1 / 9

International Units vs. NAT-Detectable Units

XX. SoGAT Meeting Warsaw 12./13. June 2007 IU vs. NAT-Detectable Units Albrecht Gröner CSL Behring Virology Marburg, Germany. International Units vs. NAT-Detectable Units. International Units inter-laboratory comparison of results (e.g., virus load in samples)

orli-lowery
Download Presentation

International Units vs. NAT-Detectable Units

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. XX. SoGAT MeetingWarsaw 12./13. June 2007IU vs. NAT-Detectable UnitsAlbrecht GrönerCSL BehringVirologyMarburg, Germany

  2. International Units vs. NAT-Detectable Units • International Units • inter-laboratory comparison of results (e.g., virus load in samples) • release of pools for fractionation (e.g., OMCLs) • NAT-detectable units (genome equivalent (GE)) • detection of virus genomes in samples • intra-laboratory comparison of results (if assay performance is very stable) 2 – Gröner 13. June 2007

  3. Conversion Factor IU  GE • Necessity to define conversion factor • quantification of virus particles in sample defined by NAT in order to assess risk for virus transmission • CPMP/BWP/5180/03 (Guideline on assessing the risk for virus transmission – new chapter 6 of the note for guidance on plasma-derived medicinal products (CPMP/BWP/269/95)) requests a quantitative estimation of the probability of a virus contaminant being present in a defined dose of final product taking into account - as a conservative approach - viral genomes as an indicator of potentially infectious virus particles in the starting material 3 – Gröner 13. June 2007

  4. Fig 1a: 97/656 International Standard 14 13 12 NIBSC - 2002 11 10 HIV 9 8 7 27 UCM 6 60 64 N M 5 17 22 04 N TMA M 4 67 17 63 M* IH M 3 30 09 61 CAS CM M 2 59 14 58 56 48 N IH B3 B3 M 1 12 19 54 45 65 05 57 CM IH CAS IH AL AS CM 0 neg 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Ecstimated RNA Copies or PCR Detectable Units (log10/ml) Detection of Virus Genome in Sample 4 – Gröner 13. June 2007

  5. Fig 1h: RU570 Subtype H (S02) 14 13 12 11 NIBSC - 2002 10 HIV 9 8 7 6 5 61 M 4 30 27 56 CAS UCM M 3 64 58 60 09 63 N B3 M CM M* 2 48 17 14 22 05 17 N TMA B3 M CM M 1 04 12 67 54 65 45 59 19 57 N IH IH IH AS AL IH CAS CM 0 neg 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Estimated RNA Copies or PCR Detectable Units (log10/ml) Monitor assays Nuclisens bDNA 3 Abbott LCx In-House Ampliscreen TMA Detection of Virus Genome in Sample 5 – Gröner 13. June 2007

  6. Detection of Virus Genome in Sample HIV NIBSC - 2002 6 – Gröner 13. June 2007

  7. Detection of Virus Genome in Sample HAV International Standard Saldanha et al. Vox Sang 2005;89:52-58 7 – Gröner 13. June 2007

  8. Detection of Virus Genome in Sample HCV International Standard Saldanha et al. Vox Sang 1999;76:149-158 8 – Gröner 13. June 2007

  9. Conversion Factor IU  GE • Is a general conversion factor necessary (and justifiable)? • Conversion factor can only be determined for each laboratory employing a validated assay • A generic conversion factor for IUs to GE is not appropriate due to differences in analytical sensitivity of assays in different laboratories • Quantitative infectivity of viruses (inf. units) vs. NAT detectable units unknown Relevance of Conversion Factor? 9 – Gröner 13. June 2007

More Related