Efficacy of thymosin α-1 plus peginterferon α-2a combination therapy compared with peginterferon α-2a monotherapy in HBeAg-positive chronic hepatitis B: a prospective, multicenter, randomized, open-label study

Thymosin α1 and Its Role in Viral Infectious Diseases: The Mechanism and Clinical Application

Thymosin α1 (Tα1) is an immunostimulatory peptide that is commonly used as an immune enhancer in viral infectious diseases such as hepatitis B, hepatitis C, and acquired immune deficiency syndrome (AIDS). Tα1 can influence the functions of immune cells, such as T cells, B cells, macrophages, and natural killer cells, by interacting with various Toll-like receptors (TLRs). Generally, Tα1 can bind to TLR3/4/9 and activate downstream IRF3 and NF-κB signal pathways, thus promoting the proliferation and activation of target immune cells. Moreover, TLR2 and TLR7 are also associated with Tα1. TLR2/NF-κB, TLR2/p38MAPK, or TLR7/MyD88 signaling pathways are activated by Tα1 to promote the production of various cytokines, thereby enhancing the innate and adaptive immune responses. At present, there are many reports on the clinical application and pharmacological research of Tα1, but there is no systematic review to analyze its exact clinical efficacy in these viral infectious diseases via its modulation of immune function. This review offers an overview and discussion of the characteristics of Tα1, its immunomodulatory properties, the molecular mechanisms underlying its therapeutic effects, and its clinical applications in antiviral therapy.

Arthrospira Enhances Seroclearance in Patients with Chronic Hepatitis B Receiving Nucleos(t)ide Analogue through Modulation of TNF-α/IFN-γ Profile

Chronic hepatitis B (CHB) virus infection, causing immune dysfunction and chronic hepatitis, is one of the leading risk factors for hepatocellular cancer. We investigated how Arthrospira affected hepatitis B surface antigen (HBsAg) reduction in CHB patients under continued nucleos(t)ide analogues (NA). Sixty CHB patients who had been receiving NA for at least one year with undetectable HBV DNA were randomized into three groups: control and oral Arthrospira at 3 or 6 g daily add-on therapy groups. Patients were followed up for 6 months. Oral Arthrospira-diet mice were established to investigate the possible immunological mechanism of Arthrospira against HBV. Within 6 months, mean quantitative HBsAg (qHBsAg) decreased in the oral Arthrospira add-on therapy group. Interestingly, interferon gamma (IFN-γ) increased but TNF-α, interleukin 6 (IL-6), hepatic fibrosis, and steatosis decreased in the add-on groups. In mice, Arthrospira enhanced both innate and adaptive immune system, especially natural killer (NK) cell cytotoxicity, B cell activation, and the interleukin 2 (IL-2), IFN-γ immune response. Arthrospira may modulate IL-2- and TNF-α/IFN-γ-mediated B and T cell activation to reduce HBsAg. Also, Arthrospira has the potential to restore immune tolerance and enhance HBsAg seroclearance in CHB patients through promoting T, B, and NK cell activation.

A Reappraisal of Thymosin Alpha1 in Cancer Therapy

Thymosin alpha1 (Tα1), an endogenous peptide first isolated from the thymic tissue in the mid-sixties, has gained considerable attention for its immunostimulatory activity that led to its application to diverse pathological conditions, including cancer. Studies in animal models and human patients have shown promising results in different types of malignancies, especially when Tα1 was used in combination with other chemo- and immune therapies. For this reason, the advancements in our knowledge on the adjuvant role of Tα1 have moved in parallel with the development of novel cancer therapies in a way that Tα1 was integrated to changing paradigms and protocols, and tested for increased efficacy and safety. Cancer immunotherapy has recently experienced a tremendous boost following the development and clinical application of immune checkpoint inhibitors. By unleashing the full potential of the adaptive immune response, checkpoint inhibitors were expected to be very effective against tumors, but it soon became clear that a widespread and successful application was not straightforward and shortcomings in efficacy and safety clearly emerged. This scenario led to the development of novel concepts in immunotherapy and the design of combination protocols to overcome these limitations, thus opening up novel opportunities for Tα1 application. Herein, we summarize in a historical perspective the use of Tα1 in cancer, with particular reference to melanoma, hepatocellular carcinoma and lung cancer. We will discuss the current limitations of checkpoint inhibitors in clinical practice and the mechanisms at the basis of a potential application of Tα1 in combination protocols.

