Pathogenesis of occult chronic hepatitis B virus infection

Occult hepatitis B infection(OBI) is characterized by hepatitis B virus(HBV) DNA in serum in the absence of hepatitis B surface antigen(HBsAg) presenting HBsAg-negative and anti-HBc positive serological patterns.Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays;but more frequently it is due to a strong suppression of viral replication and gene expression.OBI is an entity with world-wide diffusion.The failure to detect HBsAg,despite the persistence of the viral DNA,is due in most cases to the strong suppression of viral replication and gene expression that characterizes this"occult"HBV infection;although the mechanisms responsible for suppression of HBV are not well understood.The majority of OBI cases are secondary to overt HBV infection and represent a residual low viremia level suppressed by a strong immune response together with histological derangements which occurred during acute or chronic HBV infection.Much evidence suggests that it can favour the progression of liver fibrosis and the development of hepatocellular carcinoma.

Clinical characteristics and type of antithrombotic treatment in a Spanish cohort of elderly patients with atrial fibrillation according to dependency, frailty and cognitive impairment

Background Available data regarding clinical profile and management of elderly patients with atrial fibrillation （AF） according to dependency, fragility and cognitive impairment are scarce. The objective of the study was to analyze the biodemographic data, clinical profile and antithrombotic treatment according to dependency, fragility and cognitive impairment in elderly AF patients. Methods Cross- sectional and multi-center study performed in consecutive AF patients ≥ 75 years treated with oral anticoagulants ≥ 3 months attended in Internal Medicine Departments in Spain. Results A total of 837 patients （83.0 ± 5.0 years; CHA2DS2-VASc： 5.0 ± 1.4; HAS-BLED： 2.1 ± 0.9） were included. 44.4% of patients had some degree of dependency, 43.3% were fragile, and 32.3% had cognitive impairment. Patients with any of these conditions were older, had a worse clinical profile, with more comorbidities and higher risks of thromboembolic and bleeding events. All these conditions were independently associated among them. Overall, 70.8% of patients were taking vitamin K antagonists, the remaining 29.2% direct oral anticoagulants and 9.7% oral antiplatelets. This distribution was independent of the presence of dependency or fragility, but there was a trend to a higher prescription of vitamin K antagonists in those patients with cognitive impairment （75.2% vs. 68.8%; P = 0.05）. Conclusions Approximately 32%-44% of elderly anticoagulated AF patients attended have some degree of dependency, fragility and/or cognitive impairment. Patients with any of these conditions are older and have a worse clinical profile. Ap？proximately 71% of patients are taking vitamin K antagonists, regardless dependency or frailty, but with a trend to higher prescription in patients with cognitive impairment.