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1.
BackgroundThe use of simplified methods for viral load determination could greatly increase access to treatment monitoring of HIV patients in resource-limited countries.ObjectiveThe aim of the present study was to optimize and evaluate the performance of the Roche COBAS Taqman assay in HIV-RNA quantification from dried blood spots (DBS) and dried plasma spots (DPS).Study designEDTA blood samples from 108 HIV-infected women were used to prepare 129 DBS and 76 DPS on Whatman 903 card. DBS and DPS were stored at ?20 °C. HIV-1 RNA was extracted from DBS/DPS using the MiniMAG system (bioMerieux). Amplification and detection were performed using the Roche COBAS TaqMan assay. Plasma viral load results were used as standard.ResultsThere was a high correlation between measures of viral load in plasma and in DBS/DPS (r = 0.96 and 0.85 respectively, P < 0.001). Overall, viral load values in DBS and DPS tended to be lower than in plasma with mean (SD) differences of 0.32 log (0.22) for DBS and of 0.35 (0.33) for DPS. Detection rates were 96.4% for DBS and 96.1% for DPS in samples with corresponding plasma values >3.0 log copies/ml. Samples with HIV-RNA below 50 copies/ml were correctly identified in 18/19 DBS and in 7/7 DPS.ConclusionsBoth DBS and DPS provided results highly correlated to the plasma values. High detection rate was obtained with both DBS and DPS when HIV-RNA was >3.0 log copies/ml. Our results support the use of DBS/DPS to detect virologic failure in resource-limited settings.  相似文献   

2.
BackgroundIndonesia currently faces both an increasing HIV incidence and a high hepatitis B virus (HBV) burden.ObjectiveThe objective of our study is to examine the prevalence, risk factors, and genotypic distribution of HBV infection among HIV infected patients in West Java, Indonesia.Study designA cross sectional study was conducted among a cohort of HIV infected patients in 2008. Demographic and disease related variables were compared between HBV negative and positive patients. Logistic regression was applied to determine risk factors for HBV co-infection. HBV and HIV genotyping was performed in co-infected patients.ResultsOf 636 HIV-infected patients, the rate of HBV co-infection was 7%. The proportion of males was higher in HBV/HIV co-infected patients than in HIV mono-infected patients (93% vs. 72%, P = 0.001). A history of injecting drug use (IDU), but not tattooing, was associated with HBV co-infection [P = 0.035 OR 2.41 (95% CI 1.06–5.47)]. In the HIV and HBV treatment naive patients, CD4 cells counts <50 cells/mm3, HIV-RNA plasma ≥10,000 copies/ml and AST level above normal were more often found in patients with high HBV-DNA levels (≥20,000 IU/ml) as compared to those with low HBV DNA (<20.000  IU/ml) (P < 0.05). As in the general population, B3 was the dominant subtype in HBV co-infected patients.ConclusionThe prevalence of active HBV infection and the genotype distribution among HIV infected individuals is similar to the overall population in Java. However, an increased prevalence was observed in men with a history of IDU, underlining the need for routine HBV screening and monitoring.  相似文献   

3.
BackgroundDetection and quantification of HBV DNA are essential to diagnose chronic HBV infection, monitor the virological response to treatment and the possible selection of resistant viruses in order to tailor therapy. The VERIS/MDx System HBV Assay is a random-access system that quantifies HBV DNA in clinical samples using unique single sample and reagent access during the workflow process without the need to reload other tests and delivers results within 1.2 h following sampling.Objective and study designThe goal of this study was to evaluate the analytical performance of the VERIS HBV assay for HBV DNA detection and quantification in clinical samples from a series of patients chronically infected with different HBV genotypes.ResultsThe specificity of the VERIS HBV assay was estimated to be over 99.5%. The limit of detection (LOD) was estimated to be 4.1 IU/mL (95%CI: 3.20–5.90 IU/mL). Using an HBV linearity panel and controls (Seracare LifeScience), intra-assay and inter-assay coefficients of variation ranged from 0.12% to 3.64% and from 1.05% to 7.35%, respectively. The influence of the HBV genotype was evaluated from 120 clinical specimens containing HBV genotypes A to G tested in parallel with the VERIS HBV assay and the COBAS AmpliPrep/COBAS TaqMan HBV v2.0 assay. A linear relationship between the HBV DNA levels measured with both assays was found. A modest bias of HBV DNA levels was observed in the VERIS assay as compared to CAP/CTM HBV v2.0 in most of the samples tested (mean VERIS minus CAP/CTM difference: −0.395 log IU/mL). Overall, the VERIS HBV assay is well suited to monitoring clinical HBV DNA levels in infected patients according to current clinical practice guidelines.  相似文献   

