Clinical evaluation of the COBAS Amplicor HBV monitor test for measuring serum HBV DNA and comparison with the Quantiplex branched DNA signal amplification assay in Taiwan

Tenofovir disoproxil fumarate in pregnancy for prevention of mother to child transmission of hepatitis B in a rural setting on the Thailand-Myanmar border: a cost-effectiveness analysis

BACKGROUND

Hepatitis B Virus (HBV) is transmitted from mother to child which can be prevented via birth dose vaccine combined with three follow up hepatitis B vaccines, hepatitis B immunoglobulins (HBIG), and maternal antiviral treatment with Tenofovir Disoproxil Fumarate (TDF). This study evaluates the cost effectiveness of six strategies to prevent perinatal HBV transmission in a resource limited setting (RLS) on the Thailand-Myanmar border.

METHODS

The cost effectiveness of six strategies was tested by a decision tree model in R. All strategies included birth and follow up vaccinations and compared cost per infection averted against two willingness to pay thresholds: one-half and one gross domestic product (GDP) per capita. Strategies were: 1) Vaccine only, 2) HBIG after rapid diagnostic test (RDT): infants born to HBsAg+ are given HBIG, 3) TDF after RDT: HBsAg+ women are given TDF, 4) TDF after HBeAg test: HBeAg+ women are given TDF, 5) TDF after high HBV DNA: women with HBV DNA > 200,000 are given TDF, 6) HBIG & TDF after high HBV DNA: women with HBV DNA > 200,000 are given TDF and their infants are given HBIG. One-way and probabilistic sensitivity analyses were conducted on the cost-effective strategies.

RESULTS

Vaccine only was the least costly option with TDF after HBeAg test strategy as the only cost-effective alternative. TDF after HBeAg test had an incremental cost-effectiveness ratio of US$1062; which would not be considered cost-effective with the lower threshold of one-half GDP per capita. The one-way sensitivity analysis demonstrated that the results were reasonably robust to changes in single parameter values. The PSA showed that TDF after HBeAg test had an 84% likelihood of being cost effective at a willingness to pay threshold of one GDP per capita per infection averted.

CONCLUSIONS

We found that TDF after HBeAg test has the potential to be cost-effective if TDF proves effective locally to prevent perinatal HBV transmission. The cost of TDF treatment and reliability of the RDT could be barriers to implementing this strategy. While TDF after RDT may be a more feasible strategy to implement in RLS, TDF after HBeAg test is a less costly option.

A genetic variant of the NTCP gene is associated with HBV infection status in a Chinese population

Background

To investigate whether genetic variants of the HBV receptor gene NTCP are associated with HBV infection in the Han Chinese population.

Methods

We sequenced the entire 23 kb NTCP gene from 111 HBeAg-positive HBsAg carriers (PSE group), 110 HBeAg-negative HBsAg carriers (PS group), and 110 control subjects. Then, we performed association analyses of suggestively significant SNPs with HBV infection in 1075 controls, 1936 PSs and 639 PSEs.

Results

In total, 109 rare variants (74 novel) and 38 single nucleotide polymorphisms (SNPs, one novel) were screened. Of the seven non-synonymous rare variants, six were singletons and one was a double hit. All three damaging rare singletons presented exclusively in the PSE group. Of the five SNPs validated in all 3650 subjects, the T allele of rs4646287 was significantly decreased (p = 0.002) in the PS group (10.1 %) and PSE group (8.1 %) compared to the controls (10.9 %) and was decreased to 7.4 % in the PSE hepatocellular carcinoma (HCC) subgroup. Additionally, rs4646287-T was associated with a 0.68-fold (95 % CI = 0.51–0.89, p = 0.006) decreased risk of PSE compared with the controls. The NTCP mRNA level was lower in HCC tissues in “CT + TT” carriers than in “CC” carriers.

Conclusions

We found a genetic variant (rs4646287) located in intron 1 of NTCP that may be associated with increased risk of HBV infection in Han Chinese.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2257-6) contains supplementary material, which is available to authorized users.

