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1 st International Standard for HIV-1 RNA NIBSC Code 97/656. CBER, CLB and NIBSC collaborated in development of HIV-1 International Standard for NAT Three candidate standards evaluated in collaborative study
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1st International Standard for HIV-1 RNANIBSC Code 97/656 • CBER, CLB and NIBSC collaborated in development of HIV-1 International Standard for NAT • Three candidate standards evaluated in collaborative study • WHO Expert Committee (ECBS) established candidate YY as 1st International Standard for HIV-1 RNA (code 97/656) • Assigned a concentration of 100,000 IU per vial/ml (1IU ~ 0.58 copies/ml) • YY was human HIV-1-positive plasmapheresis donation diluted in defibrinated plasma • Has recently been found positive for HBV DNA SoGAT XVI
1st International Standard for HIV-1 RNACode 97/656 • In-house qualitative assay detected HBV DNA (David Padley, NIBSC) • Nested PCR positive for HBV DNA – estimated viral load at 3.5 x 104 amplifiable copies/ml (Alison Hardie, University of Edinburgh) • Procleix Triplex assay showed that 100 IU/ml dilution of HIV-1 International Standard contains 611 IU/ml HBV DNA (V Shyamala, Chiron Corporation) • What are the implications of this? SoGAT XVI
1st International Standard for HIV-1 RNA: Implications of HBV Contamination • For use in monovalent HIV-1 NAT or multivalent NAT assays that do not include HBV detection: • International Standard may still be used as directed • For use in multiplex assays that detect both HIV-1 RNA and HBV DNA : • 1st international Standard for HIV-1 may not be suitable for the quantitation of HIV-1 RNA • What difficulties will this cause for users? • Do we need to establish a second International Standard calibrated on the first? • If so, should we use candidate XX used in the collaborative study? SoGAT XVI
Development of 1st International Standard for HIV-1 RNA SoGAT XVI
Development of 1st International Standard for HIV-1 RNA Candidate XX Candidate YY Candidate ZZ --- bDN --- Monitor --Nuclisens --- Abbott --- in-house SoGAT XVI
Distribution: Approx 240 vials/year On present trend, Std will run out in 4 years, possibly sooner SoGAT XVI
1st International Standard for HIV-1 RNA: Implications of HBV Contamination • If it is agreed that candidate XX be brought in as a replacement for 1st international Standard (YY) • we will need to carry out small comparability and stability study to confirm that performance is satisfactory • This can be carried out over next 6 months in time for approval at WHO ECBS meeting in 2004 SoGAT XVI