4.
BackgroundThe diagnosis of HCV relies on the detection of viral RNA.ObjectiveTo evaluate the performance of the VERIS/MDx System HCV Assay, a new automated system for quantifying HCV RNA, and to compare with the COBAS® Ampliprep/COBAS® Taqman™ (CAPCTM) HCV Test version 2.0.Study designThe limit of detection was determined by Probit analysis with the 3rd International WHO HCV standard and precision by assaying in duplicate control samples with HCV RNA concentrations of 7.9; 5.0; 3.4; 1.6 and 0 log IU/ml over 20 days. Analytical specificity was assessed by assaying 180 samples from negative anti-HCV and HCV RNA blood donors and linearity with replicates of serial dilutions of a clinical plasma (6.4–0.6 log IU/ml). We compared the VERIS MDx HCV and CAPCTM HCV assays by testing 209 samples.ResultsThe limit of detection was 6.1 IU/ml [CI 95%: 5.0–8.3] and the precision, given by the standard deviation, was ≤0.11 log IU/ml. Specificity was 100%. The linearity ranged from 1.5 to 6.4 log IU/ml. Passing-Bablok regression analysis gave: VERIS log IU/ml = −0.33 + [1.04× CAPCTM] log IU/ml, with biases for the 25th, 50th, 75th percentiles of 0.18, −0.10 and −0.06 log IU/ml. The two assays were well correlated (ρ = 0.92, p < 0.001) and Bland-Altman analysis gave biases of 0.12, log IU/ml for genotype 1, −0.19 for genotype 2, −0.26 for genotype 3, and −0.77 for genotype 4.ConclusionThe VERIS MDx HCV assay performed well. But, we observed an under-quantification of the genotype 4 samples.  相似文献   

5.
BackgroundImmunization against hepatitis B virus (HBV) in kidney transplantation (KT) candidates and recipients is recommended. If anti-HBV surface antigen antibody (anti-HBsAb) titer of 10 IU/L is admitted to be protective, the optimal threshold, at and after KT, is unknown. In addition, the natural evolution of anti-HBsAb titers after KT is not reported.ObjectivesTo describe rates of protective immunity to HBV at time of KT (baseline) and evolution of anti-HBsAb titers during the following year.Study designWe retrospectively analyzed HBV serology at baseline, 15 days, and 4 and 12 months post-KT. No patient received vaccination during the study period, but information about previous vaccination was unavailable.ResultsAt baseline 80% of 141 recipients had anti-HBsAb titer ≥10 IU/L. Among these 113 patients, 84 had subsequent HBV serologies at day 15 and month 4, and 67 had also serology at month 12. At month 12, 25% of patients had lost protective anti-HBsAb titers (p < 0.001). The duration of protective anti-HBsAb titers was significantly longer when the initial titer was ≥ 100 IU/L versus <100 IU/L (log-rank test p < 0.0001). Protective titers at month 12 persisted in 93% of patients with initial titer ≥100 IU/L compared to 33% with 10–100 IU/L titer (p < 0.0001). In contrast, duration of protective titers did not differ according to the anti-HBV core antigen antibody status at baseline.ConclusionsDespite a high prevalence of protective anti-HBsAb titer at KT, the loss of protective immunity during the following year was considerable, particularly when initial anti-HBsAb titer was <100 IU/L.  相似文献   

