Hepatitis B virus infection in lymphatic tissues in inactive hepatitis B carriers

A case of diffuse large B-cell lymphoma with decompensated alcohol-related liver cirrhosis treated successfully by chemoimmunotherapy

Key Clinical Message

This report describes a case of diffuse large B-cell lymphoma with MYD88 L265P and KM2DT mutation and decompensated alcohol-related liver cirrhosis. And the treatment is successful in this patient, who had multiple complications and poor prognostic factors.

Abstract

This report describes a case of diffuse large B-cell lymphoma with MYD88 L265P and KM2DT mutation and decompensated alcohol-related liver cirrhosis. The lymphoma showed a complete response with no MYD88 L265P mutation after four courses of combination chemotherapy. Lymphoma is one of the most common malignant tumors, but cases of DLBCL with cirrhosis are much rarer especially with alcohol-related cirrhosis. And we reviewed the relevant mechanisms. Although we did not find a definite association between the pathogenesis of the patient's alcohol-related cirrhosis and that of diffuse large B-cell lymphoma, the treatment is successful in this patient, who had multiple complications and poor prognostic factors.

Carcinogenic mechanisms of virus-associated lymphoma

The development of lymphoma is a complex multistep process that integrates numerous experimental findings and clinical data that have not yet yielded a definitive explanation. Studies of oncogenic viruses can help to deepen insight into the pathogenesis of lymphoma, and identifying associations between lymphoma and viruses that are established and unidentified should lead to cellular and pharmacologically targeted antiviral strategies for treating malignant lymphoma. This review focuses on the pathogenesis of lymphomas associated with hepatitis B and C, Epstein-Barr, and human immunodeficiency viruses as well as Kaposi sarcoma-associated herpesvirus to clarify the current status of basic information and recent advances in the development of virus-associated lymphomas.

Exploring LIPIDs for their potential to improves bioavailability of lipophilic drugs candidates: A review

This review aims to provide a thorough examination of the benefits, challenges, and advancements in utilizing lipids for more effective drug delivery, ultimately contributing to the development of innovative approaches in pharmaceutical science. Lipophilic drugs, characterized by low aqueous solubility, present a formidable challenge in achieving effective delivery and absorption within the human body. To address this issue, one promising approach involves harnessing the potential of lipids. Lipids, in their diverse forms, serve as carriers, leveraging their unique capacity to enhance solubility, stability, and absorption of these challenging drugs. By facilitating improved intestinal solubility and selective lymphatic absorption of porously permeable drugs, lipids offer an array of possibilities for drug delivery. This versatile characteristic not only bolsters the pharmacological efficacy of drugs with low bioavailability but also contributes to enhanced therapeutic performance, ultimately reducing the required dose size and associated costs. This comprehensive review delves into the strategic formulation approaches that employ lipids as carriers to ameliorate drug solubility and bioavailability. Emphasis is placed on the critical considerations of lipid type, composition, and processing techniques when designing lipid-based formulations. This review meticulously examines the multifaceted challenges that come hand in hand with lipid-based formulations for lipophilic drugs, offering an insightful perspective on future trends. Regulatory considerations and the broad spectrum of potential applications are also thoughtfully discussed. In summary, this review presents a valuable repository of insights into the effective utilization of lipids as carriers, all aimed at elevating the bioavailability of lipophilic drugs.

Hepatitis Virus-associated Non-hodgkin Lymphoma: Pathogenesis and Treatment Strategies

Over the last decade, epidemiological studies have discovered a link between hepatitis C virus (HCV) and hepatitis B virus (HBV) infection and non-Hodgkin lymphoma (NHL). The regression of HCV-associated NHL after HCV eradication is the most compelling proof supporting HCV infection's role in lymphoproliferative diseases. HBV infection was found to significantly enhance the incidence of NHL, according to the epidemiological data. The exact mechanism of HCV leading to NHL has not been fully clarified, and there are mainly the following possible mechanisms: (1) Indirect mechanisms: stimulation of B lymphocytes by extracellular HCV and cytokines; (2) Direct mechanisms: oncogenic effects mediated by intracellular HCV proteins; (3) hit-and-run mechanism: permanent genetic B lymphocytes damage by the transitional entry of HCV. The specific role of HBV in the occurrence of NHL is still unclear, and the research on its mechanism is less extensively explored than HCV, and there are mainly the following possible mechanisms: (1) Indirect mechanisms: stimulation of B lymphocytes by extracellular HBV; (2) Direct mechanisms: oncogenic effects mediated by intracellular HBV DNA. In fact, it is reasonable to consider direct-acting antivirals (DAAs) as first-line therapy for indolent HCV-associated B-NHL patients who do not require immediate chemotherapy. Chemotherapy for NHL is affected by HBV infection and replication. At the same time, chemotherapy can also activate HBV replication. Following recent guidelines, all patients with HBsAg positive/HBV DNA≥2,000 IU/mL should be treated for HBV. The data on epidemiology, interventional studies, and molecular mechanisms of HCV and HBV-associated B-NHL are systematically summarized in this review.

New insights into hepatitis B virus lymphotropism: Implications for HBV-related lymphomagenesis

HBV is one of the most widespread hepatitis viruses worldwide, and a correlation between chronic infection and liver cancer has been clearly reported. The carcinogenic capacity of HBV has been reported for other solid tumors, but the largest number of studies focus on its possible lymphomagenic role. To update the correlation between HBV infection and the occurrence of lymphatic or hematologic malignancies, the most recent evidence from epidemiological and in vitro studies has been reported. In the context of hematological malignancies, the strongest epidemiological correlations are with the emergence of lymphomas, in particular non-Hodgkin’s lymphoma (NHL) (HR 2.10 [95% CI 1.34-3.31], p=0.001) and, more specifically, all NHL B subtypes (HR 2.14 [95% CI 1.61-2.07], p<0.001). Questionable and unconfirmed associations are reported between HBV and NHL T subtypes (HR 1.11 [95% CI 0.88-1.40], p=0.40) and leukemia. The presence of HBV DNA in peripheral blood mononuclear cells has been reported by numerous studies, and its integration in the exonic regions of some genes is considered a possible source of carcinogenesis. Some in vitro studies have shown the ability of HBV to infect, albeit not productively, both lymphomonocytes and bone marrow stem cells, whose differentiation is halted by the virus. As demonstrated in animal models, HBV infection of blood cells and the persistence of HBV DNA in peripheral lymphomonocytes and bone marrow stem cells suggests that these cellular compartments may act as HBV reservoirs, allowing replication to resume later in the immunocompromised patients (such as liver transplant recipients) or in subjects discontinuing effective antiviral therapy. The pathogenetic mechanisms at the basis of HBV carcinogenic potential are not known, and more in-depth studies are needed, considering that a clear correlation between chronic HBV infection and hematological malignancies could benefit both antiviral drugs and vaccines.

Hepatitis B virus DNA integration as a novel biomarker of hepatitis B virus-mediated pathogenetic properties and a barrier to the current strategies for hepatitis B virus cure

Chronic infection with Hepatitis B Virus (HBV) is a major cause of liver-related morbidity and mortality worldwide. HBV-DNA integration into the human genome is recognized as a frequent event occurring during the early phases of HBV infection and characterizing the entire course of HBV natural history. The development of refined molecular biology technologies sheds new light on the functional implications of HBV-DNA integration into the human genome, including its role in the progression of HBV-related pathogenesis and in triggering the establishment of pro-oncogenic mechanisms, promoting the development of hepatocellular carcinoma. The present review provides an updated and comprehensive overview of the current body of knowledge on HBV-DNA integration, focusing on the molecular mechanisms underlying HBV-DNA integration and its occurrence throughout the different phases characterizing the natural history of HBV infection. Furthermore, here we discuss the main clinical implications of HBV integration as a biomarker of HBV-related pathogenesis, particularly in reference to hepatocarcinogenesis, and how integration may act as a barrier to the achievement of HBV cure with current and novel antiviral therapies. Overall, a more refined insight into the mechanisms and functionality of HBV integration is paramount, since it can potentially inform the design of ad hoc diagnostic tools with the ability to reveal HBV integration events perturbating relevant intracellular pathways and for identifying novel therapeutic strategies targeting alterations directly related to HBV integration.