Update on hepatitis B and C virus diagnosis

Viral hepatitis B and C virus (HBV and HCV) are responsible for the most of chronic liver disease worldwide and are transmitted by parenteral route, sexual and vertical transmission. One important measure to reduce the burden of these infections is the diagnosis of acute and chronic cases of HBV and HCV. In order to provide an effective diagnosis and monitoring of antiviral treatment, it is important to choose sensitive, rapid, inexpensive, and robust analytical methods. Primary diagnosis of HBV and HCV infection is made by using serological tests for detecting antigens and antibodies against these viruses. In order to confirm primary diagnosis, to quantify viral load, to determine genotypes and resistance mutants for antiviral treatment, qualitative and quantitative molecular tests are used. In this manuscript, we review the current serological and molecular methods for the diagnosis of hepatitis B and C.

Dynamic comparison between Daan real-time PCR and Cobas TaqMan for quantification of HBV DNA levels in patients with CHB

BACKGROUND

Hepatitis B virus (HBV) DNA levels are crucial for managing chronic hepatitis B (CHB). It was unclear whether Daan real-time polymerase chain reaction test (Daan test) or COBAS TaqMan HBV DNA Test (Cobas TaqMan) was superior in measuring different HBV DNA levels in clinical specimens.

METHODS

We enrolled 67 treatment-naïve, HBV surface antigen-positive CHB patients (high baseline viral levels) who received either lamivudine/adefovir or entecavir. Serum samples were tested at baseline and treatment week 24 using the Daan test and Cobas TaqMan.

RESULTS

In the 67-baseline samples, the HBV DNA levels with the Cobas TaqMan (7.90 ± 0.73 log10 IU/mL) were significantly greater than those of the Daan test (7.11 ± 0.44 log10 IU/mL; P < 0.001). Of the 67 24-week samples (low viral levels), the Cobas TaqMan detected 59 (88.1%; 8 undetected); the Daan test detected 33 (49.3%; 34 undetected; P < 0.001). The Cobas TaqMan detected HBV DNA in 26 of 34 samples undetectable by the Daan test (range, 1.4-3.7 log10 IU/mL) or 38% of samples (26/67). The reductions in viral load after 24 weeks of oral antiviral treatment in the 33 samples that were positive for both the Daan test and the Cobas TaqMan test were significantly different (3.59 ± 1.11 log10 IU/mL versus 4.87 ± 1.58 log10 IU/mL, respectively; P = 0.001). Spearman correlation analysis showed positive correlation between results from two tests (rp = 0.602,P<0.001). The HBV genotypes and the anti-viral treatment did not affect the measurements of the HBV DNA by the Daan assay and the Cobas Taqman assay.

CONCLUSION

The Cobas Taqman was more sensitive at low viral loads than the Daan test and the change from complete to partial virological response could affect clinical decisions. The Cobas Taqman may be more appropriate for detection of HBV DNA levels.

Comparison of currently available assays for detection of hepatitis B virus DNA in the routine diagnostic laboratory

Infection with the hepatitis B virus (HBV) continues to present diagnostic and therapeutic challenges worldwide. Today, many routine diagnostic laboratories have implemented assays based on molecular techniques for the detection of HBV DNA. However, the standard algorithm for specific diagnosis of HBV infection still relies on serologic testing. Molecular assays are employed for pretreatment evaluation, clinical staging and monitoring of antiviral therapy. Furthermore, molecular methods are essential for identification of mutations in the HBV genome. Although a continuous improvement of assay performance has been observed during recent years, lack of comparability of different molecular assays remains a problem to be resolved in the future. The limited range of linearity when employing conventional PCR will be overcome by using real-time assays.

A comparison of molecular methods for hepatitis B virus (HBV) DNA detection from oral fluid samples

The objective of the present study was to evaluate four commercial DNA extraction methods and three PCR protocols for hepatitis B virus (HBV) detection in artificially contaminated oral fluid samples. The extraction protocols were selected based on ease of use and cost, and were also compared with respect to sensitivity and cost. Prior PCR optimization was conducted, in which the sample volume for DNA extraction and the concentrations of DNA and Taq DNA polymerase in the PCR were adjusted. One-round PCR, used to amplify the core region of the HBV genome, achieved high levels of sensitivity in comparison with nested and semi-nested PCR experiments that were designed for the amplification of HBV surface protein genes. Of the four extraction protocols evaluated, the RTP DNA/RNA Virus Mini kit and the QIAamp DNA Mini kit gave the highest recovery rates, presenting 20 copies of HBV DNA ml(-1) as the limit of detection. These results suggest that HBV DNA can be detected from oral fluid samples but that the optimization of the PCR assays and the choice of extraction methods must be determined by laboratories before the implementation of this method in routine diagnostics.

