Search

We evaluated the benefit of whole blood versus plasma to detect acute Zika virus infections. Comparison of Zika virus quantitative reverse transcription PCR results in single timepoint whole blood-plasma pairs from 227 patients with suspected Zika virus infection resulted in confirmation of 8 additional patients with Zika virus infection. [ABSTRACT FROM AUTHOR]

Objectives: We report a case of incomplete HIV-1 suppression on a dolutegravir, lamivudine, and abacavir single-tablet regimen with the emergence of the H51Y and G118R integrase resistance mutations., Methods: Integrase sequencing was performed retrospectively by Sanger and next-generation sequencing. Rates of emergence and decline of resistance mutations were calculated using next-generation sequencing data. Dolutegravir plasma concentrations were measured by ultra-performance liquid chromatography-tandem mass spectrometry. The effects of H51Y and G118R on infectivity, fitness, and susceptibility to dolutegravir were quantified using cell-based assays., Results: During periods of non-adherence to treatment, mutations were retrospectively documented only by next-generation sequencing. Misdiagnosis by Sanger sequencing was caused by the rapid decline of mutant strains within the retroviral population. This observation was also true for a M184V lamivudine-resistant reverse transcriptase mutation found in association with integrase mutations on single HIV genomes. Resistance rebound upon treatment re-initiation was swift (>8000 copies per day). Next-generation sequencing indicated cumulative adherence to treatment. Compared to WT HIV-1, relative infectivity was 73%, 38%, and 43%; relative fitness was 100%, 35%, and 10% for H51Y, G118R, and H51Y+G118R viruses, respectively. H51Y did not change the susceptibility to dolutegravir, but G188R and H51Y+G118R conferred 7- and 28-fold resistance, respectively., Conclusion: This case illustrates how poorly-fit drug-resistant viruses wax and wane alongside erratic treatment adherence and are easily misdiagnosed by Sanger sequencing. We recommend next-generation sequencing to improve the clinical management of incomplete virological suppression with dolutegravir., Competing Interests: Competing interests None declared, (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Hepatitis E viruses (HEV) are an underestimated global cause of enterically transmitted viral hepatitis, which may persist in immunocompromised hosts, posing a risk for progressive liver fibrosis with limited treatment options. We previously established liver-humanized mice as a model for chronic HEV infections, which can be cleared by a 2-week pegylated (peg)-Interferon(IFN)α treatment course. However, severe side effects may hamper the use of IFNα in immunocompromised transplant recipient patients. IFNλ may be a valuable alternative, as its receptor is less ubiquitously expressed., Aims: In this study, we assess the in vitro and in vivo potency of pegIFNλ to induce innate immune signalling in liver cells and to clear a persistent HEV infection in liver-humanized mice., Methods & Results: We found that human liver cells expressed the IFNλ receptor (IFNLR1) and are responsive to pegIFNλ. Treatment with pegIFNλ of liver-humanized mice persistently infected with HEV genotype 3 showed that pegIFNλ was well tolerated. Dose escalation studies showed that although HEV was not cleared at pegIFNλ doses up to 0.12 mg/kg for a maximum of 8 weeks, a dose of 0.3 mg/kg pegIFNλ treatment resulted in complete clearance of HEV antigen and HEV RNA from the liver in 8 out of 9 liver-humanized mice., Conclusions: PegIFNλ is well tolerated in mice and leads to clearance of a persistent HEV infection in liver-humanized mice., (© 2021 The Authors. Liver International published by John Wiley & Sons Ltd.)

