Pathogenesis of occult chronic hepatitis B virus infection

Suggested blood donor deferral strategy regarding hepatitis B infections in China

BACKGROUND

Hepatitis B virus (HBV) reactivity in individual immunologic and nucleic acid tests (NAT) tests does not represent the true infectious status of the blood donor. This study discusses the use of confirmatory tests to determine when deferral of blood donors is appropriate.

METHODS

HBsAg or HBV NAT reactive samples were confirmed via a neutralisation test. All the HBsAg reactive but neutralisation test negative samples were subjected to further anti-HBc testing. The receiver operating characteristic curve was used to obtain the best threshold value using signal-to-cut-off ratios of two HBsAg enzyme-linked immunosorbent assay reagents.

RESULTS

Of the 780 HBV reactive samples collected, there were 467 HBsAg reactive but HBV DNA negative samples, of which 65 (13.92%) and 402 (86.08%) were neutralisation test positive and negative, respectively. Of the 402, 91 samples (30% of tested samples) were anti-HBc reactive. HBV DNA positive specimens negative by virus neutralisation were >80% HBcAg positive. A screening strategy was proposed for Chinese blood collection agencies.

CONCLUSION

These findings suggest that adopting a screening algorithm for deferring HBV reactive blood donors based on HBsAg and NAT testing followed with HBsAg S/CO consideration and HBcAg testing can be both safe and feasible in China.

EVALUATION OF SEROLOGICAL SCREENING AND PCR-AMPLIFICATION OF HEPATITIS B VIRUS DNA AMONG IRAQI BLOOD DONORS

OBJECTIVE

The aim: Infection with the hepatitis B virus (HBV) caused by blood transfusion is a big problem throughout the world. The aim of study is to determine the faster and more accurate methods for detection of hepatitis B infections by serological screening and PCR- amplification.

PATIENTS AND METHODS

Materials and methods: A total of 140528 donors were tested for HBsAg and total anti-HBc from January to October 2021 in Iraq's National Blood Transfusion Center; however, only 100 samples with HBsAg (-) and anti-HBc (+) were collected and tested for HBV DNA using quantitative real-time PCR.

RESULTS

Results: From 2015 to 2021, the percentage of HBsAg positive donors was 0.33 percent in 2015, 0.32 percent in 2016, 0.30 percent in 2017, 0.28 percent in 2018, 0.23 percent in 2019, 0.22 percent in 2020, and 0.27 percent in 2021. Between January and October of 2021, the overall anti-HBc rate among the (140528) donors was 4.42 percent. According to our findings, only 7% of blood samples from NBTC donors with HBsAg (-) anti-HBc (+) were positive for HBV DNA. The results showed no significant change in HBs Ag (+) and total anti-HBc rates among blood donors between 2015 and 2021.

CONCLUSION

Conclusions: HBV infection could be transmitted from a blood donor with OBI. PCR (RT PCR) is substantially more sensitive and effective. Despite this the use of an anti-HBc test for blood donors could be seen as a second choice to control HBV from spreading during blood transfusions.

The Prevalence of Occult Hepatitis B Infection among Blood Donors in Lagos, Nigeria

Background:

In occult hepatitis B virus (HBV) infection, the HBV DNA is present in the blood or liver tissue in patients negative for hepatitis B surface antigen (HBsAg) with or without anti-HBV antibodies. Thus, the absence of HBsAg in the blood only reduces the risk of transmission and is not sufficient enough to ensure the absence of HBV infection.

Aim:

This study was aimed at determining the prevalence of occult HBV infection among blood donors in Lagos.

Study Designs:

A cross-sectional study was done among 101 consenting blood donors at Lagos State University Teaching Hospital, Ikeja, between November 2016 and January 2017.

Materials and Methods:

HBV DNA analysis and viral load were done at the Molecular Laboratory of National Sickle Cell Centre, Idi Araba, Lagos, for all the HBsAg negative blood donors screened by rapid kit at Ikeja.

Results:

The prevalence of occult HBV DNA among the participants was 3% consisting of 3% prevalence of HBV DNA surface antigen and 0% prevalence for precore and core of the HBV DNA.