Hepadnaviral Lymphotropism and Its Relevance to HBV Persistence and Pathogenesis

Since the discovery of hepatitis B virus (HBV) over five decades ago, there have been many independent studies showing presence of HBV genomes in cells of the immune system. However, the nature of HBV lymphotropism and its significance with respect to HBV biology, persistence and the pathogenesis of liver and extrahepatic disorders remains underappreciated. This is in contrast to studies of other viral pathogens in which the capability to infect immune cells is an area of active investigation. Indeed, in some viral infections, lymphotropism may be essential, and even a primary mechanism of viral persistence, and a major contributor to disease pathogenesis. Nevertheless, there are advances in understanding of HBV lymphotropism in recent years due to cumulative evidence showing that: (i) lymphoid cells are a reservoir of replicating HBV, (ii) are a site of HBV-host DNA integration and (iii) virus genomic diversification leading to pathogenic variants, and (iv) they play a role in HBV resistance to antiviral therapy and (v) likely contribute to reactivation of hepatitis B. Further support for HBV lymphotropic nature is provided by studies in a model infection with the closely related woodchuck hepatitis virus (WHV) naturally infecting susceptible marmots. This animal model faithfully reproduces many aspects of HBV biology, including its replication scheme, tissue tropism, and induction of both symptomatic and silent infections, immunological processes accompanying infection, and progressing liver disease culminating in hepatocellular carcinoma. The most robust evidence came from the ability of WHV to establish persistent infection of the immune system that may not engage the liver when small quantities of virus are experimentally administered or naturally transmitted into virus-naïve animals. Although the concept of HBV lymphotropism is not new, it remains controversial and not accepted by conventional HBV researchers. This review summarizes research advances on HBV and hepadnaviral lymphotropism including the role of immune cells infection in viral persistence and the pathogenesis of HBV-induced liver and extrahepatic diseases. Finally, we discuss the role of immune cells in HBV diagnosis and assessment of antiviral therapy efficacy.

Oncogenic HBV variants and integration are present in hepatic and lymphoid cells derived from chronic HBV patients

The hepatitis B virus (HBV) is a major cause of hepatocellular carcinoma (HCC), partly driven by viral integration and specific oncogenic HBV variants. However, the biological significance of HBV genomes within lymphoid cells (i.e., peripheral blood mononuclear cells, PBMCs) is unclear. Here, we collected available plasma, PBMC, liver, and tumor from 52 chronic HBV (CHB) carriers: 32 with HCC, 19 without HCC, and one with dendritic cell sarcoma, DCS. Using highly sensitive sequencing techniques, next generation sequencing, and AluPCR, we demonstrate that viral genomes (i.e., HBV DNA, RNA, and cccDNA), oncogenic variants, and HBV-host integration are often found in all sample types collected from 52 patients (including lymphoid cells and a DCS tumor). Viral integration was recurrently identified (n = 90 such hits) in genes associated with oncogenic consequences in lymphoid and liver cells. Further, HBV genomes increased in PBMCs derived from 7 additional (treated or untreated) CHB carriers after extracellular mitogen stimulation. Our study shows novel HBV molecular data and replication not only liver, but also within 63.8% of lymphoid cells analysed (including a representative lymphoid cell malignancy), that was enhanced in ex vivo stimulated PBMC.

Characterization of hepatitis B virus infection and viral DNA integration in non-Hodgkin lymphoma

Hepatitis B virus (HBV) infection has been reported to be associated with non-Hodgkin lymphoma (NHL). However, the evidence is limited to the seroepidemiological study. There is a lack of evidence showing the HBV infection and integration in NHL cells. Here, we reported that in the Shanghai area, the positive rates of serum HBsAg (OR: 3.11; 95% CI: 2.20-4.41) and HBeAg (OR: 3.99; 95% CI: 1.73-9.91) were significantly higher in patients with NHL. HBsAg, HBcAg and HBV DNA were detected in 34.4%, 45.2% and 47.0% of the NHL tissues, respectively. Furthermore, by using a high-throughput viral integration detection approach (HIVID), integrated HBV DNA was identified from 50% (6/12) HBV-related NHL tissues. There were a total of 313 HBV integration sites isolated from the NHL tissues, among which four protein-coding genes (FAT2, SETX, ITGA10 and CD63) were interrupted by HBV DNA in their exons. Seven HBV preferential target genes (ANKS1B, HDAC4, EGFLAM, MAN1C1, XKR6, ZBTB38 and CCDC91) showed significantly altered expression levels in NHL, suggesting a potential role of these genes in NHL development. Taken together, HBV integration is a common phenomenon in NHL. This finding opens up a new direction of research into the mechanistic link between HBV infection and NHL.

Hepatitis B Surface Antigen Positivity Is an Independent Unfavorable Prognostic Factor in Diffuse Large B-Cell Lymphoma in the Rituximab Era

BACKGROUND

Patients with diffuse large B-cell lymphoma (DLBCL) with concurrent hepatitis B surface antigen (HBsAg)-positive hepatitis B virus (HBV) infection have distinct clinical features. Nevertheless, the prognostic value of HBsAg in DLBCL in the rituximab era remains unclear.

MATERIALS AND METHODS

We conducted a retrospective cohort study to investigate the clinical relevance of HBsAg in immunocompetent patients with DLBCL treated with homogeneous rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone between 2002 and 2016.

RESULTS

Among 416 analyzed patients, 98 (23.6%) were HBsAg positive. HBsAg positivity was associated with a younger age and more advanced stage at diagnosis, more frequent hepatic impairment during perichemotherapy, and a trend of higher National Comprehensive Cancer Network-International Prognostic Index (NCCN-IPI) score at diagnosis. Compared with the HBsAg-negative patients, the HBsAg-positive patients had a lower overall response rate (76.5% vs. 85.5%, p = .043), poorer 5-year overall survival (OS) rate (57.2% vs. 73.5%, p < .001), and shorter 5-year progression-free survival (PFS) rate (47.2% vs. 60.7%, p = .013). Multivariate analyses showed that HBsAg positivity was an independent unfavorable prognostic indicator for OS and PFS. A scoring system incorporating HBsAg positivity, the NCCN-IPI score, and serum albumin levels proved to be useful for stratifying prognostically relevant subgroups of patients with DLBCL.

CONCLUSION

This study demonstrated that HBV infection is uniquely relevant to DLBCL. HBsAg might serve as a novel biomarker to improve clinical risk stratification of patients with DLBCL in areas with high prevalence of HBV infection. Further research investigating the etiopathogenesis of HBV infection in DLBCL is imperative.

IMPLICATIONS FOR PRACTICE

A considerable disparity exists regarding the prognostic relevance of hepatitis B surface antigen (HBsAg)-positive hepatitis B virus (HBV) infection in patients with diffuse large B-cell lymphoma (DLBCL). In this large, retrospective cohort study from an area with high prevalence of HBV infection, the authors demonstrated that HBsAg was an independent unfavorable factor significantly associated with survival, highlighting its potential as a novel prognostic indicator to improve the risk stratification of patients with DLBCL in the rituximab era.

