Tumour necrosis factor to treat chronic hepatitis B virus infection

Psoriasis, hepatitis B, and the tumor necrosis factor-alpha inhibitory agents: a review and recommendations for management

BACKGROUND

Tumor necrosis factor inhibitory agents are currently considered to be contraindicated in psoriatic patients with hepatitis B.

OBJECTIVE

We aim to provide guidance to dermatologists on the use of tumor necrosis factor inhibitor therapy in these patients.

METHODS

The current literature was reviewed regarding the use of tumor necrosis factor-alpha inhibitory agents (etanercept, adalimumab, and infliximab) in psoriatic patients with particular reference to hepatitis B infection.

RESULTS

Tumor necrosis factor-alpha inhibitor therapy may result in reactivated hepatitis B in hepatitis B surface antigen-positive patients with psoriasis. This also occurs, although less frequently in patients with an isolated positive hepatitis B core antibody. Thus, all psoriasis patients should be screened for hepatitis B surface antigen plus hepatitis B core antibody prior to the initiation of tumor necrosis factor-alpha inhibitor therapy. Infliximab has been associated with more reactivation cases than the other 2 agents and fatalities have been reported with this agent. Evidence is presented that the risk of reactivation can be greatly minimized or eliminated by early or pre-emptive antiviral therapy.

LIMITATIONS

The data is largely based on small case series that are retrospective in nature.

CONCLUSIONS

Hepatitis B screening is essential prior to the initiation of tumor necrosis factor-alpha inhibitor therapy. Psoriatic patients found to be hepatitis B surface antigen or hepatitis B core antibody-positive should be referred to an appropriate specialist for evaluation and therapy. This would allow for the safe use of tumor necrosis factor-alpha inhibitors in psoriatic patients despite recently published guidelines to the contrary.

Choice of Biologic Therapy for Patients with Rheumatoid Arthritis: The Infection Perspective

Biologicals revolutionized the treatment of Rheumatoid Arthritis (RA). The targeted suppression of key inflammatory pathways involved in joint inflammation and destruction allows better disease control, which, however, comes at the price of an elevated infection risk due to relative immunosuppression. The disease-related infection risk and the infection risk associated with the use of TNF-α inhibitors (infliximab, adalimumab, etanercept, golimumab and certolizumab pegol), rituximab, abatacept and tocilizumab are discussed. Risk factors clinicians need to take into account when selecting the most appropriate biologic therapy for RA patients, as well as precautions and screening concerning a number of specific infections, such as tuberculosis, intracellular bacterial infections, reactivation of chronic viral infections and HIV are reviewed.

Use of tumor necrosis factor-alpha inhibitors in patients with chronic hepatitis B infection

OBJECTIVE

Tumor necrosis factor-alpha (TNF-alpha) inhibitors have emerged as a potent treatment for rheumatoid arthritis (RA), but not without significant risks. In chronic hepatitis B viral infection TNF-alpha is readily produced, and viral clearance is dependent on the amount bioavailable. Limited data suggest that TNF-alpha inhibitors may facilitate uncontrolled hepatitis B viral replication. The purpose of this article was to provide a detailed review of the role of TNF-alpha in controlling hepatitis B viral infection and the clinical impact blockade might have on viral control.

METHODS

We describe a patient with chronic hepatitis B viral infection and RA treated with etanercept. We then review case reports, expert opinion, and manufacturer recommendations regarding hepatitis B viral infection, TNF-alpha, and TNF-alpha inhibitors.

RESULTS

To date, 13 patients with chronic hepatitis B infection treated with TNF-alpha inhibitors have been reported: 11 with infliximab and 2 with etanercept. Some patients received antiviral therapy for hepatitis B (specifically lamivudine) before, during, or after TNF-alpha inhibitors were started. Clinically apparent reactivation of hepatitis B virus typically occurred 1 month after the 3rd dose of infliximab. Etanercept was not associated with a similar reactivation. The difference between infliximab and etanercept in viral reactivation may be linked to the pharmacologic difference of each medication.

CONCLUSIONS

TNF-alpha inhibitors in general should be used cautiously in chronic hepatitis B viral infection. But if necessary, when deciding which agent to use, the clinician should consider the mechanism by which the body clears TNF-alpha.

