Danilo Deichsel

Sequence variation and allele nomenclature for the X-linked STRs DXS9895, DXS8378, DXS7132, DXS6800, DXS7133, GATA172D05, DXS7423 and DXS8377.

X-linked DNA markers are increasingly used in forensic kinship testing. This paper presents sequencing data of the short tandem repeats (STRs) DXS9895, DXS8378, DXS7132, DXS6800, DXS7133, GATA172D05, DXS7423, DXS8377 and proposes an allele nomenclature. Alleles were assigned according to the recommendations of the International Society of Forensic Genetics (ISFG) Commission.

An Intronic Silencer Element is Responsible for Specific Zonal Expression of Glutamine Synthetase in the Rat Liver

The most striking phenomenon of glutamine synthetase (GS) expression in the liver is its unique restriction to cells surrounding the terminal hepatic venules. Expression is positively regulated by elements located in the 5′‐upstream region and in the first intron of the gene. It was long believed that transcription factors present in GS‐positive cells and absent in GS‐negative cells are responsible for the phenomenon of zonal expression. However, strong enhancers are equally active in both types of cells. Therefore, the existence of a silencer mechanism in GS‐negative hepatocytes was postulated. In the present study, a GS silencer element was investigated that was previously identified within the first intron and was shown to be able to prevent glucocorticoid‐induced expression in cells negative for a transacting factor designated GS silencer element–binding protein. Reporter gene assays with the silencer element in combination with the most potent 5′‐enhancer of the GS gene demonstrate that the silencer element is able to prevent enhancement mediated by the 5′‐enhancer in combination with a heterologous as well as with the homologous promoter. More importantly, the effect of the silencer is shown to be restricted to GS‐negative hepatocytes. In conclusion, the phenomenon of zonal expression of GS in the liver is caused by a protein present in GS‐negative cells and absent in GS‐positive cells that interacts with the silencer element in the first intron and not by a differential expression of enhancer‐binding proteins. (HEPATOLOGY 2005.)

Quantification of large and middle proteins of hepatitis B virus surface antigen (HBsAg) as a novel tool for the identification of inactive HBV carriers

Objective Among individuals with chronic hepatitis B, those with hepatitis B e-antigen (HBeAg)-negative chronic hepatitis (CHB) can be difficult to distinguish from those with HBeAg-negative chronic HBV infection, also referred to as inactive HBV carriers (ICs), but both require different medical management. The level of HBV surface antigen (HBsAg) has been proposed as a marker to discriminate between chronic infection and hepatitis stages. HBsAg consists of large, middle and small HBs. The aim of this study was to determine whether the composition of HBsAg improved the identification of ICs among HBsAg-positive subjects with different phases of HBV infections. Design HBV large surface proteins (LHBs) and HBV middle surface proteins (MHBs) were quantified in serum samples from 183 clinically well-characterised untreated patients with acute (n=14) HBV infection, ICs (n=44), CHBs (n=46), chronic HBeAg-positive phase (n=68) and hepatitis delta coinfection (n=11) using an ELISA, with well-defined monoclonal antibodies against the preS1 domain (LHBs) and the preS2-domain (MHBs). A Western blot analysis was used to verify the quantitation of the components of HBsAg. Total HBsAg was quantified using a modified commercially available assay (HBsAg V.6.0, Enzygnost, Siemens, Erlangen). Results The composition of HBsAg showed specific patterns across different phases of hepatitis B. Individuals in the IC phase had significantly lower proportions of LHBs and MHBs than patients in acute or chronic phases irrespective of their HBV e-antigen status (p<0.0001) or HBsAg level. Both LHBs and MHBs ratios better predicted the IC phase than total HBsAg levels. Conclusion Quantification of MHBs, particularly LHBs represents a novel tool for the identification of the IC stage.

Serum HBV RNA as a Predictor of Peginterferon Alfa-2a Response in Patients With HBeAg-Positive Chronic Hepatitis B

Background Hepatitis B virus (HBV) RNA is a novel serum biomarker that has the potential to predict treatment response in patients with chronic hepatitis B. We explored whether HBV RNA serum levels can predict hepatitis B e antigen (HBeAg) seroconversion in patients treated with peginterferon alfa-2a. Methods Serum samples from HBeAg-positive patients previously treated with peginterferon alfa-2a in 2 large randomized controlled trials were retrospectively analyzed. HBV RNA levels were measured using a real-time polymerase chain reaction assay. Ability of individual biomarkers to predict HBeAg seroconversion at 24 weeks posttreatment was evaluated using receiver operating characteristics (ROC) analyses. Results The study included 131 subjects (70% male, 96% Asians, 35% HBV genotypes B, and 61% C), 76 treated with peginterferon alfa-2a alone and 55 in combination with lamivudine. Median HBV RNA levels were significantly lower, at all timepoints, in patients achieving HBeAg seroconversion. Levels of HBV RNA at treatment weeks 12 and 24 showed good ability to predict HBeAg seroconversion (area under ROC scores >0.75, P < .001). A HBV RNA cutoff of >5.5 log10 copies/mL identified 30% of nonresponders at week 12 (negative predictive value >90%). Conclusion Serum HBV RNA is an early predictor of HBeAg seroconversion in patients treated with peginterferon alfa-2a. Clinical Trials Registration NCT01705704.

Host and viral factors associated with serum hepatitis B virus RNA levels among patients in need for treatment

Hepatitis B virus (HBV) RNA in serum is a novel biomarker for intrahepatic HBV replication and treatment response. For its proper use, it is essential to identify factors influencing serum HBV RNA level. Using a rapid amplification of complimentary DNA (cDNA) ends (RACE) PCR technique (lower limit of detection [LLD], 800 copies/mL [c/mL]), serum HBV RNA levels were measured in samples of 488 untreated individuals with chronic HBV infection who were eligible to treatment according to currently used recommendations. We explored the association of serum levels of HBV RNA with patient‐ and virus‐associated factors. HBV genotype distribution was 21/10/20/46/3% for A/B/C/D/other. Mean HBV RNA serum level was 5.9 (1.6) log10 c/mL (hepatitis B e antigen [HBeAg]‐positive chronic hepatitis B [CHB], 6.5 [1.2] log c/mL; HBeAg‐negative CHB, 4.1 [1.2] log c/mL; P < 0.001). By multivariable linear regression, factors associated with lower HBV RNA level were HBeAg negativity (β = –0.69; P < 0.001), HBV genotypes A (β = –0.13; P = 0.002), B (β = –0.07; P = 0.049), and C (β = –0.61; P < 0.001) in comparison to D, and presence of HBV basal core promoter mutation either alone (β = –0.14; P = 0.001) or in combination with precore mutation (β = –0.22; P < 0.001). Higher serum alanine aminotransferase (ALT) was associated with higher HBV RNA (β = 0.23; P < 0.001). HBV RNA correlated strongly with HBV DNA (HBeAg‐pos, r = 0.72; P < 0.001; HBeAg‐neg, r = 0.78; P < 0.001) and moderately with quantitative hepatitis B surface antigen (qHBsAg; HBeAg‐pos, r = 0.54; P < 0.001; HBeAg‐neg, r = 0.19; P = 0.04) and quantitative hepatitis B surface antigen (qHBeAg; r = 0.41; P < 0.001). Conclusion: In this multiethnic cohort of 488 untreated individuals with CHB, factors associated with serum HBV RNA level were HBeAg status, serum ALT, HBV genotype, and presence of basal core promotor mutations. For the future use of serum HBV RNA as a clinical marker, it seems mandatory to take these factors into consideration. (Hepatology 2018).