patients and only 1 out of 7 patients with cryptogenetic hepatitis. As spontaneous improvement of hepatic changes is infrequent, our data indicate that in terms of histological patterns interferon therapy is effective in chronic viral hepatitis.

Effects of interferon-alpha therapy on serum and liver HBV DNA in patients with chronic hepatitis B

The aim of this study was to evaluate the effect of interferon-alpha therapy on serum and liver HBV DNA in 20 patients with chronic hepatitis B and to correlate the presence or absence of HBV DNA with the clinical response. There were 11 responders and all lost HBV DNA from the serum. Ten of the 11 were followed for 36 months following IFN treatment and remained well with absence of HBeAg and HBV DNA from the serum and with normal ALT. Five also lost HBsAg. HBV DNA became undetectable in the liver of nine of 10 of these patients in whom liver tissue was available for study. HBV DNA persisted in the liver of seven of nine nonresponders and was not detected in two in spite of the presence of HBV DNA and HBeAg in the serum of these two patients. We conclude that IFN may induce long remissions in patients with chronic hepatitis B with loss of HBV DNA from the serum and that occasionally HBV DNA may persist in the liver of such patients.

Glycyrrhizin withdrawal followed by human lymphoblastoid interferon in the treatment of chronic hepatitis B

Seventeen patients with chronic hepatitis B were treated with a 4-week administration of glycyrrhizin followed by a 4-week treatment with human lymphoblastoid interferon, then followed for 6 months after the end of treatment. All were positive for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B virus-associated DNA polymerase (DNA-p) for at least 6 months before entry. All patients were Japanese and none of them were homosexuals. Eleven patients lost DNA-p activity and 10 of them lost HBeAg. Three of these 10 patients had antibody to HBeAg. In 10 patients who became HBeAg-negative, alanine aminotransferase levels after glycyrrhizin administration were higher and initial DNA-p activities relatively lower than the levels found in seven patients who remained HBeAg-positive. The immunomodulator provided by a short course of glycyrrhizin before administration of human lymphoblastoid interferon may be an effective treatment for patients with chronic hepatitis B.

Treatment of hepatitis B virus infection with interferon. Factors predicting response to interferon

Several randomised controlled trials have been undertaken to evaluate the efficacy of alpha-interferon in the therapy of chronic hepatitis B. In patients with HBe antigen-positive disease acquired in adult life the response rates vary from 25-50%. In those infected at birth, response rates are lower. Twenty-one pretreatment variables were assessed for their significance in response prediction using data from 114 patients given alpha-interferon for chronic hepatitis B virus infection. In those patients who had received a minimum of 90 million units per m2 total dose over 12 weeks, a negative anti-human immunodeficiency virus antibody status (p less than 0.001), chronic active hepatitis on liver biopsy (p less than 0.005), high AST level (p less than 0.001), low hepatitis B virus DNA level (p less than 0.001) and a history of acute hepatitis (p less than 0.005) were all associated with an increased likelihood of response on univariate analysis. On stepwise logistic regression analysis, hepatitis B virus DNA, AST and a history of acute hepatitis predicted response independently (p less than 0.05). The most reliable combination of predictive factors was a negative anti-human immunodeficiency virus antibody status, with either a positive history of acute icteric hepatitis and AST greater than 45 IU per liter or no history of acute icteric hepatitis and AST greater than 85 IU per liter, which predicted response in 77% with a specificity of 79% (p less than 0.001). The loss of HBsAg in addition to HBeAg and hepatitis B virus DNA was more likely to occur in patients with chronic infection of less than 2 years duration (p less than 0.001).