6.
BackgroundHIV-1 RNA plasma level is a key parameter for anti-viral treatment monitoring in HIV-1 infected individuals. Plasma stability and accurate measurement of clinical state is at risk when transporting from remote areas. Dried blood spot (DBS) testing can reduce this risk.ObjectivesDetermine the performance of NucliSENS EasyQ HIV-1 v2.0 for DBS.Study design100 HIV-1 negative, and 129 HIV-1 spiked blood specimens (2180 copies/ml) were used for diagnostic specificity and system robustness. Analytical performance was tested in the range 50–85,000,000 copies/ml. Clinical reactivity was measured with specimens obtained from 224 HIV-1 infected individuals. HIV-1 RNA stability was analyzed after applying several different storage conditions.ResultsDiagnostic specificity was 100% and system robustness was demonstrated by 100% detection rate without invalids. Limit of detection (95% detection rate) was 800 copies/ml. Linear results were obtained over the whole range tested. For clinical specimens, percentage positive results were comparable for DBS (57%) and plasma (58%). DBS quantification was on average 0.36 log 10 lower as compared to plasma. Specimen stability was demonstrated for 1 week at 55 °C/60% humidity, 3 weeks at 37 °C/80% humidity, 9 weeks at 37 °C/40% humidity, 3 months at ?20 °C/70% humidity, 3 weeks at 4 °C/100% humidity, 9 months at room temperature (15–30 °C), and 9 weeks shipment simulation.ConclusionResults obtained fully support the use of DBS for the NucliSENS EasyQ HIV-1 v2.0 assay. These findings are especially of importance in cases that plasma stability is currently at risk due to for example, long transport routes from remote areas under less controlled conditions.  相似文献   

7.
BackgroundViral kinetics and host interleukin 28B (IL-28B) genotype determine treatment outcome in hepatitis C virus genotype 1 (HCV-1) infection.ObjectivesWe aimed to explore the interplay between interferon responsiveness at treatment week 4 and IL28B genotype in the achievement of a sustained virological response (SVR; undetectable HCV RNA 24-weeks after end-of-treatment).Study designsRs8099917 genotypes were determined in 528 HCV-1 patients with peginterferon/ribavirin. Interferon responsiveness were evaluated by the degree of week 4 viral reduction: <1 log10 IU/mL, 1–2 logs10 IU/mL, 2–3 logs10 IU/mL, 3–4 logs10 IU/mL and ≥4 logs10 IU/mL reduction and/or undetectable HCV RNA, respectively.ResultsThe SVR rate was significantly higher in patients with great interferon responsiveness at week 4. A great interferon responsiveness was associated with younger age (P < 0.0001), lower body mass index (P = 0.0056), lower aspartate aminotransferase levels (P = 0.0009), higher hemogloblin concentration (P = 0.0033), higher platelet counts (P < 0.0001), male gender (P < 0.0001) and rs809997 TT-genotype (P < 0.0001). Comparing to non-TT genotype patients, TT genotype patients had a significantly higher SVR rate with moderate viral reduction (1–3 logs10 IU/mL) at week 4 (58.9% vs. 18.2%, P < 0.001), and the SVR rate did not differ between TT/non-TT patients on the extreme ends (<1 or >3 log10 IU/mL reduction) of week 4 interferon responsiveness. For non-TT genotype carriers who were with <3 logs10 reduction, none (0/15) could have a complete early virological response and only 10.9% (7/64) of the patients had an SVR.ConclusionsMore profound interferon responsiveness is mandatory for HCV-1 patients with unfavorable IL-28B genotype.  相似文献   

