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Mannonen L, Jokela P, Kragh Thomsen M, Yerly S, Cilla G, Jarem D, Canchola JA, Hopkins M. Performance of the cobas EBV and cobas BKV assays: multi-site comparison of standardized quantitation. J Clin Microbiol 2024:e0026724. [PMID: 39046255 DOI: 10.1128/jcm.00267-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 06/21/2024] [Indexed: 07/25/2024] Open
Abstract
Guidelines recommend monitoring of Epstein-Barr virus (EBV) and BK virus (BKV) in solid organ and hematopoietic stem cell transplant patients. The majority of quantitative DNA testing for EBV and BKV employs unstandardized individual laboratory-developed testing solutions (LDTs), with implications for accuracy, reproducibility, and comparability between laboratories. The performance of the cobas EBV and cobas BKV assays was assessed across five laboratories, using the World Health Organization International Standards (WHO IS) for EBV and BKV, and the National Institute of Standards and Technology Quantitative Standard for BKV, and results were compared with the LDTs in use at the time. Methods were also compared using locally sourced clinical specimens. Variation was high when laboratories reported EBV or BKV DNA values using LDTs, where quantitative values were observed to differ by up to 1.5 log10 unit/mL between sites. Conversely, results from the cobas EBV and cobas BKV assays were accurate and reproducible across sites and on different testing days. Adjustment of LDTs using the international standards led to closer alignment between the assays; however, day-to-day reproducibility of LDTs remained high. In addition, BKV continued to show bias, indicating challenges with the commutability of the BKV International Standard. The cobas EBV and cobas BKV assays are automated, aligned to the WHO IS, and have the potential to reduce the variability in viral load testing introduced by differences in LDTs. Standardization of reporting values may eventually allow different centers to compare data to allow clinical decision thresholds to be established supporting improvements in patient management.IMPORTANCEThe application of center-specific cut-offs for clinical decisions and the variability of LDTs often hinder interpretation; thus, the findings reported here support the need for standardization in the field of post-transplant monitoring of EBV and BKV to improve patient management. Alongside the choice of assay, it is also important to consider which standard to use when deciding upon a testing methodology. This is a call to action for standardization, as treatment for EBV and BKV is driven by viral load test results, and the more accurate and comparable the test results are across institutions, the more informed and better the treatment decisions can be.
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Affiliation(s)
- Laura Mannonen
- Department of Clinical Microbiology, HUS Diagnostic Center, HUSLAB, Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Pia Jokela
- Department of Clinical Microbiology, HUS Diagnostic Center, HUSLAB, Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | | | - Sabine Yerly
- Laboratory of Virology, Diagnostic Department, Geneva University Hospitals, Geneva, Switzerland
| | - Gustavo Cilla
- Department of Microbiology, Donostia University Hospital and Biodonostia Health Research Institute, San Sebastián, Spain
| | - Daniel Jarem
- Clinical Development and Medical Affairs, Roche Molecular Systems, Inc., Pleasanton, California, USA
| | - Jesse A Canchola
- CDMA Biometrics, Biostatistics Group, Roche Molecular Systems, Inc., Pleasanton, California, USA
| | - Mark Hopkins
- Department of Virology, Barts Health NHS Trust, London, United Kingdom
- Department of Infection and Immunity, Liverpool University Hospitals NHS Trust, Liverpool, United Kingdom
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Lowe CF, Lawson T, Young M, Jang W, Ritchie G, Romney MG, Matic N. Stability of BK polyomavirus DNA in urine over time and analytical evaluation of an automated BKV quantitative nucleic acid test. J Med Microbiol 2024; 73. [PMID: 38265290 DOI: 10.1099/jmm.0.001789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024] Open
Abstract
Introduction. BK polyomavirus (BKPyV) quantitative testing is an important screening tool post-transplantation, although interpretation can be challenging due to lack of standardization, assay heterogeneity and variability of BKPyV DNA over time (in urine).Methods. Remnant clinical EDTA plasma and urine samples were tested by the cobas BKV test and a validated laboratory-developed test (LDT). Accuracy [positive and negative percent agreement (PPA and NPA), Pearson's correlation, Bland-Altman analysis] and reproducibility were evaluated. To assess BKPyV DNA stability in urine, prospective urine samples were maintained at two different storage temperatures and tested in triplicate over 7 days.Results. Overall PPA was 95.6 % (43/45) and NPA was 94.4 % (170/180). For plasma, Pearson's correlation (0.950) and Bland-Altman analysis (0.113±0.22 log10 IU ml-1) showed high agreement. For neat urine, Pearson's correlation (0.842) and Bland-Altman analysis (0.326±0.80 log10 IU ml-1) showed somewhat higher variability. Reproducibility was high for the cobas BKV versus the LDT. BKPyV DNA levels in neat urine remained relatively stable over 7 days at both storage temperatures, although outlier results were intermittently detected.Conclusion. The cobas BKV test showed high agreement and reproducibility compared to the reference LDT. BKPyV viral load testing in urine has known limitations, but neat urine can be processed by the cobas BKV.
