Risk of Onset of Hematological Malignancies in Patients Infected with the Hepatitis B Virus: Results from a Large-Scale Retrospective Cohort Study in China

Burden, Outcome, and Comorbidities of Extrahepatic Manifestations in Hepatitis B Virus Infections

Hepatitis B virus (HBV) infections affect approximately 296 million people around the world, and the prevalence of any past or present HBV infection during the years 2015-2018 was as high as 4.3%. Acute HBV infection often presents with nonspecific symptoms and is usually self-limited, but 5% of patients can have persistent infections leading to chronic HBV infection and the risk of turning into chronic HBV infection is significantly higher in babies with vertical transmission (95%). Patients with chronic HBV infection are usually asymptomatic, but 15 to 40% of chronic HBV carriers develop cirrhosis and/or hepatocellular carcinoma. In addition to liver-related disorders, HBV is also associated with several extrahepatic complications, including glomerulonephritis, cryoglobulinemia, neurologic disorders, psychological manifestations, polyarthritis, and dermatologic disorders. Making the diagnosis of HBV can be challenging since patients with chronic infections can remain symptom-free for decades before developing cirrhosis or hepatocellular carcinoma, and patients with acute HBV infection may have only mild, nonspecific symptoms. Therefore, understanding how this virus causes extrahepatic complications can help clinicians consider this possibility in patients with diverse symptom presentations. The pathophysiology of these extrahepatic disorders likely involves immune-related tissue injury following immune complex formation and inflammatory cascades. In some cases, direct viral infection of extrahepatic tissue may cause a clinical syndrome. Currently, the American Association for the Study of Liver Diseases recommends treatment of chronic HBV infections with interferon therapy and/or nucleos(t)ide analogs, and this treatment has been reported to improve some extrahepatic disorders in some patients with chronic HBV infection. These extrahepatic complications have a significant role in disease outcomes and increase medical costs, morbidity, and mortality. Therefore, understanding the frequency and pathogenesis of these extrahepatic complications provides important information for both specialists and nonspecialists and may help clinicians identify patients at an earlier stage of their infection.

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.

Hepatitis B virus reactivation: overview and management

Hepatitis B virus (HBV) can hide in the liver in the form of covalently closed circular DNA. When the body’s immunity changes, HBV reactivation (HBV-R) can occur. The risk of HBV-R is determined by the complex interaction among virological factors, medication factors and host factors. However, many patients do not know that they are infected with HBV, and doctors often do not invest enough time to systematically evaluate the patient’s HBV-R risk factors before immunosuppressive treatment. Therefore, HBV clinical screening should be vigorously promoted to achieve early detection and early prevention for patients with high risk of HBV-R. The mechanism, clinical features, risk factors, HBV-R under different disease etiologies, prevention and treatment of HBV-R were summarized to improve the in-depth understanding and awareness.

Establishment and characterization of HBV-associated B lymphocytes with an immortalization potential

Emerging evidences indicate that hepatitis B virus (HBV) infection is associated with non-Hodgkin lymphoma (NHL), but the mechanisms of HBV-induction lymphomagenesis remain unclear. In this report, retrospective analysis of the prevalence of hepatitis B surface antigen (HBsAg) among NHL cases demonstrated significantly higher HBsAg carrier rate among B-cell NHL cases than controls (other cancers except primary liver cancer) (adjusted odds ratio, 1.56; 95% confidence interval, 1.13–2.16). Furthermore, cells with an immortalization potential existed in the peripheral blood of 4 patients with chronic HBV infection. Characterization of these cells showed their immunophenotypes similar to that of the majority of HBsAg-positive B-cell NHL patients. Immunoglobulin (Ig) gene rearrangements confirmed the clonal Ig gene rearrangements. Cytogenetic analysis revealed abnormal karyotypes of these cells with an immortalization potential. Compared with cells with an immortalization potential that we previously found in B-cell NHL patients by the same way, these cells showed many similar features. In conclusion, cells with an immortalization potential existed in the part of patients with chronic HBV infection before lymphoma development and showed some malignant features. They may be the cellular basis of HBV-associated lymphomagenesis.