Combination of hepatitis B viral antigens and DNA for prediction of relapse after discontinuation of nucleos(t)ide analogs in patients with chronic hepatitis B

AIM

  The factors associated with hepatitis recurrence after discontinuation of nucleos(t)ide analogs (NAs) in patients with chronic hepatitis B were analyzed to predict the risk of relapse more accurately.

METHODS

  A total of 126 patients who discontinued NA therapy were recruited retrospectively. The clinical conditions of a successful discontinuation were set as alanine aminotransferase (ALT) below 30 IU/L and serum hepatitis B virus (HBV) DNA below 4.0 log copies/mL.

RESULTS

  Relapse of hepatitis B were judged to occur when maximal serum ALT became higher than 79 IU/L or when maximal serum HBV DNA surpassed 5.7 log copies/mL following NA discontinuation since these values corresponded with mean values of ALT (30 IU/L) and HBV DNA (4.0 log copies/mL), respectively. At least 90% of patients with either detectable hepatitis B e antigen or serum HBV DNA higher than 3.0 log copies/mL at the time of NA discontinuation relapsed within one year. In the remaining patients, higher levels of both hepatitis B surface and core-related antigens at the time of discontinuation, as well as a shorter course of NA treatment, were significantly associated with relapse by multivariate analysis.

CONCLUSIONS

  It appears that negative results for hepatitis B e antigen and serum HBV DNA lower than 3.0 log copies/mL are essential for successful NA discontinuation, which may be attained by a longer treatment period. Levels of hepatitis B surface and core-related antigens are also significant factors independently associated with relapse of hepatitis.

Development of a new duplex real-time polymerase chain reaction assay for hepatitis B viral DNA detection

BACKGROUND

Quantification of hepatitis B virus (HBV) DNA can be used for diagnosing HBV infection and monitoring the effect of antiviral therapy. However, probably because of mismatches between the template and primer/probe, HBV DNA in some HBV infections could not be detected using currently available commercial assays with single primer/probe. By aligning the HBV sequences, we developed a duplex real-time polymerase chain reaction (PCR) assay using two sets of primers/probes and a specific armored DNA as internal control (IC).

RESULTS

The limit of the duplex real-time PCR assay was 29.5 IU/ml, whereas the specificity was 100%. The within-run precision coefficient of variation (CV) ranged from 1.02% to 2.73%, while the between-run CV ranged from 0.83% to 1.25%. The optimal concentration of armored DNA IC in the HBV DNA duplex real-time PCR assay was 1 000 copies/ml. Data from 69 serum samples with HBV infection showed that the performance of the duplex real-time PCR assay was comparable to that of the COBAS Ampliprep/Cobas Taqman (CAP/CTM) HBV assay and was superior to those of the domestic commercial HBV assays.

CONCLUSIONS

The duplex real-time PCR assay is sufficiently sensitive, specific, accurate, reproducible and cost-effective for the detection of HBV DNA. It is suitable for high throughput screening and frequent HBV DNA level monitoring.

Mixed treatment comparison meta-analysis evaluating the relative efficacy of nucleos(t)ides for treatment of nucleos(t)ide-naive patients with chronic hepatitis B

BACKGROUND/AIMS

Five nucleoside/nucleotide treatments are now available for chronic hepatitis B (CHB). This meta-analysis aimed to assess the relative efficacy of adefovir, entecavir, lamivudine, telbivudine, tenofovir disoproxil fumarate (TDF), and nucleos(t)ide combinations in the treatment of CHB.

METHODS

A systematic review of MEDLINE and the Cochrane library was conducted to identify all studies evaluating these nucleos(t)ides in adults with CHB. Randomized controlled trials were included in the meta-analysis if they reported the proportion of patients with undetectable hepatitis B virus (HBV) DNA or hepatitis B e antigen (HBeAg) loss/seroconversion at 1 year. Bayesian mixed treatment comparison meta-analyses were conducted in WinBUGS to assess relative efficacy.