Experience with interferon in chronic hepatitis B in Egypt

Forty patients with compensated chronic active hepatitis B and elevated aminotransferases who were HBsAg and HBeAg positive were randomised to a treatment group receiving recombinant interferon alpha-2b (rIFN alpha-2b) or no treatment as a control group. The treated patients were divided into 2 groups, group I (n = 12) received IFN in a dose of 5 MU/m2 thrice weekly by subcutaneous injection for 16 weeks, and group II (n = 8) received the same dose daily for the same duration. Patients were followed up for 12 months after therapy ended. Initiation of IFN therapy was associated with an increase in aminotransferases, reaching a peak at 4-6 weeks in most patients, associated with clearance of HBeAg. At end of follow-up, 81% of the treated patients had cleared HBeAg vs 33% of the control group (p less than 0.01). Changes in other HBV markers were more frequent in the treated patients, though insignificantly. The type of response to therapy was significantly related to the duration of illness, being shortest in those who cleared HBsAg. A complete response to therapy with loss of HBsAg was associated with marked reduction in biochemical and histological activity. A partial response with clearance of HBeAg was associated with moderate improvement in biochemical parameters and ongoing activity in liver histology; whereas persistence of HBeAg was associated with elevated aminotransferases and histological deterioration in most cases. The rise in aminotransferases during seroconversion was associated with hepatic decompensation and death on 3 occasions: one during spontaneous seroconversion, and the other 2 during IFN therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of hepatitis B virus DNA polymerase by 3'-fluorothymidine triphosphate and other modified nucleoside triphosphate analogs

The 3'-fluoromodified nucleotide analogs 3'-fluorothymidine triphosphate (FdTTP), 2',3'-dideoxy-3'-fluoro-5-chlorouridine triphosphate (F-5CldUTP), 2',3'-dideoxy-3'-fluoro-5-ethyluridine triphosphate (F-5EtdUTP), 2',3'-dideoxy-3'-fluorouridine triphosphate (FdUTP), and 2',3'-dideoxy-3'-fluoro-5-fluorouridine triphosphate (F-5FdUTP) as well as 2',3'-dideoxythymidine triphosphate (ddTTP), 2',3'-didehydro-2',3'-dideoxythymidine triphosphate (ddeTTP), 3'-chlorothymidine triphosphate (CldTTP), and 3'-rhodanothymidine triphosphate (SCNdTTP) were tested for their ability to inhibit hepatitis B virus (HBV)-associated DNA polymerase activity in vitro. The ID50 values of the most potent inhibitors were 0.15 microM for FdTTP, 0.2 microM for ddeTTP, 0.45 microM for ddTTP, and 0.8 microM for F-5CldUTP. SCNdTTP, CldTTP, and F-5EtdUTP were less efficient (ID50 = 3-5 microM), and FdUTP and F-5FdUTP were the least efficient inhibitors (ID50 = 25 microM) of the enzyme activity. Kinetic analysis revealed a competitive type of inhibition for FdTTP and ddeTTP. The Ki values were estimated to be 0.04 microM and 0.08 microM, respectively, compared with a Km value for dTTP of about 0.18 microM.

Efficacy of interferon alfa-2b with or without prednisone withdrawal in the treatment of chronic viral hepatitis B. A prospective double-blind Belgian-Dutch study

A prospective, double-blind study was carried out to assess the efficacy of interferon alfa-2b, with or without pre-treatment prednisone withdrawal, in patients with chronic hepatitis B. A total of 57 Belgian and Dutch patients were included in the study. Patients were divided into four treatment groups: Group A, prednisone withdrawal followed by interferon 5 million units per day; Groups B and C, placebo followed by interferon 5 or 1 million units, respectively; and Group D, untreated controls followed for 1 year. All treated patients received interferon for 16 weeks. Two of the 14 control patients lost hepatitis B e antigen during the year of study, and only one of 15 patients in the interferon 1 million units group. Among the 28 patients receiving 5 million units of interferon (with or without prednisone withdrawal), ten (36%) cleared hepatitis B e antigen during the study or within 6 months of the end of therapy. This was associated with a marked improvement in serum transaminase levels. When comparing Groups A and B, it was found that prednisone withdrawal therapy enhanced the response to interferon in patients with pre-treatment serum alanine aminotransferase levels below 100 IU/l, bringing the seroconversion rate up to 50%, compared to 17% on interferon alone. This effect was not seen in patients with high pre-treatment transaminase levels. All treatment responders showed a marked improvement in Knodell index score, whereas in the 15 non-responders from groups A and B, overall inflammatory activity remained the same in six, improved in five and worsened in four.(ABSTRACT TRUNCATED AT 250 WORDS)