Serum concentration of gammaGT is a surrogate marker of hepatic TNF-alpha mRNA expression in chronic hepatitis C

Serum gammaGT levels and hepatic expression of tumor necrosis factor-alpha (TNF-alpha) are host factors that can independently predict the outcome of interferon (IFN) treatment in patients with chronic hepatitis C virus (HCV) infection. To explore whether a correlation exists between these two factors, we measured pretreatment gammaGT levels in serum and TNF-alpha mRNA levels in liver biopsies of chronic HCV patients. Seventy-two HCV patients treated with 3-to-5 million units of IFN-alpha three times a week were enrolled in the study. Treatment lasted 24 weeks and was followed by a 48-week follow-up period. Efficacy was assessed by measuring HCV RNA and alanine aminotransferase by the end of follow-up. Twelve patients (16.6%) showed a sustained biochemical and virological response. Normal pretreatment gammaGT levels, low HCV RNA titer, and infection with genotype other than HCV-1 were shown to be independent predictors of sustained response. Hepatic levels of TNF-alpha mRNA, quantified by polymerase chain reaction, were significantly higher in nonresponders (3.44 arbitrary units) compared to sustained responders (1.84 arbitrary units; P = 0.009). Values </=3.12 arbitrary units independently predicted a sustained response to IFN (P = 0.014). Finally, TNF-alpha mRNA levels were significantly correlated with serum gammaGT levels (r = 0.79, P < 0.0001). These findings suggest that serum gammaGT levels may represent a surrogate marker of hepatic TNF-alpha expression, thus explaining the importance of serum gammaGT levels in predicting treatment outcome.

The significance of apoptosis in the liver

Apoptosis is a form of cell death which occurs in normal as well as in pathological tissues. We provide a description of the morphological changes during apoptosis and an overview of the role of apoptosis dysregulation in the pathogenesis of non-neoplastic liver diseases.

Current status of anti-HBV chemotherapy

In the past decade, significant progress has been achieved in the battle against hepatitis B virus. In addition to the immunomodulating agents such as interferon-alpha and thymosin, many novel antiviral agents have been discovered, among which nucleoside analogues are the mainstay. New-generation compounds such as 3TC and famciclovir have shown promise in the treatment of patients chronically infected by this virus, and are on the line for approval. However, viral rebound after cessation of therapy still remains a major problem. Additionally, the reports on the drug resistance to these antiviral agents suggest that combination therapy will be the eventual strategy (Bartholomew et al., 1997; Tipples et al., 1996). Therefore, developments of safe and effective antiviral agents which do not cross-resist with currently available antiviral drugs are still much needed.

Tumor necrosis factor-alpha and interferon-gamma inhibit synergistically viral replication in hepatitis B virus-replicating cells

The effects of tumor necrosis factor-alpha and/or interferon-gamma on the replication of hepatitis B virus were examined using HB611 cells. These cells were derived from human hepatoblastoma cells, Huh6, by integrating hepatitis B virus DNA, and produce hepatitis B virus continuously. Each of the cytokines inhibited hepatitis B virus replication in the cells assessed as the amount of episomal hepatitis B virus DNA, without a decrease in cell viability. When the two cytokines were administered together, the inhibitory effect became greater. Incubation of the cells with 1,000 U/ml tumor necrosis factor-alpha decreased HBV DNA replicative intermediates by 55%, and that with 1,000 U/ml interferon-gamma decreased these by 51%. Furthermore, incubation with 1,000 U/ml tumor necrosis factor-alpha and 1,000 U/ml interferon-gamma in combination decreased HBV DNA replicative intermediates by 71%. In contrast, the amount of hepatitis B virus RNA and secretion of hepatitis B e antigen were not apparently reduced by the cytokines, and 2',5'-oligoadenylate synthetase activity was not detected in the supernatant. These results suggest that tumor necrosis factor-alpha and interferon-gamma inhibit hepatitis B virus replication by blocking some step in reverse transcription and that the 2',5'-oligoadenylate synthetase is not involved in the mechanism underlying the inhibition by these two cytokines.

Hepatic expression of tumour necrosis factor-alpha in chronic hepatitis B virus infection

AIM

To determine the hepatic expression of tumour necrosis factor-alpha (TNF alpha) in patients with chronic hepatitis B virus (HBV) infection.

METHODS

Frozen liver biopsy sections from 19 patients with chronic HBV infection were studied, 12 of whom were HBeAg positive and 10 serum HBV DNA positive. Hepatic expression of TNF alpha was determined using immunohistochemistry.

RESULTS

Only infiltrating mononuclear cells showed immunoreactive staining for TNF alpha (median 2, range 0-3; n = 19) which appeared as diffuse positive staining material in the cytoplasm. Patients with active liver disease, assessed histologically and biochemically, had a higher level of expression, both in the number of TNF alpha positive cells and the proportion of TNF alpha positive infiltrating mononuclear cells. There was no correlation between the expression of TNF alpha and serological parameters of viral infection (HBeAg and HBV DNA status and HBV DNA concentrations).

CONCLUSION

Hepatic expression of TNF alpha is increased in chronic HBV infection and is related to the activity of liver disease and not to the level of HBV replication.