RESULTS

A random-effects meta-analysis of trials on treatment-naive patients with HBeAg-positive CHB demonstrated that 94% of patients will achieve HBV DNA < 300 copies/ml after 1 year with TDF, compared with 73% for entecavir, 50% for adefovir, and 38% for lamivudine. There was a 97.7% probability that TDF enabled a greater proportion of patients to achieve HBV DNA < 300 copies/ml at 1 year than all other treatments considered in the analysis. TDF was significantly superior to all nucleos(t)ides for this outcome at the 0.05 level. There were no statistically significant differences between nucleos(t)ides in HBeAg seroconversion at 1 year, based on a fixed-effects meta-analysis in the same population. More trials on HBeAg-negative and drug-resistant patients are required to facilitate meta-analyses for these subgroups.

CONCLUSIONS

In nucleos(t)ide-naive patients with HBeAg-positive CHB, TDF is associated with the highest probability of achieving undetectable HBV DNA at 1 year of all nucleos(t)ides considered.

Performance characteristics of two real-time PCR assays for quantification of hepatitis B virus DNA

Detection and quantification for hepatitis B virus (HBV) DNA has been an essential tool in the clinical setting. We aimed to assess clinical performance of the RealArt HBV TM PCR (RealArt) assay and the COBAS TaqMan HBV (COBAS) assay. Serum levels of HBV DNA in 146 treatment-naïve chronic HBV (CHB) Taiwanese patients (118 males, 47 HBeAg + ; mean age, 34.7+/-13.0 y) were determined by both assays. The detection rate by the RealArt assay was 85.6% (125/146), which was not significantly different from the COBAS assay (89.7%, 131/146). The detection rate was also not significantly different between both assays irrespective of HBeAg seropositivity. The 2 assays were also comparable regarding quantification rate (92.8%, 116/125 vs 93.1%, 122/131). There was a positive correlation in the 109 specimens measurable by both assays (r=0.94,p<0.001). The mean HBV DNA level measured by the COBAS assay was significantly higher than the RealArt assay (5.24+/-1.83 vs 4.79+/-2.09 log IU/ml, p<0.001). This study demonstrated that both RealArt and COBAS assays were comparable regarding clinical performance in HBV DNA measurement.

Factors contributing to antiviral effect of adefovir dipivoxil therapy added to ongoing lamivudine treatment in patients with lamivudine-resistant chronic hepatitis B

PURPOSE

The antiviral effect of adefovir dipivoxil (ADV) added to ongoing lamivudine (LAM) treatment for LAM-resistant chronic hepatitis B (CHB) differs among patients. We investigated clinical factors affecting the response to ADV therapy in LAM-resistant CHB.

METHODS

The subjects were 75 LAM-resistant CHB patients treated with ADV in addition to LAM. Virological response (VR) was defined as HBV DNA clearance (<2.6 logcopies/ml) at 12 months after the start of ADV therapy. Clinical factors contributing to VR were examined by univariate and multivariate analyses.

RESULTS

Lower HBV DNA at baseline and negative hepatitis B e antigen (HBeAg) were significant factors affecting VR in univariate analysis. In multivariate analysis, lower HBV DNA at baseline (P = 0.005), negative HBeAg (P = 0.009), and higher ALT (P = 0.036) were significant independent factors contributing to VR. In HBeAg-positive patients, HBV DNA clearance was more frequently observed during ADV therapy in patients with baseline HBV DNA < or = 7.0 logcopies/ml than in those with baseline HBV DNA >7.0 logcopies/ml. By contrast, the link of lower HBV DNA at baseline to better therapeutic response was not evident in HBeAg-negative patients.

CONCLUSION

In ADV therapy added to ongoing LAM treatment for LAM-resistant CHB, lower baseline HBV DNA and negative HBeAg contributed to a better antiviral effect. Addition of ADV should be done promptly before marked increase in HBV DNA, especially in CHB patients showing LAM resistance positive for HBeAg.