Transplantation with GXHPC1 for Liver Cirrhosis: Phase 1 Trial

Currently, the only effective therapy for cirrhosis of the liver is liver transplantation. However, finding a compatible liver is difficult due to the low supply of healthy livers and the ever-increasing demand. However, stem-cell therapy may offer a solution for liver cirrhosis; for example, GXHPC1 therapy preparation contains adipose-derived mesenchymal stem cells (AD-MSCs) and was developed for the treatment of liver cirrhosis. In our previous report, animal studies suggested that treatment of a diseased liver via GXHPC1 transplantation can abrogate liver fibrosis and facilitate recovery of liver function. In our current human trial, patients with liver cirrhosis were included. Their adipose tissue was harvested from the subcutaneous fat of the abdominal wall during surgery. AD-MSCs were cultured and suspended at a concentration of 100 million cells in 1 ml of physiological saline (i.e., GXHPC1). This human study passed the Taiwan Food and Drug Administration IND inspection and received Phase I clinical trial permission. The trial was conducted with six patients with liver cirrhosis to demonstrate the safety and efficacy of administering GXHPC1. Intrahepatic injection of GXHPC1 did not cause any safety issues in the analysis of adverse drug reactions and suspected unexpected serious adverse reactions, and showed a tendency for improvement of liver function, METAVIR score, Child–Pugh score, MELD score, and quality of life for patients with liver cirrhosis.

Development and in vivo evaluation of baicalin-loaded W/O nanoemulsion for lymphatic absorption

Background: Lymphatic formations that effectively eradicate the virus in the lymphatic system will be therapeutically advantagous in hepatitis B virus (HBV) infection. Lipid-based formulation is often used to deliver drug via the lymphatic system. Baicalin nanoemulsion may be a promising drug delivery system for improved treatment of HBV infection. Objective: This study aimed to prepare, characterize, and evaluate a lipid-based nanoemulsion containing baicalin for lymphatic system absorption. Method: The presence of a nanoemulsion region was studied by pseudoternary phase diagrams. The physicochemical properties of a baicalin-loaded nanoemulsion were investigated. The oral bioavailability of the baicalin-loaded nanoemulsion was compared to that of a baicalin suspension. A chylomicron flow blocking model was used to examine the extent of lymphatic uptake. The lymph node distribution of baicalin was measured to investigate the lymphatic transport ability of the nanoemulsion compared to the suspension. Results: Compared to the baicalin suspension, the AUC_0-t and C_max values of the baicalin nanoemulsion were increased by 10.5-fold and 3.12-fold, respectively. Compared with the saline-treated rats that were orally administered the baicalin nanoemulsion, the AUC_0-t and C_max values of the nanoemulsion for the rats pretreated with cycloheximide were reduced from 23.076 ± 1.244 mg/L h to 9.236 ± 0.940 mg/L h and from 3.010 ± 0.119 mg/L to 1.567 ± 0.220 mg/L, respectively. In comparing baicalin in W/O nanoemulsion with suspension, the C_max value was found to be 11.5-fold higher in the lymph nodes of the rats treated with the nanoemulsion. Conclusion: The results indicated that a baicalin-loaded W/O nanoemulsion may be a promising drug delivery system for the treatment of chronic hepatitis B.

Reflection and observation: cell-based screening failing to detect HBV in HUMSCs derived from HBV-infected mothers underscores the importance of more stringent donor eligibility to reduce risk of transmission of infectious diseases for stem cell-based medical products

Background

In cell-based therapy, the transmission of communicable diseases imposes a substantial threat to recipients. In this study, we investigated whether cell-based screening could detect hepatitis B virus (HBV) in human umbilical cord-derived mesenchymal stem cells (HUMSCs) isolated from HBV-infected donors to understand the susceptibility of HUMSCs to HBV infection.

Methods

HBV assay was performed in HUMSCs derived from healthy and HBV-infected donors with enzyme-linked immunosorbent assay (ELISA), fluorescence quantitative PCR (FQ-PCR) assay, and droplet digital PCR (ddPCR) assay. Further, HBV DNA was assayed in HUMSCs derived from healthy donors after incubation with human sera containing a high titer of HBV using FQ-PCR.

Results

HBV antigen/antibody and DNA failed to be detected using ELISA, FQ-PCR, and ddPCR. After incubation with HBV infection sera, HBV DNA could be detected, but below the valid titer of the assay kit. The HBV DNA levels in HBV-incubated HUMSCs gradually decreased with medium change every 2 days and then significantly decreased, not even detected after passage.

Conclusions

The current cell-based screening methods could not detect HBV in HUMSCs derived from HBV-infected donors, indicating the importance of more stringent donor eligibility to reduce the risk of transmission of communicable diseases in cell-based therapy. To solve the problem of an occult HBV window period in donor eligibility determination, we recommend that the donors undergo another HBV serological test 3 months after the first serological communicable disease screening.

Reactivation of hepatitis B after liver transplantation: Current knowledge, molecular mechanisms and implications in management

Chronic hepatitis B (CHB) is a major global health problem affecting an estimated 350 million people with more than 786000 individuals dying annually due to complications, such as cirrhosis, liver failure and hepatocellular carcinoma (HCC). Liver transplantation (LT) is considered gold standard for treatment of hepatitis B virus (HBV)-related liver failure and HCC. However, post-transplant viral reactivation can be detrimental to allograft function, leading to poor survival. Prophylaxis with high-dose hepatitis B immunoglobulin (HBIG) and anti-viral drugs have achieved remarkable progress in LT by suppressing viral replication and improving long-term survival. The combination of lamivudine (LAM) plus HBIG has been for many years the most widely used. However, life-long HBIG use is both cumbersome and costly, whereas long-term use of LAM results in resistant virus. Recently, in an effort to develop HBIG-free protocols, high potency nucleos(t)ide analogues, such as Entecavir or Tenofovir, have been tried either as monotherapy or in combination with low-dose HBIG with excellent results. Current focus is on novel antiviral targets, especially for covalently closed circular DNA (cccDNA), in an effort to eradicate HBV infection instead of viral suppression. However, there are several other molecular mechanisms through which HBV may reactivate and need equal attention. The purpose of this review is to address post-LT HBV reactivation, its risk factors, underlying molecular mechanisms, and recent advancements and future of anti-viral therapy.

Genetic landscape of hepatitis B virus-associated diffuse large B-cell lymphoma

Hepatitis B virus (HBV) infection is endemic in some parts of Asia, Africa, and South America and remains to be a significant public health problem in these areas. It is known as a leading risk factor for the development of hepatocellular carcinoma, but epidemiological studies have also shown that the infection may increase the incidence of several types of B-cell lymphoma. Here, by characterizing altogether 275 Chinese diffuse large B-cell lymphoma (DLBCL) patients, we showed that patients with concomitant HBV infection (surface antigen positive [HBsAg⁺]) are characterized by a younger age, a more advanced disease stage at diagnosis, and reduced overall survival. Furthermore, by whole-genome/exome sequencing of 96 tumors and the respective peripheral blood samples and targeted sequencing of 179 tumors from these patients, we observed an enhanced rate of mutagenesis and a distinct set of mutation targets in HBsAg⁺ DLBCL genomes, which could be partially explained by the activities of APOBEC and activation-induced cytidine deaminase. By transcriptome analysis, we further showed that the HBV-associated gene expression signature is contributed by the enrichment of genes regulated by BCL6, FOXO1, and ZFP36L1. Finally, by analysis of immunoglobulin heavy chain gene sequences, we showed that an antigen-independent mechanism, rather than a chronic antigenic simulation model, is favored in HBV-related lymphomagenesis. Taken together, we present the first comprehensive genomic and transcriptomic study that suggests a link between HBV infection and B-cell malignancy. The genetic alterations identified in this study may also provide opportunities for development of novel therapeutic strategies.

