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Ro / BSD Hessen Institut für Transfusionsmedizin SoGAT XVII, Paris, Paris 2004 B19 Overview of Testing for Blood Banks W. Kurt Roth Red Cross Blood Transfusion Service Baden-Württemberg – Hessen, Institute Frankfurt am Main
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Ro / BSD Hessen Institut für Transfusionsmedizin Parvovirus B19-PCR: Testing Strategy Quantitative real-time TaqMan PCR Internal control sequence 3 external quantitative standards: 10 6, 10 5, 10 4 IU/ml on each plate External standards are spiked in negative plasma Routine donor screening on pools of 96 Testing in parallel with HCV, HIV, HBV, HAV Testing for all blood components incl. red cells and platelets No exclusive and no delayed testing for source plasma 95% detection limit: 10 3 IU / ml Decision level 10 5 IU / ml
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Ro / BSD Hessen Institut für Transfusionsmedizin
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Ro / BSD Hessen Institut für Transfusionsmedizin
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Ro / BSD Hessen Institut für Transfusionsmedizin
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Ro / BSD Hessen Institut für Transfusionsmedizin Parvo B19 Positives per Month Positives 10 5 (n)
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Ro / BSD Hessen Institut für Transfusionsmedizin B19 positives in March - April 2004 sensitivity n donations n positive donations % positive donations rate n pools n positive pools % positive pools 10 5 72,972230.031 : 3,173902192.1 10 3 72,972130*0.181 : 56190213014.4 10 5 68,147250,041 : 2,726883232.6 10 3 68,1471390,201 : 49088313915.7 * Indicates at least 1 donation/pool March April
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Ro / BSD Hessen Institut für Transfusionsmedizin B19 positive Pools 10 5 IU / ml: –Positive donation identified –Positive donation destroyed No donor deferral No donor information or counseling Reentry after donor tests PCR-negative (detection limit < 100 IU/ml) B19 „weak“ positive Pools < 10 5 IU / ml: –Positive donation not identified –All donations released (weak positive for blood bank software) –No labelling of product as B19 weak positive –Parvo B19-negative and weak positive (> 10 3 ; < 10 5 IU / ml) components for all patients at no specific risk – standard quality Parvovirus B19-PCR: Decision Making
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Ro / BSD Hessen Institut für Transfusionsmedizin Indications for B19-negative components Parvo B19-negative (< 10 3 IU / ml) components upon specific written request; individual label: „Parvovirus B19 not detectable“ –Patients with BMT, SCT –B19 antibody-negative pregant women in the 1.and 2. trimenon –HIV patients –Additional risk groups e.g. transient aplastic crisis pure red cell aplasia
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Ro / BSD Hessen Institut für Transfusionsmedizin The Netherlands approach: Cellular components B19 virus safe cellular products to risk groups only: –Pregnant women –Patients with congenital or acquired haemolytic anemia who have no antibodies –Patients with cellular immunodeficiency who have no antibodies Safe products are: –IgG antibodies against B19 in two separate blood samples, one taken at least six months after the other. –To be introduced in 1st of July 2004 –To be introduced for quarantine plasma in April 2005
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Ro / BSD Hessen Institut für Transfusionsmedizin The Netherlands Approach: Plasma Products All products derived from pooled plasma: –Highly infectd donations should be identified and removed before the individual sampkles are pooled. –For final pools the maximum permissible limit is 10 4 genome copies of B19 per millilitre. NAT for pools of 480 (10 x 48) –one central facility ín Amsterdam. –minipool NAT for HCV and HIV: pools of 48 at 4 test centers.
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Ro / BSD Hessen Institut für Transfusionsmedizin The future approach? B19 PCR and Ab testing on all donations Release PCR-only negatives and PCR negatives/Ab positives PCR negative/Ab positive products for patients at risk and source plasma Discontinue PCR and Ab testing for repeat PCR-negatives/Ab positives Continue PCR and Ab testing for first-time donors, antibody negative and PCR positive donors.
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Ro / BSD Hessen Institut für Transfusionsmedizin Parvo-B19 Seroconversion Medac IgM and IgG ELISA; Mikrogen IgG/IgM recomBlot
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