Hepatitis B virus infection in schistosomiasis mansoni

Schistosomiasis and hepatitis B virus (HBV) infection are very common in Brazil but the interrelationships between the two infections are poorly understood. We have undertaken a detailed serological study of the prevalence of HBV markers in 189 Brazilian patients with chronic schistosomiasis mansoni, 46 with hepatointestinal (HIS) and 143 with hepatosplenic (HSS) schistosomiasis, 12 of the latter having decompensated liver disease (HSSD), and in 50 control patients. Sera were tested for HBsAg, anti-e, anti-HBc, anti-HBs and HBV-DNA. Eighty-three (44%) of the 189 schistosoma patients had at least one marker of HBV infection, 18 of whom (10%) were seropositive for HBsAg. All the controls were HBsAg negative, but ten (20%) had anti-HBc and anti-HBs. There was no significant difference in the frequency of these markers between HIS (14/46, 30.4%), HSSC (43/131, 34.5%), and the controls. Among the HBsAg-positive patients, one had HIS (HBV-DNA negative), seven had HSSC (one HBV-DNA positive) and ten had HSSD (six HBV-DNA positive), a significant association of HBV carriage with HSSD (P << 0.001). Mean (+/- SD) ALT values were significantly (P < 0.001) higher in HBsAg-positive HSSD patients (70.7 +/- 18 IU/liter) than in those with HSSC (29.5 +/- 15 IU/liter). Liver biopsies were performed in 12 HBsAg-positive patients (one with HIS, three with HSSC, and eight with HSSD) and in 50 HBsAg-negative HSSC patients. Seven of the eight HSSD patients had chronic active hepatitis with cirrhosis, and one had inactive cirrhosis. All three patients with HSSC and the one with HIS had chronic persistent hepatitis, with periportal fibrosis in three.(ABSTRACT TRUNCATED AT 250 WORDS)

IL-8 as a circulating cytokine: induction by recombinant tumour necrosis factor-alpha

Tumour necrosis factor-alpha (TNF-alpha) is a pivotal cytokine at the centre of a cascade of cytokines and inflammatory mediators which modulate the host response to infection and trauma, and in particular the metabolic changes resulting in shock and subsequent multi-organ failure. The cytokine IL-8--predominantly an activator and chemotactic factor for circulating polymorphonuclear neutrophil leucocytes--is produced in response to TNF-alpha in vitro, and high circulating levels of IL-8 are found in septic primates. We have studied the release of IL-8 into the circulation of subjects with chronic hepatitis B undergoing a 10 week pilot trial of recombinant TNF-alpha (rTNF-alpha) therapy in doses of 15-100 micrograms/m2. A marked dose-dependent increase in plasma IL-8 levels was seen commencing at 30-60 min after the start of rTNF-alpha infusion and peaking between 2 and 3 h (mean peak level 4300 ng/l). The temporal pattern of IL-8 production exactly echoed that of IL-6, another component of the cytokine cascade, but peak plasma levels of IL-8 were up to 17 times higher than those of IL-6. This study confirms in vitro data suggesting that IL-8 is a component of the acute circulating cytokine cascade with a potential role in the modulation of the acute immune and metabolic response to infection and trauma.

Tumor necrosis factor alpha negatively regulates hepatitis B virus gene expression in transgenic mice

It is well known that several inflammatory cytokines can modulate hepatocellular gene expression in a complex physiological process known as the hepatic acute-phase response. Since hepatitis B virus (HBV) characteristically induces a vigorous lymphomononuclear inflammatory response in the liver during acute and chronic hepatitis, it is possible that hepatocellular HBV gene expression may also be modulated by one or more of the cytokines produced by these cells. Using bacterial lipopolysaccharide (LPS) as a surrogate inducer of inflammatory cytokines in vivo, we have tested this hypothesis in a transgenic mouse model system. In experiments with two independent transgenic mouse lineages that express the HBV envelope region under the control of either HBV or cellular promoters, we observed a 50 to 80% reduction in the hepatic steady-state content of a 2.1-kb HBV mRNA following administration of a single intraperitoneal dose of LPS. The regulatory influence of several inflammatory cytokines known to be induced by LPS was also examined in this system. The negative regulatory effect of LPS was consistently reproduced by the administration of a single nontoxic dose of tumor necrosis factor alpha, and it was occasionally observed following the administration of high doses of alpha interferon and interleukin-6, while no effect was detectable in response to high-dose interleukin-1 alpha or to gamma interferon. These observations suggest that tumor necrosis factor alpha and perhaps other cytokines may activate a heretofore unsuspected intracellular pathway that negatively regulates HBV gene expression. The intracellular mechanism(s) responsible for this effect and its pathophysiologic relevance remain to be elucidated.

