Ran Tur-Kaspa

Cytokine gene polymorphisms in patients infected with hepatitis B virus.

OBJECTIVE:Cytokines play a key role in the regulation of the immune response. The maximal capacity of cytokine production varies among individuals and correlates with the polymorphism in the cytokine gene promoters. The aim of this study was to characterize gene polymorphism in patients with chronic hepatitis B virus (HBV) infection and to determine the different patterns in patient subgroups.METHODS:The study population consisted of 77 patients with chronic HBV infection (23 low-level HBV replicative carriers, 23 compensated high-level HBV replicative carriers, 21 decompensated liver transplant candidates, and 10 patients with documented hepatocellular carcinoma). The genetic profile of five cytokines was analyzed by polymerase chain reaction–sequence-specific primer (SSP), and subjects were genotyped as high or low producers of tumor necrosis factor-α and interleukin (IL)-6, and as high, intermediate, or low producers of transforming growth factor-β1, interferon (IFN)-γ, and IL-10 based on single nucleotide substitutions. The control group included 10 healthy individuals who recovered from HBV infection and 48 healthy controls.RESULTS:A highly statistically significant difference in the distribution of the IFN-γ gene polymorphism (at position +879) was observed between patients with chronic HBV infection and controls. The majority of the patients (65.2%) exhibited the potential to produce low levels of IFN-γ (A/A genotype) compared with 37.5% of the control group (p = 0.003). Healthy individuals who recovered from HBV infection had a similar distribution of IFN-γ gene polymorphism as the healthy controls. No statistically significant difference in IFN-γ production was found between patients with low- and high-level HBV replication and between compensated and decompensated patients. There was also no statistically significant difference in the genetic ability to produce tumor necrosis factor-α (at position −308), IL-6 (at position −174), IL-10 (at position −1082, −819, and −592), and transforming growth factor-β1 (at position +10 and +25).CONCLUSION:These findings suggest an association between the genetic ability to produce low levels of IFN-γ and the susceptibility to develop chronic HBV infection.

Relapsing hepatitis A. Review of 14 cases and literature survey.

We have reviewed our experience with 14 cases of relapsing hepatitis A (RH-A), as well as 68 cases reported in the literature. Relapse occurs in 3 to 20% of patients with acute hepatitis A, and rarely takes the form of a polyphasic disease (multiple relapses). After a stage of typical hepatitis A, remission phase ensues, with partial or complete resolution of clinical and biochemical manifestations. Relapse usually occurs after a short period (usually less than 3 weeks). Relapse is usually clinically milder than the first phase, with variable liver function abnormalities and a tendency toward more marked cholestatic features. Not uncommonly, immune manifestations occur during this phase, including purpura, nephritis, and arthralgia, with common laboratory findings of rheumatoid factor as well as false-positive reaction to HCV-EIA tests. The clinical course in relapsing hepatitis A is almost always benign, and uneventful recovery is the rule with few exceptions. Steroid treatment, first reported in the present series, resulted in marked clinical improvement. Preliminary results suggest that R-HA is associated with a continuing viremia as well as shedding of virus in stools during the relapse phase. The pathogenesis of R-HA probably involves an interaction between persistent viral infection and immune mechanisms responding to the continuing antigenic stimulation.

Ablation of persistent hepatitis B by bone marrow transplantation from a hepatitis B-immune donor

Chronic hepatitis B virus (HBV) infection is still a major cause of liver disease for which no definite therapy is available. We describe here a hepatitis B surface antigen (HBsAg) carrier patient with active viral replication (HBV DNA positive) who was treated for leukemia by bone marrow transplantation (BMT) from an HBV immune donor. Following BMT from the antibody to hepatitis B core antigen (anti-HBc) positive/anti-HBs positive bone marrow donor, immune reconstitution of the recipients bone marrow resulted in clearance of the circulating HBsAg, as well as HBV DNA. The patient acquired immunity against HBV, which lasted for more than 8 months posttransplantation. Therefore, this report provides evidence that adoptive transfer of specific immunity against HBV through allogeneic BMT may lead to clearance of persistent HBV infection. Furthermore, the data support the hypothesis that the HBsAg carrier state is most probably the result of an inefficient immune response against HBV, implying that clearance of HBV may be facilitated by adoptive cellular immunotherapy.