Conclusion:

The low prevalence (3%) of occult HBV seen in our study does not make it cost-effective to routinely screen blood donors or the general population for HBV infection using DNA polymerase chain reaction.

Positive familial history for metabolic traits predisposes to early and more severe alcoholic cirrhosis: A cross-sectional study

BACKGROUND & AIMS

Familial aggregation of metabolic traits in NAFLD is well documented. However, relevance of these traits in alcoholic cirrhosis is not well studied. We aimed to explore the association of family history of metabolic traits with age at diagnosis, severity and complications of alcoholic cirrhosis.

METHODS

In a cross-sectional study, all consecutive patients with alcoholic cirrhosis presenting to our tertiary care centre were included. Family and personal history, demographic characteristics, medical history, anthropometric measurements and laboratory data were recorded. The amount and duration of alcohol consumption were also carefully recorded.

RESULTS

Out of 1084 alcoholic cirrhotics (age 48.5 ± 10.1 years, all males), family history for metabolic traits was documented in 688 (63.5%) patients. These patients had younger age at diagnosis, increased incidence of jaundice, ascites, variceal bleed and hepatic encephalopathy with consequently higher MELD and CTP score. These patients developed cirrhosis despite shorter median duration (13 years, IQR 7-20 vs 21, IQR 18-25) and lesser amount of alcohol consumption (74 g/d, IQR 24-96 vs 144, IQR 100-148). Patients with both family and personal history of metabolic traits had a higher risk by 3.3 times (95% CI 2.2-4.8) of an early age at diagnosis, 13.2 times (95% CI 8.7-20.1) of progression to cirrhosis with lesser amount of alcohol consumption and 4.6 times (95% CI 3.1-6.9) with lesser duration of alcohol consumption.

CONCLUSIONS

Positive family and personal history of metabolic traits predispose to alcoholic cirrhosis with an earlier age at onset and more severity despite lesser exposure to alcohol.

Effectiveness of PCR primers for the detection of occult hepatitis B virus infection in Mexican patients

BACKGROUND

Occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HVB) DNA in the liver of HBsAg negative individuals with or without detectable viral DNA in serum. OBI is a diagnostic challenge as it is characterized by a very low viral load, intermittently detectable through time. Individuals with OBI can develop chronic hepatic disease, including liver cirrhosis and hepatocellular carcinoma. The aim of this work was to produce tools to improve OBI detection of the HVB genotypes prevalent in Mexico.

METHODS

We designed and tested primers to detect OBI in serum samples by nested and real-time PCR. Conserved sites in the viral genome were determined by alignment of the most frequent HBV genotypes in Mexico (H, G/H, F and D) and primers spanning the entire viral genome were designed for first round and nested PCR. Primers were tested in serum samples of 45 patients not co-infected with hepatitis C virus or with HIV, out of a group of 116 HBsAg (-)/anti-HBc (+) individuals. Primers were also tested in a control group with chronic HBV. Nested PCR products obtained from HBsAg (-)/anti-HBc (+) were sequenced and used to design primers for real-time PCR (SYBR Green).

RESULTS

The most effective primer pairs to detect HBV products by nested PCR targeted ORF regions: PreS2/P, S/P, X/PreC, and C; while by real-time PCR they targeted ORF regions PreS2/P, S/P, X, and C. Out of the 45 HBsAg (-)/anti-HBc (+) patients tested, the viral genome was detected in 28 (62.2%) and 34 (75.5%), with nPCR and real-time PCR respectively.

CONCLUSION

Primers designed for real-time PCR detected up to 75.5% of suspected OBI Mexican patients, with or without liver disease, which represents an improvement from previous PCR strategies.