Comparison of clinical application of the Abbott HBV PCR kit and the VERSANT HBV DNA 3.0 test to measure serum hepatitis B virus DNA in Taiwanese patients

With an estimated 350-400 million people worldwide chronically infected with hepatitis B virus (HBV), and the subsequent serious complications caused by liver damage including cirrhosis, liver failure, and hepatocellular carcinoma, HBV infection remains a global health issue, particularly in Taiwan, an HBV-hyperendemic area. Sensitive and accurate quantification of HBV DNA is necessary to monitor patients with chronic hepatitis B who are receiving antiviral therapy to determine treatment response and adapt therapy. We evaluated and compared the clinical performance of two HBV DNA assays based on different technologies: the RealArt HBV PCR Kit (Abbott HBV DNA PCR kit, real-time polymerase chain reaction assay, detection limit: 27 IU/mL) and the VERSANT bDNA 3.0 assay (Bayer, branched DNA signal amplification assay, detection limit: 357 IU/mL). Serum levels of HBV DNA in 173 chronic HBV carriers were determined using both the RealArt HBV PCR Kit and the VERSANT bDNA 3.0 test. Of the 173 samples analyzed for baseline viral load detection, HBV DNA was quantifiable in 147 patients (82.1%) by the RealArt HBV PCR Kit, which was significantly higher than the 92 (53.2%) samples quantified by the VERSANT bDNA 3.0 assay. A total of 86 (49.7%) samples were quantifiable by both assays, whereas 25 (14.5%) were below the detection limit of both assays. The HBV DNA quantification values measured by the RealArt HBV PCR Kit and the VERSANT bDNA 3.0 assay were positively correlated (Spearman's rank correlation coefficient r = 0.932, p < 0.001). On average, the results derived from the RealArt HBV PCR Kit were 0.67 log lower than those of the VERSANT bDNA 3.0 assay. HBV DNA concentrations were significantly higher in 63 HBV e antigen (HBeAg)-seropositive patients than in 110 HBeAg-seronegative patients (5.42 +/- 2.34 logs vs. 3.21 +/- 2.27 logs, p < 0.001). The RealArt HBV PCR Kit is more sensitive and has a wider dynamic range than the VERSANT bDNA 3.0 assay in the clinical setting of chronic hepatitis B patients. The sensitivity and wide dynamic range of the PCR assay allow optimal monitoring and timely adaptation of antiviral therapy. Nevertheless, the HBV DNA values measured by the RealArt HBV PCR Kit and the VERSANT bDNA 3.0 assay were significantly correlated.

Initial viral response is the most powerful predictor of the emergence of YMDD mutant virus in chronic hepatitis B patients treated with lamivudine

AIM

Lamivudine (LAM) has been widely used to treat chronic hepatitis B (CHB) patients, but the emergence of a LAM-resistant virus greatly limits its therapeutic efficacy. In this study, we tried to identify factors affecting the emergence of a LAM-resistant virus in CHB patients treated with LAM.

METHODS

The subjects were 190 CHB patients in continuous LAM therapy (139 males, mean age 50 years, 87 HBeAg-positive). The mean duration of follow-up was 39 months (range 12-104). The initial viral response (IVR) was defined as HBV DNA < 4.0 logcopies/mL, and the initial biochemical response (IBR) as normalization of alanine aminotransferase (ALT) (<40 IU/L) at 6 months.

RESULTS

IVR was positive in 86% of the patients. The cumulative emergence rates of LAM-resistant virus were 10% at 1 year, 30% at 2 years and 46% at 3 years. In univariate analysis, factors contributing to the emergence of LAM-resistant virus were baseline HBV DNA > 6.5 logcopies/mL (P = 0.0044), HBeAg-positivity (P = 0.0062), IBR (P = 0.01) and IVR (P < 0.0001). The cumulative emergence rates of LAM-resistant virus in IVR-positive and -negative patients were 4% and 41% at 1 year, and 41% and 79% at 3 years. In multivariate analysis, only IVR was an independent factor affecting the emergence of LAM-resistant virus (P < 0.0001).

CONCLUSION

IVR is a useful factor for predicting the emergence of LAM-resistant virus in CHB patients treated with LAM. For IVR-negative patients, therapeutic options other than LAM monotherapy should be used because of the high incidence of the emergence of LAM-resistant virus.