HBV infection potentiates resistance to S-phase arrest-inducing chemotherapeutics by inhibiting CHK2 pathway in diffuse large B-cell lymphoma

A considerable number of diffuse large B-cell lymphoma (DLBCL) patients are infected with hepatitis B virus (HBV), which is correlated with their poor outcomes. However, the role of HBV infection in DLBCL treatment failure remains poorly understood. Here, our data demonstrated that HBV infection was closely associated with poorer clinical prognosis independent of its hepatic dysfunction in germinal center B-cell type (GCB type) DLBCL patients. Interestingly, we found that DLBCL cells expressing hepatitis B virus X protein (HBX) did not exhibit enhanced cell growth but did show reduced sensitivity to methotrexate (MTX) and cytarabine (Ara-C), which induced S-phase arrest. Mechanism studies showed that HBX specifically inhibited the phosphorylation of checkpoint kinase 2 (CHK2, a key DNA damage response protein). CHK2 depletion similarly conferred resistance to the S-phase arrest-inducing chemotherapeutics, consistent with HBX overexpression in DLBCL cells. Moreover, overexpression of wild-type CHK2 rather than its unphosphorylated mutant (T68A) significantly restored the reduced chemosensitivity in HBX-expressing cells, suggesting that HBV infection conferred resistance to chemotherapeutics that induced S-phase arrest by specifically inhibiting the activation of CHK2 response signaling in DLBCL.

Compartmental HBV evolution and replication in liver and extrahepatic sites after nucleos/tide analogue therapy in chronic hepatitis B carriers

BACKGROUND

Hepatitis B virus (HBV) variants are associated with nucleos/tide analogue (NA) response and liver disease but it is unknown whether NA influences extrahepatic HBV persistence.

OBJECTIVES

To investigate HBV replication and genetic evolution in hepatic and extrahepatic sites of chronic hepatitis B (CHB) before and after NA therapy.

STUDY DESIGN

A total of 13 paired plasma, peripheral blood mononuclear cells (PBMC), were collected from chronic HBV carriers at baseline and after a median 53 weeks NA therapy as well as liver biopsy (N=7 baseline, N=5 follow-up). HBV covalently closed circular DNA (cccDNA) and messenger (m) RNA in liver and PBMC were analyzed. HBV polymerase (P)/surface (S), basal core promoter (BCP)/pre-core (PC)/C gene clonal sequencing was done in plasma, peripheral blood mononuclear cells (PBMC), and liver.

RESULTS

Compare to baseline, at ∼53 weeks follow-up, there was no significant change in HBV cccDNA levels in liver (0.2-0.08 copies/hepatocyte, p>0.05) or in PBMC 0.003-0.02 copies/PBMC, p>0.05), and HBV mRNA remained detectable in both sites. At baseline, BCP variants were higher in PBMC vs. liver and plasma. After therapy, drug resistant (DR) and immune escape (IE) variants increased in liver but IE and PC variants were more frequent in PBMC. HBV P/S diversity was significantly higher in PBMC compared to plasma.

CONCLUSION

Continuous HBV replication occurs in liver and PBMC and shows compartmentalized evolution under selective pressure of potent NA therapy.

Hepatitis B Virus Replication in CD34+ Hematopoietic Stem Cells From Umbilical Cord Blood

BACKGROUND Hepatitis B virus (HBV) is a hepatotropic virus that can infect extrahepatic tissue. Whether hematopoietic stem cells (HSCs) can be infected by HBV and serve as a potential virus reservoir is still unknown. In this study, the susceptibility of CD34+ HSCs to HBV was investigated. MATERIAL AND METHODS Cord blood-derived CD34+ HSCs were exposed to HBV in vitro, and immunocytochemistry, transmission electron microscopy, and RT-PCR were used to identify viral-related proteins and specific viral genomic sequences. Then, CD34+ HSCs were challenged by different titers of HBV, and intracellular and supernatant HBV DNA, and hepatitis B surface antigen (HBsAg) levels, were examined. In addition, CD34+ peripheral blood stem cells (PBSCs) from chronic HBV carriers were isolated and cultured, and HBV DNA levels were measured. RESULTS HBV-infected CD34+ cells showed positive signals for HBsAg by DAB staining and TRITC staining, and HBV particles were identified. RT-PCR results showed that the 403 bp PCR products corresponding to the amplified hepatitis B S gene fragment were observed in CD34+ HSCs infected by HBV. In addition, supernatant and intracellular HBV DNA increased with the proliferation of CD34+ HSCs. Similar results were obtained from intracellular HBsAg quantification tests. In addition, HBV DNA levels both in cells and in supernatants of CD34+ PBSCs increased proportionally, and the increments of HBV DNA in the supernatants paralleled those found in cells. CONCLUSIONS HBV can replicate in CD34+ HSCs in cord blood or peripheral blood of chronic HBV carriers.

Hepatitis B virus replication is upregulated in proliferated peripheral blood lymphocytes

Increasing evidence indicates that the hepatitis B virus (HBV) replicates in peripheral blood mononuclear cells (PBMCs), but at a low level. The present study aimed to establish a reliable and sensitive method that effectively detects HBV viral products for monitoring antiviral therapy, organ transplantation screening, and diagnosing occult HBV infection. In the present study, PBMCs (obtained from six healthy volunteers) were inoculated with HBV, and cultured with phytohemagglutinin (PHA) and interleukin‑2 (IL‑2) to stimulate cell proliferation. PBMCs were harvested, and quantitative detection of HBV DNA in cell suspension and intracellular hepatitis B surface antigen (HBsAg) was conducted on days 0, 1, 6 and 12, respectively. In situ hybridization, immunohistochemistry and reverse transcription‑polymerase chain reaction (RT‑PCR) were performed to analyze the HBV infection. The results demonstrated that HBV DNA increased concurrently with proliferation of PBMCs isolated from three of six healthy volunteers, and the mean number of PBMCs on day 12 was 13.61 times higher than the initially seeded cell number (P<0.01). The mean copies of HBV DNA at day 12 were 2.98 times higher compared with initial levels (P<0.05). Furthermore, intracellular HBsAg levels increased concurrently with proliferation of PBMCs in one group of cultured PBMCs, which was accompanied by increased HBV DNA levels. In addition, HBV nucleic acids were detected in PBMCs using in situ hybridization. Intracellular HBsAg was observed in PBMCs and HBV RNA was also detected by RT‑PCR. The present study demonstrated that HBV replicates in proliferating PBMCs, which were induced by PHA and IL‑2. This method offers a novel investigative tool to detect HBV infection in PBMCs and to monitor the course of HBV infection.

Simple and Reliable Method to Quantify the Hepatitis B Viral Load and Replicative Capacity in Liver Tissue and Blood Leukocytes

BACKGROUND

A functional cure of chronic hepatitis B (CHB) is feasible, but a clear view of the intrahepatic viral dynamics in each patient is needed. Intrahepatic covalently closed circular DNA (cccDNA) is the stable form of the viral genome in infected cells, and represents the ideal marker of parenchymal colonization. Its relationships with easily accessible peripheral parameters need to be elucidated in order to avoid invasive procedures in patients.

OBJECTIVES

The goal of this study was to design, set up, and validate a reliable and straightforward method for the quantification of the cccDNA and total DNA of the hepatitis B virus (HBV) in a variety of clinical samples.

PATIENTS AND METHODS

Clinical samples from a cohort of CHB patients, including liver biopsies in some, were collected for the analysis of intracellular HBV molecular markers using novel molecular assays.

RESULTS

A plasmid construct, including sequences from the HBV genome and from the human gene hTERT, was generated as an isomolar multi-standard for HBV quantitation and normalization to the cellular contents. The specificity of the real-time assay for the cccDNA was assessed using Dane particles isolated on a density gradient. A comparison of liver tissue from 6 untreated and 6 treated patients showed that the treatment deeply reduced the replicative capacity (total DNA/cccDNA), but had limited impact on the parenchymal colonization. The peripheral blood mononuclear cells (PBMCs) and granulocytes from the treated and untreated patients were also analyzed.