Combination of entecavir with thymosin alpha-1 in HBV-related compensated cirrhosis: a prospective multicenter randomized open-label study

ABSTRACT Background: Thymosin alpha-1 (Ta-1) suppresses HBV viral replication, while the evidence of combination effect with nucleoide is still limited. We aimed to investigate the efficacy and safety of combination therapy of Ta-1 with entecavir (ETV) in patients with compensated liver cirrhosis.

RESEARCH DESIGN AND METHODS

A total of 690 patients were randomized to receive Ta-1 plus ETV (n = 351) or ETV monotherapy (n = 339) for 52 weeks after 26 weeks of ETV treatment, followed by continued entecavir therapy. The primary endpoint was defined as liver decompensation, hepatocellular carcinoma (HCC) or death.

RESULTS

The median followed up was 38.2 months. The cumulative incidence of liver decompensation, HCC, or death were similar between two groups. During the Ta-1 combination treatment, the HCC incidence was 1.7% in combination group and 2.1% in ETV group, without new HCC cases developed during week 39 to week 77 in combination group. The virologic response, serologic response, biochemical response was similar between two groups at week 104. Both therapies were well-tolerated.

CONCLUSION

There was no significant difference between two groups in endpoint events, while combination therapy with Ta-1 has a tendency to inhibit the development of HCC.

Treatment of AECHB and Severe Hepatitis (Liver Failure)

This chapter describes the general treatment and immune principles and internal management for AECHB and HBV ACLF, including ICU monitoring, general supportive medications/nutrition/nursing, immune therapy, artificial liver supportive systems, hepatocyte/stem cell, and liver transplant, management for special populations, frequently clinical complications and the utilization of Chinese traditional medicines.

Early clinical indicators of severe hepatitis B include acratia, gastrointestinal symptoms, a daily increase in serum bilirubin >1 mg/dL, toxic intestinal paralysis, bleeding tendency and mild mind anomaly or character change, and the presence of other diseases inducing severe hepatitis. Laboratory indicators include T-Bil, PTA, cholinesterase, pre-albumin and albumin. The roles of immune indicators (such as IL-6, TNF-α, and fgl2), gene polymorphisms, HBV genotypes, and gene mutations as early clinical indicators.

Intensive Care Unit monitor patients with severe hepatitis include intracranial pressure, infection, blood dynamics, respiratory function, renal function, blood coagulation function, nutritional status and blood purification process. Nursing care should not only include routine care, but psychological and special care (complications).

Nutrition support and nursing care should be maintained throughout treatment for severe hepatitis. Common methods of evaluating nutritional status include direct human body measurement, creatinine height index (CHI) and subject global assessment of nutrition (SGA). Malnourished patients should receive enteral or parenteral nutrition support.

Immune therapies for severe hepatitis include promoting hepatocyte regeneration (e.g. with glucagon, hepatocyte growth factor and prostaglandin E1), glucocorticoid suppressive therapy, and targeting molecular blocking. Corticosteroid treatment should be early and sufficient, and adverse drug reactions monitored. Treatments currently being investigated are those targeting Toll-like receptors, NK cell/NK cell receptors, macrophage/immune coagulation system, CTLA-4/PD-1 and stem cell transplantation.