Which patients with chronic hepatitis B virus infection will respond to alpha-interferon therapy? A statistical analysis of predictive factors

Twenty-one pretreatment variables were assessed for their significance in response prediction using data from 114 patients given alpha-interferon for chronic hepatitis B virus infection. In those patients who had received a minimum of 90 million units per m2 total dose over 12 weeks, a negative anti-human immunodeficiency virus antibody status (p less than 0.001), chronic active hepatitis on liver biopsy (p less than 0.005), high AST level (p less than 0.001), low hepatitis B virus DNA level (p less than 0.001) and a history of acute hepatitis (p less than 0.005) were all associated with an increased likelihood of response on univariate analysis. On stepwise logistic regression analysis, hepatitis B virus DNA, AST and a history of acute hepatitis predicted response independently (p less than 0.05). The most reliable combination of predictive factors was a negative anti-human immunodeficiency virus antibody status, with either a positive history of acute icteric hepatitis and AST greater than 45 IU per liter or no history of acute icteric hepatitis and AST greater than 85 IU per liter, which predicted response in 77% with a specificity of 79% (p less than 0.001). The loss of HBsAg in addition to HBeAg and hepatitis B virus DNA was more likely to occur in patients with chronic infection of less than 2 years duration (p less than 0.001).

Histological improvement after anti-viral treatment for chronic hepatitis B virus infection

Sequential liver biopsies were taken from 66 patients with chronic hepatitis B virus (HBV) infection being followed in randomised controlled trials of therapy with alpha interferons or adenine arabinoside 5'-monophosphate. In the group of 23 patients responding to treatment with the permanent loss of HBe antigen and HBV-DNA from their serum, there was a significant reduction in hepatic inflammatory activity and none developed cirrhosis. In contrast, inflammatory activity continued in the group of 24 patients that did not respond to therapy, and in the group of 19 patients who received no therapy. Two untreated controls progressed to cirrhosis. Further studies confirmed that in those clearing HBeAg and HBV-DNA from the serum, HBcAg and HBeAg were also lost from the liver. This study demonstrates that, as in natural seroconversion, successful treatment of chronic HBV infection is associated with loss of hepatic as well as serum markers of HBV replication, and is followed by a reduction in hepatic inflammation. Antiviral therapy may prevent progression to cirrhosis in some cases.

Treatment of acute and chronic viral hepatitis

Over the 12 years since the first introduction of interferon for the treatment of chronic hepatitis B, progress has apparently been slow. Nevertheless, it now appears that at least one third of chronic hepatitis virus carriers, particularly those with more severe disease, and a similar, perhaps greater, proportion of those with chronic parenteral non-A, non-B hepatitis, can be successfully treated with alpha-interferon. In the not too distant future, controlled trials of alpha-interferons in these situations will be complete and they will be a yardstick by which other future therapies can be judged. Already a number of trials are in progress to determine which agents might, in addition to interferon, augment the response rates. The situation clinically is analogous to that for tuberculosis in the 1950s and for cancer chemotherapy only a decade or so ago. The prospects of prevention of the progression to cirrhosis, and perhaps in the long term reduction in the incidence of hepatocellular carcinoma, are exciting, and with the introduction of a number of new cytokines available through recombinant technology, each with novel antiviral activities, the future prospects are exciting indeed.

Treatment of the chronic hepatitis B virus carrier state

Chronic hepatitis B is no longer untreatable. With the advent of powerful antiviral agents such as adenine arabinoside, and, more importantly, with recombinant DNA technology and advanced culture systems able to produce large quantities of interferons, the prospects for treating patients with chronic hepatitis B virus (HBV) infection have changed completely. In the U.K., carriers not infected at birth are currently being treated with an approximately 50% chance of permanently inhibiting viral replication. In some of these, viral markers appear to be completely eliminated.