Monoclonal antibody HCV-AbXTL68 in patients undergoing liver transplantation for HCV: results of a phase 2 randomized study.

A randomized, double‐blind, dose‐escalation study evaluated the safety and efficacy of hepatitis C virus (HCV)‐AbXTL68, a neutralizing, high‐affinity, fully human, anti‐E2 monoclonal antibody, in 24 HCV‐positive patients undergoing liver transplantation. HCV‐AbXTL68 or placebo was administered at doses from 20‐240 mg as 2‐4 infusions during the first 24 hours after transplantation, followed by daily infusions for 6 days, weekly infusions for 3 weeks, and either 2 or 4 weekly infusions for 8 weeks. Serum concentrations of total anti‐E2 obtained during daily infusions of 120‐240 mg HCV‐AbXTL68 were 50‐200 μg/mL above concentrations in the placebo group. Median serum concentration of HCV RNA dropped below baseline in all groups immediately after transplantation. On day 2, median change from baseline in HCV RNA was −1.8 and −2.4 log in the 120‐mg and 240‐mg groups, respectively, compared with −1.5 log with placebo. The difference was lost after day 7 when the dosing frequency was reduced. The coincidence of increases in anti‐E2 with decreases in HCV RNA concentration indicate that the dose‐related changes in HCV RNA concentration were a result of HCV‐AbXTL68 administration in the 120‐ and 240‐mg groups. The overall incidence of nonfatal serious adverse events was higher with placebo (60%) vs. all active treatments combined (42%). In conclusion, HCV‐AbXTL68 may decrease serum concentrations of HCV RNA in patients after liver transplantation. Studies evaluating more frequent daily dosing at doses >120 mg are necessary to investigate sustained viral suppression in this population. Liver Transpl 12:1381–1389. 2006.

Lamivudine prevents reactivation of hepatitis B and reduces mortality in immunosuppressed patients: systematic review and meta‐analysis

Summary.  To assess the effects of prophylactic lamivudine on reactivation and mortality following immunosuppressive therapy in hepatitis B surface antigen (HBsAg)‐positive patients, we performed a meta‐analysis. Systematic review and meta‐analysis of randomized and nonrandomized prospective controlled trials and retrospective comparative case series were identified through The Cochrane Hepato‐Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and LILACS. The primary outcomes were virological reactivation, clinical reactivation and mortality. Secondary outcomes included hepatitis B virus (HBV)‐related mortality, liver histology, discontinuation or disruption of immunosuppressive therapy, lamivudine‐resistant HBV strains and adverse events. A total of 21 studies were included, two of which were randomized controlled trials. Clinical and virological reactivation were significantly reduced in the lamivudine group [odds ratio (OR) 0.09; 95% confidence interval (CI) 0.05–0.15 and OR 0.04; 95% CI 0.01–0.14 respectively]. All‐cause mortality was significantly reduced in the lamivudine group (OR 0.36; 95% CI 0.23–0.56) which translates to only 11 patients who need to be treated to prevent one death. Lamivudine significantly reduced HBV‐related mortality, and discontinuations or disruptions of the immunosuppressive treatment. No adverse effects of lamivudine were recorded, and resistance to lamivudine occurred in low rates. We demonstrated a clear benefit of lamivudine in terms of clinical and virological HBV reactivation, overall mortality, HBV‐related mortality and interruptions or discontinuations in the immunosuppressive treatment. Lamivudine should be administered prophylactically to HBsAg‐positive patients who are about to receive immunosuppressive therapy.

Vitamin D: An innate antiviral agent suppressing hepatitis C virus in human hepatocytes†‡

