Can serum HBV-DNA be used as a primary end point to assess efficacy of new treatments for chronic hepatitis B?

Telbivudine protects renal function in patients with chronic hepatitis B infection in conjunction with adefovir-based combination therapy

Previous studies have demonstrated that the treatment of chronic hepatitis B (CHB) infection with adefovir (ADV) can impair renal function. In contrast, treatment with telbivudine (LdT) improves renal function in CHB patients. The aim of this study was to evaluate the renoprotective effect of LdT in CHB patients receiving ADV-based combination therapy. The effects of treatment with ADV + LdT on renal function were compared to those resulting from treatment with ADV + entecavir (ETV), ADV + lamivudine (LAM), ADV alone and ETV alone. The consecutive cohort analysis included 831 CHB patients who received ADV + LdT, ADV + LAM, ADV + ETV, ADV alone or ETV alone for 96 weeks. Alterations in estimated glomerular filtration rate (eGFR) were compared between the five groups using a linear mixed-effects model. HBV DNA levels were also compared between the five groups during the 96-week period. Among the five treatment groups, significant improvements in eGFR were observed in the ADV + LdT and ADV + LAM groups over time (P < 0.001 for each group compared with baseline eGFR). In patients with a baseline eGFR between 50 and 90 mL/min, the change in eGFR was the most significant in the ADV + LdT group (+0.641 mL/min; P < 0.001). Age, gender, baseline eGFR and treatment option were significant predictive factors for eGFR changes. In conclusion, our results suggest that the combination therapy of LdT and ADV is significantly associated with renoprotective effects in CHB patients when compared with other ADV-based combination or single therapies.

Simultaneous quantitation of serum HBV DNA and HBeAg can distinguish between slow and fast viral responses to antiviral therapy in patients with chronic hepatitis B

BACKGROUND: The quantitation of serum HBeAg is not commonly used to monitor viral response to therapy in chronic hepatitis B. METHODS: In this study, 21 patients receiving varying therapies were followed and their viral response monitored by concomitant viral load and HBeAg quantitation in order to study the meaning and the kinetics of both parameters. RESULTS: It was possible to distinguish between three different patterns of viral response. The first was characterized by a simultaneous decrease in serum HBV DNA and HBeAg. The second pattern was characterized by a decrease in serum HBeAg but persistent detection of HBV DNA. The third pattern was characterized by undetectable HBV DNA with persistent HBeAg positivity, which points to a non-response (Pattern III-B) except when HBeAg levels showed a slow but steady drop, characterizing a "slow responder" patient (Pattern III-A). CONCLUSIONS: The first pattern is compatible with a viral response. A long-term HBeAg seropositivity with a slow and persistent decrease (Pattern III-A) is also compatible with a viral response and calls for a prolongation of anti-viral treatment.

Treatment of chronic hepatitis B: recommendations from an Italian workshop

The changing scenario of hepatitis B virus therapy has encouraged the organisation of a workshop, endorsed by three Italian scientific societies, aimed at defining the current recommendations for hepatitis B virus treatment. Liver histology and stage of disease remain fundamental for treatment decisions; interferon and nucleoside/nucleotide analogues-based therapy represent different strategies for different phases of the hepatitis B virus disease. The recommendations defined: new and lower cut-off of hepatitis B virus-DNA for eligibility to therapy according to disease stage, how to optimise the use of nucleoside/nucleotide analogues and to individualise the monitoring of response and what to do with treatment failures. Specific recommendations have also been given for cirrhosis patients, those immune suppressed and co-infected with HIV and other hepatitis viruses.

Molecular testing in the diagnosis and management of chronic hepatitis B

Hepatitis B virus (HBV) is an enveloped virus with a small (3.2-kb) partially double-stranded DNA genome that causes acute and chronic infections. The impact of these infections on public health worldwide is enormous, with an estimated prevalence of 2 billion acute infections and 360 million chronic infections globally. This review focuses on chronic hepatitis B and the molecular assays used in its diagnosis and management. Background information, including that about features of the hepatitis B virion, viral replication, and epidemiology of infection, that is important for understanding chronic hepatitis B and molecular diagnostic tests for HBV is provided. To facilitate an understanding of the utility of molecular testing for chronic hepatitis B, the four stages of chronic hepatitis B infection that are currently recognized, as well as an additional entity, occult hepatitis B, that can be diagnosed only by sensitive nucleic acid amplification methods, are reviewed in detail, including available therapeutic agents. The molecular diagnostic content focuses on tests for HBV DNA quantification, genotyping, and mutation detection (including precore/core promoter and antiviral resistance mutations). The discussion of these tests encompasses their current utility and performance characteristics, drawing from current clinical guidelines and other studies from the literature. In recognition of the continual evolution of this field, the final section describes emerging molecular markers with future diagnostic potential.

