背景:测量瓜氨酸化蛋白质/肽(ACPA)的抗体的商业测定显示较差的定量一致性。诊断行业从未采用国际免疫协会联盟-疾病控制和预防中心(IUIS-CDC)的ACPA参考标准。最近,美国国家生物标准与控制研究所(NIBSC)制定了新的候选ACPA标准(18/204)。我们使用不同的市售ACPA测定法评估了两种参考材料。
方法:这是一项国际研究,其中分析了NIBSC候选ACPA标准和IUIS-CDCACPA参考材料,以及来自类风湿关节炎(RA)个体和1073个个体的诊断样本。
结果:对于来自RA患者和非RA患者的参考材料和样本,两种测定之间的定量ACPA结果存在较大差异.对于大多数化验,IUIS-CDC标准的值低于NIBSC18/204的值,IUIS-CDC/NIBSC比率在几个但不是所有的化验。当NIBSC18/204用作校准器时,在几个评估的测定中,ACPA结果的比对得到了改善.此外,NIBSC18/204可以使一些但不是所有测定的临床解释一致。
结论:采用ACPA测定的国际标准是非常可取的。候选NIBSC18/204标准改进了大多数ACPA测定的标准化和比对,因此可能被推荐用作商业测定中的参考。
BACKGROUND: Commercial assays measuring antibodies to citrullinated protein/peptide (ACPA) show poor quantitative agreement. The diagnostic industry has never adopted the International Union of Immunological Societies-Centers for Disease Control and Prevention (IUIS-CDC) ACPA reference standard. Recently, the National Institute for Biological Standards and Control (
NIBSC) prepared a new candidate ACPA standard (18/204). We evaluated both reference materials using different commercially available ACPA assays.
METHODS: This is an international study in which the
NIBSC candidate ACPA standard and the IUIS-CDC ACPA reference material were analysed together with 398 diagnostic samples from individuals with rheumatoid arthritis (RA) and in 1073 individuals who did not have RA using nine commercial ACPA assays.
RESULTS: For both reference materials and samples from individuals with RA and individuals who did not have RA, there were large differences in quantitative ACPA results between assays. For most assays, values for the IUIS-CDC standard were lower than values for NIBSC 18/204 and the IUIS-CDC/
NIBSC ratio was comparable for several, but not all assays. When
NIBSC 18/204 was used as a calibrator, an improvement in alignment of ACPA results across several of the evaluated assays was obtained. Moreover,
NIBSC 18/204 could align clinical interpretation for some but not all assays.
CONCLUSIONS: Adoption of an international standard for ACPA determination is highly desirable. The candidate NIBSC 18/204 standard improved the standardisation and alignment of most ACPA assays and might therefore be recommended to be used as reference in commercial assays.