Evolution of the serologic and virologic course of occult HBV infection in therapy experienced HIV co-infected patients

We investigated how the natural course of occult hepatitis B virus (HBV) infection (OBI) may evolve during HIV co-infection and long term HBV-active HAART. From a cohort of 181 HIV infected patients who were consecutively recruited over a 5 year period, 28 HBV co-infected patients with sequential sera (n = 98) were identified. Iterative HBV serology and viral loads were determined before and during treatment. The viral HBsAg gene was then serially amplified, directly sequenced, and molecularly characterized. Persistent detection of anti-HBs did not result in a modification to the clinical course of OBI. In contrast, reactivation of chronic HBV infection, hepatic enzymatic flares and cases of HBV reinfection were evident among anti-HBs negative OBI patients, and this was a notable finding. Of the 14 chronic HBV infected patients, eight progressed to persistent OBI after initiation of HBV-active HAART, increasing the number of patients with OBI in the study. Long term HBV-active HAART was not found to have a notable impact on low level viremia during OBI. While the HBsAg gene sequences isolated from chronic HBV infection were genetically stable over time, OBI-associated variants (sP111R, sT127P, sY161F) were neither stable nor predominant during the course of infection. This study is the first of its kind from South Africa to show the occurrence of hepatic enzymatic flares, HBV reactivation, and reinfection in HAART-exposed HIV co-infected patients with OBI. Among the cases studied, there was further evidence that OBI-associated variants may not play a significant role in the pathogenesis of OBI.

Characterization of hepatitis B virus in Amerindian children and mothers from Amazonas State, Colombia

BACKGROUND

Hepatitis B Virus (HBV) infection is a worldwide public health problem. In the 1980's a highly effective and safe vaccine against HBV was developed, although breakthrough infection still occasionally occurs because of the emergence of escape mutants. The aim of this study was to identify HBV genotypes and escape mutants in children and their mothers in Amerindian communities of the Amazonas State, Southern Colombia.

METHODS

Blood specimens collected from children and mothers belonging to 37 Amerindian communities in Amazonas state, were screened for HBsAg and anti-HBc using ELISA. The partial region containing the S ORF was amplified by nested PCR, and amplicons were sequenced. The phylogenetic analysis was performed using the MEGA 5.05 software.

RESULTS

Forty-six children (46/1275, 3.6%) and one hundred and seventy-seven mothers (177/572, 30.9%) were tested positive for the anti-HBc serological marker. Among them, 190 samples were tested for viral genome detection; 8.3% (2/31) serum samples obtained from children and 3.1% (5/159) from mothers were positive for the ORF S PCR. The predominant HBV genotype in the study population was F, subgenotype F1b; in addition, subgenotype F1a and genotype A were also characterized. Two HBV escape mutants were identified, G145R, reported worldwide, and W156*; this stop codon was identified in a child with occult HBV infection. Other mutations were found, L109R and G130E, located in critical positions of the HBsAg sequence.

CONCLUSIONS

This study aimed to characterize the HBV genotype F, subgenotypes F1b and F1a, and genotype A in Amerindian communities and for the first time escape mutants in Colombia. Further investigations are necessary to elucidate the frequency and the epidemiological impact of the escape mutants in the country.

Impact of family history of metabolic traits on severity of non-alcoholic steatohepatitis related cirrhosis: A cross-sectional study

BACKGROUND & AIMS

Familial aggregation of metabolic traits with fatty liver disease is well documented. However, there is scarcity of data regarding such association with non-alcoholic steatohepatitis (NASH)-related cirrhosis. This study was aimed to explore the association of family history of metabolic traits with severity of cirrhosis.

METHODS

In a cross-sectional study, all consecutive patients with NASH-related cirrhosis presenting to our tertiary care centre were included. Family history, personal history, demographic characteristics, medical history, anthropometric measurements and laboratory data were recorded.

RESULTS

Of the 1133 cirrhotics (68.1% males, age 51.4±10.9 years); 779 (68.8%) had family history for metabolic traits. These patients had lower age at diagnosis (45.4±10.6 vs 49.6±11.2 years), higher Child-Turcotte-Pugh (CTP) score (7.8±1.9 vs 6.6±1.5), higher model for end stage liver disease (MELD) score (12.9±6.1 vs 10.9±4.1) and more incidence of decompensation in the form of ascites (46.3% vs 25.7%), jaundice (12.1% vs 6.2%) and hepatic encephalopathy (26.1% vs 11.0%). Patients with family and personal history of metabolic traits, had an increased risk of an early diagnosis of cirrhosis at<45 years of age (OR: 3.1, 95% CI 2.1-4.4), CTP≥10 (OR: 4.6, 95% CI 2.3-9.1), MELD>15 (OR: 6.6, 95% CI 3.8-11.5) with ≥1 features of decompensation (OR: 4.2, 95% CI 2.9-6.1). Family history of diabetes alone, also had higher risk of cirrhosis with MELD>15 (OR: 4.3, 95% CI 2.4-5.3, P<.001).

