Pas, S.D.

Performance evaluation of the new Roche cobas AmpliPrep/cobas TaqMan HCV test, version 2.0, for detection and quantification of hepatitis C virus RNA (Article)

2013-01-01T00:00:00Z

To evaluate the analytical performance and explore the clinical applicability of the new Roche cobas AmpliPrep/cobas TaqMan HCV test, v2.0 (CAP/CTM v2.0), a platform comparison was performed on panels and diagnostic samples with the Roche cobas AmpliPrep/cobas TaqMan HCV test (CAP/CTM v1.0), the Siemens Versant HCV RNA 3.0 branched DNA (bDNA) test, the Abbottm2000 RealTime HCV assay (Realtime assay), and the Siemens Versant HCV transcription-mediated amplification (TMA) test (TMA assay). The analytical performance of the CAP/CTM v2.0 on WHO and Acrometrix panels and clinical specimens of patients infected with HCV genotype 1, 2, 3, 4, 5, or 6 relative to that of the CAP/CTM v1.0 was significantly improved. In a qualitative comparison of the CAP/CTM v2.0 relative to the TMA assay on genotype 1 to 4 samples, the two tests proved to be almost equally sensitive. Response-guided therapy in one of five HCV genotype 4-infected patients previously tested with the CAP/CTM v1.0 would have significantly changed if tested with the CAP/CTM v2.0. In conclusion, the Roche CAP/CTM v2.0 has significantly better performance characteristics than the former CAP/CTM HCV v1.0 and the bDNA assay and performance characteristics comparable to those of the Realtime assay. Copyright

Clinical implications of chronic hepatitis e virus infection in heart transplant recipients (Article)

2013-01-01T00:00:00Z

Background: Recent reports have shown that hepatitis E virus (HEV) infection can become chronic in solid-organ transplant recipients, but few studies have systematically investigated the clinical consequences of this chronic HEV infection in solid-organ transplant (SOT) recipients. Methods: We have undertaken an in-depth study of 6 chronic HEV-infected heart transplant recipients to gain further insight into the clinical, biochemical and virologic presentation of this disorder. Results: In 6 patients (2.3%) chronic HEV infection, genotype 3, was identified. Immunosuppression in these patients was tacrolimus-based, combined with either everolimus or prednisolone and/or mycophenolate mofetil. Median follow-up after case detection was 26 months (range 21 to 40 months). All chronic HEV cases had elevated liver enzyme values. IgM antibodies at presentation were positive in 2 of 6 (33%) patients. Liver histology in 4 of 6 (67%) patients showed advanced fibrosis within 2 years after infection. One patient spontaneously cleared the HEV infection: 1 after dose reduction of immunosuppressive therapy and 3 during ribavirin therapy. One patient has yet to clear the virus and remains on ribavirin therapy. Conclusions: Chronic HEV infection in heart transplant (HTx) recipients may lead to rapid fibrosis of the liver. We advise additional HEV RNA screening in solid-organ transplant recipients with elevated liver enzymes, because antibody production is often delayed, as demonstrated in these patients. Dose reduction of immunosuppressive therapy should be the first intervention strategy to achieve viral clearance in chronic HEV-infected immunocompromised patients. Ribavirin treatment should be considered in cases of chronic HEV.

Incidence of viral respiratory pathogens causing exacerbations in adult cystic fibrosis patients (Article)

2013-01-01T00:00:00Z

Respiratory infections caused by respiratory viruses are common in paediatric cystic fibrosis (CF) patients and are associated with increased morbidity. There is only little data on the incidence of viral respiratory pathogens causing exacerbations in the adult CF patient population. In this observational pilot study we show, by using molecular as well as conventional techniques for viral isolation, that during 1 y a viral pathogen could be isolated in 8/24 (33%) adult CF patients who presented with a pulmonary exacerbation. This result shows that there is a considerable incidence of viral pathogens in pulmonary exacerbations in adult CF patients. Newly identified viruses such as pandemic influenza A/H1N1, human metapneumovirus, human bocavirus, and human coronavirus NL63 were not detected in our population, except for 1 human coronavirus NL63.