Comparison of VERSANT Hepatitis B virus DNA 3.0 Assay with Digene Hybrid Capture II Hepatitis B virus DNA test in relation to clinical status of Hepatitis B virus

BACKGROUND

Some differences exist among various Hepatitis B virus (HBV) DNA quantification assays due to lack of standardization and besides clinical usefulness has not been firmly elucidated in Korean HBV patients.

METHODS

We compared Bayer VERSANT HBV DNA 3.0 Assay (VERSANT 3.0) with Digene Hybrid Capture II HBV DNA Test (HC-II) according to HBeAg status and ALT levels in 232 HBV-infected Korean patients. One hundred and seventeen sera with undetectable DNA levels by HC-II were further analyzed by Real-Q HBV quantification assay (BioSewoom).

RESULTS

Although VERSANT 3.0 and HC-II showed an excellent correlation (r=0.9739), the results (copies/mL) by VERSANT 3.0 were 0.45 log(10) higher than those by HC-II. HBV DNA levels were higher in HBeAg-positive group than in HBeAg-negative group (P=0.002), and in abnormal ALT group than in normal ALT group (P<0.0001). The detection rate of HBV DNA by VERSANT 3.0 was lower in HBeAg-negative and normal ALT group (n=68) than in HBeAg-positive or abnormal ALT group (n=164) (35.3% vs 89.6%, P<0.0001). Fifty two sera out of 61 sera with undetectable DNA by VERSANT 3.0 were measurable by Real-Q with mean value of 3.26 log(10) copies/mL.

CONCLUSIONS

VERSANT 3.0 and HC-II showed an excellent correlation, but a little difference (0.45 log10) existed. VERSANT 3.0 effectively measured clinically relevant HBV DNA levels in most HBV-infected patients in Korea. However, more sensitive assays are needed for patients with negative HBeAg and normal ALT to see the low copies of HBV DNA levels.

Early response to lamivudine therapy in clinically non-cirrhotic chronic hepatitis B patients with decompensation

This study aimed to elucidate the rate and predictors of early (6 months) therapeutic responses to lamivudine, the rate of early mortality and the use of the model for end-stage liver disease (MELD) and Index in predicting the survival in patients with a clinical diagnosis of non-cirrhotic chronic hepatitis B with decompensation. Ninety-eight patients with lamivudine therapy were enrolled and MELD and Index scores were calculated. Surviving patients were treated with lamivudine for more than 6 months. Four (4.1%) of the 98 patients died after initiation of lamivudine therapy. After a 6-month lamivudine therapy, 80 (85.1%) patients and 71 (75.5%) patients had normal alanine aminotransferase (ALT) values and negative hepatitis B virus (HBV) DNA (<200 copies/mL), respectively, and hepatitis B e antigen (HBeAg)-negative patients had a significantly higher rate of negative HBV DNA than HBeAg-positive patients (P=0.002). The rates of HBeAg seroconversion and negative HBV DNA were 28.8 and 63.5%, respectively, and patients with HBeAg seroconversion had a significantly higher rate of negative HBV DNA (P=0.004). By multivariate analyses, older age, HBV nongenotype B infection, negative HBeAg and higher ALT levels were factors associated with negative HBV DNA, and a higher ALT level was associated with HBeAg seroconversion at month 6 after lamivudine therapy. MELD score and Index score were significantly associated with death and areas under the receiver operating characteristic curve for predicting survival were 0.936 and 0.907 respectively. We concluded that after 6-month lamivudine therapy, the patients who survived achieved favourable biochemical, virological responses and rate of HBeAg seroconversion. Both MELD and Index scoring systems are good models to predict the 6-month survival.

Type B fulminant hepatitis is closely associated with a highly mutated hepatitis B virus strain

OBJECTIVE

Genome-wide sequences of hepatitis B virus strain associated with type B fulminant hepatitis have not been compared with those of acute self-limited hepatitis. We carried out full-length sequencing analysis of viral strains derived from patients with type B acute liver injury.