Vitamin D supplementation was reported to improve the probability of achieving a sustained virological response when combined with antiviral treatment against hepatitis C virus (HCV). Our aim was to determine the in vitro potential of vitamin D to inhibit HCV infectious virus production and explore the mechanism(s) of inhibition. Here we show that vitamin D3 remarkably inhibits HCV production in Huh7.5 hepatoma cells. These cells express CYP27B1, the gene encoding for the enzyme responsible for the synthesis of the vitamin D hormonally active metabolite, calcitriol. Treatment with vitamin D3 resulted in calcitriol production and induction of calcitriol target gene CYP24A1, indicating that these cells contain the full machinery for vitamin D metabolism and activity. Notably, treatment with calcitriol resulted in HCV inhibition. Collectively, these findings suggest that vitamin D3 has an antiviral activity which is mediated by its active metabolite. This antiviral activity involves the induction of the interferon signaling pathway, resulting in expression of interferon‐β and the interferon‐stimulated gene, MxA. Intriguingly, HCV infection increased calcitriol production by inhibiting CYP24A1 induction, the enzyme responsible for the first step in calcitriol catabolism. Importantly, the combination of vitamin D3 or calcitriol and interferon‐α synergistically inhibited viral production. Conclusion: This study demonstrates for the first time a direct antiviral effect of vitamin D in an in vitro infectious virus production system. It proposes an interplay between the hepatic vitamin D endocrine system and HCV, suggesting that vitamin D has a role as a natural antiviral mediator. Importantly, our study implies that vitamin D might have an interferon‐sparing effect, thus improving antiviral treatment of HCV‐infected patients. (HEPATOLOGY 2011;)

Lamivudine treatment for acute severe hepatitis B: a pilot study.

Abstract: Background: Experience with lamivudine treatment of immunocompetent patients with acute hepatitis B is limited.

Cell transformation induced by hepatitis C virus NS3 serine protease

Persistent infection with hepatitis C virus (HCV) may lead to hepatocellular carcinoma (HCC). It has been suggested that HCV‐encoded proteins are directly involved in the tumorigenic process. The HCV nonstructural protein NS3 has been identified as a virus‐encoded serine protease. To study whether HCV NS3 has oncogenic activity, nontumorigenic rat fibroblast (RF) cells were stably transfected with an expression vector containing cDNA for the NS3 serine protease (nucleotides 3356–4080). The NS3 serine protease activity was determined in the transfected cells. The transfected cells grew rapidly and proliferated serum independently, lost contact inhibition, grew anchorage independently in soft agar and induced significant tumour formation in nude mice. Cells transfected with an expression vector containing a mutated NS3 serine protease (serine 139 to alanine at the catalytic site) showed no transforming abilities; their growth was dependent on serum and they did not grow anchorage independently in soft agar. Moreover, cells transfected with the NS3 serine protease and treated with the chymotrypsin inhibitors TPCK and PMSF (a serine protease inhibitor) lost their transforming feature. These results suggest that the NS3 serine protease of HCV is involved in cell transformation and that the ability to transform requires an active enzyme.

Corticosteroids stimulate hepatitis B virus DNA, mRNA and protein production in a stable expression system

The effect of corticosteroids (Dexamethasone) on hepatitis B virus was investigated in human hepatoblastoma cells stable transfected with recombinant HBV DNA. Dexamethasone was found to cause elevation of HBsAg, HBeAg and viral DNA production. HBV poly(A)+ RNA was significantly increased in cells treated with Dexamethasone. Furthermore, pulse labelled nuclear HBV RNA was also stimulated by Dexamethasone. These findings, suggest that corticosteroids enhance expression of viral gene products by stimulating HBV transcription.

Suppression of hepatitis C virus by the flavonoid quercetin is mediated by inhibition of NS3 protease activity

Summary.  Phytochemicals exert antiviral activity and may play a potential therapeutic role in hepatitis C virus (HCV) infection. In this work, we aimed to isolate NS3 inhibitors from traditional Indian medicinal plants that were found, in our earlier study, to inhibit HCV NS3 protease activity and to evaluate their potential to inhibit HCV replication. A potent inhibitory effect of NS3 catalytic activity was obtained with Embelia ribes plant extracts. Quercetin, a ubiquitous plant flavonoid, was identified as the active substance in the fractioned extract. It was found to inhibit NS3 activity in a specific dose‐dependent manner in an in vitro catalysis assay. Quercetin inhibited HCV RNA replication as analysed in the subgenomic HCV RNA replicon system. It also inhibited HCV infectious virus production in the HCV infectious cell culture system (HCVcc), as analysed by the focus‐forming unit reduction assay and HCV RNA real‐time PCR. The inhibitory effect of quercetin was also obtained when using a model system in which NS3 engineered substrates were introduced in NS3‐expressing cells, providing evidence that inhibition in vivo could be directed to the NS3 and do not involve other HCV proteins. Our work demonstrates that quercetin has a direct inhibitory effect on the HCV NS3 protease. These results point to the potential of quercetin as a natural nontoxic anti‐HCV agent reducing viral production by inhibiting both NS3 and heat shock proteins essential for HCV replication.