In addition to conventional drugs and radioiodine, corticosteroids and artificial liver treatment can also be considered for severe hepatitis patients with hyperthyreosis. Patients with gestational severe hepatitis require preventive therapy for fetal growth restriction, and it is necessary to choose the timing and method of fetal delivery. For patients with both diabetes and severe hepatitis, insulin is preferred to oral antidiabetic agents to control blood glucose concentration. Liver toxicity of corticosteroids and immune suppressors should be monitored during treatment for severe hepatitis in patients with connective tissue diseases including SLE, RA and sicca syndrome. Patient with connective tissue diseases should preferably be started after the antiviral treatment with nucleos(t)ide analogues.

An artificial liver can improve patients’ liver function; remove endotoxins, blood ammonia and other toxins; correct amino acid metabolism and coagulation disorders; and reverse internal environment imbalances. Non-bioartificial livers are suitable for patients with early and middle stage severe hepatitis; for late-stage patients waiting for liver transplantation; and for transplanted patients with rejection reaction or transplant failure. The type of artificial liver should be determined by each patient’s condition and previous treatment purpose, and patients should be closely monitored for adverse reactions and complications. Bio- and hybrid artificial livers are still under development.

MELD score is the international standard for choosing liver transplantation. Surgical methods mainly include the in situ classic type and the piggyback type; transplantation includes no liver prophase, no liver phase or new liver phase. Preoperative preparation, management of intraoperative and postoperative complications and postoperative long-term treatment are keys to success.

Severe hepatitis belongs to the categories of “acute jaundice”, “scourge jaundice”, and “hot liver” in traditional Chinese medicine. Treatment methods include Chinese traditional medicines, acupuncture and acupoint injection, external application of drugs, umbilical compress therapy, drip, blow nose therapy, earpins, and clysis. Dietary care is also an important part of traditional Chinese medicine treatment.

Immunotherapy for hepatitis B in the direct acting antiviral era: Reevaluating the thymosin α1 efficacy trials in the light of a combination therapy approach

Hepatitis B virus (HBV) causes both acute and chronic hepatitis and infects large numbers of individuals worldwide. Unfortunately, prediction of typical clinical outcome is problematic and there is considerable variability in the frequency, duration and severity of disease progression. The mainstay of HBV treatment is directed towards the suppression of HBV replication by nucleos(t)ide analogs (NUCs). The use of immunomodulators such as α-Interferon and thymosin α1 can, in select patients, results in elimination of both HBsAg and HBeAg. Given the observation that viral clearance is most effective in the presence of a strong immune response, this review summarizes data suggesting that the use of a combination of an immune modulator such as Tα1 with a highly effective NUC may result in a more successful therapeutic approach in patients with chronic hepatitis B (CHB). Results from small studies using combination Tα1 and NUCs are encouraging, and ongoing clinical trials combining entecavir with Tα1 are anticipated to provide important data assessing the use of a combination of Tα1 with a NUC to achieve resolution of CHB.

聚乙二醇干扰素α-2a联合胸腺肽α1治疗慢性乙型肝炎疗效的系统评价

目的

系统评价聚乙二醇干扰素α-2a(pegylated interferon α-2a, Peg-IFNα-2a)联合胸腺肽α1(thymosin α 1, Tα1)与单用Peg-IFNα-2a治疗慢性乙型肝炎(chronic hepatitis B, CHB)的疗效及安全性.

方法

检索PubMed、EMBASE、The Cochrane Library、CBM、CNKI、VIP和WanFang Data, 查找Peg-IFNα-2a联合Tα1治疗CHB的随机对照试验(randomized controlled trial, RCT), 检索年限从建库至2016-10, 由2位评价员根据纳入与排除标准独立筛选文献, 从纳入的文献中提取资料并进行质量评价, 采用RevMan5.3软件进行Meta分析.