Background & Aims: Hepatitis D virus infection (HDV) is considered the most severe form of viral hepatitis. In this study, we aimed to evaluate the prevalence of HDV infection in a tertiary center of a large, multi-ethnic city in the Netherlands. Moreover, we validate the reliability of a novel anti-HDV CLIA assay., Methods: All HBsAg-positive patients visiting the outpatient clinic between 2017 and 2019 were tested for HDV serology. Seropositive serum samples were further assessed by HDV RNA PCR and Sanger sequencing to identify the HDV genotype., Results: The CLIA assay was 100% sensitive and 98% specific. Out of 925 patients 3.7% tested seropositive for HDV, and HDV viremia was confirmed in 2.0%. The majority of patients had a non-Dutch background and did not speak English or Dutch. We detected HDV genotype 5 (N = 3), and genotype 1 (N = 15). Phylogenetic analysis demonstrated HDV1 clusters composed of sub-Saharan Africa isolates, central Asian, Turkish, Iranian and European isolates., Conclusions: The prevalence of HDV infection in a tertiary center in the Netherlands was 2.0% among HBsAg-positive individuals, and mainly in non-Dutch individuals. Only HDV genotype 1 and 5 isolates were detected, which was found to match with the patient's country of origin., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Humanized liver mouse models are crucial tools in liver research, specifically in the fields of liver cell biology, viral hepatitis and drug metabolism. The livers of these humanized mouse models are repopulated by 3-dimensional islands of fully functional primary human hepatocytes (PHH), which are notoriously difficult to maintain in vitro. As low efficiency and high cost hamper widespread use, optimization is of great importance. In the present study, we analyzed experimental factors associated with Hepatitis E virus (HEV) infection and PHH engraftment in 2 xenograft systems on a Nod-SCID-IL2Ry -/- background: the alb- urokinase plasminogen activator mouse model (uPA-NOG, n=399); and the alb- HSV thymidine kinase model (TK-NOG, n = 198). In a first analysis, HEV fecal shedding in liver humanized uPA-NOG and TK-NOG mice with comparable human albumin levels was found to be similar irrespective of the mouse genetic background. In a second analysis, sex, mouse age at transplantation and hepatocyte donor were the most determinant factors for xenograft success in both models. The sexual imbalance for xenograft success was related to higher baseline ALT levels and lower thresholds for ganciclovir induced liver morbidity and mortality in males. These data call for sexual standardization of human hepatocyte xenograft models, but also provide a platform for further studies on mechanisms behind sexual dimorphism in liver diseases.

Background: Previous studies on the association between cytomegalovirus (CMV) infection and cardiac allograft vasculopathy (CAV) were conducted on patients transplanted in the prevalganciclovir prophylaxis era. The aim of our study is to evaluate this relation in heart transplantation (HTx) recipients treated according to current prophylactic and immunosuppressive regimens., Methods: This single-center retrospective study included all consecutive adult patients that underwent HTx between January 1, 2000, and May 31, 2018. Clinically relevant CMV infection was defined as either plasma CMV DNAemia ≥ 1000 IU/mL with/without clinical symptoms or <1000 IU/mL with symptoms. The primary endpoint was first manifestation of CAV diagnosed by coronary angiography. For statistical analysis, the cause-specific hazard regression model was applied, with clinically relevant CMV infection and any CMV infection as time-dependent variables., Results: In total, 260 patients were included in the analysis. The median (interquartile range) follow-up was 7.88 (4.21-12.04) years. During the follow-up, clinically relevant CMV infection was diagnosed in 96 (37%) patients and CAV in 149 (57%) patients. In the multivariate regression analysis, independent predictors of CAV were: number of rejection episodes (cause-specific hazard ratio [95% confidence interval]: 1.18 [1.04-1.34], P = 0.01), hypertension (1.61 [1.11-2.34], P = 0.01), treatment with mycophenolate mofetil (0.68 [0.47-0.97], P = 0.03). No significant association was observed between CMV infection and CAV, except for patients who experienced a breakthrough CMV infection (n = 24) during prophylaxis (1.94 [1.11-3.40], P = 0.02)., Conclusions: In the era of contemporary immunosuppression and valganciclovir prophylaxis, a significant effect of CMV infection on the risk of CAV was seen only among HTx recipients with CMV breakthrough infection.

