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Performance evaluation of the Beckman Coulter DxN VERIS Hepatitis C Assay on the DxN VERIS MDx system
Abstracts / Journal of Clinical Virology 70 (2015) S1–S126
results among the different sites makes VERIS MDx CMV assay a helpful and reliable tool for CMV DNA viral load determination. http://dx.doi.org/10.1016/j.jcv.2015.07.201 Abstract No: 1541 Presentation at ESCV 2015: Poster 2 Performance evaluation of the Beckman Coulter DxN VERIS Hepatitis C Assay on the DxN VERIS MDx system Christenson 1 ,
Lofaro 2 ,
L. R. Chamberlin 2 , P. Conroy 3
T.
Roddy 2 ,
J.
1 University of Maryland Medical Center, United States 2 Beckman Coulter, Inc., United States 3 Quest Diagnostics, United States
Background: Hepatitis C virus (HCV) infection is a major public health problem with an estimated 160 million people chronically infected worldwide. The goal of HCV treatment is to cure infection. Real-time polymerase chain reaction (PCR) assays offer the ability to measure HCV viral load as an aid in the management of individuals undergoing anti-viral treatment. The DxN VERIS Hepatitis C (HCV) Assay (Investigational Use Only) is a quantitative molecular assay for the detection of human HCV designed for use on the DxN VERIS MDx System. The system is a fully automated, nucleic acid real- time PCR system that integrates sample introduction, nucleic acid extraction, reaction set- up, real-time PCR amplification and detection, and results interpretation. Objective: Evaluate the performance of the DxN VERIS HCV Assay on the automated DxN VERIS MDx System including reproducibility, specificity, and comparison to the Roche COBAS® AmpliPrep/COBAS® TaqMan® HCV Test (CE Marked). Methods The DxN VERIS HCV Assay reports HCV in International Units (IU)/mL calibrated to the 4th HCV WHO International Standard (NIBSC 06/102). The assay uses 1.0 mL of plasma sample for each determination. IU/mL values were converted to log IU/mL for analyses done using SAS v.9.3 software. Reproducibility was performed using 2 lots of reagent on three DxN VERIS MDx systems (3 sites) over 5 days for each reagent lot. Seven panel members spanning the measuring range of the assay (12 to 1 × 108 IU/mL), along with three commercial quality control samples, were tested. Clinical specificity was determined by testing 366 HCV IgG antibody and RNA negative plasma samples on two DxN VERIS MDx systems. Method: Comparison was evaluated by testing paired plasma samples on the DxN VERIS HCV Assay and the Roche COBAS® AmpliPrep/COBAS® TaqMan® HCV Test (CE Marked) at two sites (two DxN VERIS MDx systems) per assay. Results The total imprecision of DxN VERIS HCV Assay was between 2.5% and 12.6% coefficient of variation (CV) across the assay measuring range in log IU/mL. The DxN VERIS HCV Assay correctly read negative samples as not detected with a point estimate of 100% specificity and lower bound of the 95% confidence interval of 99.0%. The DxN VERIS HCV Assay had comparable recoveries to the Roche assay with a Passing-Bablok regression equation of VERIS = −0.31 + 1.11(Roche), r = 0.98, with n = 151. Conclusion: The DxN VERIS HCV Assay on the DxN VERIS MDx System is a fully automated quantitative molecular assay that showed acceptable results on standard measures of assay performance. http://dx.doi.org/10.1016/j.jcv.2015.07.202
S87
Abstract No: 1543 Presentation at ESCV 2015: Poster 2 Detection of human polyomaviruses JC and BK in brain tissues from patients with progressive multifocal leukoencephalopathy using in situ hybridization and polymerase chain reaction Fujs Komlo Kristina 1 , M. Popovic 2 , J.B. Kocjan 1 , M. Zivanovic 3 , K. Seme 1 , M. Poljak 1 1
Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia 2 Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia 3 General Hospital Dr Franc Derganc Nova Gorica, Sempeter pri Gorici, Slovenia Background: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease, caused by polyomavirus JC (JCV) that affects a proportion of immunosuppressed patients, including those with HIV/AIDS, lymphoproliferative disorders and patients on immunosuppressive therapy. Histopathological examination of brain biopsies and/or detection of JCV DNA in CSF are used to back clinical diagnosis and magnetic resonance imaging findings that are consistent with PML. Final confirmation is made by detection of JCV in brain biopsy or autopsy tissue using immunohistochemistry and molecular methods, usually in situ hybridization (ISH) and PCR. Methods: Seven archival formalin-fixed, paraffin-embedded brain tissue specimens (3 biopsies and 4 autopsies), collected from seven Slovene patients (2 females and 5 males) with pathohistologically diagnosed PML between 1992 and 2014 were included in the study. As baseline disease, three of the enrolled patients had lymphoma, two patients had HIV/AIDS, one patient had leukemia and one patient was a renal-transplant recipient. The presence of JCV and BKV was evaluated by ISH using a commercially available probes specific for JCV and BKV (Enzo, JCV and BKV BioProbe® ; Labeled Probe), and by multiplex real-time PCR test TIBMOLBIOL LightMix® ; Kit for the detection of Polyomaviruses JC and BK, which enables simultaneous detection and discrimination of JCV and BKV DNA. Results: The presence of JCV DNA was detected in all seven PML cases by ISH. Interestingly, JCV DNA was found only in 6/7 PML cases by PCR. Even though BKV DNA was detected in 4/7 (57.1%) PML cases using ISH, commercial PCR was negative for the presence of BKV DNA in all seven samples. Additionally, BKV DNA was absent in all seven samples after using BKV type-specific in-house real-time PCR. Conclusion: Simultaneous presence of JCV and BKV in brain tissues of patients with PML has been occasionally described previously. The detection of BKV in 4/7 brain tissue samples by ISH only, indicates false-positive ISH result due to non-specific BKV probe hybridization. http://dx.doi.org/10.1016/j.jcv.2015.07.203
results among the different sites makes VERIS MDx CMV assay a helpful and reliable tool for CMV DNA viral load determination. http://dx.doi.org/10.1016/j.jcv.2015.07.201 Abstract No: 1541 Presentation at ESCV 2015: Poster 2 Performance evaluation of the Beckman Coulter DxN VERIS Hepatitis C Assay on the DxN VERIS MDx system Christenson 1 ,
Lofaro 2 ,
L. R. Chamberlin 2 , P. Conroy 3
T.
Roddy 2 ,
J.
1 University of Maryland Medical Center, United States 2 Beckman Coulter, Inc., United States 3 Quest Diagnostics, United States
Background: Hepatitis C virus (HCV) infection is a major public health problem with an estimated 160 million people chronically infected worldwide. The goal of HCV treatment is to cure infection. Real-time polymerase chain reaction (PCR) assays offer the ability to measure HCV viral load as an aid in the management of individuals undergoing anti-viral treatment. The DxN VERIS Hepatitis C (HCV) Assay (Investigational Use Only) is a quantitative molecular assay for the detection of human HCV designed for use on the DxN VERIS MDx System. The system is a fully automated, nucleic acid real- time PCR system that integrates sample introduction, nucleic acid extraction, reaction set- up, real-time PCR amplification and detection, and results interpretation. Objective: Evaluate the performance of the DxN VERIS HCV Assay on the automated DxN VERIS MDx System including reproducibility, specificity, and comparison to the Roche COBAS® AmpliPrep/COBAS® TaqMan® HCV Test (CE Marked). Methods The DxN VERIS HCV Assay reports HCV in International Units (IU)/mL calibrated to the 4th HCV WHO International Standard (NIBSC 06/102). The assay uses 1.0 mL of plasma sample for each determination. IU/mL values were converted to log IU/mL for analyses done using SAS v.9.3 software. Reproducibility was performed using 2 lots of reagent