8.
BackgroundThe most important reason for measuring HIV-1 viral load (VL) is to monitor the effectiveness of antiretroviral therapy (ART), both for the initial therapeutic response and sustained responses. Maintaining low or undetectable HIV-1 VL levels can reduce both the risks of progression to AIDS and transmission of infection to others.ObjectivesTo evaluate the diagnostic accuracy of Xpert® HIV-1 Viral Load (VL) assay compared to the Abbott RealTime HIV-1 assay, including assessing specificity by testing plasma specimens from confirmed HIV-1 negative blood donors.Study designSubjects were enrolled from 4 participating sites, 2 in Europe and 2 in the USA. Fresh plasma samples were tested prospectively, while frozen plasma samples were collected prospectively, and tested retrospectively after selection of specimens to cover the assay’s quantification range (40 cp/mL–10,000,000 cp/mL). Eligibility criteria included a clinician ordered HIV-1 VL test from a confirmed HIV-1 positive adult (≥18 years) with a known antiviral treatment status. Exclusion criteria included previous enrollment in this study or improper specimen collection. Human blood donor specimens determined to be HIV-1 negative by standard blood bank antibody and nucleic acid amplification methods were used to assess specificity.ResultsOf the 764 specimens collected, 752 were eligible for inclusion but 5 were not tested by the Xpert, leaving 747 specimens tested (28.2% from females and 71.8% from males). Valid results were obtained for 724/747 (96.9%) specimens tested using the Xpert HIV-1 VL assay. The Xpert HIV-1 VL assay detected or quantified 568/724 (78.5%) specimens, while the RealTime HIV-1 assay detected or quantified 559/724 (77.2%). Of the 724 specimens tested by both assays, 390 were quantified by both assays and showed strong correlation: r = 0.9847, with an R2 = 0.9696. Bland-Altman analysis showed good agreement between the two assays (381/390; 97.7%) with a distribution within 0.5 log10 cp/mL centered around zero. Xpert yielded VLs for 393 (80%) of the 494 quantifiable samples by Abbott. VLs of those specimens quantified by one of the assays, and either detected but not quantified or not detected by the other assay were all <170 cp/mL. Specificity of the Xpert assay was found to be 100% (109/109), 95% CI: 96.7–100.0.ConclusionVery good correlation was seen between the Xpert HIV-1 VL and Abbott RealTime HIV-1 assays, with added benefits for Xpert HIV-1 VL of: (1) lot-to-lot consistency traceable to WHO International Standard, (2) requiring both high and low level internal controls to be in range to have a valid result, (3) use of a single HIV-1 target for PCR and (4) faster turn-around-time for results, no need to wait to do batch testing of specimens. In summary, Xpert HIV-1 VL generated accurate VL results that if implemented could allow for actionable and timely treatment decisions during the same clinic visit. This scenario could reduce the loss to follow up often seen when these test results take days to weeks to become available to the clinician and patient.  相似文献   

9.
BackgroundBaseline serum HCV-RNA predicts sustained virological response in chronic hepatitis C patients treated with antiviral therapy. A threshold at 6 million IU/mL has been proposed to best discriminate treatment outcomes on sofosbuvir-based regimens. In comparison with the general population, immunosuppressed individuals exhibit greater viral load values.ObjectivesTo estimate the rate and predictors of serum HCV-RNA above 6 million IU/mL in chronic hepatitis C patients on care outside clinical trials.Study designSerum HCV-RNA values recorded from all chronic hepatitis C patients consecutively attended at our clinic during the last decade were analyzed. Testing had been performed using the COBAS TaqMan HCV test v2.0.ResultsA total of 816 individuals with detectable serum HCV-RNA were identified. The main characteristics of this population were as follows: mean age 48.6 years-old; 73.4% males; mean ALT 82.6 IU/L; mean HCV-RNA 6.02 log IU/mL; 80.6% HCV genotypes 1 or 4; 34.9% advanced liver fibrosis; 35.4% IL28B-CC alleles. HIV coinfection in 78.7%, of whom 91% were on antiretroviral therapy.Overall, 127 (15.6%) had serum HCV-RNA values >6 million IU/mL. This high viremia was found in 18.2% of HIV-positive versus 5.7% of HIV-negative subjects (p < 0.001). In multivariate analysis, serum HCV-RNA >6 million IU/mL was only significantly associated with HIV coinfection (OR: 4.03; 95% CI: 1.98–8.19, p < 0.01) and HCV genotypes 1 or 4 (OR: 1.88; 95% CI: 1.05–3.37, p = 0.03).ConclusionsSerum HCV-RNA >6 million IU/mL is roughly seen in 6% of chronic hepatitis C monoinfected patients, and increases up to 18% in HIV coinfection.  相似文献   