Presence of precore and core promoter mutants limits the probability of response to peginterferon in hepatitis B e antigen-positive chronic hepatitis B (Article)

2012-07-01T00:00:00Z

Peginterferon (PEG-IFN) treatment of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) results in HBeAg loss in 30% of patients, but clearance of hepatitis B virus (HBV) DNA and hepatitis B surface antigen (HBsAg) from serum is less often achieved. We investigated whether the presence of precore (PC) and basal core promoter (BCP) mutants before PEG-IFN treatment affects serological and virological response. A total of 214 HBeAg-positive CHB patients treated with PEG-IFN±lamivudine for 52 weeks in a global randomized trial were classified at baseline as wildtype (WT) or non-WT (detectable mutants at PC/BCP) by line-probe assay. Response was assessed at 6 months posttreatment and through long-term follow-up (LTFU). Mutants were detected in 64% of patients, in varying frequencies across HBV genotypes A through D. Patients with WT had higher baseline HBV DNA, HBeAg, and HBsAg levels than patients with non-WT. Patients with WT were more likely to achieve HBeAg loss with HBV DNA <10,000 copies/mL (response, 34 versus 11%, P < 0.001) and HBsAg clearance (18 versus 2%, P < 0.001) at week 78 than non-WT patients. Among WT patients who achieved HBeAg clearance at week 78, 78% had undetectable HBV DNA and 61% achieved HBsAg clearance at LTFU (versus 26% and 15% in non-WT patients, P < 0.001 for both). The presence of WT virus at baseline was an independent predictor of response (odds ratio [OR] 2.90, 95% confidence interval [CI]: 1.15-7.31, P = 0.023) and HBsAg clearance (OR 5.58, 95% CI: 1.26-24.63, P = 0.013) and patients with non-A genotypes with detectable mutants had a low probability of response. Conclusion: The presence of only WT virus at baseline is a strong predictor of response (HBeAg loss with HBV DNA <10,000 copies/mL) to PEG-IFN for HBeAg-positive CHB. Patients with detectable PC and/or BCP mutants have a lower probability of response and are less optimal candidates for PEG-IFN therapy.

A family-wide rt-pcr assay for detection of paramyxoviruses and application to a large-scale surveillance study (Article)

2012-04-04T00:00:00Z

Family-wide molecular diagnostic assays are valuable tools for initial identification of viruses during outbreaks and to limit costs of surveillance studies. Recent discoveries of paramyxoviruses have called for such assay that is able to detect all known and unknown paramyxoviruses in one round of PCR amplification. We have developed a RT-PCR assay consisting of a single degenerate primer set, able to detect all members of the Paramyxoviridae family including all virus genera within the subfamilies Paramyxovirinae and Pneumovirinae. Primers anneal to domain III of the polymerase gene, with the 3′ end of the reverse primer annealing to the conserved motif GDNQ, which is proposed to be the active site for nucleotide polymerization. The assay was fully optimized and was shown to indeed detect all available paramyxoviruses tested. Clinical specimens from hospitalized patients that tested positive for known paramyxoviruses in conventional assays were also detected with the novel family-wide test. A high-throughput fluorescence-based RT-PCR version of the assay was developed for screening large numbers of specimens. A large number of samples collected from wild birds was tested, resulting in the detection of avian paramyxoviruses type 1 in both barnacle and white-fronted geese, and type 8 in barnacle geese. Avian metapneumovirus type C was found for the first time in Europe in mallards, greylag geese and common gulls. The single round family-wide RT-PCR assay described here is a useful tool for the detection of known and unknown paramyxoviruses, and screening of large sample collections from humans and animals.

Real-time PCR versus viral culture on urine as a gold standard in the diagnosis of congenital cytomegalovirus infection (Article)

2012-02-01T00:00:00Z

Background: Cytomegalovirus (CMV) infection is the most common cause of congenital infection. Whereas CMV PCR has replaced viral culture and antigen detection in immunocompromised patients because of higher sensitivity, viral culture of neonatal urine is still referred to as the gold standard in the diagnosis of congenital CMV infection. Objective: To compare real-time CMV PCR with shell vial culture on urine in the diagnosis of congenital CMV, in a multicenter design. Study design: A series of neonatal urines (n= 340), received for congenital CMV diagnostics and routinely assessed with shell vial CMV culture, was retrospectively tested by real-time CMV PCR. Results: The proportion of newborns found to be congenitally infected by real-time CMV PCR was 8.2% (28/340, 95%CI 5.6-11.8%), and 7.4% (25/340, 95%CI 4.9-10.8%) by rapid culture. When considering rapid culture as reference, real-time PCR was highly sensitive (100%), whereas sensitivity of rapid culture was 89.3% when considering real-time PCR as reference. Conclusions: Our results, supported by analytical and clinical data on CMV DNA detection in neonatal urine, suggest enhanced sensitivity of recent PCR techniques when compared to viral culture. There is considerable rationale to favor real-time CMV PCR as a gold standard in the diagnosis of congenital CMV infection. A large-scale study combining both laboratory and clinical data is required to determine the exact time frame for sampling of neonatal urine when using real-time PCR.