A controlled study of treatment with recombinant interferon alpha in chronic hepatitis B virus infection: induction and maintenance schedules

To determine the antiviral effect of recombinant-interferon (rIFN)-alpha in hepatitis B virus (HBV) chronic infection, a controlled study was carried out. A total of 20 HBsAg chronic carriers (18 chronic active hepatitis and 2 chronic persistent hepatitis) were included. All of them had remained HBeAg, HBV-DNA and HBV-DNA polymerase (HBV-DNAp) positive at least six months before treatment. The patients were randomly assigned to two groups: control (n = 10), and treatment (n = 10). A dose of 5.5 megaunits of rIFN-alpha/m2 body surface was administered every day for 21 days (induction) and twice a week for six months thereafter (maintenance). No basal differences were observed between the two groups. No case of intolerable toxicity was observed. One treated patient died in a car crash in the second month. At the end of the first week of therapy, 7/10 (70%) of the treated patients became HBV-DNAp negative. However, in the fifth month only 2 patients remained HBV-DNAp negative and also became HBV-DNA and HBeAg negative. In contrast, no changes in viral markers among control cases were observed. In conclusion, rIFN-alpha has an antiviral effect on chronic HBV infection; however, the induction plus maintenance schedule is not useful to obtain a permanent effect.

Lymphoblastoid interferon therapy of chronic HBV infection. A comparison of 12 vs. 24 weeks of thrice weekly treatment

This study set out to examine the relative effectiveness and tolerability of 12- versus 24-week courses of thrice weekly intramuscular lymphoblastoid interferon in the treatment of hepatitis B 'e' antigen (HBeAg)-positive chronic hepatitis B virus (HBV) infection, and to identify pretreatment factors predicting the outcome of therapy. Twenty patients were randomised to each treatment group. Treatment was associated with clearance of HBeAg and HBV-DNA in 59% of the 32 male patients, whereas none of the eight women responded (48% overall response rate). This response rate in males is at least three times the recorded spontaneous seroconversion rates in this population. Most of the women (5/8) were of Oriental origin and had minimal disease, factors that may have influenced response. The longer course was poorly tolerated and was therefore no more effective: eight of 20 patients withdrew because of side-effects. Variables associated with response included high AST (aspartate transaminase), short duration of disease and previous history of acute hepatitis. A response to antiviral therapy was accompanied by clinical and biochemical evidence of improvement in liver disease.

Loss of HBsAg with interferon therapy in chronic hepatitis B virus infection

46 male chronic hepatitis B virus (HBV) carriers with active viral replication were randomised, with stratification for histology and sexual preference, to receive six months' lymphoblastoid interferon or no therapy. After nine to eighteen months' follow-up, HBeAg was no longer detectable and anti-HBe was present in 6 of the 23 treated patients. HBsAg was not detectable in 5 of these patients and 3 had anti-HBs. All of the controls remained positive for HBeAg and HBsAg. Seroconversion from HBeAg to anti-HBe was preceded in all cases by a pronounced increase in serum aspartate aminotransferase levels of more than ten times the upper limit of normal at eight to twelve weeks; this response was exclusively associated with interferon therapy. These results suggest that loss of HBsAg and a hepatitis-like illness in the third month of therapy are direct effects of interferon treatment.