CONCLUSIONS

A straightforward method for the quantification of intracellular HBV molecular parameters in clinical samples was developed and validated. The widespread use of such versatile assays could better define the prognosis of CHB, and allow a more rational approach to time-limited tailored treatment strategies.

Are current screening protocols for chronic hepatitis B virus infection adequate?

Chronic hepatitis B virus (HBV) infection screening usually includes only HBV surface antigen (HBsAg) testing; HBV core and surface antibody (anti-HBc, anti-HBs) assays, indicating resolved infection and immunity, are not routinely performed. Yet, serum HBV DNA is measurable in approximately 10% of HBsAg-negative/anti-HBc-positive cases, representing occult HBV infection (OBI). Patient blood samples from 2 Veterans Affairs medical center look-back investigations were screened for HBV infection using HBsAg enzyme immunoassays. Supplementary testing included anti-HBc and anti-HBs enzyme immunoassays. For anti-HBc-positive samples, HBV DNA testing was performed. Background OBI prevalence was further estimated at these 2 facilities based on HBV serology testing results from 1999-2012. Finally, a literature review was performed to determine OBI prevalence in the published literature. Of 1887 HBsAg-negative cohort patients, 98 (5.2%) were anti-HBc positive/anti-HBs negative; and 175 (9.3%), anti-HBc positive/anti-HBs positive. Six of 273 were HBV DNA positive, representing 0.3% of the total tested and 2.2% who were anti-HBc positive/anti-HBs negative or anti-HBc positive/anti-HBs positive. Among 32,229 general population veterans at these 2 sites who had any HBV testing, 4/108 (3.7%) were HBV DNA positive, none of whom were part of the cohort. In 129 publications with HBsAg-negative patients, 1817/1,209,426 (0.15%) had OBI. However, excluding blood bank studies with greater than 1000 patients, the OBI rate increased to 1800/17,893 (10%). OBI is not rare and has implications for transmission and disease detection. HBsAg testing alone is insufficient for detecting all chronic HBV infections. These findings may impact blood donation, patient HBV screening, follow-up protocols for patients assumed to have cleared the infection, and initiation of immunosuppression in patients with distant or undetected HBV.

Outcomes including liver histology after liver transplantation for chronic hepatitis B using oral antiviral therapy alone

The outcomes of hepatitis B virus (HBV)-related hepatitis after liver transplantation (LT) without hepatitis B immune globulin (HBIG) is not well documented. This study aims to determine the outcomes of chronic hepatitis B (CHB) patients using an HBIG-free regimen. All biopsies performed 3 months or more after LT in consecutive CHB patients transplanted from 2003 to 2012 were reviewed. None of the patients received HBIG. Results of all liver histologies were reviewed to determine the cause of graft dysfunction. Of the 435 patients transplanted during this period, 263 liver biopsies were performed in 144 patients. Thirty-six patients were positive for hepatitis B surface antigen (HBsAg) with undetectable HBV DNA at the time of biopsy, and none had histological evidence of HBV infection. Of the 263 biopsies, 44 (17%) had evidence of fibrosis. There was a significantly higher rate of fibrosis in those with large duct obstruction compared to those without (51% versus 9%, respectively; P < 0.001). Of the 291 patients without a liver biopsy during the same period, 43 were HBsAg+. Seven patients had evidence of virological rebound, of whom 6 had evidence of rtM204V/I mutation and 1 had recurrence of hepatocellular carcinoma with low-level rebound and wild-type virus. In conclusion, for patients without virological rebound, positive serum HBsAg was not associated with histological evidence of HBV-related hepatitis after LT. To prevent virological rebound, nucleos(t)ide analogues with higher barriers to resistance should be used.

Study of the Association of Mutant HBsAg Gene and Hodgkin and Non-Hodgkin Lymphoma

Background:

Hepatitis B Virus (HBV) is responsible for chronic, acute, and fulminant hepatitis, which are prevalent worldwide. Chronic HBV may lead to cirrhosis and hepatocellular carcinoma. Several epidemiological studies have indicated that hepatitis B virus is involved in B-cell Hodgkin and Non-Hodgkin Lymphoma (NHL).

Objectives:

The aim of this study was to evaluate the association between hepatitis B infection and Hodgkin and non-Hodgkin Lymphoma.

Materials and Methods:

Paraffin embedded of 41 block samples including 12 (29.26%) Hodgkin and 29 (70.73%) non-Hodgkin patients were collected. Next, DNA extraction was carried out for all the samples followed by HBV DNA detection by the nested polymerase chain reaction (PCR). The positive HBV DNA samples were sequenced, and HBV genotypes and HBV subtypes were determined.

Results:

Three out of 12 (25%) Hodgkin samples and seven out of 29 (24.13%) non-Hodgkin showed positive HBV DNA results. The results of sequencing revealed that the D genotype was predominant among the positive HBV patients. Interestingly an unpredictable amino acid proline was detected in position 88 of the HBs gene, which indicates a new mutation in the “S” region of HBV DNA in patients with Hodgkin and non-Hodgkin lymphoma.

Conclusions:

A high rate of 25% and 24.13% of HBV DNA was detected among patients with Hodgkin and non-Hodgkin lymphoma, respectively.

Management of chronic hepatitis B before and after liver transplantation

Liver transplantation remains the only curative option for eligible patients with complications of chronic hepatitis B (CHB) infection, including severe acute hepatitis flares, decompensated cirrhosis, and hepatocellular carcinoma. In general, all patients with CHB awaiting liver transplantation should be treated with oral nucleos(t)ide analogs (NAs) with high barriers to resistance to prevent potential flares of hepatitis and reduce disease progression. After liver transplantation, lifelong antiviral therapy is also required to prevent graft hepatitis, which may lead to subsequent graft loss. Although combination therapy using NA and hepatitis B immune globulin (HBIG) has been the regimen most widely adopted for over a decade, recent studies have demonstrated that newer NAs with low rates of resistance are effective in preventing graft hepatitis even without the use of HBIG, achieving excellent long term outcome. For patients without pre-existing resistant mutations, monotherapy with a single NA has been shown to be effective. For those with resistant strains, a combination of nucleoside analog and nucleotide analog should be used. To date, clinical trials using therapeutic vaccination have shown suboptimal response, as CHB patients likely have an immune deficit against HBV epitopes. Future strategies include targeting different sites of the hepatitis B replication cycle and restoring the host immunity response to facilitate complete viral eradication.

Toll-like receptor-mediated immune responses are attenuated in the presence of high levels of hepatitis B virus surface antigen

It has been recently shown that Toll-like receptor (TLR) signalling in murine nonparenchymal liver cells (NPCs) is suppressed in the presence of Hepatitis B virus surface antigen (HBsAg). It is not clear, however, whether this is also relevant for the adaptive immune responses and how this effect is mediated. Peripheral blood mononuclear cells (PBMCs) from Hepatitis B virus (HBV) patients and controls were stimulated by TLR ligands in the absence or presence of autologous serum. Interestingly, TLR-mediated cytokine expression (Interleukin-6 and -10) as well as TLR3-induced interferon (IFN) expression in PBMCs of HBV patients was significantly higher than in the healthy volunteers, showing a negative correlation with the levels of HBsAg. In addition, TLR3-mediated IFN-γ production was inhibited in the presence of HBV-containing serum. To mechanistically analyse this observation, murine Kupffer cells (KCs) and sinusoidal endothelial cells (LSECs) were stimulated with TLR3 ligands in the presence or absence of HBsAg. Mixed lymphocyte reactions were performed to study T-cell activation induced by TLR-stimulated NPCs. Gene expression of cytokines and TLR3 was analysed by quantitative rt-PCR, and activation of transcription factors was assessed by Western blot or reporter gene assays. TLR-induced expression of interferon γ, interferon sensitive genes and proinflammatory cytokines in murine KCs and LSECs was efficiently suppressed in the presence of HBsAg, whereas the expression of anti-inflammatory cytokines was enhanced. Activation of NFκB, IRF-3 and MAPKs in these liver cells was potently suppressed by HBsAg. T-cell activation mediated through TLR3-stimulated KCs or LSECs was suppressed by HBsAg which could be reverted by anti-IL-10 antibodies. These findings may, at least in part, explain how HBV evades innate and adaptive immune responses to maintain a persistent infection.

