A proinflammatory role for interleukin-22 in the immune response to hepatitis B virus

BACKGROUND & AIMS

T-helper (Th)17 cells that secrete interleukin (IL)-22 have immunomodulatory and protective properties in the liver and other tissues. IL-22 induces expression of proinflammatory genes but is also mitogenic and antiapoptotic in hepatocytes. Therefore, it could have multiple functions in the immune response to hepatitis B virus (HBV).

METHODS

We examined the role of IL-22 in regulating liver inflammation in HBV transgenic mice and measured levels of IL-22 in HBV-infected patients.

RESULTS

In HBV transgenic mice, injection of a single dose of IL-22 increased hepatic expression of proinflammatory genes but did not directly inhibit virus replication. When splenocytes from HBV-immunized mice were transferred into HBV transgenic mice, the severity of the subsequent liver damage was ameliorated by neutralization of IL-22. In this model, IL-22 depletion did not affect interferon gamma-mediated noncytopathic inhibition of virus replication initiated by HBV-specific cytotoxic T cells, but it significantly inhibited recruitment of antigen-nonspecific inflammatory cells into the liver. In patients with acute HBV infections, the percentage of Th17 cells in peripheral blood and concentration of IL-22 in serum were significantly increased.

CONCLUSIONS

IL-22 appears to be an important mediator of the inflammatory response following recognition of HBV by T cells in the liver. These findings might be relevant to the development of cytokine-based therapies for patients with HBV infection.

A note for the global stability of a delay differential equation of hepatitis B virus infection

The global stability for a delayed HIV-1 infection model is investigated. It is shown that the global dynamics of the system can be completely determined by the reproduction number, and the chronic infected equilibrium of the system is globally asymptotically stable whenever it exists. This improves the related results presented in [S. A. Gourley,Y. Kuang and J.D.Nagy, Dynamics of a delay differential equation model of hepatitis B virus infection, Journal of Biological Dynamics, 2(2008), 140-153].

Steroid withdrawal in adult liver transplantation: occurrence at a single center

BACKGROUNDS

Steroids are the predominant immunosuppressive agent used after liver transplantation even though patients may experience steroid-related side effects.

AIMS

The objective of this study was to determine whether steroid use influenced the outcomes of liver transplantations.

METHODS

Three hundred forty-four adult patients underwent liver transplantation between May 2002 and December 2007. We reviewed the medical records of these patients, excluding those younger than 18 years old or those who died within the first month. The protocol withdrawal group (group 1) ceased steroid use within 5 months after transplantation, while the late withdrawal group (group 2) continued steroid use beyond this 5-month posttransplantation period.

RESULTS

All patients were classified according to the onset of steroid withdrawal (group 1: n = 243; group 2: n = 99). The incidences of biopsy-confirmed and treated acute rejection episodes (ARE) at 12 and 24 months posttransplantation were 7.8% and 12.3% in group 1, but 25.3% and 27.3% in group 2, respectively (P = .001). The incidence of hepatitis B virus (HBV) recurrence in group 2 was higher than that in group 1 (P = .007). The HBV-free survival rates at 1 and 2 years posttransplantation were 99.0% and 97.1% in group 1 and 96.1% and 92.1% in group 2, respectively. New-onset diabetes, avascular necrosis of the femoral head, corticosteroid-resistant ARE, hepatocellular carcinoma recurrence, as well as graft and patient survivals did not differ between the two groups.

CONCLUSIONS

Acute rejection episodes and HBV recurrence occurred less frequently when steroids were discontinued within 5 months after liver transplantation.

Screening of hepatitis B and C and human immunodeficiency virus in infertile couples in Saudi Arabia

OBJECTIVE

To determine the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) in a group of infertile couples attending a tertiary care facility in Saudi Arabia.