Spontaneous hepatitis B e antigen to antibody seroconversion and reversion in Chinese patients with chronic hepatitis B virus infection

Five hundred twelve (373 men, 139 women) patients, aged 1-75 yr, with chronic hepatitis B virus infection seen during a 5-yr period were analyzed. Of these, 43.8% were hepatitis B e antigen (HBeAg)-positive, 49.2% were positive for hepatitis B e antibody, and 7% were negative for both HBeAg and hepatitis B e antibody at presentation. The cumulative probability of clearing HBeAg at the end of the first, second, and third years was 17%, 30%, and 34%, respectively. The probability of clearing HBeAg increased with the age of the patients. Reversion to HBeAg occurred in 7.8% of patients who were HBeAg-negative at presentation and 32.3% of HBeAg-positive patients who cleared HBeAg. In 70.6% of these patients, serum hepatitis B virus-deoxyribonucleic acid was persistently positive or became detectable at the time of HBeAg reversion. Most reversions occurred during the "e-window" phase. The reversions were transient in 31.8% of the cases. Recognition of the dynamics of these serologic changes is important in the evaluation of therapeutic regimens aimed at suppression of HBV replication and call for controlled trials with adequate duration of follow-up. Biochemical exacerbation of liver disease accompanied 38.7% of HBeAg to hepatitis B e antibody seroconversions and 34.8% of reversions. Such exacerbations may be mistaken for acute attacks of hepatitis B in patients not previously recognized to be hepatitis B surface antigen carriers and, in the absence of serial serologic data, are indistinguishable from superimposed non-A, non-B hepatitis.

Clearance of hepatitis B surface antigen (HBsAg) after surgical resection of hepatocellular carcinoma

The serum HBsAg in 4 chronic HBsAg carrier patients with hepatocellular carcinoma (HCC) cleared within 4-38 months after surgical resection of their hepatic tumors. Two patients developed anti-HBs. During the follow-up period from 21 to 28 months after HBsAg clearance, none of the patients regained positive serum HBsAg. Two patients who had had tissue HBsAg present, exclusively in the tumor, showed quick HBsAg clearance after resection. The other 2 patients had a delayed HBsAg clearance. One had tissue HBsAg in both the tumor and nontumoral liver. Only 1 patient had tissue HBsAg in the liver, but not in the tumor. During the same period of observation of 323 chronic HBsAg carriers, who had a variety of histologically-verified chronic liver diseases and were followed for more than 6 months, only 1 cleared the antigen. The spontaneous HBsAg clearance in our HBsAg carriers (1/323) was significantly lower than that (4/64) of HBsAg-positive HCC patients with tumor resection, P less than 0.004. The mechanisms of HBsAg clearance in HCC patients after surgical resection of tumors are discussed.

Intrahepatic distribution of hepatitis B surface and core antigens in chronic hepatitis B virus infection. Hepatocyte with cytoplasmic/membranous hepatitis B core antigen as a possible target for immune hepatocytolysis

The intrahepatic distribution of hepatitis B core antigen (HBcAg) and surface antigen (HBsAg) was studied in 32 patients with chronic type B hepatitis, and the results were correlated with the status of hepatitis B e antigen/antibody (HBeAg/anti-HBe) and with the histologic activity of the patients. In HBeAg-positive patients with minor hepatitis activity, HBcAg was distributed mainly in the nuclei, whereas HBsAg was diffusely located on the plasma membrane as well as focally in the cytoplasm. In HBeAg-positive patients with chronic active liver disease, although the distribution pattern of HBsAg in liver remained unchanged, the expression of nuclear HBcAg decreased significantly with concomitant increase in cytoplasmic/membranous HBcAg expression. In HBsAg carriers who were anti-HBe positive, HBcAg was undetectable anywhere, whereas HBsAg could be seen only in the cytoplasm. These results suggest that membranous expression of HBsAg relates closely to active viral replication but is probably not responsible for the observed histologic activities. In contrast, cytoplasmic/membranous expression of HBcAg correlates with high degree of liver inflammatory activity. It is therefore suggested that hepatocytes with cytoplasmic/membranous HBcAg expression might be the target cells for immune hepatocytolysis.

