sogat, berne 2006bts src berne ltd. evaluation of the procleix tigris system at the blood...

SoGAT, Berne 2006 BTS SRC Berne Ltd.

Evaluation of the Procleix Evaluation of the Procleix TIGRIS System at the Blood TIGRIS System at the Blood

Transfusion Service Berne Ltd.Transfusion Service Berne Ltd.

Dr. Martin Stolz


NAT testing in progressNAT testing in progress

HCV-PCR since 01 ‘1999 HIV-1 PCR since 03‘ 2002 increased blood safety automized test procedures


Procleix TIGRIS SystemProcleix TIGRIS System fully automated NAT screening system combined detection of 3 viruses: HIV-1, HCV and HBV extraction/amplification/detection in one tube extraction based upon magnetic

bead technology amplification based upon the

TMA technology using RNA as amplified targed

detection by chemiluminescence specific discrimination assays

for virus identification


Design of the evalution studyDesign of the evalution study

Assay validation: – sensitivity, specificity, robustness & cross-contamination

Test performance under routine conditions– routine samples– pools of 8 or individual donations– pooling with Tecan pipetting robots– analysis with Procleix TIGRIS system


SensitivitySensitivity

HIV-1: 24.9 IU/ml (95 % C.I.: 20.2 – 33.3 IU/ml)

ca. 13.9 copies/ml

HCV: 3.7 IU/ml (95 % C.I.: 3.1 – 4.8 IU/ml) ca. 23.3 copies/ml

HBV: 7.6 IU/ml (95 % C.I.: 6.0 – 11.1 IU/ml) ca. 41.0 copies/ml


Robustness and reproducibilityRobustness and reproducibility Procleix TIGRIS system: excellent robustness against

cross-contamination reproducibility: intra-, inter-assay precision and between

laboratories confirmed reliable test: 3 x 95% positive cut off value

(HIV-1: 75 IU/ml, HCV: 11 IU/ml, HBV: 23 IU/ml)

high robustness against inhibiting substances i.e. 100 I.U. heparin per sample

no interference with lipaemic or haemolytic samples as a frequent donation related factor


Specificity – System EvaluationSpecificity – System Evaluation

number of samples 1385 97.88% 1287 99.15% 2672 98.49%

number of invalids 14 0.99% 10 0.77% 24 0.88%

CLT: clot detected 2 0.14% 10 0.77% 12 0.44%

QNS: Insufficient sample for processing

6 0.42% 0 0.00% 6 0.22%

RDA: Reagent Dispense Failure - Amp

1 0.07% 0 0.00% 1 0.04%

initial reactive 16 1.13% 1 0.08% 17 0.63%

false reactive 15 1.06% 0 0.00% 15 0.55%

confirmed 1 0.07% 1*) 0.08% 2 0.07%

Pools of 8 combinedindividual donors

*) positive sample was a HBV window period donation


SummarySummary very good test sensitivity, robustness and reliability clear discrimination between reactive and non reactive samples low level of invalid samples elevated level of „false“ positives with pools of 8 observed pool resolving requires more time and large sample quantities fully automated NAT screening system test and software easy to handle high throughput: single donation testing feasable very high degree of automatisation, but demanding hardware

and little flexibility


AcknowledgmentsAcknowledgments

Christiane Schmidseder Rita Hubschmid Roger Hellmüller Dr. Christoph Niederhauser Dr. Philippe Schneider

(BTS Lausanne) Chiron Corp.


Window period HBV donationWindow period HBV donation

identified by single donation testing donation already transfused at time of testing recipient developed a HBV viraemie 3 weeks post

transfusion viral load of the initial donation not available, but… initial HBV titer must have been quite low:

no longer detectable in a dilution of 1:8 and 1:24

101'621 IU/ml in 2nd donation 35 days later

sogat, berne 2006bts src berne ltd. evaluation of the procleix tigris system at the blood...

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