METHODS

A retrospective cross-sectional observational study was performed by reviewing medical records of 500 couples referred to the Reproductive Endocrine and Infertility Medicine Department of the Women's Specialized Hospital at King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia between January 2006 and December 2008. All patients were screened for HBV markers (hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B core antibody, hepatitis Be antigen), anti-HCV, anti-HIV types I and II using enzyme linked immunoassay technique.

RESULTS

The overall prevalence of HBV in the population studied was 1.8% (n=17). For females HBV prevalence was 1.5% (n=7), and for males it was 2.1% (n=10). Overall HCV prevalence in this group was 0.5%. All females were negative for HCV, while males had a prevalence of 1.1% (n=5). All males and females were negative for HIV.

CONCLUSION

We found a high prevalence for HBV and HCV in a group of Saudi infertile population. The HIV prevalence was found to be 0%. Due to the risks of cross sectional and vertical transmission of these infections, and despite the low incidence of HIV infection and the cost implications, it is important to screen all Saudi infertile couples for these infections prior to embarking on fertility treatments.

Recent aspects of vasculitis and future direction

Vasculitis is pathologically identified as specific cellular inflammation, vessel destruction, and tissue necrosis. Current classifications of vasculitis such as the Chapel Hill Classification (CHCC) and American College of Rheumatology (ACR) guidelines are not sufficiently adequate for clinicians to diagnose vasculitis. The biomarkers that are currently in clinical use such as PR3-ANCA and MPO-ANCA, only help in diagnosing small vessel vasculitis and their sensitivity and specificity are not sufficient. However, recent developments related to the pathogenesis and etiopathogenesis of vasculitis have the potential to contribute to new and improved biomarkers. The determination of diverse roles of ANCA and synergistic effects of infection, genetic, environmental factors and drugs on pathogenesis is quite important. The demonstration of a new autoantibody directed to hLAMP-2 and the resemblance to some microbial structures, in addition to the determination of the possible roles of hepatitis B and C on vasculitis are important findings. These hints may lead to new biomarker developments, providing a better method to diagnose vasculitis. The evidence on T cell immunity as circulatory and lesional will likely contribute to the development of new drugs for vasculitis.

Oxidative stress and antioxidants in hepatic pathogenesis

Long term hepatitis B virus (HBV) infection is a major risk factor in pathogenesis of chronic liver diseases, including hepatocellular carcinoma (HCC). The HBV encoded proteins, hepatitis B virus X protein and preS, appear to contribute importantly to the pathogenesis of HCC. Both are associated with oxidative stress, which can damage cellular molecules like lipids, proteins, and DNA during chronic infection. Chronic alcohol use is another important factor that contributes to oxidative stress in the liver. Previous studies reported that treatment with antioxidants, such as curcumin, silymarin, green tea, and vitamins C and E, can protect DNA from damage and regulate liver pathogenesis-related cascades by reducing reactive oxygen species. This review summarizes some of the relationships between oxidative stress and liver pathogenesis, focusing upon HBV and alcohol, and suggests antioxidant therapeutic approaches.

Pre-acute hepadnaviral infection is associated with activation-induced apoptotic death of lymphocytes in the woodchuck (Marmota monax) model of hepatitis B

Woodchucks (Marmota monax) infected with woodchuck hepatitis virus (WHV) represent a highly valuable immunopathogenic model of hepatitis B virus (HBV) infection. Both WHV and HBV are noncytopathic hepadnaviruses which induce a strong but delayed virus-specific cellular immune response believed to be a cause of hepatitis. The reason behind this postponement is not well understood and its dissection in the woodchuck model has been hampered by the lack of appropriate research tools. In this study, we applied an assay for the simultaneous detection of cell apoptosis and proliferation to determine the fate of T lymphocytes after WHV infection leading to acute hepatitis. The results revealed that pre-acute WHV infection is associated with the significantly heightened susceptibility of T lymphocytes to activation-induced apoptotic death. This suggests that T lymphocyte function is compromised very early in the course of hepadnaviral infection and this may directly contribute to the postponement of virus-specific T cell response.