Controlled clinical trial of acyclovir in chronic hepatitis B virus infection

A randomised, controlled trial comparing acyclovir, 45 mg/kg/day as a continuous IV infusion for 28 days, with no other therapy, was carried out in 30 stable HBsAg carriers seropositive for HBeAg for more than 6 months. Twenty-eight had hepatitis B virus DNA-polymerase activity and/or hepatitis B virus DNA in serum at entry into the study. There were no significant adverse effects of therapy. At 12 months, seroconversion from HBeAg to anti-HBe had occurred in four of 15 treated patients, one of whom had also developed anti-HBs, compared with only one of 15 in the untreated group (95% confidence limits 12% and 51%). Seroconversion from HBeAg to anti-HBe was accompanied by return of serum liver function tests to normal and improved liver histology. The results of this study indicate that acyclovir is of no significant benefit in chronic HBeAg carriers with stable disease.

A review of the efficacy of adenine arabinoside and lymphoblastoid interferon in the Royal Free Hospital studies of hepatitis B virus carrier treatment: identification of factors influencing response rates

We have reviewed the results of treating over 100 HBV carriers with adenine arabinoside, adenine arabinoside monophosphate and lymphoblastoid interferon. In the homosexual group of carriers, adenine arabinoside and its monophosphate have no value. However in this group, lymphoblastoid interferon will produce a response in over 50% of cases. This lack of effectiveness of adenine arabinoside monophosphate in this group may stem from its immunosuppressant properties. In heterosexual carriers both adenine arabinoside monophosphate and lymphoblastoid interferons are effective in approximately 50% to 60% of cases. However, the response rate is different in the various racial groups. Northern European and Mediterranean people appear to respond whereas those from the Far East do not. This may reflect the fact that there are at least two mechanisms by which the chronic carrier state may arise. In 5% to 10% of adults, a relative deficiency of alpha interferon production exists, and this defect is found in the majority of HBV carriers in Western Europe. In these, interferon acts as a replacement therapy and excellent results may be obtained if the patient is treated early in the course of the disease. It would appear that as the duration of the infection increases, the virus may integrate into interferon-reactive consensus sites and prevent the cell from responding to interferon. In patients infected at birth, transplacental anti-HBc appears to modulate the immune response and, along with immaturity of the immune system at this age, results in failure to lyse infected cells. These patients do not benefit from interferon treatment: some form of immune manipulation is required.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for a deficiency of interferon production in patients with chronic hepatitis B virus infection acquired in adult life

Ninety per cent of patients infected in adult life with the hepatitis B virus clear the virus completely and 10% develop chronic infection. There is evidence for the involvement of interferon in the clearance of acute hepatitis B virus infection. We report that, in in vitro tests, some hepatitis B virus carriers have a reduced capacity to produce alpha- and gamma-interferon which is unrelated to the level of viral replication and to the severity of the liver disease and that the level of 2-5 oligoadenylate synthetase in their livers is only minimally elevated compared to controls. Treatment with lymphoblastoid (alpha-) interferon leads to a marked rise in 2-5 oligoadenylate synthetase activity. These data indicate that some patients with chronic hepatitis B virus infection acquired in adult life have a partial deficiency of production of alpha-interferon but can respond to exogenous alpha-interferon. These observations provide a logical basis for attempts to treat this condition with interferons.

Lymphoblastoid alpha-interferon weekly, daily and combined with acyclovir for chronic HBeAg-positive hepatitis

Patients with chronic hepatitis B and active viral replication had no change in DNA-polymerase (DNA-p) and HBeAg when treated with weekly injections of lymphoblastoid alpha-interferon (IFN) for 4-10 weeks. Daily IFN (2.5 MU/m2 for a period of 4 weeks) was associated with a significant fall (P less than 0.05) in DNA-p but not in HBeAg; DNA-p remained or became negative in 3 out of 10 patients after stopping therapy. Combination of IFN and intravenous acyclovir (ACV, 15 mg/kg twice daily) led to a significantly greater fall in DNA-p and HBeAg, while tolerance of the combination therapy was excellent. Four out of 5 patients became DNA-p-negative and three HBeAg-negative; subsequently two became HBsAg-negative with anti-HBs. We conclude that weekly IFN appears ineffective. Daily IFN depressed hepatitis B virus replication, but does not change markedly the natural course of the disease. Combination therapy with ACV may be more effective than IFN alone and is well tolerated.

