Hepatitis B virus infection: pathogenesis, reactivation and management in hematopoietic stem cell transplant recipients

Hepatitis B Virus Infection in Patients Receiving Allogeneic Hematopoietic Stem Cell Transplantation

Considering a steady increase in the number of allogeneic hematopoietic stem cell transplantations (allo-HSCT) worldwide and the significant proportion of the world’s population that has been exposed to hepatitis B virus (HBV) infection, HBV reactivation following allo-HSCT remains an important issue for post-transplant morbidity and mortality. Antiviral prophylaxis can reduce HBV replication, severity of HBV-related hepatitis, and mortality; therefore, identification of patients at risk is crucial. It is recommended that all recipients and donors should be screened for active or prior HBV infection, including HBsAg, antiHBc, and antiHBs. Adoptive immunity transfer from the donor seems to have protective effects against HBV reactivation. Antiviral prophylaxis should be initiated in all HBsAg-positive patients. HBsAg-negative, antiHBc-positive patients remain at risk; therefore, antiviral prophylaxis should be considered if baseline serum HBV DNA is detectable. In HBsAg-negative, antiHBc-positive patients without detectable HBV DNA, close monitoring of viral load with an on-demand therapy is necessary. Entecavir or tenofovir rather than lamivudine are more appropriate for the emergence of lamivudine resistance. The treatment duration remains unclear, with 6- to 12-month therapy after cessation of immunosuppressive therapy commonly recommended. Here we review the updated evidence and recent recommendations regarding HBV reactivation in patients undergoing allo-HSCT for individualized therapy.

A prospective trial of vaccine to prevent hepatitis B virus reactivation after hematopoietic stem cell transplantation

Hepatitis B virus (HBV) reactivation reportedly occurs frequently after hematopoietic stem cell transplantation (HSCT) in resolved HBV-infected patients. Here, 50 patients with resolved HBV infections and scheduled to undergo HSCT were enrolled; all subjects were vaccinated with three doses of hepatitis B vaccine 12 months after HSCT and the incidence of HBV reactivation was monitored. The patients' characteristics were: median age, 61 (34-72) years; male/female, 27/19; allogeneic/autologous, 40/6; bone marrow/peripheral blood stem cells/cord blood, 26/16/4. Of the 46 patients who underwent HSCT, 19 were excluded and did not make it to vaccination due to relapse of underlying disease, HBV reactivation within 12 months of HSCT, or transfer of patients. The remaining 27 were vaccinated 12 months after HSCT and monitored for 2 years. Six showed HBV reactivation, with a 2-year cumulative reactivation incidence of 22.2%; the same incidence was 27.3% only in allogeneic HSCT patients. Factors associated with HBV reactivation included the discontinuation of immunosuppressants (P = 0.0379) and baseline titers of antibody against hepatitis B surface antigen (P = 0.004). HBV reactivation with vaccination following HSCT could occur despite maintenance of serum anti-HBs at more than protective levels.

Discontinuation of antiviral prophylaxis increased the risk of hepatitis B virus reactivation in glomerulonephritis patients under immunotherapy: a real-life observation

PURPOSE

Antiviral prophylaxis is proved to be effective in reducing the risk of hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-positive patients under immunotherapy. But outcomes referring to discontinuation of antiviral prophylaxis in these patients are lacking.

METHODS

We performed a retrospective study of 105 HBsAg-positive patients under immunotherapy for glomerulonephritis and evaluated the incidence and risk factors for HBV reactivation.

RESULTS

Among 105 patients, 55.24% completed antiviral prophylaxis, while 20.00% discontinued and 24.76% rejected antiviral prophylaxis. HBV reactivation was significantly different among completion, discontinuation, and rejection of antiviral prophylaxis: 5.17% versus 38.10% versus 15.38% in the incidence of HBV reactivation (P = 0.001), 3.45% versus 23.81% versus 11.54% in HBV DNA ≥ 5 Log copies/ml (P = 0.023), and 0 versus 14.29% versus 3.85% in hepatitis B e antigen seroconversion from negative to positive (P = 0.014). Survival curve showed the median occurrence time of HBV reactivation in discontinuation group was 32 months (95% CI 24-39 months), earlier than 69 months (95% CI 65-72 months) of completion group and 43 months (95% CI 37-49 months) of rejection group (χ² = 13.780, P = 0.001). Univariate and multivariate analysis identified two independent risk factors for HBV reactivation: baseline HBV DNA detectable (OR 5.009, 95% CI 1.717-16.335, P = 0.012) and discontinuation of antiviral prophylaxis (OR 5.213, 95% CI 1.688-18.105, P = 0.011).