American Chemical Society-239th national meeting--Investigating new therapeutic candidates: part 1. 21-25 March 2010, San Francisco, CA, USA

The American Chemical Society 239th National Meeting, held in San Francisco, included topics covering developments related to the chemical optimization of therapeutics. This conference report highlights selected presentations on agents under investigation for the treatment of neurological disorders, malaria, HBV and diabetes. Investigational drugs discussed include PF-4888086, PF-4778574 and SAM-531 (all Pfizer Inc), a series of spirotetrahydro-beta-carbolines from Novartis AG, a series of biaryl ether analogs from Merck & Co Inc, and PF-04620110 (Pfizer Inc/Bristol-Myers Squibb Co).

Obesity and diabetic hyperglycemia were associated with serum alanine aminotransferase activity in patients with hepatitis B infection

Several studies have reported that obesity and diabetes are important risk factors for elevated blood aminotransferase activity in individuals with no underlying causes of liver disease. The aim of this study was to determine whether obesity and fasting glucose level were associated with hepatic dysfunction in patients with hepatitis B infection. A total of 934 patients with hepatitis B infection were enrolled, among whom increased alanine aminotransferase (ALT) activity (> or =40 IU/L) was observed in 25.1%. By univariate analysis, factors associated with increased ALT activity among patients with hepatitis B infection included body mass index (BMI), fasting blood glucose level, and blood triglyceride and high-density cholesterol levels. By multivariate logistic regression analysis, BMI and fasting blood glucose level were independent predictors of elevated ALT activity, with odds ratios of 1.73 (95% confidence interval, 1.17-2.56) for subjects with a BMI greater than or equal to 25 kg/m2 and 1.88 (95% confidence interval, 1.06-3.33) for subjects with a fasting blood glucose greater than or equal to 126 mg/dL. Even in subjects with ALT activity within the reference range, ALT activity was found to be associated with BMI. In conclusion, a BMI greater than or equal to 25 kg/m2 and a fasting blood glucose level greater than or equal to 126 mg/dL were risk factors for increased ALT activity in subjects with hepatitis B infection, suggesting that obesity and diabetic fasting hyperglycemia may aggravate liver injury in this population.

Pathogenesis of hepatitis B virus infection

The adaptive immune response is thought to be responsible for viral clearance and disease pathogenesis during hepatitis B virus infection. It is generally acknowledged that the humoral antibody response contributes to the clearance of circulating virus particles and the prevention of viral spread within the host while the cellular immune response eliminates infected cells. The T cell response to the hepatitis B virus (HBV) is vigorous, polyclonal and multispecific in acutely infected patients who successfully clear the virus and relatively weak and narrowly focussed in chronically infected patients, suggesting that clearance of HBV is T cell dependent. The pathogenetic and antiviral potential of the cytotoxic T lymphocyte (CTL) response to HBV has been proven by the induction of a severe necroinflammatory liver disease following the adoptive transfer of HBsAg specific CTL into HBV transgenic mice. Remarkably, the CTLs also purge HBV replicative intermediates from the liver by secreting type 1 inflammatory cytokines thereby limiting virus spread to uninfected cells and reducing the degree of immunopathology required to terminate the infection. Persistent HBV infection is characterized by a weak adaptive immune response, thought to be due to inefficient CD4+ T cell priming early in the infection and subsequent development of a quantitatively and qualitatively ineffective CD8+ T cell response. Other factors that could contribute to viral persistence are immunological tolerance, mutational epitope inactivation, T cell receptor antagonism, incomplete down-regulation of viral replication and infection of immunologically privileged tissues. However, these pathways become apparent only in the setting of an ineffective immune response, which is, therefore, the fundamental underlying cause. Persistent infection is characterized by chronic liver cell injury, regeneration, inflammation, widespread DNA damage and insertional deregulation of cellular growth control genes, which, collectively, lead to cirrhosis of the liver and hepatocellular carcinoma.