10.
BackgroundHBsAg quantitation may be useful for managing patients with hepatitis B virus (HBV) infection.ObjectivesWe explored the clinical implications of HBsAg quantitation for patients with HBsAg levels >250 IU/ml (Abbott Diagnostics).Study designTwo hundred and thirty-three HBV-infected patients comprising 29 immune tolerance cases, 49 treatment-naïve HBeAg-positive chronic hepatitis B (CHB) cases, 91 inactive HBV carrier cases, and 64 treatment-naïve HBeAg-negative CHB cases were analyzed. HBsAg was quantified by the Architect HBsAg assay (Abbott Diagnostics) after a 1:500 automated dilution.Results and conclusionsHBsAg (log 10 IU/ml) was established for immune tolerance (4.50 ± 0.43), HBeAg-positive CHB (4.17 ± 0.66), inactive HBV carrier (3.32 ± 0.44), and HBeAg-negative CHB (3.23 ± 0.40); (p = 4.92 × 10−35). No significant difference was observed between inactive HBV carrier and HBeAg-negative CHB (p = 0.247). The proportions of HBsAg <2000 IU/ml for inactive HBV carrier and HBeAg-negative CHB were 51.6% and 59.3%, respectively (p = 0.341). Positive correlations between HBsAg and HBV DNA were observed for immune tolerance (p = 1.23 × 10−4) and HBeAg-positive CHB (p = 0.003), but not for HBeAg-negative CHB (p = 0.432). A negative correlation between HBsAg and age was observed for immune tolerance (p = 0.030), HBeAg-positive CHB (p = 0.016), and inactive HBV carrier (p = 0.001), but not in HBeAg-negative CHB (p = 0.249). No significant differences between HBsAg and ALT for HBeAg-positive (p = 0.338) or HBeAg-negative CHB (p = 0.564) were observed. For patients with HBsAg quantitation >250 IU/ml, HBsAg may reflect HBV DNA replication for HBeAg-positive cases. HBsAg is not a suitable marker for evaluating hepatitis activity and distinguishing between cases of HBeAg-negative CHB and inactive HBV carrier state.  相似文献   

11.
BackgroundCompletely automated systems for monitoring CMV-DNA in plasma samples are now available.ObjectivesEvaluate analytical and clinical performances of the VERIS™/MDx System CMV Assay®.Study designAnalytical performance was assessed using quantified quality controls. Clinical performance was assessed by comparison with the COBAS® Ampliprep™/COBAS® Taqman CMV test using 169 plasma samples that had tested positive with the in-house technique in whole blood.ResultsThe specificity of the VERIS™/MDx System CMV Assay® was 99% [CI 95%: 97.7–100]. Intra-assay reproducibilities were 0.03, 0.04, 0.05 and 0.04 log10 IU/ml (means 2.78, 3.70, 4.64 and 5.60 log10 IU/ml) for expected values of 2.70, 3.70, 4.70 and 5.70 log10 IU/ml. The inter-assay reproducibilities were 0.12 and 0.08 (means 6.30 and 2.85 log10 IU/ml) for expected values of 6.28 and 2.80 log10 IU/ml. The lower limit of detection was 14.6 IU/ml, and the assay was linear from 2.34 to 5.58 log10 IU/ml. The results for the positive samples were concordant (r = 0.71, p < 0.0001; slope of Deming regression 0.79 [CI 95%: 0.56–1.57] and y-intercept 0.79 [CI 95%: 0.63–0.95]). The VERIS™/MDx System CMV Assay® detected 18 more positive samples than did the COBAS® Ampliprep™/COBAS® Taqman CMV test and the mean virus load were higher (0.41 log10 IU/ml). Patient monitoring on 68 samples collected from 17 immunosuppressed patients showed similar trends between the two assays. As secondary question, virus loads detected by the VERIS™/MDx System CMV Assay® were compared to those of the in-house procedure on whole blood. The results were similar between the two assays (−0.09 log10 IU/ml) as were the patient monitoring trends.ConclusionThe performances of the VERIS™/MDx System CMV Assay® facilitated its routine use in monitoring CMV-DNA loads in plasma samples.  相似文献   