Lipid-based drug carriers for prodrugs to enhance drug delivery

The combination of lipid drug delivery systems with prodrugs offers several advantages including improved pharmacokinetics, increased absorption, and facilitated targeting. Lipidization and use of lipid carriers can increase the pharmacological half-life of the drug, thus improving pharmacokinetics and allowing less frequent dosing. Lipids also offer advantages such as increased absorption through the intestines for oral drug absorption and to the CNS for brain delivery. Furthermore, the use of lipid delivery systems can enhance drug targeting. Endogenous proteins bind lipids in the blood and carry them to the liver to enable targeting of this organ. Drugs with significant side effects in the stomach can be specifically delivered to enterocytes by exploiting lipases for prodrug activation. Finally, lipids can be used to target the lymphatic system, thus bypassing the liver and avoiding first-pass metabolism. Lymphatic targeting is also important for antiviral drugs in the protection of B and T lymphocytes. In this review, both lipid-drug conjugates and lipid-based carriers will be discussed. An overview, including the chemistry and assembly of the systems, as well as examples from the clinic and in development, will be provided.

Characterization of the occult hepatitis B virus variants circulating among the blood donors from eastern India

A previous study from West Bengal documented very high rate of occult HBV infection (OBI) among the HBsAg negative blood donors. This study was aimed to characterize the OBI strains circulating among the blood donors and to estimate the risk associated with the prevailing viral variants/mutants. Blood samples from 2195 voluntary blood donors were included in the study. HBsAg, HBeAg, anti-HBc, and anti-HBs statuses of the samples were done by ELISA based detection. PCR amplification and sequencing were done to determine HBV genotypes, basal core promoter (BCP), and precore (Pre-C) mutations. Among the study samples, 268 were anti-HBc positive/HBsAg negative, among which 65 (24.25%) were HBV DNA positive. Phylogenetic analysis revealed the presence of HBV/D (87.23%), HBV/A (8.51%), and HBV/C (4.26%) (P < 0.0001). HBV/D3 (65.85%) was the significantly prevalent subgenotype over HBV/D2 (26.83%) and HBV/D1 (7.31%) (P = 0.0003). Considerable prevalence of differential BCP (1752C, 1753C, 1762T/1764A, 1753C+1762T/1764A, 1773C, and 1814C) and reverse transcriptase (rt) gene (rtI91L, rtL93P, rtS106C, rtR110G, rtN118T, rtS119T, rtY126H, rtG127W/R, rtC136R, and rtY158H) mutations was identified. Association of specific HBV subgenotypes with OBI was interesting and needs further study. Clinically relevant mutations were prevalent among the OBI strains which are of serious concern.

Delivery Systems for Lymphatic Targeting

The lymphatic system has a critical role in the immune system’s recognition and response to disease, and it is an additional circulatory system throughout the entire body. Most solid cancers primarily spread from the main site via the tumour’s surrounding lymphatics before haematological dissemination. Targeting drugs to lymphatic system is quite complicated because of its intricate physiology. Therefore, it tends to be an important target for developing novel therapeutics. Currently, nanocarriers have encouraged the lymphatic targeting, but still there are challenges of locating drugs and bioactives to specific sites, maintaining desired action and crossing all the physiological barriers. Lymphatic therapy using drug-encapsulated colloidal carriers especially liposomes and solid lipid nanoparticles emerges as a new technology to provide better penetration into the lymphatics where residual disease exists. Optimising the proper procedure, selecting the proper delivery route and target area and making use of surface engineering tool, better carrier for lymphotropic system can be achieved. Thus, new methods of delivering drugs and other carriers to lymph nodes are currently under investigation.

Distribution of total DNA and cccDNA in serum and PBMCs may reflect the HBV immune status in HBsAg+ and HBsAg- patients coinfected or not with HIV or HCV

BACKGROUND

The potential reservoir role of serum and peripheral blood mononuclear cells (PBMCs) for total HBV DNA (tDNA) and cccDNA still remains unknown.

MATERIAL AND METHODS

We analyzed tDNA and cccDNA with a single sensitive and validated standardized real-time PCR method in serum and PBMCs in two populations of chronic HBV infection coinfected or not with HCV and/or HIV viruses: a retrospective cohort of 130 HBsAg-negative (HBsAg-) patients with "anti-HBc alone" or anti-HBc and anti-HBs antibodies (Ab) and a cohort of 70 HBsAg-positive patients, 16 of them being prospectively followed under treatment.

RESULTS

Among HBsAg- patients, HBV DNA was detected in serum or PBMCs in about half of the cases with various distributions of tDNA and cccDNA: in HIV-negative patients with an "antiHBc alone" profile, tDNA was mostly detected in PBMCs suggesting a possible active role of PBMCs; although cccDNA was not detected in PBMCs in HIV-positive patients, tDNA and cccDNA were mostly observed in serum, suggesting a specific pattern of more "persistent" than "occult" infection in this population. Patients with anti-HBc and anti-HBs Ab harbored tDNA in serum or in PBMCs, regardless of their HIV or HCV status, raising the question of a viral reactivation risk during immunosupression in these patients. Among HBsAg+ patients, tDNA was detected in serum and PBMCs of 88.5% of the cases and cccDNA in 22%. Levels of tDNA in both compartments were highly correlated during treatment, suggesting a passive reservoir role for PBMCs.

CONCLUSION

The respective distribution of tDNA and cccDNA in serum and PBMCs may reflect the different immune statuses of the host in HBsAg+ and HBsAg- patients. The frequency of HBV DNA in PBMCs from AgHBs- patients suggests a viral reactivation risk during immunodepression in those patients.

Role of peripheral blood mononuclear cell transportation from mother to baby in HBV intrauterine infection

PURPOSE

We aimed to investigate the role of peripheral blood mononuclear cell transportation from mother to baby in hepatitis B virus (HBV) intrauterine infection.

METHODS

Thirty HBsAg-positive pregnant women in the second trimester and their aborted fetuses were included in this study. Enzyme-linked-immunosorbent-assay was utilized to detect HBsAg in the peripheral blood of pregnant women and the femoral vein blood of their aborted fetuses. HBV-DNA in serum and peripheral blood mononuclear cells (PBMC) and GSTM1 alleles of pregnant women and their aborted fetuses were detected by nested polymerase chain reaction (PCR) and seminested PCR, respectively. We also examined the location of placenta HBsAg and HBcAb using immunohistochemical staining. The expression of placenta HBV-DNA was detected by in situ hybridization.

RESULTS

For the 30 aborted fetuses, the HBV intrauterine infection rate was 43.33%. The HBV-positive rates of HBsAg in peripheral blood, serum, and PBMC were 10% (3/30), 23.33% (7/30), and 33.33% (10/30), respectively. Maternal-fetal PBMC transport was significantly positively correlated with fetal PBMC HBV-DNA (P = 0.004). Meanwhile, the rates of HBV infection gradually decreased from the maternal side to the fetus side of placenta (decidual cells > trophoblastic cells > villous mesenchymal cells > villous capillary endothelial cells). However, no significant correlation between placenta HBV infection and HBV intrauterine infection was observed (P = 0.410).

