1. Evaluation of Candidate Standard XX (97/650)
Clare Davis
Division of Retrovirology
National Institute for Biological Standards and Control
(NIBSC) UK
SoGAT Paris 2004

2. 1st International Standard for HIV-1 RNA (NIBSC code 97/656)
Established as International Standard in 1999 (Holmes et al, 2001).
Assigned a concentration of 100,000 IU per vial/ml.
Based on HIV-1 PCR positive, antibody negative plasmapheresis donation.
Virus diluted 1:312.5 in base matrix (defibrinated plasma).
2400 vials freeze-dried. Held at -200C.
Preparation showed good stability and correlation amongst assays.
Discussions at SoGAT – Jul 2003 (PEI) raised:
Low Stocks (~ 650).
Presence of HBV DNA – problematical for multiplex assays.
SoGAT Paris 2004

3. --- bDNA --- Monitor --Nuclisens --- Abbott --- in-house
SoGAT Paris 2004

4. Re-evaluation of Candidate XX
Non-syncitium inducing HIV-1 genotype B field isolate field isolate (donated by Dr. P. Simmonds).
Supplied as a low passage virus.
Further propagated on human PBMC’s, supernatant stored in LN2.
Virus diluted 1:250 in pooled human plasma.
2200 vials of material freeze-dried.
SoGAT Paris 2004

5. Study Details Study purpose:- 9 Laboratories participating.
Calibrate XX against HIV-1 RNA International Standard.
Confirm stability of XX
Determine values in current assays
9 Laboratories participating.
International Standard and Candidate XX randomly coded.
Participants asked to test samples in 3 independent assays.
Initially 10 fold dilution
Then 2 subsequent assays half log dilutions around the end point.
NIBSC to analyse data.
SoGAT Paris 2004

6. Preliminary analysis of data so far….. Quantitative
Lab Number
Assay Used
Sample A
(copies/ml Log 10)
Sample B 7
COBAS Taq Man
5.50
5.07 22
Amplicor
5.55
4.96 58
bDNA V3
5.21
4.69 73
COBAS Amplicor
5.84
5.26
Overall Mean
5.52
4.99
Values obtained in previous study
SoGAT Paris 2004

7. (log 10 detectable units/ml)
Qualitative
Lab Number
Assay Used
Sample A
(log 10 detectable units/ml)
Sample B 70
In house
4.69 71
5.36
4.11 72
5.15
5.29
Overall Mean
5.06
4.70
Values obtained in previous study
SoGAT Paris 2004

8. Conclusion
Preliminary analysis of data shows good correlation with previous study.
Hope to submit report to ECBS Aug 04.
Please return any outstanding data to us by end Jun 04.
SoGAT Paris 2004