12.
13.
BackgroundInfants born to chronic hepatitis B virus (HBV) infected mothers may be infected in spite of receiving passive-active immunoprophylaxis.ObjectivesThe purpose of this study was to assess the outcome of infants born to women actively infected by HBV.Study designFrom April 2004 to September 2009, infants born to women actively infected by HBV received hepatitis B immune globulin (HBIG) and the first dose of hepatitis B vaccine at birth. The second and third doses of HBV vaccine were administered at 1 and 6 months of age. Post-vaccination tests to detect HBsAg and anti-HBs were assessed between 12 and 15 months of age. Those who had anti-HBs titers < 10 mIU/ml received the second series of HBV vaccine.ResultsThirty-four and 201 infants were born to HBeAg-seropositive and anti-HBe-seropositive mothers, respectively. HBsAg was detected in 6 (17.6%) infants born to HBeAg-seropositive mothers and in 3 (1.5%) to anti-HBe-seropositive mothers (p = 0.0001). Anti-HBs ≥ 10 mIU/ml were achieved in 26 (76.5%) and 178 (88.6%) infants of HBeAg-seropositive and anti-HBe-seropositive mothers, respectively (p > 0.05). Twenty-two (9.4%) infants were non-responders and 11(50%) of them responded to the second series of HBV vaccine.ConclusionsThe results show that infants of HBeAg-seropositive mothers have higher risk of developing of HBV infection. Some HBsAg-seronegative infants may not respond to passive-active immunoprophylaxis and may remain at risk of HBV infection.  相似文献   

14.
BackgroundQuantification of cytomegalovirus (CMV) DNA by real-time PCR is currently considered an alternative diagnostic approach for the evaluation of active infection in transplant patients. The pp65 antigenemia assay has been used as reference test for monitoring active CMV infection and guiding preemptive therapy in transplant recipients. However, this assay suffers from some limitations: need for immediate processing of the samples, labour-intensive process, lack of standardization and subjective result interpretation.ObjectivesThe aim of this study was to evaluate the performance of a new commercially available real-time PCR assay coupled with a fully automated DNA extraction system (COBAS Ampliprep/COBAS Taqman CMV Test, Roche Diagnostics) for the detection of CMV-DNA in plasma comparing it with pp65 antigenemia assay for monitoring active CMV infection in solid organ transplant recipients (SOTRs).Study designA total of 266 consecutive samples from 45 SOTRs were monitored with pp65 antigenemia and in parallel with CMV-DNA quantitation by real-time PCR assay.ResultsFifty-eight samples resulted PCR-positive, 163 negative and for 45 samples the CMV-DNA values obtained were below the lower limit of quantification (<150 copies/ml); pp65 antigen was detected in 47 samples and resulted negative in 219 specimens. Concordance between the two evaluations was 76.7%; also a good correlation was observed (r = 0.718). Considering the existing treatment criteria based on pp65 antigenemia evaluation corresponding to pp65 levels  20 positive cells/200,000, preemptive therapy was administered to four asymptomatically infected patients. The corresponding cut-off value of CMV-DNA load calculated for discrimination between self-clearing infections and those requiring therapy was 2500 copies/ml (or 2275 IU/ml).ConclusionThe fully automated real-time PCR from Roche provided specific and sensitive results and represented a rapid and simple assay for the evaluation and monitoring of CMV infection in SOTRs. Further studies are required to validate the threshold level for the initiation of preemptive therapy.  相似文献   