CONCLUSION

Family and personal history of metabolic traits are associated with early age at diagnosis of cirrhosis with more severity and decompensation and so, has a prognostic importance in NASH-related cirrhotics.

Association between TGFβ1 polymorphisms and chronic hepatitis B infection in an Iranian population

INTRODUCTION:

Transforming growth factor-beta 1 (TGFβ1) is a potent suppressive cytokine that contributes to chronic hepatitis B (CHB) infection. Disparities in TGFβ1 production among individuals have been attributed to TGFβ1 genetic polymorphisms. We examined whether three putative polymorphisms in TGFβ1[-509 C/T (rs1800469), +869 C/T (rs1800470), and +11929 C/T (rs1800472)]are associated with CHB infection in a South-Eastern Iranian population.

METHODS:

In total, 341 subjects were recruited, including 178 patients with CHB and 163 healthy individuals as controls. Genotyping of the three TGFβ1 SNPs was performed by tetra amplification refractory mutation system-PCR.

RESULTS:

TheTGFβ1 +869 TT vs.CC genotype in codominant (OR=0.445, p=0.012) and TT vs. TC+CC in the recessive (OR=0.439, p=0.003) model as well as the variant allele T vs. C(OR=0.714, p=0.038) were associated with lower CHB infection risk. However, the +11929 C/T polymorphism was associated with increased CHB risk, and the CT vs. CC genotype (OR=2.77, P=0.001) and T variant allele (OR=2.53, P=0.002) were risk factors for CHB. Furthermore, TTT (+869/-509/+11929) and CCC haplotypes were risk and protective factors for CHB, respectively. We found no significant association between viral DNA load and TGFβ1 genotype or hepatic enzyme levels (p >0.05).

CONCLUSIONS:

Results indicated that the TGFβ1+869TT genotype and T allele were protective factors, whereas the +11929 CT genotype and T allele were risk factors for CHB infection.

Prevalence of hepatitis B and C markers in a population of an urban university in Rio de Janeiro, Brazil: a cross-sectional study

BACKGROUND AND RATIONALE

Epidemics of hepatitis B and C are a public health burden, and their prevalence in Brazil varies among regions. We determined the prevalence of hepatitis markers in an urban university population in order to support the development of a comprehensive program for HBV immunization and HBV/HCV diagnosis. Students, employees, and visitors (n = 2,936, 31 years IQR 24.5-50, female = 69.0% and 81.1% with at least 12 years of education) were enrolled from May to November 2013. Antibodies against hepatitis B surface antigen (anti-HBs), against hepatitis B core antigen (anti-HBc), and hepatitis B surface antigen (HBsAg) were detected with enzyme immunoassays and anti-hepatitis C virus (anti-HCV) antibodies with a chemiluminescence immunoassay. The results were confirmed with polymerase chain reaction for HCV and nucleic acid amplification test for hepatitis B virus (HBV).

RESULTS

The overall prevalence of markers among the participants was 0.136% (95% confidence interval [CI]: 0.003-0.270) for HBsAg, 6.44% (95% CI: 5.55-7.33%) for anti-HBc, 50.8% (95% CI: 48.9-52.7%) for anti-HBs > 10 mIU/mL, and 0.44% (95% CI: 0.20-0.68) for anti-HCV. Almost 30.4% had anti-HBs titers > 100 mIU/mL. Participants with a detectable HCV viral load (n = 9) were infected with genotype 1a.

CONCLUSIONS

In an urban university population, in which 80% of participants had > 11 years of education, prevalence increased with age, and self-declared ethnicity for anti-HBc and with age, marital status and professional activity for anti-HCV antibodies. A periodical offer of HCV rapid testing should be implemented, and HBsAg rapid testing should be offered to individuals above 20 years of age.

