title: Screening of blood donors for hepatitis C virus RNA with the MagNA Pure-COBAS AmpliScreen method.
abstract: BACKGROUND
  This report describes the validation results and the performance characteristics of a new, semiautomated minipool nucleic acid amplification method for testing of blood products to reduce the transmission of hepatitis C virus (HCV) by transfusions.
  
  
  METHODS
  Minipools of 96 donations were prepared with the Tecan Genesis pipettors. Nucleic acids were isolated from plasma samples with the MagNA Pure LC instrument (Roche Diagnostics GmbH) and amplified and detected with the COBAS AmpliScreen second-generation HCV assay (Roche Molecular Systems, Inc.). Sensitivity of the method was determined with the WHO International Standard for HCV RNA (NIBSC 96/790) as a reference. The risk of cross-contamination during the nucleic acid extraction and postelution steps was studied with a highly viremic sample.
  
  
  RESULTS
  Detection limit of the assay (95% hit rate) was calculated to be 11.7 IU per mL. Altogether 2,423 minipools (232,600 donations) were screened with the following performance characteristics: initially false-reactive results (0%), failure of run control detection (0.45%), and failure of internal control detection (0.90%). Two cross-contamination cases caused by a highly viremic sample were found during the validation phase but not in the routine screening period, although nine HCV RNA-positive minipool samples were observed.
  
  
  CONCLUSIONS
  This combination of HCV RNA screening methods showed the detection limit that is well below the sensitivity requirements of the regulatory bodies. Robustness of the validated HCV RNA screening method has proved to be acceptable for routine screening of blood donors on a large scale.
authors.affiliation: Finnish Red Cross Blood Service, Kivihaantie 7, FIN-00310 Helsinki, Finland. pekka.palomaki@bts.redcross.fi
authors.forename: Pekka
authors.initials: P
authors.lastname: Palomäki
authors.forename: Susanna
authors.initials: S
authors.lastname: Wessberg
authors.forename: Katri
authors.initials: K
authors.lastname: Tuomi
authors.forename: Harri
authors.initials: H
authors.lastname: Laitinen
mesh_terms: D001771:Blood Banks / Q000592:standards; D001782:Blood Donors; D005069:Evaluation Studies as Topic; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification*; D006526:Hepatitis C / Q000097:blood / Q000517:prevention & control*; D006801:Humans; D008403:Mass Screening / Q000379:methods* / Q000592:standards; D021141:Nucleic Acid Amplification Techniques / Q000379:methods* / Q000592:standards; D012367:RNA, Viral / Q000097:blood / Q000235:genetics / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000094902:Blood Banking / Q000379:methods
chemical_list: D012367:RNA, Viral