15.
BackgroundMaternal transmission is the most common cause of HCV infection in children. HIV co-infection and high levels of plasma HCV-RNA have been associated with increased HCV transmission rates.ObjectivesWe assessed the vertical HCV transmission rate in the HIV–HCV co-infected group of pregnant women on cART.Study designWe conducted a retrospective study in a Dutch cohort of HIV-positive pregnant women and their children. We identified co-infected mothers. Results of the HCV tests of the children were obtained.ResultsAll 21 women were on cART at the time of delivery. We analyzed data of the 24 live-born children at risk for mother-to-child transmission (MTCT) of HCV between 1996 and 2009. HIV-RNA was <500 copies/ml during 18/24 [75%] deliveries, the median CD4+ cell count was 419 cells/μl (290–768). There was no transmission of HIV. The median plasma HCV-RNA in our cohort of 23 non-transmitting deliveries in 21 women was 3.5 × 10E5 viral eq/ml (IQR 9.6 × 104–1.5 × 106 veq/mL). One of 24 live-born children was found to be infected with HCV genotype 1. At the time of delivery the maternal plasma HIV-RNA was <50 copies/ml, the CD4+ cell count was 160 cells/μl and maternal plasma HCV-RNA was 4.6 × 10E6 veq/ml. This amounted to a prevalence of HCV-MTCT of 4%.ConclusionIn this well-defined cohort of HIV–HCV co-infected pregnant women, all treated with cART during pregnancy, a modest rate of vertical HCV transmission was observed.  相似文献   

16.
17.
BackgroundMore than 240 million people are chronically infected by hepatitis B virus (HBV) worldwide. Envelope proteins play a crucial role in viral cellular entry and immune recognition. The loss of HBs antigen (HBsAg) correlated with a good clinical prognosis is rarely achieved with or without treatment (3–16%).ObjectivesHBV envelope variability was investigated according to HBsAg persistence.Study designThe cohort consisted of 15 HBV genotype A-infected patients divided into “resolvers”, with HBsAg clearance, and “non-resolvers”, with HBsAg persistence and in subgroups: acute (n = 5, AHBV) or chronic infection (n = 4, CHBV) and HBV/HIV coinfection (n = 6, CHBV/HIV). HBV S and preS sequences were studied by direct and ultra-deep sequencing. Amino acid sequences were analyzed with bioinformatics for predicted antigenicity.ResultsIn S gene, the complexity was lower in AHBV than in chronic-infected patients (p = 0.046). Major mutations, detected using direct sequencing, were more frequent in AHBV developing chronicity (p = 0.01) than in AHBV resolvers. In the Major Hydrophilic Region, more frequent mutations were observed in non-resolvers versus resolvers (p = 0.047) and non-resolvers tended to have more haplotypes with a reduced predicted antigenicity (p = 0.07). Most of the mutations in preS/S region were found rather in epitopic than in non-epitopic areas (p = 0.025). Interestingly, the mutation sY161F found in 3/8 non-resolvers was associated with a decrease in predicted antigenicity (28%; AnTheProt).ConclusionsHBsAg persistence was correlated with mutations and deletions in areas playing a key role in immune recognition. These data suggest that variability in HBV envelope could favor immune escape in various clinical settings of HBV genotype A-infected patients.  相似文献   