Long-term therapy with tenofovir is effective for patients co-infected with human immunodeficiency virus and hepatitis b virus (Article)

2010-12-01T00:00:00Z

Background & Aims We investigated the long-term efficacy and renal safety of tenofovir disoproxil fumarate (TDF), administered to patients co-infected with human immunodeficiency virus and hepatitis B virus (HBV) as part of an antiretroviral therapy. Methods We performed a multicenter, prospective cohort study of 102 patients co-infected with human immunodeficiency virus and HBV who were treated with TDF. Results At baseline, 80% of patients had a detectable viral load (HBV DNA >20 IU/mL). Among patients positive for hepatitis B e antigen (HBeAg) (n = 67), 92% had a virologic response (HBV DNA <20 IU/mL) after 5 years of treatment. There was no difference between patients with or without lamivudine resistance at baseline (P = .39). Loss rates of HBeAg and hepatitis B s antigen (HBsAg) were 46% and 12%, respectively. Among HBeAg-negative patients (n = 15), 100% had a virologic response after 4 years of treatment and 2 (13%) lost HBsAg. Twenty subjects (20%, all HBeAg-negative) had undetectable HBV DNA at baseline; during a median follow-up period of 52 months (interquartile range, 4163 mo), 19 (95%) maintained a virologic response and 2 (10%) lost HBsAg. Overall, one patient acquired a combination of resistance mutations for anti-HBV drugs and experienced a virologic breakthrough. Three (3%) patients discontinued TDF because of increased serum creatinine levels. The estimated decrease in renal function after 5 years of TDF therapy was 9.8 mL/min/1.73 m2, which was most pronounced shortly after TDF therapy was initiated. Conclusions TDF, administered as part of antiretroviral therapy, is a potent anti-HBV agent with a good resistance profile throughout 5 years of therapy. Only small nonprogressive decreases in renal function were observed.

Performance evaluation of the new roche cobas ampliprep/cobas taqman HIV-1 test version 2.0 for quantification of human immunodeficiency virus type 1 RNA (Article)

2010-04-01T00:00:00Z

Despite FDA approval and CE marking of commercial tests, manufacturer-independent testing of the technical aspects of newly developed tests is important. To evaluate the analytical performance and explore the clinical applicability of the new Roche COBAS AmpliPrep COBAS TaqMan HIV-1 test, version 2.0 (CAP/CTM v2.0), platform comparison was performed with the Roche CAP/CTM test, version 2.0, the COBAS Amplicor HIV-1 Monitor Test, version 1.5 (CAP/CA v1.5), the COBAS AmpliPrep COBAS TaqMan HIV-1 Test (CAP/ CTM v1.0), and the Abbott m2000 RealTime HIV-1 assay on panels and diagnostic samples. Specificity was tested for HIV-2 samples. Furthermore, samples from HIV-1-seropositive individuals with CAP/CA v1.5-measured viral loads below 50 HIV-1 RNA copies per ml (cp/ml) and replicates of HIV-1-seronegative plasma were tested in a checkerboard analysis. CAP/CTM v2.0 is HIV-1 specific, with broad genotype inclusivity and no serious underquantification of viral load relative to the other assays used. Low viral loads below the threshold of quantification for CAP/CA v1.5 are observed with CAP/CTM v2.0. A CAP/CTM v2.0-measured viral load of >50 copies/ml in these samples correlated with therapy failure. In conclusion, CAP/CTM v2.0 is an accurate and reliable test for HIV-1 viral load measurement relative to the other assays used with respect to specificity, sensitivity, and genotype inclusivity. Copyright

The effect of primer-template mismatches on the detection and quantification of nucleic acids using the 5′ nuclease assay (Article)

