Coombes Laura, Rigsby Peter, Sesardic Dorothea, Stickings Paul
Division of Bacteriology, National Institute for Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK.
Biostatistics Section, National Institute for Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK.
Biologicals. 2016 Nov;44(6):556-566. doi: 10.1016/j.biologicals.2016.07.005. Epub 2016 Sep 30.
We present the results of a collaborative study for the establishment of a replacement International Standard (IS) for diphtheria toxoid for use in flocculation test and its calibration in Lf units. Calibration was performed using Ramon flocculation method, standardized using the 2nd IS. The candidate standard was assigned a unitage of 1870 Lf/ampoule based on results from 25 laboratories in 15 different countries and was established as the 3rd IS for diphtheria toxoid for use in flocculation test by the WHO Expert Committee on Biological Standardization (ECBS) in October 2015. The study also assessed the use of alternative methods for measuring Lf. Participants were asked to determine the Lf value of the candidate standard using an Enzyme Linked Immunosorbent Assay (ELISA) established at NIBSC, or other suitable in-house method. 10 laboratories performed ELISA according to the NIBSC protocol, 1 laboratory performed flocculation using laser-light scattering according to an in-house protocol, and 1 laboratory performed another in-house ELISA. Results suggest these methods may provide suitable alternatives to the Ramon flocculation test, subject to validation, and that the new standard could act as a suitable reference preparation in these methods.
我们展示了一项合作研究的结果，该研究旨在建立用于絮凝试验的白喉类毒素替代国际标准品（IS）及其以絮状单位（Lf）进行校准。使用Ramon絮凝法进行校准，并以第2个国际标准品进行标准化。根据来自15个不同国家的25个实验室的结果，候选标准品被赋予1870 Lf/安瓿的单位量，并于2015年10月被世界卫生组织生物标准化专家委员会（ECBS）确立为用于絮凝试验的第3个白喉类毒素国际标准品。该研究还评估了测量Lf的替代方法的使用情况。要求参与者使用在国家生物制品检定所（NIBSC）建立的酶联免疫吸附测定（ELISA）或其他合适的内部方法来确定候选标准品的Lf值。10个实验室按照NIBSC方案进行ELISA，1个实验室按照内部方案使用激光散射进行絮凝试验，1个实验室进行另一种内部ELISA。结果表明，这些方法经过验证后可能为Ramon絮凝试验提供合适的替代方法，并且新的标准品可以作为这些方法中合适的参考制剂。