Control of cccDNA function in hepatitis B virus infection

The template of hepatitis B virus (HBV) transcription, the covalently closed circular DNA (cccDNA), plays a key role in the life cycle of the virus and permits the persistence of infection. Novel molecular techniques have opened new possibilities to investigate the organization and the activity of the cccDNA minichromosome in vivo, and recent advances have started to shed light on the complexity of the mechanisms controlling cccDNA function. Nuclear cccDNA accumulates in hepatocyte nuclei as a stable minichromosome organized by histone and non-histone viral and cellular proteins. Identification of the molecular mechanisms regulating cccDNA stability and its transcriptional activity at the RNA, DNA and epigenetic levels in the course of chronic hepatitis B (CH-B) infection may reveal new potential therapeutic targets for anti-HBV drugs and hence assist in the design of strategies aimed at silencing and eventually depleting the cccDNA reservoir.

Gastroenterology in developing countries: issues and advances

Developing countries shoulder a considerable burden of gastroenterological disease. Infectious diseases in particular cause enormous morbidity and mortality. Diseases which afflict both western and developing countries are often seen in more florid forms in poorer countries. Innovative techniques continuously improve and update gastroenterological practice. However, advances in diagnosis and treatment which are commonplace in the West, have yet to reach many developing countries. Clinical guidelines, based on these advances and collated in resource-rich environments, lose their relevance outside these settings. In this two-part review, we first highlight the global burden of gastroenterological disease in three major areas: diarrhoeal diseases, hepatitis B, and Helicobacter pylori. Recent progress in their management is explored, with consideration of future solutions. The second part of the review focuses on the delivery of clinical services in developing countries. Inadequate numbers of healthcare workers hamper efforts to combat gastroenterological disease. Reasons for this shortage are examined, along with possibilities for increased specialist training. Endoscopy services, the mainstay of gastroenterology in the West, are in their infancy in many developing countries. The challenges faced by those setting up a service are illustrated by the example of a Nigerian endoscopy unit. Finally, we highlight the limited scope of many clinical guidelines produced in western countries. Guidelines which take account of resource limitations in the form of "cascades" are advocated in order to make these guidelines truly global. Recognition of the different working conditions facing practitioners worldwide is an important step towards narrowing the gap between gastroenterology in rich and poor countries.

The changes of hepatic hemodynamics and functional hepatic reserve after splenectomy with periesophagogastric devascularization

BACKGROUND/AIMS

The results of much research on the variation of the hepatic hemodynamic and functional hepatic reserve after splenectomy with periesophagogastric devascularization are very different, some are even converse. The purpose of this study is to observe the variation.

METHODOLOGY

From July 2006 to August 2007, thirty patients with portal hypertension caused by hepatitis B cirrhosis underwent splenectomy with periesophagogastric devascularization in our medical group in West China Hospital of Sichuan University. The PVPG (portal venous pressure gradient) was measured by inductor continually during operation. Moreover, the HAF (hepatic artery flow), PVF (portal venous flow) and hepatic arterial RI (resistant index) were measured with Doppler sonography. The EHBF (effective hepatic blood flow) and ICGR15 (indocyanine green retention rate at 15 minutes) were obtained respectively by indocyanine green clearance test before and after the operation. The MELD (model for end stage liver disease) score was calculated at the same time.

RESULTS

The four values of PVPG after laparotomy, ligating the splenic artery, splenectomy and periesophagogastric devascularization showed a tendency to decrease progressively. The PVF decreased and HAF increased in compensation after operation. The EHBF increased, and both the ICGR15 and the MELD score decreased postoperatively.

CONCLUSIONS

After splenectomy with periesophagogastric devascularization, the functional hepatic reserve increases at least in the short term notwithstanding the PVPG and PVF decrease.

