title: A second-generation ELISA (STRATIFY JCV™ DxSelect™) for detection of JC virus antibodies in human serum and plasma to support progressive multifocal leukoencephalopathy risk stratification.
abstract: BACKGROUND
  JC virus (JCV) infection is a prerequisite for development of progressive multifocal leukoencephalopathy (PML). The development and validation of a two-step enzyme-linked immunosorbent assay (ELISA) that detects JCV antibodies in human serum or plasma and its clinical utility for stratification of PML risk have been described.
  
  
  OBJECTIVE
  To develop a second-generation JCV antibody ELISA kit with improved assay performance characteristics.
  
  
  METHODS
  The assay design was optimized by pre-coating the JC virus-like particles (VLP) on microtiter plates. Assay cut-points were statistically established using sera from >1300 multiple sclerosis patients from natalizumab clinical studies. The assay was analytically validated and then used to determine the presence of JCV antibodies in both treatment-naïve and natalizumab-treated MS patients, as well as in natalizumab-treated PML patients.
  
  
  RESULTS
  An improved assay for detection of JCV antibodies in human serum and plasma was developed. Key enhancements included improved delineation and reproducibility of low JCV antibody responses and assay ease of use. The assay was validated, demonstrating good agreement with the original two-step JCV antibody ELISA, and similar seroprevalence of 50%-60%. Samples from 63 natalizumab-treated PML patients collected 6-180 months prior to PML diagnosis tested JCV antibody positive. One patient tested JCV antibody negative 15 months prior to PML diagnosis but JCV antibody positive 2 months prior to PML diagnosis.
  
  
  CONCLUSIONS
  The validated second-generation JCV antibody ELISA offers improved assay design as a kit and enhanced performance characteristics that advance routine clinical use of the assay as a PML risk stratification tool.
authors: Focus Diagnostics, Cypress, CA, USA. plee@focusdx.com
authors: Peter
authors: P
authors: Lee
authors: Tatiana
authors: T
authors: Plavina
authors: Albert
authors: A
authors: Castro
authors: Melissa
authors: M
authors: Berman
authors: Dipeshkumar
authors: D
authors: Jaiswal
authors: Suzanne
authors: S
authors: Rivas
authors: Brian
authors: B
authors: Schlain
authors: Meena
authors: M
authors: Subramanyam
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D007577:JC Virus / Q000276:immunology*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology / Q000821:virology; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications / Q000188:drug therapy / Q000276:immunology / Q000821:virology; D000069442:Natalizumab; D015203:Reproducibility of Results; D012307:Risk Factors
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000914:Antibodies, Viral; D000069442:Natalizumab