1. SoGAT XVII/Paris, 2004 Proficiency Testing of In-House Developed HIV-1 NAT for Blood Screening Michael Chudy, Paul-Ehrlich-Institut Division of Virology, Section of Molecular Pathology Langen, Germany; Email: chumi@pei.de

2. German Regulations for Blood Components and FFP: Implementation of HIV-1 NAT  BAnz. [Fed. Gazette] No 90, 9506; 05/16/2001  detection limit of HIV-1 RNA: 10,000 IU/ml for single donation  prospective implementation 01/01/2002  08/27/2001: PEI announcement  HIV-1 subtypes: M group  PEI collaborative study of in-house NAT assays for detection of HIV-1 and HCV RNA; participation on voluntary basis (10/01/2001)  HIV-1 NAT implementation postponed PEI

3. Collaborative Study: In-house NAT Assays PEI

4. Collaborative Study 2001: Conclusions  HCV NAT (in-house):  homogeneous results (sensitivity, specificity, and proficiency)  no differences between SD- and MP-testing  HIV-1 NAT (in-house):  results less homogeneous  further improvements and validation  regular proficiency studies for in-house NAT assays organised by PEI  acceptance: successful participation PEI

5. German Regulations for Blood Components and FFP: Implementation of HIV-1 NAT  BAnz. [Fed. Gazette] No 103, 12269; 06/05/2003  implementation 05/01/2004  validation of in-house assays  acceptance of in-house assays: successful participation in PEI proficiency study PEI

6. Proficiency Study for In-house HIV-1 NAT Assays: : Objective Evaluation of in-house NAT assays for detection of HIV-1 in blood donations:  analytical sensitivity  subtype sensitivity  specificity  proficiency PEI

7. Proficiency Study for In-house HIV-1 NAT Assays: Study Design Focus on the detection limit: 10,000 IU HIV1-RNA/ml single donation Materials Reference preparations (WHO: 31,600, 10,000 2x, 3,160 IU/ml/PEI: 10,000 IU/ml) HIV-1 subtypes (A, C, CRF_AE, G, H; each 10,000 IU/ml) NHP pool (2x) Simulation of the pool size (volume, dilution) Lab and sample encoding Samples frozen at -80°C/shipment on dry ice Results: reactive/non-reactive (data sheet) PEI

8. Proficiency Study for In-house HIV-1 NAT Assays: Participants Overall 30 participants  29 labs: blood screening; 2 labs only pooling/1 lab: manufacturer of plasma prod.  SD 1x; MP-8 1x; MP-10 3x; MP-15 2x, MP-20 4x, MP-24 2x, MP-40 1x, MP-48 5x; and MP- 96 11 x  7 labs with virus enrichment  NA extraction: 14 labs Qiagen/5 labs Roche/4 labs NucliSens/5 labs other  23 real-time PCR (20x TaqMan/3x LC Hybr.)  2x CA HIV-1 Monitor/3x RT-PCR +Gene Scanning PEI

9. Proficiency Study In-house HIV-1 NAT: Results

10. Proficiency Study for In-house HIV-1 NAT Assays (2003): Conclusions PEI Results more homogeneous compared to the results of the study in 2001 No differences in respect with the used pool size Due to the test results, 2 test labs switched to commercial assays Assessment of in-house assays: validation studies and successful participation in proficiency study Conclusion: In-house assays are suitable for blood screening CE-marking of in-house assays: open question