结果

最终纳入7个RCT, 包括640例患者. Meta分析结果显示: 与单用Peg-IFNα-2a治疗CHB相比, 联合Tα1治疗结束时明显提高了血清ALT复常率(OR = 2.94, 95%CI: 1.59-5.44, P = 0.0006)、HBV-DNA阴转率(OR = 2.53, 95%CI: 1.76-3.64, P<0.00001)、乙型肝炎e抗原(hepatitis B e antigen, HBeAg)阴转率(OR = 2.21, 95%CI: 1.43-3.40, P = 0.0003)、HBeAg血清转换率(OR = 2.53, 95%CI: 1.48-4.30, P = 0.0006)、乙型肝炎表面抗原阴转率(OR = 2.67, 95%CI: 1.07-6.69, P = 0.04). 联合治疗后不增加Peg-IFNα-2a的不良反应(流感样症状)发生率, 差异无统计学意义(OR = 0.8, 95%CI: 0.24-2.63, P = 0.71).

结论

Peg-IFNα-2a联合Tα1治疗CHB结束时的疗效优于单用Peg-IFNα-2a, 其安全性良好, 但受纳入研究数量和质量的限制, 停药后的长期效果如何尚缺乏证据, 需开展更多高质量的RCT进一步研究.

Thymosin α1 therapy subsequent to radical hepatectomy in patients with hepatitis B virus-associated hepatocellular carcinoma: A retrospective controlled study

The clinical efficacy of thymosin α1 (Tα1) therapy in patients with hepatocellular carcinoma (HCC) subsequent to radical hepatectomy is unclear. In the present study, the impact of Tα1 therapy on outcomes in HCC patients after radical hepatectomy was retrospectively evaluated. Medical records were retrospectively reviewed for 146 patients with hepatitis B virus (HBV)-associated HCC who were treated by radical hepatectomy and subsequently with Tα1 therapy, as well as for 412 control patients with HBV-associated HCC treated by radical hepatectomy. Propensity score matching was used to minimize confounding variables due to baseline differences. Liver function, recurrence-free survival and overall survival rates were compared between the two groups. Serum markers of liver function were significantly improved in the Tα1 group compared with the control group. The 1-, 2- and 3-year overall survival rates were 87.2, 82.0 and 68.4% in the Tα1 group and 78.2, 64.2 and 49.7% in the control group (P=0.011). The 1-, 2- and 3-year recurrence-free survival rates were 79.7, 70.8 and 67.3% in the Tα1 group and 69.9, 61.5 and 51.6% in the control group (P=0.019). The results suggested that post-hepatectomy Tα1 therapy improves liver function and significantly prolong recurrence-free and overall survival in patients with HBV-associated HCC.

Chronic hepatitis B: immune pathogenesis and emerging immunotherapeutics

Hepatitis B virus (HBV) evades, subverts, activates and regulates host immune components, thereby impacting its natural history and disease pathogenesis. Recent advances in our understanding of immune interactions in chronic viral infection and tumor therapy are applicable to chronic hepatitis B (CHB). With recent successes of tumor immunotherapy, there is a renewed interest in exploring immunotherapeutics in achieving sustained and functional cure of chronic hepatitis B. In this review, we discuss aspects of host innate and adaptive immune regulatory and pathogenic responses relevant for HBV infection. We also highlight several immune modulatory approaches in clinical development to treat CHB.

Thymosin From Bombyx mori Is Down-Regulated in Expression by BmNPV Exhibiting Antiviral Activity

Thymosins have been highly conserved during evolution. These hormones exist in many animal species and play an essential role in many biological events. However, little is known regarding the physiological function of silkworm Bombyx mori thymosin (BmTHY). In this study, we investigated the expression pattern of BmTHY in a Bombyx mori larval ovarian cell line (BmN) challenged with Bombyx mori nuclear polyhydrosis virus (BmNPV) and the antiviral effect of recombinant BmTHY (rBmTHY) for Bombyx mori against BmNPV. Western-blot assay and qRT-PCR analysis revealed that the level of BmTHY protein expression and transcription decreased over time when BmN cells were infected by BmNPV. Treatment with endotoxin-free rBmTHY led to a significant reduction in viral titer in the supernatant of BmN cells challenged with BmNPV. The results from antiviral tests performed in vitro and in vivo showed that endotoxin-free rBmTHY improved the survival rate of Bombyx mori infected with BmNPV. These findings suggest that BmTHY exerts immunomodulatory effects on Bombyx mori, rendering them resistant to viral infection.