18.
BackgroundPreemptive antiviral therapy relies on viral load measurements and is the mainstay of cytomegalovirus (CMV) prevention in hematopoietic cell transplant (HCT) recipients. However, optimal CMV levels for the initiation of preemptive therapy have not been defined.ObjectivesThe objectives of our work were to evaluate the relationship between plasma CMV DNA levels at initiation of preemptive therapy with time to resolution of viremia and duration of treatment.Study designRetrospective analysis of HCT recipients undergoing serial CMV PCR testing between June 2011 and June 2014 was performed.Results221 HCT recipients underwent preemptive therapy for 305 episodes of CMV viremia. Median time to resolution was shorter when treatment was initiated at lower CMV levels (15 days at 135–440 international units (IU)/mL, 18 days at 441–1000 IU/mL, and 21 days at >1000 IU/mL, P < .001). Prolonged viremia lasting >30 days occurred less frequently when treatment was initiated at 135–440 IU/mL compared to 441–1000 IU/mL and >1000 IU/mL (1%, 15%, 24%, P < .001). Median treatment duration was also shorter in the lower viral load groups (28, 34, 37 days, P < .001).ConclusionInitiation of preemptive therapy at low CMV levels was associated with shorter episodes of viremia and courses of antiviral therapy. These data support the utility of initiating preemptive CMV therapy at viral loads as low as 135 IU/mL in HCT recipients.  相似文献   

19.
BackgroundHIV Ag/Ab combination assays are recommended by CDC for routine screening and several HIV Ag/Ab combination tests are now FDA-approved. Maintaining high specificity and consistent sensitivity across diverse HIV strains is critical for these assays to accurately detect HIV infection and expedite delivery of patient results.ObjectivesTo evaluate performance of three FDA-approved HIV tests: ARCHITECT HIV Combo (Abbott), ADVIA Centaur HIV Combo (Siemens) and BioPlex HIV Ag-Ab (Bio-Rad).Study designSensitivity and specificity were evaluated using an extensive panel of 28 HIV infected human specimens and 17 cultured virus isolates representing multiple genotypes, 6 seroconversion panels, 4 human samples with acute infection, WHO p24 standard and 4020 clinical specimens.ResultsThe p24 limit of detection (LOD) for the WHO standard was 0.19 IU/ml, 0.70 IU/ml, and 1.77 IU/ml in BioPlex, ARCHITECT, and Centaur respectively. The distribution of LODs across 15 HIV-1 isolates was substantially narrower in ARCHITECT (5–33 pg/ml) than in BioPlex (11–198 pg/ml) and Centaur (6–384 pg/ml). All assays detected antibodies to the majority of HIV-1 and HIV-2 variants. However, reduced sensitivity was observed for Centaur in detection of antibodies to HIV-1 group M (CRF02_AG), O and N variants. BioPlex and ARCHITECT showed better seroconversion sensitivity than Centaur, detecting one bleed (3–7 days) earlier in 4 (BioPlex) and 3 (ARCHITECT) of 6 seroconversion panels. ARCHITECT demonstrated the highest specificity (99.90–100%) compared to BioPlex (99.80%) and Centaur (99.42%).ConclusionsThe overall performance of ARCHITECT and BioPlex was superior to Centaur, especially for detection of acute HIV infection.  相似文献   

20.
BackgroundLittle is known about the clinical implication of hepatitis B virus (HBV) infection in Epstein–Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC).ObjectiveThis study aimed to investigate the clinical characteristics and prognostic factors in patients with newly-diagnosed NPC with HBV infection.Study designA total of 722 patients with pathologically-diagnosed NPC who received comprehensive treatment at First People's Hospital of Foshan between June 2006 and December 2011 were enrolled in this retrospective study; 79 and 643 patients were HBsAg(+) and HBsAg(−), respectively. The correlations between HBV (HBsAg status and HBV DNA load) and EBV DNA were analyzed, further long-term survival and prognostic factors also were explored.ResultsWe reported NPC patients with HBsAg(+) represented worse outcome, and distant-failure especially liver metastasis was more common in these patients. HBV infection was more frequent in younger patients and male patients. No correlation was observed between the pre-treatment plasma EBV DNA load (cutoff, 1500 copies/ml) and HBsAg status (positive or negative; r = −0.036, P = 0.392), or the pre-treatment plasma EBV DNA load and HBV DNA load (r = 0.042, P = 0823).ConclusionsBoth HBV and EBV infection is an independent negative prognostic factor for long-term survival, distant metastasis, especially liver metastasis, was more common in NPC patients with HBsAg(+), and it seemed no link between EBV DNA load and HBsAg status in NPC.  相似文献   

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