The factor VIII inhibitor assays can be standardized: results of a workshop

作者:Verbruggen B*; Dardikh M; Polenewen R; Van Duren C; Meijer P
来源:Journal of Thrombosis and Haemostasis, 2011, 9(10): 2003-2008.
DOI:10.1111/j.1538-7836.2011.04479.x

摘要

Background: The Bethesda and the Nijmegen assays are commonly used for the measurement of inhibitor levels in hemophilia A patients. Despite test innovations, the between-laboratory coefficient of variation (CVb) of factor VIII inhibitor test data in external quality surveys remains very high (40-60%) with a high degree of false-negative and false-positive results resulting in undesired effects on treatment. Objectives: Organization of a workshop in order to address the causes of this phenomenon and to suggest ways to improve the assays. Methods: Fifteen laboratories showing a high CVb in regular surveys and using a variety of methods participated in the wet workshop, which included four different sessions where variables probably contributing to the high CVb (e. g. use of [non-]buffered plasma, FVIII-deficient plasma, sample dilution and APTT reagents) were investigated. Results: The CVb varied from 30% to 70% in the first session of the workshop when the participants used their own test settings and reagents. The use of buffered normal pooled plasma and FVIII-deficient plasma as a reference sample by all participants did not significantly alter the CVb (35-50%) but decreased the number of false positives. However, the use of buffered pooled plasma in combination with standardized sample dilution procedures by all participants showed a significant improvement (CVb, 10-20%). Conclusions: These results may contribute to improvement of FVIII inhibitor testing. However, improved inter-laboratory comparison of factor VIII inhibitor assay results can only be reached when further local standardization is implemented.

  • 出版日期2011-10