on three DxN VERIS MDx systems (3 sites) over 5 days for each reagent lot. Seven panel members spanning the measuring range of the assay (12 to 1 × 108 IU/mL), along with three commercial quality control samples, were tested. Clinical specificity was determined by testing 366 HCV IgG antibody and RNA negative plasma samples on two DxN VERIS MDx systems. Method: Comparison was evaluated by testing paired plasma samples on the DxN VERIS HCV Assay and the Roche COBAS® AmpliPrep/COBAS® TaqMan® HCV Test (CE Marked) at two sites (two DxN VERIS MDx systems) per assay. Results The total imprecision of DxN VERIS HCV Assay was between 2.5% and 12.6% coefficient of variation (CV) across the assay measuring range in log IU/mL. The DxN VERIS HCV Assay correctly read negative samples as not detected with a point estimate of 100% specificity and lower bound of the 95% confidence interval of 99.0%. The DxN VERIS HCV Assay had comparable recoveries to the Roche assay with a Passing-Bablok regression equation of VERIS = −0.31 + 1.11(Roche), r = 0.98, with n = 151. Conclusion: The DxN VERIS HCV Assay on the DxN VERIS MDx System is a fully automated quantitative molecular assay that showed acceptable results on standard measures of assay performance. http://dx.doi.org/10.1016/j.jcv.2015.07.202
S87
Abstract No: 1543 Presentation at ESCV 2015: Poster 2 Detection of human polyomaviruses JC and BK in brain tissues from patients with progressive multifocal leukoencephalopathy using in situ hybridization and polymerase chain reaction Fujs Komlo Kristina 1 , M. Popovic 2 , J.B. Kocjan 1 , M. Zivanovic 3 , K. Seme 1 , M. Poljak 1 1
Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia 2 Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia 3 General Hospital Dr Franc Derganc Nova Gorica, Sempeter pri Gorici, Slovenia Background: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease, caused by polyomavirus JC (JCV) that affects a proportion of immunosuppressed patients, including those with HIV/AIDS, lymphoproliferative disorders and patients on immunosuppressive therapy. Histopathological examination of brain biopsies and/or detection of JCV DNA in CSF are used to back clinical diagnosis and magnetic resonance imaging findings that are consistent with PML. Final confirmation is made by detection of JCV in brain biopsy or autopsy tissue using immunohistochemistry and molecular methods, usually in situ hybridization (ISH) and PCR. Methods: Seven archival formalin-fixed, paraffin-embedded brain tissue specimens (3 biopsies and 4 autopsies), collected from seven Slovene patients (2 females and 5 males) with pathohistologically diagnosed PML between 1992 and 2014 were included in the study. As baseline disease, three of the enrolled patients had lymphoma, two patients had HIV/AIDS, one patient had leukemia and one patient was a renal-transplant recipient. The presence of JCV and BKV was evaluated by ISH using a commercially available probes specific for JCV and BKV (Enzo, JCV and BKV BioProbe® ; Labeled Probe), and by multiplex real-time PCR test TIBMOLBIOL LightMix® ; Kit for the detection of Polyomaviruses JC and BK, which enables simultaneous detection and discrimination of JCV and BKV DNA. Results: The presence of JCV DNA was detected in all seven PML cases by ISH. Interestingly, JCV DNA was found only in 6/7 PML cases by PCR. Even though BKV DNA was detected in 4/7 (57.1%) PML cases using ISH, commercial PCR was negative for the presence of BKV DNA in all seven samples. Additionally, BKV DNA was absent in all seven samples after using BKV type-specific in-house real-time PCR. Conclusion: Simultaneous presence of JCV and BKV in brain tissues of patients with PML has been occasionally described previously. The detection of BKV in 4/7 brain tissue samples by ISH only, indicates false-positive ISH result due to non-specific BKV probe hybridization. http://dx.doi.org/10.1016/j.jcv.2015.07.203