The dynamics of a delay model of hepatitis B virus infection with logistic hepatocyte growth

Chronic HBV affects 350 million people and can lead to death through cirrhosis-induced liver failure or hepatocellular carcinoma. We analyze the dynamics of a model considering logistic hepatocyte growth and a standard incidence function governing viral infection. This model also considers an explicit time delay in virus production. With this model formulation all model parameters can be estimated from biological data; we also simulate a course of lamivudine therapy and find that the model gives good agreement with clinical data. Previous models considering constant hepatocyte growth have permitted only two dynamical possibilities: convergence to a virus free or a chronic steady state. Our model admits a third possibility of sustained oscillations. We show that when the basic reproductive number is greater than 1 there exists a biologically meaningful chronic steady state, and the stability of this steady state is dependent upon both the rate of hepatocyte regeneration and the virulence of the disease. When the chronic steady state is unstable, simulations show the existence of an attracting periodic orbit. Minimum hepatocyte populations are very small in the periodic orbit, and such a state likely represents acute liver failure. Therefore, the often sudden onset of liver failure in chronic HBV patients can be explained as a switch in stability caused by the gradual evolution of parameters representing the disease state.

[Evaluation of the effect of living donor liver transplantation on the treatment of severe hepatitis]

OBJECTIVE

To evaluate the effect of living donor liver transplantation on the treatment of severe hepatitis.

METHODS

18 patients with severe hepatitis received liver transplantation (transplanted severe hepatitis group), 28 patients with sever hepatitis received non surgical treatment (non-transplanted severe hepatitis group), and 30 patients with end stage liver cirrhosis (without cancer) received liver transplantation (transplanted cirrhosis group). The vital sign, blood coagulation, and renal function were monitored during operation. After liver transplantation, patients received immunosuppressive therapy (including tacrolimus or cyclosporine A, mycophenolate, mofetil and corticosteroids), intensive care, antiviral therapy (including lamivudine and HBIg) and other treatments (including restoration of liver function and prevention of blood coagulation). Pre-operation data, operation procedure, liver function, renal function and the operation complications of three groups were compared, and survival rate at 1, 6 and 12 months after operation was followed.

RESULTS

There was no significant difference in the operation time, warm ischemia time, hypothermic ischemia time and Graft-to-recipient weight ratio between the two transplantation groups. The blood loss volume and blood transfusion volume in the transplanted severe hepatitis group were higher than that those in the cirrhosis transplantation group (t = 0.001, 0.004). The levels of TBil, ALT and AST at day 7 after operation were (100.5 +/- 96.4)mumol/L, (215.3 +/- 195.7) U/L , (209.8 +/- 188.6) U/L in the transplanted severe hepatitis group, and (53.3 +/- 31.9)mumol/L, (56.3 +/- 22.1) U/L, (51.3 +/- 13.5) U/L in the transplanted cirrhosis group (t = 0.017, 0.021, 0.004). However, there was no significant difference in the levels of Alb and Cr between these two groups (P > 0.05). Survival rate was 88.89%, 83.33% 83.33% in the transplanted severe hepatitis group, and 96.67%, 93.33% 93.33% in the transplanted cirrhosis group at 1, 6 and 12 months after transplantation.

CONCLUSION

Living donor liver transplantation is one of effect ways for the treatment of severe hepatitis.

[HBV as one of the causes for development of cholelithiasis]

The aim of this study was to identify the influence of HBV on gall bladder and to establish necessity and terms of preventive measures. For this reason we have examined 58 patients, passed through cholecystectomy and 142 patients with B hepatitis. Patients of this group were followed up during 18 months. In the first group presence HBsAg in the gall bladder tissue was identified using immunoferment analysis and immunofluorescent testing. In all cases the blood was tested for specific markers (HBsAg, Anti-HB-cor antibodies of G and M classes). In the second group 75 patients were investigated prospectively. Observation using ultrasound was performed to find out the changes of gall bladder and bile. In this group preventive measures against gallstone formation were performed. 67 patients were investigated retrospectively and prevention was not performed among them. In 10 cases of cholecystectomy (17,2%) out of 58, HBsAg in the gall bladder tissue was identified both, with immunoferment analysis and immunofluorescent testing. The ultrasound examination revealed morpho-functional changes of gall bladder and bile in the acute stage of hepatitis B and also in following period. There were no cases of development of gallstones in the group where preventive measures using dietary fiber-rich food "Margi" were conducted, in the second group, where such measures have not been performed, gallstones developed in 5 patients (7,46%) out of 67, during 6-18 months after the acute B hepatitis. This results allow us to conclude, that cholecystopathogenic influence of HBV leads to the morpho-functional changes of gall bladder. This fact must be assessed as a risk factor for development of cholelithiasis and confirms necessity of early longlasting preventive measures.