Occult Hepatitis B virus infection in previously screened, blood donors in Ile-Ife, Nigeria: implications for blood transfusion and stem cell transplantation

BACKGROUND

Hepatitis B virus (HBV) transmission through blood transfusion is reduced by screening for hepatitis B surface antigen (HBsAg). However this method cannot detect the presence of occult hepatitis B virus infection. This study sought to determine the prevalence of occult hepatitis B virus infection among blood donors in Ile-Ife, Nigeria. For the first time in Nigeria we employed an automated real-time PCR- method to investigate the prevalence of occult HBV in blood donors.

METHODS

Blood donors screened with HBsAg immunochromatographic rapid test kits at the blood transfusion units of two hospitals and found to be negative were recruited into the study. Questionnaires to elicit risk factors for HBV infection were administered and then 10 ml of blood was collected from each donor. Plasma samples obtained from these HBsAg negative blood donors were screened again for HBsAg using an enzyme-linked immunosorbent assay (ELISA) method, and those found negative were screened for the presence of total antibody to the HBV core antigen (anti-HBc) using ELISA method. Those positive to anti-HBc were then tested for HBV DNA, using an automated real-time PCR method.

RESULTS

Five hundred and seven blood donors found HBsAg negative by immunochromatographic rapid test kits at both blood transfusion units, were tested for HBsAg using ELISA and 5 (1 %) were HBsAg positive. The 502 found negative were tested for anti-HBc and 354 (70.5 %) were found positive implying previous exposure to HBV and 19 (5.4 %) of the 354 anti-HBc positive had HBV DNA signifying occult HBV infection. No risk factors were found to be associated with the presence of HBV DNA among those who tested positive.

CONCLUSION

Occult HBV infection exists in blood donors in Ile-Ife, Nigeria and the use of HBsAg alone for screening prospective donors will not eliminate the risk of HBV transmission in blood transfusion or stem cell transplantation.

Psoriasis: Biologic treatment and liver disease

Patients with moderate or severe psoriasis have a high prevalence of chronic liver disease. Chronic liver disease in these patients is related to metabolic syndrome, alcohol abuse or viral infections. Therefore, treatment of these patients is challenging. Classic systemic treatments may be contraindicated because of their immunosuppressive and hepatotoxic potential. First-line therapy in this setting is generally ultraviolet B phototherapy combined with topical treatment, but its feasibility and efficacy are sometimes limited. The therapeutic options are further restricted by concomitant psoriatic arthritis. Biologic treatments have shown to be effective in psoriasis and psoriatic arthritis, and they are largely devoid of liver toxicity. Anti-tumor necrosis factor-alpha (TNF-α) treatments have proven to be effective and safe in patients with chronic hepatitis C virus (HCV) infections and other non-infectious chronic liver disorders, including alcoholic and non-alcoholic liver diseases. However, in chronic hepatitis B virus (HBV), anti-TNF-α treatments carry a potential risk of HBV reactivation. Anti-interleukin-12/23 treatments are also effective in patients with psoriasis, but data regarding their safety in chronic hepatitis infections are still limited. Safety reports in patients with psoriasis and chronic HCV infection are contradictory, and in chronic HBV evidence indicate a high risk of viral reactivation. Moreover, concerns remain about the long-term safety of both TNF-α antagonists and ustekinumab. Non-viral liver diseases such as alcoholic and non-alcoholic liver diseases are more prevalent in patients with psoriasis than in the general population. TNF-α antagonists have also been prescribed in these patients. Although data are still scarce in this setting, results suggest a favorable profile in patients with psoriasis and non-alcoholic liver diseases. We review the literature regarding all these aspects.

Occult hepatitis B virus and hepatocellular carcinoma

Occult hepatitis B virus (HBV) infection (OBI) is a challenging pathobiological and clinical issue that has been widely debated for several decades. By definition, OBI is characterized by the persistence of HBV DNA in the liver tissue (and in some cases also in the serum) in the absence of circulating HBV surface antigen (HBsAg). Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma (HCC) development. OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection. Indeed, in OBI as in HBV-positive infection, HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome, and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein - provided with potential transforming properties. Furthermore, OBI may indirectly favor HCC development. It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life, and substantial clinical evidence indicates that OBI can accelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.