2010-01-01T00:00:00Z

Real-time polymerase chain reaction (PCR) is the current method of choice for detection and quantification of nucleic acids, especially for molecular diagnostics. Complementarity between primers and template is often crucial for PCR applications, as mismatches can severely reduce priming efficiency. However, little quantitative data on the effect of these mismatches is available. We quantitatively investigated the effects of primer-template mismatches within the 3′-end primer region on real-time PCR using the 5′-nuclease assay. Our results show that single mismatches instigate a broad variety of effects, ranging from minor (<1.5 cycle threshold, eg, A-C, C-A, T-G, G-T) to severe impact (>7.0 cycle threshold, eg, A-A, G-A, A-G, C-C) on PCR amplification. A clear relationship between specific mismatch types, position, and impact was found, which remained consistent for DNA versus RNA amplifications and Taq/Moloney murine leukemia virus versus rTth based amplifications. The overall size of the impact among the various master mixes used differed substantially (up to sevenfold), and for certain master mixes a reverse or forward primer-specific impact was observed, emphasizing the importance of the experimental conditions used. Taken together these data suggest that mismatch impact follows a consistent pattern and enabled us to formulate several guidelines for predicting primer-template mismatch behavior when using specific 5-nuclease assay master mixes. Our study provides novel insight into mismatch behavior and should allow for more optimized development of real-time PCR assays involving primer-template mismatches.

Entecavir shows limited efficacy in HBeAg-positive hepatitis B patients with a partial virologic response to adefovir therapy (Article)

2009-04-01T00:00:00Z

Background/Aims: We investigated the efficacy of entecavir in lamivudine-experienced and -naïve patients with persistently high HBV DNA during adefovir treatment. Methods: Fourteen chronic hepatitis B patients (57% lamivudine-experienced) with a viral load above 5 log10 copies/mL after 12 months of adefovir therapy and thereafter were treated with entecavir 1 mg daily. Results: During a median follow-up of 15 months (range: 8-23 months) one of six lamivudine-naïve and none of the eight lamivudine-experienced patients achieved undetectable HBV DNA (<373 copies/mL). HBeAg loss occurred in none of the subjects. Two lamivudine-experienced patients demonstrated the rtM204I mutation; no other entecavir-resistant substitutions were detected (rtI169, rtT184, rtS202, and rtM250). Two of three patients with genotypic adefovir resistance at baseline demonstrated a rapid virologic response to entecavir, but undetectable HBV DNA was not achieved. To attain a better antiviral response the dosage of entecavir was increased to 2 mg daily in two patients, resulting in further viral load decline for both of them. Conclusions: Entecavir monotherapy dosed at 1 mg resulted in a slow reduction of viral load in both lamivudine-experienced and -naïve patients with persistently high HBV DNA during adefovir therapy. Increasing the dosage of entecavir led to further HBV DNA decline.

An improved approach to identify epidemiological and phylogenetic transmission pairs of source and contact tracing of hepatitis B (Article)

2009-03-01T00:00:00Z

The transmission of infectious diseases can be traced using epidemiological and molecular information. In the current study, the congruence was assessed between sequence data of the hepatitis B virus (HBV) and epidemiological information resulting from source and contact tracing of patients seen at the Municipal Public Health Service in Rotterdam between 2002 and 2005. HBV genotypes A-G were present in 62 acute and 334 chronic HBV patients. At the sequence level, the identical sequences of members of epidemiological transmission pairs and the rarity of such pairs provided strong support for correctness of the hypothesized transmission routes.The molecular support for epidemiological transmission pairs derived from source and contact tracing was further assessed by using topological constraints in parsimony analyses in agreement with epidemiological information, and by taking the presence of polymorphic sites of HBV within patients into account. This, in principle, allows mutations in epidemiological clusters. Of 22 epidemiological clusters, six could be refuted, four clusters received support from the molecular analysis, and support for the remaining twelve clusters was ambiguous. Two of the four epidemiological pairs that received molecular support had diverged (by 3 and 15 mutations). These results show that levels of divergence cannot be used simply as an indicator of the likelihood that groups of sequences constitute transmission pairs. Instead, to confirm or refute transmission pairs, it is necessary to assess the likelihood of a common origin of HBV variants in epidemiologically defined transmission groups relative to the HBV diversity in the local community.

On-treatment monitoring of adefovir therapy in chronic hepatitis B: Virologic response can be assessed at 24 weeks (Article)