Background: Respiratory tract infections are among the most common infections during winter season. Rapid diagnostics is required for clinical decision making regarding isolation of patients and appropriate therapy., Objectives: The aim of this study was to evaluate the analytical and clinical performance characteristics of the Panther Fusion® respiratory panel using published laboratory-developed real-time PCR assays (LDT)., Study Design: Analytical sensitivity of Panther Fusion® Flu A/B/RSV was assessed by testing dilutions of cell culture isolates. Clinical performance assessment included the complete Panther Fusion® respiratory panel (Flu-A/B/RSV, PIV 1-4 and AdV/hMPV/RV) and consisted of a retrospective and a prospective study-arm. The retrospective evaluation included 201, stored (-80 °C) samples collected between February 2006 and January 2017. Prospective evaluation was performed on 1045 unselected pretreated respiratory tract samples from patients presented to our hospital between November 2017 and May 2018., Results: Analytical sensitivity was generally slightly lower for the Panther Fusion® assays. Clinical specificity and sensitivity was between 96 %-100 % and 71.9 %-100 %, respectively. Discrepant results were found in 146 samples of which 88 samples tested LDT positive / Panther Fusion® negative and 58 samples were LDT negative / Panther Fusion® positive. A total of ten discrepant samples with Ct-values <30 were sequenced to confirm the presence of 7 RV-C not-detected by LDT and 1 RV-A and 2 ADV-2 not detected by Panther Fusion®., Conclusions: The Panther Fusion® provides a random-access system with continuous loading and much shorter sample-to-answer times compared to LDT, albeit with a slightly less clinical sensitivity compared to the LDT., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Hepatitis E Virus (HEV) mutations following ribavirin treatment have been associated with treatment non-response and viral persistence, but spontaneous occurring genomic variations have been less well characterized. We here set out to study the HEV genome composition in 2 patient sample types and 2 infection models. Near full HEV genome Sanger sequences of serum- and feces-derived HEV from two chronic HEV genotype 3 (gt3) patients were obtained. In addition, viruses were sequenced after in vitro or in vivo expansion on A549 cells or a humanized mouse model, respectively. We show that HEV acquired 19 nucleotide mutations, of which 7 nonsynonymous amino acids changes located in Open Reading Frame 1 (ORF1), ORF2, and ORF3 coding regions, after prolonged in vitro culture. In vivo passage resulted in selection of 8 nucleotide mutations with 2 altered amino acids in the X domain and Poly-proline region of ORF1. Intra-patient comparison of feces- and serum-derived HEV gt3 of two patients showed 7 and 2 nucleotide mutations with 2 and 0 amino acid changes, respectively. Overall, the number of genomic alterations was up to 1.25× per 1000 nucleotides or amino acids in in vivo samples, and up to 2.84× after in vitro expansion of the same clinical HEV strain. In vitro replication of a clinical HEV strain is therefore associated with more mutations, compared to the minor HEV genomic alterations seen after passage of the same strain in an immune deficient humanized mouse; as well as in feces and blood of 2 immunosuppressed chronically infected HEV patients. These data suggest that HEV infected humanized mice more closely reflect the HEV biology seen in solid organ transplant recipients.

Background: Clinical signs and symptoms of different airway pathogens are generally indistinguishable, making laboratory tests essential for clinical decisions regarding isolation and antiviral therapy. Immunochromatographic tests (ICT) and direct immunofluorescence assays (DFA) have lower sensitivities and specificities than molecular assays, but have the advantage of quick turnaround times and ease-of-use., Objective: To evaluate the performance of a rapid molecular assay, ARIES FluA/B & RSV, using laboratory developed RT-PCR assays (LDA), ICT (BinaxNOW) and DFA., Methods: Analytical and clinical performance were evaluated in a retrospective study arm (stored respiratory samples obtained between 2006-2015) and a prospective study arm (unselected fresh clinical samples obtained between December 2015 and March 2016 tested in parallel with LDAs)., Results: Genotype inclusivity and analytical specificity was 100%. However, ARIES was 0.5 log, 1-2logs and 2.5logs less sensitive for fluA, RSV and fluB respectively, compared to LDA. In total, 447 clinical samples were included, of which 15.4% tested positive for fluA, 9.2% for fluB and 26.0% for RSV, in both LDA and ARIES. ARIES clinical sensitivity compared to LDA was 98.6% (fluA), 93.3% (fluB) and 95.1% (RSV). Clinical specificity was 100% for all targets. ARIES detected 10.6% (4 fluA, 8 fluB, 11 RSV) and 26.9% (7 fluA, 3 fluB, 22 RSV) more samples compared to DFA and ICT, all confirmed by LDA., Conclusion: Although analytically ARIES is less sensitive than LDA, the clinical performance of the assay in our tertiary care setting was comparable, and significantly better than that of the established rapid assays., (Copyright © 2016 Elsevier B.V. All rights reserved.)