Hepatic expression of type A and type B receptors for tumor necrosis factor

We have examined the in-situ distribution of type A and type B receptors for tumor necrosis factor (TNF) in normal and diseased human liver biopsy specimens. In normal liver tissue, no or very small amounts of TNF receptors were found. In acute and chronic inflammatory liver diseases, a strong up-regulation of the expression of both TNF receptors was found on hepatocytes, bile duct epithelium, sinusoidal lining cells and mononuclear inflammatory cells. With immunoelectronmicroscopy, all these cells showed cytoplasmic, in addition to membranous staining, suggesting active synthesis of the receptor or, alternatively, internalization of the receptor and its ligand. This up-regulated expression of both type A and type B receptors for TNF was similar in acute and chronic active hepatitis, and was not related to the etiology of the liver disease, nor restricted to areas of liver inflammation. Our results indicate that hepatocytes, sinusoidal endothelial cells, bile duct epithelial cells and mononuclear inflammatory cells, by displaying receptors for TNFs, represent target cells for both these cytokines. Up-regulated expression of type A and type B receptors for TNFs endows these cells with augmented responsiveness for the pleiomorphic biological activities of these cytokines during liver injury.

Increased tumor necrosis factor-alpha receptor number in chronic hepatitis B virus infection

Production of the antiviral cytokine, tumor necrosis factor-alpha is increased in chronic hepatitis B virus infection, and clinical studies of tumor necrosis factor-alpha have indicated a proviral effect at higher doses. To determine whether this might be related to abnormal cell surface tumor necrosis factor-alpha receptor expression, binding characteristics of cell surface tumor necrosis factor-alpha receptor on peripheral blood mononuclear cells in chronic hepatitis B virus carriers were studied using radioiodinated recombinant tumor necrosis factor-alpha. The specific binding curves generated were analyzed according to the method of Scatchard to determine cell surface receptor numbers and dissociation constants. A single class of cell surface tumor necrosis factor-alpha receptor was demonstrated on peripheral blood mononuclear cells and mononuclear subsets. The median number (range) of cell surface tumor necrosis factor-alpha receptors on peripheral blood mononuclear cells from controls (n = 11), chronic hepatitis B virus patients seropositive for hepatitis B virus DNA (n = 8) and seronegative for hepatitis B virus DNA (n = 8) were 2,329 (range = 1,538 to 3,133), 3,375 (range = 2,300 to 6,718) (p less than 0.01) and 3,113 (range = 2,229 to 5,246) (p less than 0.05) sites/cell, respectively. They all had similar dissociation constants of 8.4 x 10(-10) mol/L (range = 4.1 to 16.9), respectively. Further dissection of the peripheral blood mononuclear cells showed that this increase in cell surface receptor number was confined to the monocyte fraction (p less than 0.01). Plasma tumor necrosis factor-alpha levels in five patients with increased monocyte cell surface tumor necrosis factor-alpha receptor numbers were also elevated.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased production of tumour necrosis factor alpha in chronic hepatitis B virus infection

Plasma tumour necrosis factor alpha (TNF) and in-vitro TNF production by peripheral blood mononuclear cells (PBMC) were studied in 22 HBsAg seropositive patients and compared with 23 normal and 10 disease controls. Plasma TNF and unstimulated TNF production correlated (Rs = 0.55, p = 0.012) and were significantly elevated in HBsAg and HBeAg seropositive patients (p less than 0.001, p = 0.006) compared with normal controls. TNF production was also elevated in these patients when PBMC were stimulated with interferon-gamma (p less than 0.05) or LPS (p = 0.035). Plasma TNF and TNF production in HBsAg anti-HBe seropositive subjects were not elevated. TNF production in unstimulated cells correlated with serum HBV DNA level (R = 0.53, p = 0.02) but not with serum aspartate transaminase (AST) or histological activity. It is concluded that PBMC are activated to produce TNF both spontaneously and in response to second stimuli in chronic hepatitis B virus infection and that this activity is related to the presence of viral replication.

Dose-dependent increase in plasma interleukin-6 after recombinant tumour necrosis factor infusion in humans

Several studies have shown that the cytokine interleukin-6 (IL-6) is produced in response to tumour necrosis factor (TNF) in vitro. This study examines the in vivo relation between these two cytokines with assays of plasma IL-6 and TNF levels in subjects with chronic hepatitis B undergoing immunomodulatory therapy with recombinant TNF (rTNF). Plasma IL-6 was detected from 20 min after rTNF infusion with levels peaking after 2-3 h and levels correlated with the dose of rTNF administered (r = 0.67, P = 0.004). Peak levels of IL-6 (mean 295, range 266-297 ng/l) were lower than those seen in certain disease states despite the very high peak levels of rTNF (mean 11,750, range 5623-18,620 ng/l). These findings suggest that the very high levels of IL-6 found in certain disease states are not purely the result of circulating TNF. Other factors such as endotoxin or other cytokines may also play a role in determining levels of plasma IL-6.