2009-02-01T00:00:00Z

Patients with chronic hepatitis B (CHB) who will and those who will not respond to adefovir (ADV) monotherapy need to be identified at an early stage in order to adjust treatment and prevent future development of antiviral resistance. In a single-centre cohort study, we investigated 76 CHB patients [50% hepatitis B e antigen (HBeAg)-positive] treated with long-term ADV monotherapy. During a median follow-up of 122 (24-185) weeks, 42 (55%) patients achieved virologic response (VR), defined as HBV-DNA levels <103copies/mL, and 10 patients (13%) developed genotypic ADV resistance. Independent baseline predictors of VR were HBeAg negativity [hazard ratio (HR) 2.98; 95% confidence interval (CI) 1.24-7.19; P = 0.02], high alanine aminotransferase (ALT) levels (HR 1.11; 95% CI 1.05-1.18; P = 0.001), and low HBV-DNA levels (HR 0.56; 95% CI 0.41-0.75; P < 0.001). HBV-DNA at week 24 demonstrated a higher predictive value for VR than HBV-DNA at week 48. Important predictors of genotypic resistance were presence of cirrhosis (HR 6.54; 95% CI 1.39-30.9; P = 0.018), and not achieving VR during treatment (HR 6.60; 95% CI 1.35-32.4; P = 0.008). Patients without VR at week 24 already demonstrated a trend towards the emergence of ADV resistance (P = 0.07). HBV-DNA at week 24 was a better on-treatment predictor of VR than HBV-DNA at week 48, and ADV-resistant mutations developed more frequently in patients without VR at week 24. Therefore, our study suggests that virologic response to ADV therapy can be assessed at 24 weeks, instead of the generally recommended 48 weeks.

Evaluation of vaccination strategies against infection with feline immunodeficiency virus (FIV) based on recombinant viral vectors expressing FIV Rev and OrfA (Article)

2008-12-15T00:00:00Z

In recent years it has become clear that cell-mediated immunity is playing a role in the control of lentivirus infections. In particular, cytotoxic T lymphocyte responses have been associated with improved outcome of infection, especially those directed against the regulatory proteins like Rev and Tat, which are expressed early after infection. Therefore, there is considerable interest in lentiviral vaccine candidates that can induce these types of immune responses. In the present study, we describe the construction and characterisation of expression vectors based on recombinant Semliki Forest virus system and modified vaccinia virus Ankara for the expression of feline immunodeficiency virus (FIV) accessory proteins Rev and OrfA. These recombinant viral vectors were used to immunize cats using a prime-boost regimen and the protective efficacy of this vaccination strategy was assessed after challenge infection of immunized cats with FIV.

Evaluation of ISCOM-adjuvanted subunit vaccines containing recombinant feline immunodeficiency virus Rev, OrfA and envelope protein in cats (Article)

2008-05-19T00:00:00Z

For the development of feline immunodeficiency virus (FIV) vaccines mostly structural proteins have been evaluated for their capacity to induce protective immunity. In the present study, subunit vaccines containing recombinant FIV accessory proteins Rev and OrfA were evaluated in cats. Cats were vaccinated repeatedly with these proteins, adjuvanted with immune stimulating complexes (ISCOMs). In addition, cats were vaccinated with bacterially expressed fragments spanning the entire FIV envelope protein, either alone or in combination with the regulatory proteins. Subsequently, the cats were challenged with a homologous FIV strain to assess the level of protective immunity achieved with the respective vaccination regimens. Although the vaccines proved to be immunogenic, vaccinated cats were not protected from infection with FIV.

Comparison of reverse hybridization, microarray, and sequence analysis for genotyping hepatitis B virus (Article)

2008-04-01T00:00:00Z

Hepatitis B virus (HBV) genotyping has become important in epidemiological and clinical diagnoses, given the relationship between the viral genotype and the progression of disease or the appearance of antiviral resistance. Since genotyping by sequence and phylogenetic analyses is not convenient in the clinical setting, we evaluated InnoLipa HBV genotyping (Innogenetics, Belgium) and an HBV DNA-Chip (bioMerieux, France) prototype assay and compared their sequencing of the gold standard S gene, using a cohort of 275 individual patient samples. All but two samples, belonging to distant and individual subgroups within a single genotype, were detected by InnoLipa HBV assay. Four samples with dual infections belonging to genotypes A and G were identified only by InnoLipa HBV assay. Using an HBV DNA-Chip assay, one sample could not be amplified due to a low viral load. Four samples were identified as genotype C and two as genotype D by sequencing but were classified as genotype A (two samples) and D (two samples) and as A (one sample) and G (one sample) by the DNA-Chip assay. In conclusion, the InnoLipa HBV genotyping strip assay detected dual infections and was an easy and quick tool for genotyping, with a sensitivity of 99.3% and a specificity of 100% compared to sequence analysis. HBV DNA-Chip assay showed a sensitivity and specificity of 97.5 and 97.8%, respectively. Copyright

Coronavirus HKU1 in an Italian pre-term infant with bronchiolitis (Article)

