Gray E, Walker D, Heath A, Barrowcliffe T W
National Institute for Biological Standards and Control' Potters Bar, Hertfordshire, UK.
Thromb Haemost. 1996 Dec;76(6):1114-7.
A collaborative study has been organised by NIBSC to examine the performance of FIXa assays between laboratories, and to investigate the need for a standard. Ampoules of 3 materials, one monocomponent concentrate (coded C) and 2 different preparations of purified human FIXa (one proposed reference preparation, coded A and a test material coded B), have been assayed in 11 laboratories for FIXa using either the NIBSC method or a local method, with local standards (if available, coded D) to determine their potencies. The data showed high between assay variability; with the exception of one laboratory, most of the between assay variation expressed as %geometric coefficients of variation (gcv) were over 15%. The interlaboratory gcv when preparation B was assayed against the local standard was over 1700%, suggesting that most of the local standards are poorly calibrated. The %gcv was improved to 80% when reference A was used as the standard. These data clearly show that an international reference standard for FIXa would help to standardise FIXa preparations and would also improve in house assays for FIXa. However, an accelerated degradation study has shown that reference A is not suitable as a long term standard and another material with suitable stabilizers has to be established as an international standard for FIXa.
国家生物制品检定所（NIBSC）组织了一项合作研究，以检验各实验室之间FIXa检测方法的性能，并调查是否需要一个标准品。已在11个实验室中使用NIBSC方法或当地方法，以当地标准品（若有，编码为D）对3种材料的安瓿进行了FIXa检测，这3种材料分别为一种单组分浓缩物（编码为C）和2种不同的纯化人FIXa制剂（一种为拟议的参考制剂，编码为A，另一种检测材料编码为B），以确定它们的效价。数据显示检测之间的变异性很高；除一个实验室外，大多数检测间变异以几何变异系数（gcv）百分比表示超过15%。以制剂B与当地标准品进行检测时，实验室间gcv超过1700%，这表明大多数当地标准品校准不佳。以参考品A作为标准品时，gcv百分比改善至80%。这些数据清楚地表明，FIXa的国际参考标准品将有助于使FIXa制剂标准化，还将改善FIXa的内部检测。然而，一项加速降解研究表明，参考品A不适合作为长期标准品，必须确立另一种含有合适稳定剂的材料作为FIXa的国际标准品。
