title: Development of a BK virus real-time quantitative assay using the bioMérieux analyte-specific reagents in plasma specimens.
abstract: OBJECTIVE
  Viral load testing for BK virus (BKV) has become the standard of care for diagnosing BKV infection and monitoring therapy in kidney transplant patients. However, there are currently no US Food and Drug Administration-approved assays and no standardization among available tests.
  
  
  METHODS
  This study evaluated the performance of the analyte-specific reagent (ASR) BKV primers r-gene and probe r-gene reagents (bioMérieux, Marcy l'Étoile, France) soon to become available on the US market for accuracy, linearity, precision, analytical sensitivity, specificity, and correlation with the Qiagen (Germantown, MD) BKV ASR test using commercial material and patient plasma samples.
  
  
  RESULTS
  The assay was linear from 204 to 3.92 million (2.31-6.6 log10) DNA copies/mL (coefficient of determination: R(2) =0.999). A dilution series demonstrated limits of detection and quantitation of 2.14 log10 and 2.30 log10 copies/mL (95% hit rate detection), respectively. Interrun precision was highly reproducible, with coefficients of variance ranging from 2.2% to 6.0%. A comparison of 34 matched samples showed a good agreement (R(2) = 0.87) between the bioMérieux BKV laboratory test and the Qiagen BKV ASR assay results, with an average negative bias (-0.28 log10 copies/mL).
  
  
  CONCLUSIONS
  The laboratory-developed test with bioMérieux BKV reagents is a reliable and sensitive assay for BKV DNA quantitation compared with the Qiagen ASR test.
authors.affiliation: From the Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, and From the Department of Pathology and Laboratory Medicine, NewYork-Presbyterian Hospital, New York, NY. har2006@med.cornell.edu.
authors.forename: Hanna
authors.initials: H
authors.lastname: Rennert
authors.affiliation: From the Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, and From the Department of Pathology and Laboratory Medicine, NewYork-Presbyterian Hospital, New York, NY.
authors.forename: Helen
authors.initials: H
authors.lastname: Fernandes
authors.affiliation: From the Department of Pathology and Laboratory Medicine, NewYork-Presbyterian Hospital, New York, NY.
authors.forename: Zahid
authors.initials: Z
authors.lastname: Gilani
authors.affiliation: From the Department of Pathology and Laboratory Medicine, NewYork-Presbyterian Hospital, New York, NY.
authors.forename: John
authors.initials: J
authors.lastname: Sipley
mesh_terms: D001739:BK Virus; D004279:DNA, Viral / Q000097:blood*; D006801:Humans; D007202:Indicators and Reagents; D027601:Polyomavirus Infections / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014412:Tumor Virus Infections / Q000175:diagnosis
chemical_list: D004279:DNA, Viral; D007202:Indicators and Reagents
keywords: BK virus quantitation; Real-time PCR test; Renal nephropathy; Viral loads