Identification of factors influencing response rate to antiviral therapy of chronic hepatitis B virus infection. A review of the efficacy of adenine arabinoside and lymphoblastoid interferon in the Royal Free Hospital studies

We have reviewed the results of treating over 100 HBV carriers with adenine arabinoside, adenine arabinoside monophosphate and lymphoblastoid interferon. In the homosexual group of carriers, adenine arabinoside and its monophosphate have no value. However, in this group, lymphoblastoid interferon will produce a response in over 50% of cases. The lack of effectiveness of adenine arabinoside monophosphate in this group may stem from its immunosuppressant properties. In heterosexual carriers both adenine arabinoside monophosphate and lymphoblastoid interferon are effective in approximately 50-60% of cases. However, the response rate is different in the various racial groups. Northern European and Mediterranean people appear to respond whereas those from the Far East do not. This may reflect the fact that there are at least 2 mechanisms by which the chronic carrier state may arise. In 5-10% of adults, a relative deficiency of alpha-interferon production exists and this defect is found in the majority of HBV carriers in Western Europe. In these, interferon acts as a replacement therapy and excellent results may be obtained if the patient is treated early in the course of the disease. It would appear that as the duration of the infection increases, the virus may integrate into interferon-reactive consensus sites and prevent the cell from responding to interferon. In patients infected at birth, transplacental anti-HBc appears to modulate the immune response and along with immaturity of the immune system at this age, results in failure to lyse infected cells. These patients do not benefit from interferon treatment: some form of immune manipulation is required.(ABSTRACT TRUNCATED AT 250 WORDS)

Interferon therapy of chronic hepatitis B virus infection in Chinese

Hepatitis B virus (HBV) infection is prevalent in Chinese populations. 40.4% of 383 Chinese HBV carriers studied were HBeAg-positive. The annual rate of spontaneous clearance of HBeAg was 11%. Twenty-six patients with HBsAg- and HBeAg- and HBeAg-positive non-malignant chronic liver disease randomised to receive recombinant alpha-2 interferon or no treatment have been followed for 6 months or longer. Seven of the 20 treated patients cleared HBeAg during or shortly after treatment but this was sustained in only 1 patient. One of the 6 controls had transient loss of HBeAg. It is too early to conclude whether interferon has any long-term effect on the suppression of HBV replication in Chinese patients. Sixty-nine patients with histologically proven hepatocellular carcinoma were randomised to receive adriamycin or interferon. Although there was no significant benefit on survival, interferon therapy was associated with greater than 25% regression in tumor size in 12.5% of patients and less toxicity.

Treatment of chronic HBeAg-positive hepatitis with acyclovir. A controlled trial

In a previous study a partial inhibition of viral replication was observed in HBeAg-positive patients after acyclovir (ACV) treatment. To assess those results and to evaluate different treatment regimens, a randomized controlled trial with ACV given at 45 mg/kg/day by continuous infusion (in 5 patients) or by intermittent 8-hourly infusion (in 6 patients) for 28 days versus placebo has been performed in 20 patients affected by chronic hepatitis positive for both HBsAg and HBeAg for at least 6 months. Patients were stratified for sex, presence of cirrhosis and homosexual activity. Modest inhibition of serum DNA polymerase activity was observed after intermittent ACV treatment but not with the continuous infusion. After a 8-12 months follow-up, 2 of 10 of the ACV-treated patients and 3 of the controls had become HBeAg-negative, with 1 and 2 seroconversions to anti-HBe in the treated and placebo group respectively. No adverse effects were observed in ACV-treated patients after continuous infusion, but 2 of 6 patients who received intermittent therapy had to stop treatment, because of abdominal colics and elevation of the serum creatinine. Our data confirm that ACV partially inhibits viral replication in HBeAg-positive patients but without significantly affecting the rate of seroconversion to anti-HBe.