CONCLUSIONS

Discontinuation of antiviral prophylaxis increased the risk of HBV reactivation in HBsAg-positive patients under immunotherapy for glomerulonephritis.

Hepatitis B virus reactivation in breast cancer patients undergoing chemotherapy: A review and meta-analysis of prophylaxis management

Hepatitis B virus (HBV) reactivation during or after chemotherapy in patients with breast cancer has become a remarkable clinical problem. Prophylactic nucleos(t)ide analogues (NAs) are recommended for patients with breast cancer who are hepatitis B surface antigen (HBsAg) positive before chemotherapy. We performed an up-to-date meta-analysis to compare the efficacy of prophylactic lamivudine use with nonprophylaxis in HBsAg-positive breast cancer patients undergoing chemotherapy. PubMed, the Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched for relevant articles until June 2016. Eligible articles comparing the efficacy of prophylactic lamivudine use with nonprophylaxis in HBsAg-positive breast cancer patients undergoing chemotherapy were identified. Eight studies which had enrolled 709 HBsAg-positive breast cancer patients undergoing chemotherapy were analysed. Lamivudine prophylaxis significantly reduced the rates of chemotherapy-associated hepatitis B flares in chronic hepatitis B in breast cancer compared with patients with nonprophylaxis (odds ratio [OR]=0.15, 95% confidence interval [CI]: 0.07-0.35, P<.00001). Chemotherapy disruption rates attributed to HBV reactivation in the prophylaxis groups were significantly lower than the nonprophylaxis groups (OR=0.17, 95% CI: 0.07-0.43, P=.0002). Patients with lamivudine prophylaxis had a higher risk for tyrosine-methionine-aspartate-aspartate (YMDD) motif mutations than patients with nonprophylaxis (OR=6.33, 95% CI: 1.01-39.60, P=.05). Prophylactic antiviral therapy management is necessary for HBsAg-positive breast cancer patients undergoing chemotherapy, in spite of high correlation with lamivudine-resistant HBV variants with YMDD motif mutations.

Hepatitis B reactivation in HBsAg-negative/HBcAb-positive patients receiving immunosuppressive therapy for glomerulonephritis: a retrospective analysis

PURPOSE

The aim of this study is to investigate the prevalence and risk factors for hepatitis B virus (HBV) reactivation in HBsAg-negative/HBcAb-positive patients receiving immunosuppressive therapy for glomerulonephritis.

METHODS

We performed a retrospective study of 745 HBsAg-negative/HBcAb-positive patients undergoing immunosuppressive therapy for glomerulonephritis from years 2003 to 2012 at the department of nephrology, China-Japan Friendship Hospital, Beijing, China. The patients were divided into HBV reactivation group (n = 27) and non-HBV reactivation group (n = 718).

RESULTS

The prevalence of HBV reactivation in patients receiving immunosuppressive therapy for glomerulonephritis was up to 3.62% in serological status of HBsAg-negative/HBcAb-positive. HBV reactivation was associated with several findings: greater proportion of lupus nephritis (25.93 vs. 9.61%, p = 0.014), much higher percentage of HBsAb-negative (74.07 vs. 23.82%, p < 0.001), longer duration of immunosuppressive treatment (100 vs. 70.06%, p < 0.001), as well as more cases of combined immunosuppressant (92.59 vs. 61.56%, p = 0.001). After univariate and multivariate analysis, three variables remained as independent risk factors for HBV reactivation: serological status of HBsAb-negative (OR 8.375, 95% CI 3.674-19.776, p = 0.001), length of immunosuppressive treatment more than 1 year (OR 1.308, 95% CI 1.121-1.358, p = 0.024), and combined immunosuppressant (OR 6.342, 95% CI 1.675-30.166, p = 0.003).

CONCLUSIONS

HBV reactivation is not uncommon in HBsAg-negative/HBcAb-positive glomerulonephritis patients treated with immunosuppressant, and the prevalence was up to 3.62%. Patients with serological status of HBsAb-negative, more than 1 year of immunosuppressive therapy, and combined immunosuppressant are independent risk factors for HBV reactivation.