METHODS

Nine acute self-limited hepatitis and 6 fulminant hepatitis patients were the subjects of this study. Full-length sequencing analysis of viral DNA was done by PCR-direct sequencing.

RESULTS

Higher frequencies in fulminant hepatitis strains compared with acute hepatitis ones were observed in the T1762/A1764 (p < 0.05), A1896 (p = 0.09) and M1753 (M = C or A) (p = 0.09) mutations. Viruses related to fulminant hepatitis possessed the higher number of nucleotide substitutions than those related to acute hepatitis in the whole virus genome (p < 0.01) and various regions including preS/S gene (p < 0.05), precore/core gene (p < 0.01), polymerase gene (p < 0.05) and basic core promoter/core upstream regulatory sequence (p < 0.01). The high number of nucleotide substitutions in viruses related to fulminant hepatitis was predominantly non-synonymous in the preS/S and precore/core genes.

CONCLUSION

Development of type B fulminant hepatitis may be associated with a highly mutated hepatitis B virus strain.

Comparison of liver histopathology between chronic hepatitis C patients and chronic hepatitis B and C-coinfected patients

BACKGROUND

The aim of the present study was to compare the histological characteristics of livers between chronic hepatitis C (CHC) patients with and without hepatitis B virus (HBV) coinfection.

METHODS

A total of 336 CHC patients (male/female: 204/132, mean age: 46.1 +/- 11.7 years) were enrolled in the study; 32 patients (9.8%) were positive for hepatitis B surface antigen (HBsAg). The histological characteristics of livers were described according to the Knodell and Scheuer scoring system.

RESULTS

The proportion of non-intralobular necrosis (score 0) was significantly lower and the mean intralobular necrosis score was higher among CHC patients with HBV coinfection than those without coinfection (43.8% vs 64.5%; 0.84 +/- 1.05 vs 0.53 +/- 0.89). The epidemiological and virological parameters, and other histological scores (periportal necrosis, portal inflammation, total necroinflammation and fibrosis) were not significantly different between these two groups.

CONCLUSION

Chronic hepatitis C patients with HBV coinfection tend to have more severe intralobular necrosis than those with isolated HCV infection.

Adefovir dipivoxil treatment of lamivudine-resistant chronic hepatitis B

Adefovir dipivoxil (ADV)-resistant mutations have been identified in treating hepatitis B virus (HBV) infection. This study aimed to analyze the response, the incidence of ADV resistance and the virologic characteristics of ADV therapy. A total of 29 CHB patients with confirmed lamivudine (LAM)-resistant HBV were treated with ADV for more than 52 weeks. Serum HBV DNA, HBV genotypes and sequences of HBV polymerase reverse-transcriptase domain were determined. Rates for the biochemical response, HBeAg loss, HBeAg seroconversion and virologic response (< 200 copies/mL of HBV DNA) were 82.8, 23.5, 11.8, and 48.3%, respectively, at week 52 of treatment. Lower pre-treatment mean HBV DNA level was the only significant factor associated with negative HBV DNA after ADV therapy. Six (20.7%) patients had clearance of LAM-resistant YMDD variants with replacement by the wild type HBV at week 52. The rtN236T, rtA181V/T and rtI233V were not identified before ADV therapy and the genotypic mutation of rtN236T was detected in one (3.4%) patient. In conclusion, the 52-week ADV treatment for patients with LAM-resistant HBV variants significantly achieved normalization of ALT levels, reduced serum HBV DNA levels and induced HBeAg loss and seroconversion. The emergence of ADV-resistant mutations seemed rare at weeks 52.

Early mortality in taiwanese lamivudine-treated patients with chronic hepatitis B-related decompensation: evaluation of the model for end-stage liver disease and index scoring systems as prognostic predictors

BACKGROUND

Both Model for End-stage Liver Disease (MELD) and Index scores have been used to predict mortality in patients with end-stage liver disease and cirrhosis in Western countries.

OBJECTIVES

This study aimed to determine mortality rates, identify prognostic indicators, and determine the usefulness of these 2 scoring systems in predicting short-term (6-month) survival in Taiwanese patients with chronic hepatitis B (CHB)-related decompensation who were treated with lamivudine.