Ulinastatin and/or thymosin α1 for severe sepsis: A systematic review and meta-analysis

OBJECTIVE

Ulinastatin (UTI) and thymosin α1 (Tα1) have been investigated for their immunoregulatory properties in patients with severe sepsis. However, it is unclear whether immunomodulatory therapy using UTI combined with Tα1 (UCT), UTI alone (UA), or Tα1 alone (TA) improves the disease outcome. The objective of this study was to analyze the effectiveness of UCT, UA, and TA for the treatment of severe sepsis.

METHODS

PubMed, EMBASE, and Cochrane Library databases were investigated from inception to September 2015. Randomized controlled trials (RCTs) examining the treatment of patients with severe sepsis by UCT, UA, and TA were defined as eligible. Data were analyzed using Review Manager 5.3, and the RCTs were evaluated by the Cochrane Handbook 5.1.0. The quality of the evidence was evaluated according to the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE).

RESULTS

Ten articles and 12 studies were included in this systematic review and meta-analysis. The primary outcome measures indicated that UCT was associated with significantly lower 28-day mortality (risk ratio [RR], 0.67; 95% confidence interval [CI], 0.57-0.80; p < 0.00001; n = 915; GRADE rating, moderate) and 90-day mortality (RR, 0.75; 95% CI, 0.61-0.93; p = 0.009; n = 547; GRADE rating, moderate); UA was associated with no significant difference in the 28-day mortality (RR, 0.60; 95% CI, 0.30-1.20; p = 0.15; n = 182; GRADE rating, low), and there was no report on 90-day mortality; TA was associated with significantly lower 28-day mortality (RR, 0.72; 95% CI, 0.55-0.93; p = 0.01; n = 494; GRADE rating, low), but there was no significant difference in the 90-day mortality (RR, 0.84; 95% CI, 0.54-1.31; p = 0.45; n = 91; GRADE rating, very low). In the secondary outcome measures, there was obvious heterogeneity in the length of the intensive care unit stay and that of the mechanical ventilation, length of the antibiotics and vasopressor use, and 28-day Acute Physiology and Chronic Health Evaluation II (APACHE II) scores.

CONCLUSION

Treatment of severe sepsis with UCT reduced both the 28-day and the 90-day mortality, whereas treatment with TA reduced only the 28-day mortality. The effects of UCT, UA, and TA on intensive care unit stay, mechanical ventilation, antibiotics and vasopressor use, and 28-day APACHE II scores of septic patients are still unclear. Additional high-quality RCTs are needed to define clearly the guidelines for the treatment of severe sepsis.

LEVEL OF EVIDENCE

Systematic review, level IV.

Chronic hepatitis B: A wave of new therapies on the horizon

This year marks the 50th anniversary of the discovery of the Australia antigen (Blumberg et al., 1965), which in 1967 was identified to be the hepatitis B virus (HBV) surface antigen. Even though several antiviral medications have been in use for the management of chronic HBV infection for more than 20years, sustained clearance of HBsAg, similar to the sustained viral response (SVR) or cure in chronic hepatitis C, occurs in only a minority of treated patients. Moreover, even after 10years of effective suppression of HBV viremia with current therapy, there is only a 40-70% reduction in deaths from liver cancer. Recent success in developing antivirals for hepatitis C that are effective across all genotypes has renewed interest in a similar cure for chronic HBV infection. In this article, we review a wave of newly identified drug targets, investigational compounds and experimental strategies that are now under clinical evaluation or in preclinical development. The paper forms part of a symposium in Antiviral Research on "An unfinished story: From the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."