Flowcytometric quantitation of hepatitis B viral antigens in hepatocytes from regular and fine-needle biopsies

The aim of the study was to investigate the use of flow cytometry, as an alternative for immunohistochemistry, for the detection of viral antigens in the liver of patients with chronic hepatitis B virus (HBV) infection. Hepatocytes were obtained from regular- and fine-needle biopsy from HBV positive (n=17) and negative (n=7) patients and quantified by flow cytometry for intracellular hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg). Number of HBsAg positive hepatocytes ranged from 0 to 83%. A significant correlation was found between the percentage of infected hepatocytes and the intracellular expression level of HBsAg (R=0.841, p<0.001). The specificity and sensitivity of flow cytometry was similar to immunohistochemistry. Of the patients on anti-viral treatment with undetectable serum HBV DNA (<400 copies/ml), two had high HBsAg expression in the liver. HBcAg staining was found in 3 out of 15 patients, with 2-3% positive hepatocytes. The results obtained with fine-needle aspiration biopsy (n=12) were comparable to regular biopsy. In conclusion, flowcytometric quantitation of HBV antigens is sensitive and provides relevant information on the course of infection. The minimally invasive fine-needle biopsy provides a useful alternative for regular-needle biopsy for monitoring intrahepatic antiviral responses during therapy.

HBV-DNA Suppression and Disease Course in HBV Cirrhosis Patients on Long-Term Lamivudine Therapy

In hepatitis B virus (HBV) cirrhosis patients on long-term lamivudine (LAM), the relationships between HBV suppression, development of viral resistance and disease outcome are unclear. We analysed the dynamic of serum HBV-DNA and its relationship with the clinical course of 59 patients (52 males, mean age 51.4 ±8.4 years, 12 HBeAg positive and 47 HBeAg negative, and 57 genotype D and two genotype A) with cirrhosis (45 in Child-Turcotte-Pugh class A) and high levels of serum HBV-DNA (median 14.7x107 genomes/ml) treated with LAM [median (range): 44 (15–78) months]. A total of 50 patients (84.7%) achieved a virological response (serum HBV-DNA negative by PCR) during the first 6 months of therapy, and nine (13.3%) achieved a reduction in viral load of >3 log10. Mutations in the YMDD motif of HBV polymerase were documented in 26 patients [median (range) 18: (7–42) months]. At the time of the emergence of mutants, 22 patients had HBV-DNA <105 genomes/ml and normal alanine aminotransferase (ALT) levels. The appearance of virological resistance was followed by an increase of HBV-DNA to ≥105 genomes/ml and of ALT values in 19 out of 26 patients [median (range): 8 (3–19) months]. Event-free survival was significantly longer ( P=0.001) in patients who maintained virological suppression than in those who did not have a complete virological response or suffered a breakthrough. Patients with advanced cirrhosis were more likely to develop liver failure after the emergence of YMDD mutants. The risk of development of hepatocellular carcinoma in patients with compensated cirrhosis and YMDD mutations was maintained, regardless of HBV-DNA serum levels.

Profound and maintained HBV-DNA suppression correlates with a better outcome. Early identification of LAM resistance mutations allows switching to other antivirals before liver decompensation or hepatocellular carcinoma development.

Usefulness of dried blood samples for quantification and molecular characterization of HBV-DNA

The purpose of this study was to assess the use of dried blood spot (DBS) samples for hepatitis B virus (HBV) DNA quantification, HBV genotyping, and detection of G1896A precore mutants and variants in the YMDD polymerase motif. We studied DBS and serum samples from 82 patients with chronic HBV infection (23 hepatitis B e antigen [HBeAg]-positive and 39 HBeAg-negative), 20 HBeAg-inactive carriers, and 15 HBeAg-negative patients under lamivudine therapy (selected from chronic HBV patients). DBS samples consisted of approximately 20 microL of blood applied to 5-mm paper disks. HBV DNA quantification and HBV precore mutant detection were done using real-time polymerase chain reaction, HBV genotyping using restriction fragment length polymorphism, and YMDD variant detection by Inno-lipa assay. DBS and serum results were compared. HBV DNA was detected in a range of 10(2)-10(8) copies/mL, with low intra-assay and inter-assay variation (<10%). Median DBS HBV DNA (copies/mL) was: 3.7 x 10(6) in HBeAg-positive, 6.2 x 10(5) in HBeAg-negative, and 5.5 x 10(2) in inactive carriers (P <.05). HBV DNA was positive in serum (median 5 x 10(3) copies/mL) but negative in DBS for five inactive carriers. The correlation coefficient between HBV DNA concentration in DBS versus serum samples was r(2) = 0.96 (P <.001). The sensitivity of HBV DNA detection in DBS samples was 1 log(10) lower than in serum samples. Concordance between DBS and serum for HBV genotyping, and for precore mutant and YMDD variant detection was optimal. DBS storage for 7 days at room temperature and 21 days at -20 degrees C revealed no decrease in HBV DNA levels or integrity. In conclusion, the DBS sample is useful for HBV DNA quantification, genotyping, and detection of precore mutant and YMDD variants. All four determinations can be completed with a single drop of dried blood.