Occult HBV infection: a faceless enemy in liver cancer development

The hepatitis B virus (HBV) represents a worldwide public health problem; the virus is present in one third of the global population. However, this rate may in fact be higher due to occult hepatitis B virus infection (OBI). This condition is characterized by the presence of the viral genome in the liver of individuals sero-negative for the virus surface antigen (HBsAg). The causes of the absence of HBsAg in serum are unknown, however, mutations have been identified that produce variants not recognized by current immunoassays. Epigenetic and immunological host mechanisms also appear to be involved in HBsAg suppression. Current evidence suggests that OBI maintains its carcinogenic potential, favoring the progression of fibrosis and cirrhosis of the liver. In common with open HBV infection, OBI can contribute to the establishment of hepatocellular carcinoma. Epidemiological data regarding the global prevalence of OBI vary due to the use of detection methods of different sensitivity and specificity. In Latin America, which is considered an area of low prevalence for HBV, diagnostic screening methods using gene amplification tests for confirmation of OBI are not conducted. This prevents determination of the actual prevalence of OBI, highlighting the need for the implementation of cutting edge technology in epidemiological surveillance systems.

IL-17A in hepatitis B infection: friend or foe?

Hepatitis B virus (HBV) is one of the most prevalent and infectious agents that leads to liver disease in humans. Five clinical forms of HBV infection exist, including fulminant, acute, chronic, asymptomatic and occult. The chronic, asymptomatic and occult forms are long-term infections that can lead to hepatocellular carcinoma (HCC) and liver cirrhosis. The mechanisms responsible for progression of these forms of the infection to HCC and liver cirrhosis are not yet clearly understood or characterised. However, genetic and immunological parameters may play important roles in the disease. IL-17A is an important cytokine involved in early immune responses against fungal and bacterial infections, but its role in the response against viral infections is yet to be fully clarified. The crucial roles of IL-17A in the pathogenesis of autoimmune and destructive immune-related diseases have been documented and may provide insights into its functions during hepatitis infection. Therefore, the aim of this review was to address the recent information regarding the status and association of IL-17A during hepatitis B infection and its related disorders, including HCC and liver cirrhosis.

NK cells in hepatitis B virus infection: a potent target for immunotherapy

Viruses, including hepatitis B virus (HBV), are the most prevalent and infectious agents that lead to liver disease in humans. Hepatocellular carcinoma (HCC) and cirrhosis of the liver are the most serious complications arising from prolonged forms of hepatitis B. Previous studies demonstrated that patients suffering from long-term HBV infections are unable to eradicate HBV from hepatocytes completely. The mechanisms responsible for progression of these forms of infection have not yet been clarified. However, it seems that there are differences in genetic and immunological parameters when comparing patients to subjects who successfully clear HBV infections, and these may represent the causes of long-term infection. Natural killer (NK) cells, the main innate immune cells that target viral infections, play important roles in the eradication of HBV from hepatocytes. NK cells carry several stimulatory and inhibitor receptors, and binding of receptors with their ligands results in activation and suppression of NK cells, respectively. The aim of this review is to address the recent information regarding NK cell phenotype, functions and modifications in hepatitis B. This review addresses the recent data regarding the roles of NK cells as novel targets for immunotherapies that target hepatitis B infection. It also discusses the potential to reduce the risk of HCC or cirrhosis of the liver by targeting NK cells.

Important roles played by TGF-β in hepatitis B infection

Hepatitis B virus (HBV) which includes, fulminant, acute, chronic, asymptomatic, and occult HBV infection is the most prevalent virus that leads to human liver diseases. Chronic, asymptomatic, and occult infection can induce further sever diseases such as hepatocellular carcinoma (HCC) and cirrhosis of the liver. The underlying mechanisms that allow progression of the prolonged forms of the infection and subsequent HCC or cirrhosis of the liver are yet to be clarified. However, many researchers have suggested that immunological and genetic parameters may play important roles in the etiology of hepatitis B. Transforming growth factor beta (TGF-β) is an important cytokine with dual regulatory functions in the immune system and in the responses against viral infections. However, the pathways and mechanisms controlling these are not fully understood. The crucial roles of TGF-β in the development of Th17 and T regulatory lymphocytes, the main cell types involved in autoimmunity and destructive immune related diseases, have been documented and this provides insights into TGF-β function during hepatitis infection and subsequent HCC and cirrhosis of the liver. Recent findings also confirm that TGF-β directly alters hepatocyte function during hepatitis B, hence, the aim of this review is to address the current data regarding the association and status of TGF-β with hepatitis B infection and its related disorders including HCC and cirrhosis of the liver.