2007-03-01T00:00:00Z

Antibodies specific for hypervariable regions 3 to 5 of the feline immunodeficiency virus envelope glycoprotein are not solely responsible for vaccine-induced acceleration of challenge infection in cats (Article)

2004-07-01T00:00:00Z

In a previous vaccination study in cats, the authors reported on accelerated feline immunodeficiency virus (FIV) replication upon challenge in animals vaccinated with a candidate envelope subunit vaccine. Plasma transfer studies as well as antibody profiles in vaccinated cats indicated a causative role for antibodies directed against the hypervariable regions HV3, HV4 and HV5 (HV3–5) of the envelope glycoprotein. The present study was designed to investigate further the contribution of antibodies in envelope vaccine-induced acceleration of FIV infection. To this end, regions HV3–5 of the envelope glycoprotein were deleted from the original vaccine, thus addressing the contributing role of antibodies directed against these hypervariable regions. Interestingly, this approach did not prevent acceleration of challenge infection. Analysis of the antibody responses in the respective groups suggested that removal of HV3–5 redirected the humoral immune response towards other regions of the envelope glycoprotein, indicating that these regions can also induce antibodies that accelerate virus replication.

Antibodies specific for hypervariable regions 3 to 5 of the feline immunodeficiency virus envelope glycoprotein are not solely responsible for vaccine-induced acceleration of challenge infection in cats (Article)

2004-01-01T00:00:00Z

In a previous vaccination study in cats, the authors reported on accelerated feline immunodeficiency virus (FIV) replication upon challenge in animals vaccinated with a candidate envelope subunit vaccine. Plasma transfer studies as well as antibody profiles in vaccinated cats indicated a causative role for antibodies directed against the hypervariable regions HV3, HV4 and HV5 (HV3-5) of the envelope glycoprotein. The present study was designed to investigate further the contribution of antibodies in envelope vaccine-induced acceleration of FIV infection. To this end, regions HV3-5 of the envelope glycoprotein were deleted from the original vaccine, thus addressing the contributing role of antibodies directed against these hypervariable regions. Interestingly, this approach did not prevent acceleration of challenge infection. Analysis of the antibody responses in the respective groups suggested that removal of HV3-5 redirected the humoral immune response towards other regions of the envelope glycoprotein, indicating that these regions can also induce antibodies that accelerate virus replication.

Identification of a new variant in the YMDD motif of the hepatitis B virus polymerase gene selected during lamivudine therapy (Article)

2002-01-01T00:00:00Z

A new hepatitis B virus variant selected during lamivudine treatment was detected, in which the methionine (rtM204) in the so-called YMDD motif in the C domain of the catalytic site of the polymerase gene was replaced by a serine (rtM204S). This change simultaneously resulted in a tyrosine-195 into valine variant (sY195V) in the surface protein HBsAg. The detection of this YSDD variant was initially observed, after an increase of HBV DNA levels, by sequencing of amplification products from day 586. A specific RFLP assay was developed that could identify 10% of YSDD-containing variants in the virus pool, which enabled detection of this new variant virus at day 506. However, by cloning several PCR products and sequencing individual recombinant clones, the mutation was first identified at day 477, before a significant increase of HBV DNA was observed in serum. The mutation was followed by a leucine to methionine change at position 180 (rtL180M). The consequences of this mutation for disease management and diagnostic strategies are discussed.

Development of a quantitative real time detection assay for hepatitis B virus DNA and comparison with two commercial assays. (Article)

2000-01-01T00:00:00Z

A highly reproducible and sensitive real-time detection assay based on TaqMan technology was developed for the detection of hepatitis B virus (HBV) DNA and compared with two commercially available assays. The assay was validated with the Viral Quality Control panel, which also includes EUROHEP HBV DNA standards. This real-time PCR detection system had a dynamic range of 373 to 10(10) genome copies per ml and showed an excellent correlation with both the commercial HBV Digene Hybrid Capture II microplate assay (Digene Diagnostics) and the HBV MONITOR assay (Roche Diagnostics). To demonstrate its clinical utility, four chronically HBV-infected patients treated with lamuvidine were monitored using the three different assays. From the results we concluded that this assay is an excellent alternative for monitoring of HBV-infected patients in routine diagnostics and clinical practice, enabling the analysis of a large dynamic range of HBV DNA in a single, undiluted sample.

Development of a quantitative real-time detection assay for hepatitis B virus DNA and comparison with two commercial assays (Article)

2000-01-01T00:00:00Z