CONCLUSIONS

HBV intrauterine infection was primarily due to peripheral blood mononuclear cell maternal-fetal transportation in the second trimester in pregnant women.

Uracil DNA glycosylase counteracts APOBEC3G-induced hypermutation of hepatitis B viral genomes: excision repair of covalently closed circular DNA

The covalently closed circular DNA (cccDNA) of the hepatitis B virus (HBV) plays an essential role in chronic hepatitis. The cellular repair system is proposed to convert cytoplasmic nucleocapsid (NC) DNA (partially double-stranded DNA) into cccDNA in the nucleus. Recently, antiviral cytidine deaminases, AID/APOBEC proteins, were shown to generate uracil residues in the NC-DNA through deamination, resulting in cytidine-to-uracil (C-to-U) hypermutation of the viral genome. We investigated whether uracil residues in hepadnavirus DNA were excised by uracil-DNA glycosylase (UNG), a host factor for base excision repair (BER). When UNG activity was inhibited by the expression of the UNG inhibitory protein (UGI), hypermutation of NC-DNA induced by either APOBEC3G or interferon treatment was enhanced in a human hepatocyte cell line. To assess the effect of UNG on the cccDNA viral intermediate, we used the duck HBV (DHBV) replication model. Sequence analyses of DHBV DNAs showed that cccDNA accumulated G-to-A or C-to-T mutations in APOBEC3G-expressing cells, and this was extensively enhanced by UNG inhibition. The cccDNA hypermutation generated many premature stop codons in the P gene. UNG inhibition also enhanced the APOBEC3G-mediated suppression of viral replication, including reduction of NC-DNA, pre-C mRNA, and secreted viral particle-associated DNA in prolonged culture. Enhancement of APOBEC3G-mediated suppression by UNG inhibition was not observed when the catalytic site of APOBEC3G was mutated. Transfection experiments of recloned cccDNAs revealed that the combination of UNG inhibition and APOBEC3G expression reduced the replication ability of cccDNA. Taken together, these data indicate that UNG excises uracil residues from the viral genome during or after cccDNA formation in the nucleus and imply that BER pathway activities decrease the antiviral effect of APOBEC3-mediated hypermutation.

De novo activation of HBV with escape mutations from hepatitis B surface antibody after living donor liver transplantation

BACKGROUND

De novo activation of HBV occurs after liver transplantation from hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (anti-HBc)-positive donors, even under hepatitis B immunoglobulin (HBIG) prophylaxis. One reason for the activation of HBV is the emergence of HBV with escape mutations from hepatitis B surface antibody (anti-HBs). The aim of this study is to clarify the clinical features for de novo activation of HBV with anti-HBs escape mutations after liver transplantation.

METHODS

Clinical features of 75 patients who received HBIG prophylaxis >6 months after liver transplantation with liver grafts from anti-HBc-positive donors were retrospectively analysed.

RESULTS

Among the 75 recipients, 19 (25%) developed de novo activation of HBV. Of the 19 recipients, the emergence of HBV with anti-HBs escape mutations was confirmed in 7 patients. The rate of de novo activation of HBV with anti-HBs escape mutations was 12% at 5 years. Sequence analysis revealed mutations in the common 'a' determinant region of the surface gene, including G145R, G145A and Q129P, in HBsAg. Administration of entecavir immediately after the occurrence of de novo HBV activation resolved hepatitis and induced clearance of serum HBsAg and HBV DNA in all four patients receiving entecavir.

CONCLUSIONS

Escape mutations from anti-HBs caused de novo activation of HBV under HBIG prophylaxis after liver transplantation. Early administration of entecavir was effective on de novo activation of HBV with anti-HBs escape mutations.

Intestinal lymphatic transport for drug delivery

Intestinal lymphatic transport has been shown to be an absorptive pathway following oral administration of lipids and an increasing number of lipophilic drugs, which once absorbed, diffuse across the intestinal enterocyte and while in transit associate with secretable enterocyte lipoproteins. The chylomicron-associated drug is then secreted from the enterocyte into the lymphatic circulation, rather than the portal circulation, thus avoiding the metabolically-active liver, but still ultimately returning to the systemic circulation. Because of this parallel and potentially alternative absorptive pathway, first-pass metabolism can be reduced while increasing lymphatic drug exposure, which opens the potential for novel therapeutic modalities and allows the implementation of lipid-based drug delivery systems. This review discusses the physiological features of the lymphatics, enterocyte uptake and metabolism, links between drug transport and lipid digestion/re-acylation, experimental model (in vivo, in vitro, and in silico) of lymphatic transport, and the design of lipid- or prodrug-based drug delivery systems for enhancing lymphatic drug transport.

Re-appearance of hepatitis B virus following therapy with rituximab for lymphoma is not rare in Japanese patients with past hepatitis B virus infection

BACKGROUND AND AIM

De novo hepatitis B virus (HBV)-related hepatitis is a well-known fatal complication following chemo-immunosuppressive therapy in patients with past HBV infection (HB surface antigen and serum HBV DNA negative, but HB core antibody and/or HB surface antibody positive). This research was conducted to evaluate the incidence of and clinical features associated with re-appearance of serum HBV DNA following chemo-immunosuppressive therapy in Japanese patients with past HBV infection.

METHODS

This is a retrospective review. Forty-five patients with past HBV infection who had received chemo-immunosuppressive therapy for haematological disease were followed up for >6 months, to determine whether the serum test for HBV changed from negative to positive (i.e. re-appearance of serum HBV DNA following chemo-immunosuppressive therapy).

RESULTS

Re-appearance of serum HBV DNA was confirmed in five (20.8%) of the 24 patients who had received treatment regimens containing rituximab, but in none of the 21 patients who had not received treatment regimens containing rituximab (P=0.035). The HBV genotype could be determined in four of the five aforementioned patients, and in all four, HBV genotype C, which is the most prevalent genotype in Japan, was identified.

CONCLUSION

This research showed that re-appearance of serum HBV DNA is not rare in Japanese patients treated with chemotherapy regimens containing rituximab, and no other factors related to such re-appearance of serum HBV DNA could be identified. Well-designed clinical studies, including immunological and genetic analyses of the host and of the HBV, are required for further elucidation.

Targeted drug delivery to lymphocytes: a route to site-specific immunomodulation?

Lymphocytes are central to the progression of autoimmune disease, transplant rejection, leukemia, lymphoma and lymphocyte-resident viral diseases such as HIV/AIDs. Strategies to target drug treatments to lymphocytes, therefore, represent an opportunity to enhance therapeutic outcomes in disease states where many current treatment regimes are incompletely effective and promote significant toxicities. Here we demonstrate that highly lipophilic drug candidates that preferentially access the intestinal lymphatics after oral administration show significantly enhanced access to lymphocytes leading to improved immunomodulatory activity. When coadministered with such drugs, lipids enhance lymphocyte targeting via a three tiered action: promotion of drug absorption from the gastrointestinal tract, enhancement of lymphatic drug transport and stimulation of lymphocyte recruitment into the lymphatics. This strategy has been exemplified using a highly lipophilic immunosuppressant (JWH015) where coadministration with selected lipids led to significant increases in lymphatic transport, lymphocyte targeting and IL-4 and IL-10 expression in CD4+ and CD8+ lymphocytes after ex vivo mitogen stimulation. In contrast, administration of a 2.5-fold higher dose of JWH015 in a formulation that did not stimulate lymph transport had no effect on antiinflammatory cytokine levels, in spite of equivalent drug exposure in the blood. The current data suggest that complementary drug design and delivery strategies that combine highly lipophilic, lymphotropic drug candidates with lymph-directing formulations provide enhanced selectivity, potency and therapeutic potential for drug candidates with lymphocyte associated targets.