Occult hepatitis B: clinical viewpoint and management

Occult HBV infection (OBI) is defined as HBV DNA detection in serum or in the liver by sensitive diagnostic tests in HBsAg-negative patients with or without serologic markers of previous viral exposure. OBI seems to be higher among subjects at high risk for HBV infection and with liver disease. OBI can be both a source of virus contamination in blood and organ donations and the reservoir for full blown hepatitis after reactivation. HBV reactivation depends on viral and host factors but these associations have not been analyzed thoroughly. In OBI, it would be best to prevent HBV reactivation which inhibits the development of hepatitis and subsequent mortality. In diverse cases with insufficient data to recommend routine prophylaxis, early identification of virologic reactivation is essential to start antiviral therapy. For retrieving articles regarding OBI, various databases, including OVID, PubMed, Scopus, and ScienceDirect, were used.

Repeated exposure to trace amounts of woodchuck hepadnavirus induces molecularly evident infection and virus-specific T cell response in the absence of serological infection markers and hepatitis

Exposure to multiple small doses of hepatitis B virus (HBV) is a frequent occurrence in high-risk groups, including close relatives of infected individuals, primary care givers, and intravenous drug users. It remains uncertain whether such repeated contact may culminate in a symptomatic infection coinciding with hepatitis in individuals not immunoprotected. In this study, we evaluated consequences of multiple exposures to small, liver-nonpathogenic amounts of infectious hepadnavirus in the woodchuck model of hepatitis B. Virus-naïve animals were intravenously injected with 6 weekly doses of 110 DNase digestion-protected virions of woodchuck hepatitis virus (WHV), injected again with 6 weekly 110-virion doses after 7.5 months, and then challenged or not with a liver-pathogenic dose of 1.1 × 10(6) virions of the same inoculum. The data revealed that two rounds of such repeated exposure did not result in serologically evident infection or hepatitis. However, a low-level WHV DNA-positive infection accompanied by a WHV-specific T cell response in the absence of antiviral antibody reactivity was established. The kinetics of the virus-specific and mitogen-induced (generalized) T cell responses and the inability to induce immunoprotection against challenge with a large, liver-pathogenic virus dose were closely comparable to those previously reported for occult infection initiated by a single liver-nonpathogenic dose of WHV. Thus, repeated exposures to small quantities of hepadnavirus induce molecularly evident but serologically silent infection that does not culminate in hepatitis or generate immune protection. The findings imply that the HBV-specific T cell response encountered in the absence of serological markers of infection likely reflects ongoing occult 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.

Occult hepatitis B virus infection: A complex entity with relevant clinical implications

Occult hepatitis B virus (HBV) infection is a world-wide entity, following the geographical distribution of detectable hepatitis B. This entity is defined as the persistence of viral genomes in the liver tissue and in some instances also in the serum, associated to negative HBV surface antigen serology. The molecular basis of the occult infection is related to the life cycle of HBV, which produces a covalently closed circular DNA that persists in the cell nuclei as an episome, and serves as a template for gene transcription. The mechanism responsible for the HBsAg negative status in occult HBV carriers is a strong suppression of viral replication, probably due to the host’s immune response, co-infection with other infectious agents and epigenetic factors. There is emerging evidence of the potential clinical relevance of occult HBV infection, since this could be involved in occult HBV transmission through orthotopic liver transplant and blood transfusion, reactivation of HBV infection during immunosuppression, impairing chronic liver disease outcome and acting as a risk factor for hepatocellular carcinoma. Therefore it is important to bear in mind this entity in cryptogenetic liver diseases, hepatitis C virus/HIV infected patients and immunosupressed individuals. It is also necessary to increase our knowledge in this fascinating field to define better strategies to diagnose and treat this infection.