A randomized, controlled, clinical study of thymosin alpha-1 versus interferon-alpha in [corrected] patients with chronic hepatitis B lacking HBeAg in China [corrected]

Prognosis, Prevention and Research Prospects of Progression to Severe Hepatitis B (Liver Failure)

This chapter describes the factors involved in the disease prognosis, parameters of outcome evaluations, principles and techniques for progression prevention. In last section, the future perspectives in both basic and clinical investigations towards unmet medical needs in AECHB and HBV ACLF are discussed.

Factors affecting the prognosis of patients with severe hepatitis B include those related to the virus (including viral load, HBeAg expression, and gene mutation), patient age, co-morbidity, TBil, INR, serum Cr, and the host genetic background. Indicators associated with patient prognosis include TBil, total cholesterol, albumin and prealbumin, hepatic encephalopathy, kidney damage, alpha-fetoprotein and vitamin D binding protein, blood sodium level, virus HBeAg expression and genotype, and blood glucose.

In addition to TBil, INR, hepatic encephalopathy, Cr level and AFP as indicators for prognosis of severe hepatitis, some other parameters such as clinical signs, symptoms, serum levels of total cholesterol and albumin and natrium, and coagulation factors are all valuable in assessment. The roles of cell apoptosis, liver regeneration and immunological parameters in assessing patient prognosis are under study. Prognostic evaluating systems include MELD score, MELD-Na score, iMELD score, KCI and CTP score.

Prevention of severe hepatitis B should be started in asymptomatic patients. Close observation, sufficient rest, adequate nutrition, meticulous nursing and psychological care, preventing and removing exacerbating factors, treating concomitant diseases, reasonable antiviral and comprehensive therapies are helpful to prevent CHB patients from developing to severe hepatitis. For patients who already have severe hepatitis B, the prevention and management of complications is important for lowering mortality rate.

New research directions in acute-on-chronic liver failure include: (1) Additional well controlled studies using present or new liver systems are warranted. Other approaches include the use of granulocyte colony stimulating factor to treat infections as well as the potential of use of stem cells to restore immune integrity and enhance liver regeneration. (2) Using new cell lines and animal models to understand the molecular biology of HBV, the immune response and to develop novel therapies. (3) Development of new anti-HBV strategies, e.g. silencing or remove cccDNA, enhancing immunologic clearance of HBV infection, inhibiting virus entry or HBc expression and using CRISP to disrupt cccDNA.

Historical review of thymosin α 1 in infectious diseases

INTRODUCTION

Thymosin α 1 (Tα1) is a peptidic biological response modifier, which plays a significant role in activating and regulating various cells of the immune system. For the above-mentioned activities it is expected to exert a clinical benefit in the treatment of diseases where the immune system is altered.

AREAS COVERED

Several clinical trials have been carried out with Tα1 for treatment or prevention of many different infectious diseases such as hepatitis B and C, sepsis and Aspergillosis in bone marrow-transplanted patients. Data available on the use of Tα1 in infectious disease as well as a vaccine enhancer will be reviewed to possibly generate new working hypothesis.

EXPERT OPINION

Tα1 has been widely used in thousands of patients. Nevertheless, there are some issues that have not yet been properly addressed (i.e., dose, schedule, combination treatments, end-points to be evaluated in clinical trials). In the most recent clinical trials Tα1 has been used at higher doses than those commonly used in the past showing a direct proportionality between the dose and the effect. The safety profile of Tα1 is excellent and it is virtually devoid of toxicity.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2012 update. Hepatol Int. 2012;6:531-561. [PMID: 26201469 DOI: 10.1007/s12072-012-9365-4]

Large volume of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2008. These include further studies in asymptomatic subjects with chronic HBV infection and community-based cohorts, the role of HBV genotype/naturally occurring HBV mutations, the application of non-invasive assessment of hepatic fibrosis and quantitation of HBV surface antigen and new drug or new strategies towards more effective therapy. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings was discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

Thymosin alpha 1: biological activities, applications and genetic engineering production

Thymosin alpha 1 (Tα1), a 28-amino acid peptide, was first described and characterized from calf thymuses in 1977. This peptide can enhance T-cell, dendritic cell (DC) and antibody responses, modulate cytokines and chemokines production and block steroid-induced apoptosis of thymocytes. Due to its pleiotropic biological activities, Tα1 has gained increasing interest in recent years and has been used for the treatment of various diseases in clinic. Accordingly, there is an increasing need for the production of this peptide. So far, Tα1 used in clinic is synthesized using solid phase peptide synthesis. Here, we summarize the genetic engineering methods to produce Tα1 using prokaryotic or eukaryotic expression systems. The effectiveness of these biological products in increasing the secretion of cytokines and in promoting lymphocyte proliferation were investigated in vitro studies. This opens the possibility for biotechnological production of Tα1 for the research and clinical applications.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update. Hepatol Int. 2008;2:263-283. [PMID: 19669255 DOI: 10.1007/s12072-008-9080-3.]

Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon alpha2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update

Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon alpha2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included.

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.

Comparison of the efficacy of thymosin alpha-1 and interferon alpha in the treatment of chronic hepatitis B: a meta-analysis

Chronic hepatitis B virus (HBV) infection is a serious problem because of its worldwide distribution and possible adverse sequelae, such as cirrhosis and hepatocellular carcinoma. Thymosin alpha-1 (Talpha1) is an immune modifier that has been shown to be effective for chronic hepatitis B (CHB) in some trials. But the trials comparing Talpha1 vs. interferon alpha (IFNalpha) treatment in CHB have been small and the results have been inconsistent. So we conducted a meta-analysis to compare the efficacy of Talpha1 and IFNalpha in the treatment of CHB. Generally, four randomized controlled trials including 199 CHB patients who received Talpha1 or IFNalpha treatment were identified through MEDLINE and EMBASE online search. Virological (for hepatitis B e antigen (HBeAg) positive patients, loss of HBV DNA and HBeAg; for HBeAg negative patients, loss of HBV DNA), biochemical (normalization of transaminases) and complete responses (fulfill criteria of biochemical and virological response simultaneously) were analyzed using the intention-to-treat method. The odds ratio (OR) was used to measure the magnitude of the efficacy. The ORs (95% confidence interval) of the virological response, biochemical response and complete response of Talpha1 over IFNalpha at the end of 6 months treatment were 0.62 (0.35, 1.10), 0.60 (0.34, 1.05) and 0.54 (0.30, 0.97), respectively. The ORs (95% confidence interval) of the virological response, biochemical response and complete response of Talpha1 over IFNalpha at the end of follow-up (6 months post-treatment) were 3.71 (2.05, 6.71), 3.12 (1.74, 5.62) and 2.69 (1.47, 4.91), respectively. These data showed that compared with IFNalpha, the benefit of Talpha1 was not immediately significant at the end of therapy, but virological, biochemical and complete response had a tendency to increase or accumulate gradually after the therapy. For three of the four trials that studied HBeAg-negative patients, the results are mostly applicable to HBeAg-negative CHB.

Efficacy of thymosin alpha-1 and interferon alpha in treatment of chronic viral hepatitis B: A randomized controlled study

AIM: To observe the efficiency and safety of thymosin-α1 treatment in patients with hepatitis B e antigen (HBeAg) and HBV DNA positive chronic hepatitis.

METHODS: Sixty-two patients were randomly divided into groups A and B. The patients in group A received subcutaneous injection of 1.6 mg thymosin-α1, twice a week (T-α1 group) for six months, and the patients in group B received 5 MU interferon alpha (IFN-α) each day for fifteen days, then three times weekly (IFN-α group) for six months. The results between two groups treated with and the group untreated with IFN-α which was followed up for 12 mo (historical control group consisting of 30 patients) were compared, and three groups were comparable between each other (P > 0.05) at baseline (age, sex, clinical history, biochemical, and serological parameters).

RESULTS: At the end of treatment, complete response, which was defined as alanine aminotransferase (ALT) normalization and HBV DNA and HBeAg loss, occurred in 9 of 29 (31.0%) patients in the T-α1 group and in 15 of 33 (45.5%) patients in the IFN-α group (χ² = 1.36, P > 0.05). After a follow-up period of six months, a complete response was observed in 14 of 29 (48.3%) patients in the T-α1 group and in 9 of 33 (27.3%) patients in the IFN-α group (χ² = 2.93, P > 0.05). Compared with the results observed in the historical control (HC) group untreated with IFN-α which was followed up for 12 mo, the rate of complete response was significantly higher in IFN-α group at the end of therapy (1 of 30 vs 15 of 33, χ² = 14.72, P < 0.001) and in the T-α1 group at the end of follow-up (1 of 30 vs 14 of 29, χ² = 15.71, P < 0.001). In T-α1 and IFN-α treatment groups, the area under (the plasma concentration time) curve (AUC) of negative HBV DNA and HBeAg was 34%, 17%, 31% and 19% smaller than that in the HC group. By the end of the follow-up period, the proportions of ALT normalization and negative HBV DNA in the T-α1 group were significantly higher than those in the IFN-α and HC groups. The odds of ALT normalization and negative HBV DNA at the end of the follow-up was three-fold higher in the T-α1 group than in the IFN-α group. Unlike IFN-α, T-α1 was well tolerated by all patients, and no side effects appeared in T-α1 group.

CONCLUSION: The results suggest that a 6-mo course of T-α1 therapy is effective and safe in patients with chronic hepatitis B. T-α1 is able to reduce HBV replication in patients with chronic hepatitis B. Furthermore, T-α1 is better tolerated than IFN-α and can gradually induce more sustained ALT normalization and HBV DNA and HBeAg loss. However, a response rate of 48.3% is still less ideal. A more effective therapeutic approach warrants further study.