Total and covalently closed circular DNA detection in liver tissue of long-term survivors transplanted for HBV-related cirrhosis

BACKGROUND

Life-long prophylaxis against HBV recurrence is recommended in patients transplanted for HBV-related disease. The risk of HBV reactivation is due to persistence of covalently closed circular (ccc) DNA in hepatocytes. Whether cccDNA persists in livers of long-term transplant survivors who received conventional prophylaxis is unknown.

AIM

To investigate the presence of intrahepatic total and cccDNA in transplanted patients with no evidence of biochemical markers of HBV recurrence.

METHODS

Intrahepatic total and cccDNA were assessed using sensitive nested and real-time PCR from 44 HBsAg-positive patients (75% male; mean age 55.2+/-8.9 years) who had undetectable serum HBV-DNA at transplant. The mean follow-up after transplant was 88.3 months (range, 18-159).

RESULTS

One patient underwent HBV recurrence after transplant and was the only who tested positive for both intrahepatic total HBV-DNA and cccDNA. Of the 43 patients negative for all serological markers of HBV infection, only 2 tested positive for intrahepatic total HBV-DNA, but none for cccDNA.

CONCLUSIONS

Most patients with undetectable HBV-DNA at transplant, who received conventional HBV prophylaxis, have no evidence of intrahepatic total HBV-DNA and cccDNA. cccDNA should be considered a new additional diagnostic tool, also to identify patients at low risk of HBV recurrence after liver transplantation.

Occult hepatitis B virus infection of peripheral blood mononuclear cells among treatment-naive patients with chronic lymphocytic leukemia

Recent guidelines emphasise the risk of hepatitis B virus (HBV) reactivation among patients with hematologic malignancies of B lineage, in which HBV has been recently hypothesised to play a pathogenetic role. We aimed to determine the prevalence of occult HBV infection (OBI) of peripheral blood mononuclear cells, defined as detection of sequences from >or=2 HBV genes in subjects lacking hepatitis B surface antigen, among patients with treatment-naive chronic lymphocytic leukemia (CLL). HBV DNA sequences from four HBV genes (S, X, core and pol) were searched for in archival material obtained at diagnosis (N = 173), and from age and sex-matched controls. OBI was observed in 17/173 (10%) patients and 5/173 (3%) controls (OR = 3.6, 95% CI 1.37-9.79, p = 0.014). OBI was not associated with differences on 5-year survival and biological predictors, but patients with CLL with OBI had significantly lower peripheral blood lymphocyte count. After 8 years of observation without treatment, one OBI positive patient with CLL converted into positive HBsAg serology and developed active hepatitis. In conclusion, OBI is significantly more prevalent among patients with CLL than in age and sex-matched controls, and may contribute to the susceptibility of patients with CLL to HBV reactivation, whether exposed or not to biological agents.

Evaluating the risk of hepatitis B reactivation in patients with haematological malignancies: is the serum hepatitis B virus profile reliable?

BACKGROUND/AIM

Patients with an occult hepatitis B virus (HBV) infection undergoing deep immunosuppression are potentially at risk of HBV reactivation. In order to assess whether a polymerase chain reaction (PCR) assay for HBV DNA in serum could be used to predict the reactivation of an occult HBV infection, we performed a retrospective study in a cohort of Sicilian patients with oncohaematological diseases.

METHODS

We studied by a highly sensitive ad hoc nested PCR for serum HBV DNA 75 HBsAg-negative oncohaematological patients requiring chemotherapy.

RESULTS

Thirty-three patients (44%) were HBV seronegative (anti-HBc and anti-HBs negative) and 42 patients (56%) were HBV seropositive (anti-HBc and/or anti-HBs positive). Baseline serum HBV DNA was positive in nine out of 33 HBV-seronegative patients and in nine out of 42 HBV-seropositive patients (27.3 vs. 21.4%; P=NS). HBsAg seroconversion was observed in five out of 33 seronegative vs. six out of 42 seropositive patients (15 vs. 14%, P=0.9), and in five out of 18 HBV DNA-positive vs. six out of 57 HBV DNA-negative patients (27.7 vs. 10.6%P=0.11). Hepatitis C virus infection was found in 18 patients (24.3%), although with no correlation to HBV serological status, presence of serum HBV DNA or frequency of HBsAg seroconversion.

CONCLUSIONS

In oncohaematological patients undergoing chemotherapy, highly sensitive serum HBV DNA testing at baseline has a 28% predictive ability to forecast HBsAg seroconversion in HBV DNA-positive patients, and a 90% ability to forecast persistent HBsAg negativity in HBV DNA-negative patients, a better performance than serological tests.

Bone marrow-derived mesenchymal stem cells are capable of mediating hepatitis B virus infection in injured tissues

We have previously showed that endothelial progenitor cells (EPCs) through uptake of hepatitis B virus (HBV) may play a critical role in mediating extrahepatic HBV diseases. However, it remains to be elucidated whether mesenchymal stem cells (MSCs) are capable of mediating HBV trans-infection into extrahepatic tissues.

METHODS AND RESULTS

In this study, we showed that HBV antigens, HBV DNA and the viral particles were detected in MSCs after 3 days virus challenge. Neither HBV covalently closed circular DNA nor pregenomic RNA were detected in MSCs. Intravenously transplantation of HBV-exposed MSCs into myocardial infarction mouse model resulted in incorporation of HBV into injured heart and other damaged tissues.

CONCLUSION

These results indicate that MSCs could serve as an additional extrahepatic virus reservoir, which may play a role at least in part in mediating HBV trans-infection into the injured tissues through the process of MSCs recruitment.

Lipid-based delivery systems and intestinal lymphatic drug transport: a mechanistic update

After oral administration, the majority of drug molecules are absorbed across the small intestine and enter the systemic circulation via the portal vein and the liver. For some highly lipophilic drugs (typically log P > 5, lipid solubility > 50 mg/g), however, association with lymph lipoproteins in the enterocyte leads to transport to the systemic circulation via the intestinal lymph. The attendant delivery benefits associated with lymphatic drug transport include a reduction in first-pass metabolism and lymphatic exposure to drug concentrations orders of magnitude higher than that attained in systemic blood. In the current review we briefly describe the mechanisms by which drug molecules access the lymph and the formulation strategies that may be utilised to enhance lymphatic drug transport. Specific focus is directed toward recent advances in understanding regarding the impact of lipid source (both endogenous and exogenous) and intracellular lipid trafficking pathways on lymphatic drug transport and enterocyte-based first-pass metabolism.

Infection of hepatitis B virus in extrahepatic endothelial tissues mediated by endothelial progenitor cells

Background

Hepatitis B virus (HBV) replication has been reported to be involved in many extrahepatic viral disorders; however, the mechanism by which HBV is trans-infected into extrahepatic tissues such as HBV associated myocarditis remains largely unknown.

Results

In this study, we showed that human cord blood endothelial progenitor cells (EPCs), but not human umbilical vein endothelial cells (HUVECs) could be effectively infected by uptake of HBV in vitro. Exposure of EPCs with HBV resulted in HBV DNA and viral particles were detected in EPCs at day 3 after HBV challenge, which were peaked around day 7 and declined in 3 weeks. Consistently, HBV envelope surface and core antigens were first detected in EPCs at day 3 after virus challenge and were retained to be detectable for 3 weeks. In contrast, HBV covalently closed circular DNA was not detected in EPCs at any time after virus challenge. Intravenous transplantation of HBV-treated EPCs into myocardial infarction and acute renal ischemia mouse model resulted in incorporation of HBV into injured heart, lung, and renal capillary endothelial tissues.

Conclusion

These results strongly support that EPCs serve as virus carrier mediating HBV trans-infection into the injured endothelial tissues. The findings might provide a novel mechanism for HBV-associated myocarditis and other HBV-related extrahepatic diseases as well.