Hepatitis B Reactivation During Immunosuppressive Therapy or Cancer Chemotherapy, Management, and Prevention: A Comprehensive Review-Screened

CONTEXT

Due to the close relationship between the immune system and the hepatitis B virus (HBV) replication, it is essential to monitor patients with current or past HBV infection under any type of immunosuppression. Cancer chemotherapy, immunosuppressive therapies in autoimmune diseases, and immunosuppression in solid organ and stem cell transplant recipients are the major reasons for hepatitis B virus reactivation (HBVr). In this review, the challenges associated with HBVr are discussed according to the latest studies and guidelines. We also discuss the role of treatments with different risks, including anti-CD20 agents, tumor necrosis factor-alpha (TNF-α) inhibitors, and other common immunosuppressive agents in various conditions.

EVIDENCE ACQUISITION

Through an electronic search of the PubMed, Google Scholar, and Scopus databases, we selected the studies associated with HBVr in different conditions. The most recent recommendations were collected in order to reach a consensus on how to manage patients at risk of HBVr.

RESULTS

It was found that the positive hepatitis B surface antigen (HBsAg), the high baseline HBV DNA level, the positive hepatitis B virus e antigen (HBeAg), and an absent or low hepatitis B surface antibody (HBsAb) titer prior to starting treatment are the most important viral risk factors. Furthermore, rituximab, anthracycline, and different types of TNF-α inhibitors were identified as the high-risk therapies. By analyzing the efficiency of prophylaxis on the prevention of HBVr, it was concluded that those with a high risk of antiviral resistance should not be used in long-term immunosuppressants. Receiving HBV antiviral agents at the commencement of immunosuppressant therapy or chemotherapy was demonstrated to be effective in decreasing the risk of HBVr. Prophylaxis could also be initiated before the start of therapy. For most immune suppressive regimes, antiviral therapy should be kept up for at least 6 months after the cessation of immunosuppressive drugs. However, the optimal time of prophylaxis keeping should be increased in cases associated with rituximab or hematopoietic stem cell transplants. According to the latest studies and guidelines from different bodies, recommendations regarding screening, monitoring, and management of HBVr are outlined.

CONCLUSIONS

Identification of patients at the risk of HBVr before immunosuppressive therapy is an undeniable part of treatment. Starting the antiviral therapy, based on the type of immunosuppressive drugs and the underlying disease, could lead to better management of disease.

Preparation by alkaline treatment and detailed characterisation of empty hepatitis B virus core particles for vaccine and gene therapy applications

Hepatitis B virus (HBV) core (HBc) virus-like particles (VLPs) are one of the most powerful protein engineering tools utilised to expose immunological epitopes and/or cell-targeting signals and for the packaging of genetic material and immune stimulatory sequences. Although HBc VLPs and their numerous derivatives are produced in highly efficient bacterial and yeast expression systems, the existing purification and packaging protocols are not sufficiently optimised and standardised. Here, a simple alkaline treatment method was employed for the complete removal of internal RNA from bacteria- and yeast-produced HBc VLPs and for the conversion of these VLPs into empty particles, without any damage to the VLP structure. The empty HBc VLPs were able to effectively package the added DNA and RNA sequences. Furthermore, the alkaline hydrolysis technology appeared efficient for the purification and packaging of four different HBc variants carrying lysine residues on the HBc VLP spikes. Utilising the introduced lysine residues and the intrinsic aspartic and glutamic acid residues exposed on the tips of the HBc spikes for chemical coupling of the chosen peptide and/or nucleic acid sequences ensured a standard and easy protocol for the further development of versatile HBc VLP-based vaccine and gene therapy applications.

Prophylactic antiviral therapy in allogeneic hematopoietic stem cell transplantation in hepatitis B virus patients

AIM: To investigate the timing, safety and efficacy of prophylactic antiviral therapy in patients with hepatitis B virus (HBV) infection undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS: This prospective study recruited a total of 57 patients diagnosed with malignant hematological diseases and HBV infection at the First Affiliated Hospital of Sun Yat-sen University between 2006 and 2013. The patients were classified as hepatitis B surface antigen (HBsAg)-positive or HBsAg-negative/ antiHBc-positive. Patients were treated with chemotherapy followed by antiviral therapy with nucleoside analogues. Patients underwent allo-HSCT when serum HBV DNA was < 10³ IU/mL. Following allo-HSCT, antiviral therapy was continued for 1 year after the discontinuation of immunosuppressive therapy. A total of 105 patients who underwent allo-HSCT and had no HBV infection were recruited as controls. The three groups were compared for incidence of graft-vs-host disease (GVHD), drug-induced liver injury, hepatic veno-occlusive disease, death and survival time.