Current and future antiviral drug therapies of hepatitis B chronic infection

Despite significant improvement in the management of chronic hepatitis B virus (HBV) it remains a public health problem, affecting more than 350 million people worldwide. The natural course of the infection is dynamic and involves a complex interplay between the virus and the host’s immune system. Currently the approved therapeutic regimens include pegylated-interferon (IFN)-α and monotherapy with five nucleos(t)ide analogues (NAs). Both antiviral treatments are not capable to eliminate the virus and do not establish long-term control of infection after treatment withdrawal. IFN therapy is of finite duration and associates with low response rates, liver decompensating and numerous side effects. NAs are well-tolerated therapies but have a high risk of drug resistance development that limits their prolonged use. The imperative for the development of new approaches for the treatment of chronic HBV infection is a challenging issue that cannot be over-sided. Research efforts are focusing on the identification and evaluation of various viral replication inhibitors that target viral replication and a number of immunomodulators that aim to restore the HBV specific immune hyporesponsiveness without inducing liver damage. This review brings together our current knowledge on the available treatment and discusses potential therapeutic approaches in the battle against chronic HBV infection.

Thymosin alpha1 based immunomodulatory therapy for sepsis: a systematic review and meta-analysis

OBJECTIVES

Thymosin alpha1 (Tα1) is considered a promising immunomodulatory drug. However, it is still unclear whether Tα1 should be recommended for the management of sepsis. Here we conducted a systematic review and meta-analysis to assess the efficacy of Tα1 based immunomodulatory therapy on the clinical outcomes of septic patients.

METHODS

We searched for relevant clinical trials published before Dec. 12, 2014 through electronic databases. All articles about Tα1 based immunomodulatory therapy for sepsis were included regardless of language. Two authors independently selected studies, extracted data and assessed the quality of each included study. We polled the data related to all-cause mortality with Review Manager 5.1.

RESULTS

Twelve controlled trials were evaluated in all. Tα1 based immunomodulatory therapy had a significant trend toward lower all-cause mortality among patients with sepsis (pooled risk ratio 0.68, 95%CI 0.59-0.78, p<0.00001, 12 trials, n=1480).

CONCLUSIONS

Tα1 based immunomodulatory therapy was associated with a lower mortality in septic patients. Nevertheless, these findings should be interpreted cautiously because of the poor quality and small number of participants of the included trials. More well-designed worldwide multicenter clinical trials are needed to provide a conclusive guideline for clinical practice.

Immunotherapeutic interventions in chronic hepatitis B virus infection: a review

Chronic hepatitis B virus (HBV) infection is a public health challenge worldwide. Antiviral agents (nucleos(t)ide analogues, NAs) and immune-based therapies (IFN-α or Pegylated-IFN-α) are two therapeutic approaches available currently against chronic hepatitis B (CHB). However, these approaches are associated with the development of acquired drug resistance or poor response rates and are accompanied by numerous side effects. Furthermore, due to defective innate and adaptive immune responses, HBV cannot be effectively controlled or completely eliminated, which may ultimately result in liver decompensation and hepatocelluar carcinoma. The imperative for development of new approaches targeting CHB cannot be overstated. Various immunotherapeutic interventions have been tried as adjuvants to inhibit HBV replication. In this paper, we will review immunotherapeutic interventions in the treatment of CHB.

Results of treatment of chronic hepatitis B with pegylated interferon

Persistent viral eradication or suppression through a defined course of Pegylated-interferon (PegIFN) or the administration of a long-term potent nucleot(s)ide analogues (NUCs) can impact positively the natural course of HBV infection by preventing disease progression. Despite the higher rates of off-therapy response achieved with PegIFN compared with NUC, its benefits are restricted to a subgroup of patients only. To increase the rates of patients who may benefit from PegIFN treatment, minimizing the adverse events, careful patient selections based on baseline features and on treatment HBsAg kinetics for individual treatment optimization are required.