BaCKgRoUND aND aIMS: Hepatitis delta virus (HDV) infection is associated with fast progression to liver cirrhosis and liver complications. Previous studies have, however, been mainly from tertiary care centers, with risk for referral bias toward patients with worse outcomes. Furthermore, the impact of HDV viremia per se on liver-related outcomes is not really known outside the human immunodeficiency virus co-infection setting. We have therefore evaluated the long-term impact of HDV viremia on liver-related outcomes in a nationwide cohort of patients with hepatitis B and D co-infection, cared for at secondary care centers in Sweden. appRoaCH aND ReSUltS: In total, 337 patients with anti-HDV positivity, including 233 patients with HDV RNA viremia and 91 without HDV viremia at baseline, were retrospectively studied, with a mean follow-up of 6.5 years (range, 0.5-33.1). The long-term risks for liver-related events (i.e., hepatocellular carcinoma [HCC], hepatic decompensation, or liver-related death/transplantation) were assessed, using Cox regression analysis. The risk for liver-related events and HCC was 3.8-fold and 2.6-fold higher, respectively, in patients with HDV viremia compared with those without viremia, although the latter was not statistically significant. Among patients with HDV viremia with no baseline cirrhosis, the cumulative risk of being free of liver cirrhosis or liver-related events was 81.9% and 64.0% after 5 and 10 years of follow-up, respectively. This corresponds to an incidence rate of 0.04 cases per person-year. CoNClUSIoNS: HDV RNA viremia is associated with a 3.8-fold higher risk for liver-related outcomes. The prognosis was rather poor for patients with HDV viremia without cirrhosis at baseline, but it was nevertheless more benign than previous estimates from tertiary centers. Our findings may be of importance when making decisions about treatment and evaluating potential outcomes of upcoming antivirals against HDV. (Hepatology 2020;72:1177-1190). H epatitis delta virus (HDV) is considered to cause the most severe form of chronic viral hepatitis, with fast progression to liver cirrhosis and liver complications. (1,2) Previous studies evaluating the natural course of HDV infection have, however, been mainly from tertiary centers, with risk for referral bias toward patients with worse outcomes. (3-7) Published data on the rate of liver disease progression in patients with HDV viremia without cirrhosis are scarce, and knowledge of the outcomes in an unbiased population is lacking.

BackgroundHepatocytes infected by hepatitis B virus (HBV) produce different HBV RNA species, including pregenomic RNA (pgRNA), which is reverse transcribed during replication. Particles containing HBV RNA are present in serum of infected individuals, and quantification of this HBV RNA could be clinically useful.MethodsIn a retrospective study of 95 patients with chronic HBV infection, we characterised HBV RNA in serum in terms of concentration, particle association and sequence. HBV RNA was detected by real-time PCR at levels almost as high as HBV DNA.ResultsThe HBV RNA was protected from RNase and it was found in particles of similar density as particles containing HBV DNA after fractionation on a Nycodenz gradient. Sequencing the epsilon region of the RNA did not reveal mutations that would preclude its binding to the viral polymerase before encapsidation. Specific quantification of precore RNA and pgRNA by digital PCR showed almost seven times lower ratio of precore RNA/pgRNA in serum than in liver tissue, which corresponds to poorer encapsidation of this RNA as compared with pgRNA. The serum ratio between HBV DNA and HBV RNA was higher in genotype D as compared with other genotypes.ConclusionsThe results suggest that HBV RNA in serum is present in viral particles with failing reverse transcription activity, which are produced at almost as high rates as viral particles containing DNA. The results encourage further studies of the mechanisms by which these particles are produced, the impact of genotype, and the potential clinical utility of quantifying HBV RNA in serum.Electronic supplementary materialThe online version of this article (10.1186/s12985-018-0994-7) contains supplementary material, which is available to authorized users.

HBsAg levels reflect clinical stage and liver disease, and a combined quantification of HBsAg and HBV DNA may improve clinical staging.

Deepened knowledge on response of biota and ecological processes following fire is essential for a future with warmer climate and more disturbances. In 2014 the first mega-fire (13,100 ha) for at least a century in Scandinavia hit south-central Sweden, in a production forest landscape shaped by clearcutting forestry. Ecological dynamics is followed in >20 projects from universities, authorities and citizen science initiatives, rapidly accumulating substantial amounts of data. We outline projects and summarize their results during the first four years, demonstrating a rapid succession of fungi, lichens, vascular plants, birds, mammals, ticks, butterflies, beetles, and drastically altered carbon dynamics. We characterize forest operations including regeneration measures and point to patterns in pest and pathogen infestations. 8,000 ha is set aside for natural succession, with the rest harvested and managed for forest production, offering excellent opportunities for studies on salvage logging effects, already evident for birds. We demonstrate a strong regrowth of deciduous trees, and the protected part will in some decades likely develop into the largest deciduous-dominated area in boreal north Europe outside Russia. Continued studies of biodiversity and ecological processes are urgent for this unique area.

Background Quantification of hepatitis B virus (HBV) DNA and surface antigen (HBsAg) serum levels have become increasingly important for the assessment of clinical stage and response to treatment for chronic hepatitis B. Effective immune clearance results in reduction of viremia by 4–5 log units and HBsAg levels by 2 log, but these processes are not well understood. Thus, it is uncertain to what extent mechanisms that inhibit transcription of the pregenomic RNA (pgRNA), an RNA intermediate, contribute to suppression of viremia. Likewise, it is unclear if transcriptional regulation is important for the excessive production of surface antigen (HBsAg) that is a hallmark of HBV infection. Methods HBV RNA and cccDNA were quantified in 19 liver biopsies from patients with chronic HBV infection, as well as in transfected Huh7.5 cells and in PLC/PRF/5 cells carrying integrated HBV genome. Results Patients negative for HBeAg had 2.15 log lower levels of cccDNA in liver tissue, 4.84 log lower serum levels of HBV DNA and 1.45 log lower serum levels of HBsAg, than HBeAg-positive patients. The pgRNA in liver tissue correlated strongly with cccDNA (R 2 = 0.87, p<0.0001) and HBV DNA levels in serum (R 2 = 0.81, p<0.0001), whereas S-RNA correlated strongly with cccDNA (R 2 = 0.65, p<0.0001) and HBsAg levels (R 2 = 0.57, p = 0.0003). The S-RNA/pgRNA ratio was higher in HBeAg-negative patients (ratio 40 vs. 3, p = 0.01) and in PLC/PRF/5 cells, and was in transfected Huh7.5 cells not influenced by mutations in the HBV core promoter. Conclusion The reduction of viremia that is observed after loss of HBeAg was mainly explained by reduced cccDNA load in the liver, whereas the contribution of down-regulation of pgRNA transcription was relatively small. Enhanced transcription of S-RNA does not explain excessive production of HBsAg.