RESULTS: A total of 29 of the 41 subjects with chronic GVHD exhibited extensive involvement and 12 exhibited focal involvement. Ten of the 13 subjects with chronic GVHD in the HBsAg(-)/hepatitis B core antibody(+) group exhibited extensive involvement and 3 exhibited focal involvement. Five of the 10 subjects with chronic GVHD in the HBsAg(+) group exhibited extensive involvement and 5 exhibited focal involvement. The non HBV-infected group did not differ significantly from the HBsAg-negative/antiHBc-positive and the HBsAg-positive groups which were treated with nucleoside analogues in the incidence of graft-vs-host disease (acute GVHD; 37.1%, 46.9% and 40%, respectively; P = 0.614; chronic GVHD; 39%, 40.6% and 40%, respectively; P = 0.98), drug-induced liver injury (25.7%, 18.7% and 28%, respectively; P = 0.7), death (37.1%, 40.6% and 52%, respectively; P = 0.4) and survival times (P = 0.516). One patient developed HBV reactivation (HBsAg-positivity) due to early discontinuation of antiviral therapy.

CONCLUSION: Suppression of HBV DNA to < 10³ IU/mL before transplantation, continued antiviral therapy and close monitoring of immune markers and HBV DNA after transplantation may assure the safety of allo-HSCT.

Cytomegalovirus infection in patients who underwent allogeneic hematopoietic stem cell transplantation in Portugal: a five-year retrospective review

Cytomegalovirus (CMV) infection is 1 of the leading causes of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (aHSCT), mainly within the first 100 days after transplantation. We aimed to characterize CMV infection in a cohort of 305 patients with different malignancies undergoing aHSCT at the Portuguese Institute of Oncology of Porto between January 2008 and December 2012. In total, 184 patients (60.3%) developed CMV infection, mainly viral reactivations rather than primary infections (96.2% versus 3.8%, respectively). The majority of patients (166 of 184) developed CMV infection ≤100 days after transplantation, with median time to infection of 29 days (range, 0 to 1285) and median duration of infection of 10 days (range, 2 to 372). Multivariate analysis revealed that CMV infection was increased in donor (D)-/recipient (R)+ and D+/R+ (odds ratio [OR], 10.5; 95% confidence interval [CI], 4.35 to 25.4; P < .001) and in patients with mismatched or unrelated donors (OR, 2.54; 95% CI, 1.34 to 4.80; P = .004). Cox regression model showed that the risk of death was significantly increased in patients >38 years old (OR, 1.89; 95% CI, 1.14 to 3.12; P = .0137), who underwent transplantation with peripheral blood (OR, 3.02; 95% CI, 1.33 to 6.86; P = .008), with mismatched or unrelated donor (OR, 2.16; 95% CI, 1.48 to 3.13; P < .001), and who developed CMV infection (OR, 1.76; 95% CI, 1.07 to 2.90; P = .025). Moreover, patients who developed CMV infection had a significantly reduced median post-transplantation survival (16 versus 36 months; P = .002).

Immunosuppression in Patients with Chronic Hepatitis B

After hepatitis B virus (HBV) infection, HBV DNA persists in minute amounts in hepatocyte nuclei even in individuals with “resolved” infection. Viral replication and development of liver disease depend on the balance between viral mechanisms promoting persistence and host immune control. Patients with active or inactive disease or resolved HBV infection are at risk for reactivation with immunosuppressive therapy use. HBV reactivation varies from a clinically asymptomatic condition to one associated with acute liver failure and death. We review recent studies on HBV reactivation during immunomodulatory therapies for oncologic, gastroenterological, rheumatic, and dermatologic disorders. Risk calculation should be determined through HBV screening and assessment of immunosuppressive therapy potency. We also discuss monitoring for reactivation, prophylactic antiviral therapy, and treatment of reactivation. Prophylactic antiviral treatment is needed for all HBsAg carriers and selected patients who have anti-HBc without HBsAg and is critical for preventing viral reactivation and improving outcomes.

Management of chronic hepatitis B: Canadian Association for the Study of the Liver consensus guidelines

Chronic hepatitis B (CHB) is a dynamic disease that is influenced by host and virological factors. The management of CHB has become more complex with the increasing use of long-term oral nucleos⁄tide analogue antiviral therapies and the availability of novel diagnostic assays. Furthermore, there is often a lack of robust data to guide optimal management such as the selection of therapy, duration of treatment, potential antiviral side effects and the treatment of special populations. In November 2011, the Canadian Liver Foundation and the Canadian Association for the Study of the Liver convened a consensus conference to review the literature and analyze published data, including other international expert guidelines on CHB management. The proceedings of the consensus conference are summarized and provide updated clinical practice guidelines to assist Canadian health care providers in the prevention, diagnosis, assessment and treatment of CHB.