METHODS

This study was conducted at the Kaohsiung Medical University Hospital and the Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan. Eligible patients were aged 18 to 85 years with CHB with related decompensation (with either serum total bilirubin level, >or=3 mg/dL or prolonged prothrombin time, >or=3 seconds) and were treatment naive. All patients were treated with lamivudine 100 mg PO (tablet) once daily; surviving patients were treated for at least 6 months. The clinical data, including hepatitis B surface antigen, hepatitis B e antigen, and hepatitis B virus (HBV) DNA, were measured before treatment. Pre-treatment MELD and Index scores were calculated for all patients.

RESULTS

Ninety-six patients were enrolled (79 men, 17 women; mean [SD] age, 44.5 [15.2] years). Thirteen (13.5%) patients died within 6 months. Higher international normalized ratio (INR) for prothrombin time, lower albumin level, and higher HBV DNA level (>or=10(5) copies/mL) were factors significantly associated with death. The areas under the receiver operating characteristic curve for predicting survival by the MELD and Index scores were 0.822 and 0.788, respectively. Albumin level, which was not included in the scoring systems, also was found to be a significant predictor.

CONCLUSIONS

: We found that with a 13.5% mortality rate, albumin, INR, and HBV DNA levels were good prognostic indicators in Taiwanese patients with CHB-related decompensation treated with lamivudine therapy. The MELD and Index scoring systems were good predictors of 6-month survival in the patients in this study.

Genotypes and viremia of hepatitis B and D viruses are associated with outcomes of chronic hepatitis D patients

BACKGROUND & AIMS

Genotypes and viremia of hepatitis D virus (HDV) and hepatitis B virus (HBV) may be associated with outcomes. This study evaluated the impact of viral genotypes and viremia on outcomes of dual HBV and HDV infection.

METHODS

Viremia and viral genotypes were analyzed in 194 consecutive chronic hepatitis B patients with HDV superinfection and correlated with outcomes.

RESULTS

The numbers of HBV genotype A, B, C, and nonclassified were 4, 57, 23, and 110, respectively. There were 51 genotype I HDV, 74 genotype II HDV, 8 genotype IV HDV, and 61 nonclassified HDV genotype. In a median follow-up of 135 months, 24 progressed to cirrhosis and 41 developed hepatocellular carcinoma. Patients infected with genotype I HDV had a lower remission rate (15.2% vs 40.2%; P = .007) and more adverse outcomes (cirrhosis, hepatocellular carcinoma, or mortality) (52.2% vs 25.0%; P= .005) than those with genotype II HDV. Patients infected with genotype C HBV had a lower remission rate (0 vs 32.1%; P = .005) and more adverse outcomes (70.0% vs 33.9%; P = .005) than those with genotype B HBV. The presence of HBV or HDV viremia was associated with lower remission rates compared with those negative for both (26.4% and 24.3% vs 69.2%; P < .001). In multivariate analysis, age, genotype C HBV, and genotype I HDV were independent factors associated with adverse outcomes.

CONCLUSIONS

In chronic HBV and HDV dual infections, older age, genotype I HDV, and genotype C HBV correlated with adverse outcomes.

Rational design of DNA sequences for nanotechnology, microarrays and molecular computers using Eulerian graphs

Nucleic acids are molecules of choice for both established and emerging nanoscale technologies. These technologies benefit from large functional densities of 'DNA processing elements' that can be readily manufactured. To achieve the desired functionality, polynucleotide sequences are currently designed by a process that involves tedious and laborious filtering of potential candidates against a series of requirements and parameters. Here, we present a complete novel methodology for the rapid rational design of large sets of DNA sequences. This method allows for the direct implementation of very complex and detailed requirements for the generated sequences, thus avoiding 'brute force' filtering. At the same time, these sequences have narrow distributions of melting temperatures. The molecular part of the design process can be done without computer assistance, using an efficient 'human engineering' approach by drawing a single blueprint graph that represents all generated sequences. Moreover, the method eliminates the necessity for extensive thermodynamic calculations. Melting temperature can be calculated only once (or not at all). In addition, the isostability of the sequences is independent of the selection of a particular set of thermodynamic parameters. Applications are presented for DNA sequence designs for microarrays, universal microarray zip sequences and electron transfer experiments.