New findings in life sciences described from National Blood Service
2008 JAN 13 -- Scientists discuss in 'Interlaboratory variation in the detection of HPA-specific alloantibodies and in molecular HPA typing' new findings in life sciences. "Platelet immunology quality assurance exercises have been organized by National Institute for Biological Standards and Control since 1991 and, as of 2006, 35 laboratories participate in the serology section. Molecular human platelet antigen (HPA) typing has been included in the exercises since 1998 and, as of 2006, 29 laboratories participate in this part of the exercise," researchers in Oxford, the United Kingdom report. "This report details the performance of laboratories in these two areas. Every 6 months laboratories are sent up to four coded serum/plasma samples for testing in their in-house assays for HPA antibody detection/identification and four coded whole blood samples to be typed for HPA-1, -2, -3 -5 and (since 2003) -15 by their molecular typing assays ('genotyping'). Fifty-two sera containing HPA-specific alloantibodies and 13 sera that were inert, contained only human leucocyte antigen (HLA) class I or high-titre anti-A+B antibodies were distributed; 15 sera were issued in more than one exercise. The percentage of participating laboratories that were able to detect HPA-specific alloantibodies ranged from 15.0 to 100%; the percentage that were able to correctly determine the specificities also ranged from 15.0 to 100%. Over the 20 serology exercises the percentage of laboratories classified as poor performers ranged from 3.1 to 36.7%. A total of 12 780 individual HPA genotyping results were assessed. The overall error rate was 0.7% but there was considerable variation between HPA alleles. Over 11 exercises the percentage of laboratories classified as poor performers varied from 6.3 to 26.3%. The ability to detect and to identify platelet-specific alloantibodies varied widely between laboratories and between various examples of antibodies issued. An increase in the number of laboratories screening for HPA-15 antibodies was seen, although detection and identification of these antibodies was problematic. The majority of examples of HPA-3a antibodies and some examples of HPA-1a and -5b were also difficult to detect and identify. In addition, this scheme has shown that despite the apparent reliability of molecular typing techniques, mistakes do occur, particularly with certain systems," wrote D. Allen and colleagues, National Blood Service. The researchers concluded: "Approximately one in five laboratories participating in the serology exercises and one in seven participating in the genotyping exercises were classified as poor performer at one point or more during the series of exercises." Allen and colleagues published their study in Vox Sanguinis (Interlaboratory variation in the detection of HPA-specific alloantibodies and in molecular HPA typing. Vox Sanguinis, 2007;93(4):316-24). For additional information, contact D. Allen, National Blood Service, Oxford, UK. Publisher contact information for the journal Vox Sanguinis is: Blackwell Publishing Ltd., 9600 Garsington Rd., Oxford OX4 2DG, Oxon, England. Keywords: United Kingdom, Oxford, Life Sciences, Regulatory Actions, Immunology, Hematology. This article was prepared by Medical Letter on the CDC & FDA editors from staff and other reports. Copyright 2008, Medical Letter on the CDC & FDA via NewsRx.com.
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