Nucleotide analogs for patients with HBV-related hepatocellular carcinoma increase the survival rate through improved liver function

BACKGROUND AND AIM

This study evaluated the outcomes of antiviral therapy with nucleotide analogs for hepatitis B virus infection-related hepatocellular carcinoma.

METHODS

Thirty patients orally received nucleotide analogs and, as a matched control group, 20 patients who were not treated with nucleotide analogs were selected. We compared changes in liver function, HCC recurrence and survival rate between both groups.

RESULTS

In the nucleotide analog group, serum albumin, AST and ALT were significantly improved compared with baseline values. The Child-Pugh score was significantly decreased in the nucleotide analog group. Furthermore, of the 36 patients curatively treated with the initial treatment, more patients in the nucleotide analog group improved or maintained their Child-Pugh score at the time of recurrent HCC than in the control group (p=0.023). The cumulative recurrent-free survival rate of HCC did not significantly differ between the two groups; however, the cumulative survival rates of not only curative-treated patients but also all patients in the nucleotide analog group were significantly higher than those of patients in the control group (p=0.047 and p=0.02, respectively).

CONCLUSION

The results suggest that nucleotide analog treatment increases the survival rate in patients with HCC by contributing to the improvement of remnant liver function.

[Occult hepatitis B virus infection in chronic viral hepatitis patients with non-A to E hepatitis virus infection]

OBJECTIVE

To observe the status of occult hepatitis B virus infection in chronic viral hepatitis patients with non-A to E hepatitis virus infection and explore the diagnostic value of fluorescence quantitative polymerase chain reaction (FQ-PCR) technique for occult hepatitis B virus infection.

METHODS

The amount of HBV-DNA in serum and liver tissue from 57 patients with non-A to E hepatitis virus infection who were diagnosed as chronic viral hepatitis by Menghini method liver biopsy were detected by using FQ-PCR technique, then the relation between the viral load of HBV DNA in liver tissue and hepatic inflammatory activity were analyzed.

RESULTS

Thirteen (22.81%), 22 (38.60%) patients were positive for HBV DNA in serum and liver tissue, respectively. The positive rate and the level of HBV DNA quantity in liver tissue were significantly higher than those in serum; HBV DNA was found positive in both serum and liver tissue in 13 cases, negative in both serum and liver tissue in 35, positive in liver tissue but negative in serum in 9, and in none of the cases HBV DNA was positive in serum but negative in liver tissue (P < 0.01). The logarithmic value of HBV DNA from 13 patients in liver tissue and in serum was respectively: (6.62 +/- 1.21) copies/g vs.(4.03 +/- 1.06) copies/ml, P < 0.01. The hepatic lesions of all HBV DNA positive patients were active pathologic changes, but the level of HBV DNA in liver tissue was not significantly correlated with the grade of hepatic inflammation activity (P > 0.05).

CONCLUSION

Occult HBV infection is the etiology of part of the chronic viral hepatitis patients with non-A-E hepatitis virus infection. Missed diagnosis will occur if diagnosis of hepatitis B is only based on detection of serum HBV markers. It is useful for improvement of the diagnostic level of HBV infection via detection of HBV DNA quantitatively in serum especially in liver tissue of chronic viral hepatitis patients with non-A-E hepatitis virus infection by using FQ-PCR technique. The chronic viral hepatitis patients with occult HBV infection should be also given effective anti-viral therapy.