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Affiliation(s)
- Christopher F Lowe
- Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada
| | - Tanya Lawson
- Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
| | - Matthew Young
- Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
| | - Willson Jang
- Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
| | - Gordon Ritchie
- Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada
| | - Marc G Romney
- Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada
| | - Nancy Matic
- Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada
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Massey J, Artuz C, Dyer Z, Jackson K, Khoo M, Visweswaran M, Withers B, Moore J, Ma D, Sutton I. Diversification and expansion of the EBV-reactive cytotoxic T lymphocyte repertoire following autologous haematopoietic stem cell transplant for multiple sclerosis. Clin Immunol 2023; 254:109709. [PMID: 37495004 DOI: 10.1016/j.clim.2023.109709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/07/2023] [Accepted: 07/23/2023] [Indexed: 07/28/2023]
Abstract
Both genetic susceptibility and environmental exposures are thought to be involved in multiple sclerosis (MS) pathogenesis. Of all viruses potentially relevant to MS aetiology, Epstein-Barr virus (EBV) is the best-studied. EBV is a B cell lymphotropic virus which is able to evade the immune system by establishing latent infection in memory B cells, and EBV reactivation is restricted by CD8 cytotoxic T cell (CTL) responses in immune competent individuals. Autologous haematopoietic stem cell transplantation (AHSCT) is considered to be the most effective therapy in the treatment of relapsing MS even though chemotherapy-induced lymphopenia can associate with the re-emergence of latent viruses. Despite the increasing interest in EBV and MS pathogenesis the relationship between AHSCT, EBV and viral immunity in people with MS has not been investigated to date. This study analysed immune responses to EBV in a well characterised cohort of 13 individuals with MS by utilising pre-AHSCT, and 6-, 12- and 24-month post AHSCT bio-banked peripheral blood mononuclear cells and plasma samples. It is demonstrated that the infused stem cell product contains latently EBV-infected memory B cells, and that EBV viremia occurs in the immune-compromised recipient post-transplant. High throughput TCR analysis detected expansion and diversification of the CD8 CTL responses reactive with EBV lytic and latent antigens from 6 to 24 months following AHSCT. Increased levels of latent EBV infection found within the B cell pool following treatment, as measured by EBV genomic detection, did not associate with disease relapse. This is the first study of EBV immunity following application of AHSCT in the treatment of MS and not only raises important questions about the role of EBV infection in MS pathogenesis, but is of clinical importance given the expanding clinical trials of adoptive EBV-specific CTLs in MS.
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Affiliation(s)
- Jennifer Massey
- Department of Neurology, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia; Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia.
| | - Crisbel Artuz
- Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Zoe Dyer
- Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia
| | - Katherine Jackson
- Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
| | - Melissa Khoo
- Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Malini Visweswaran
- Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Barbara Withers
- Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia; Department of Haematology, St Vincent's Hospital; Darlinghurst, NSW 2010, Australia
| | - John Moore
- Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia; Department of Haematology, St Vincent's Hospital; Darlinghurst, NSW 2010, Australia
| | - David Ma
- Blood Stem Cell and Cancer Research Group, St Vincent's Centre for Applied Medical Research, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia; Department of Haematology, St Vincent's Hospital; Darlinghurst, NSW 2010, Australia
| | - Ian Sutton
- School of Clinical Medicine, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW, Sydney, Australia; Department of Neurology, St Vincent's Clinic; Darlinghurst, NSW 2010, Australia
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