To value C-reactive protein (CRP) trueness verification materials and to perform the CRP trueness verification program in Beijing.

The CRP value of trueness verification materials were assigned by the international reference material ERM DA-474/IFCC, using 10 clinical routine detection systems at departments of clinical laboratory of Beijing Chaoyang and Luhe Hospital Affiliated to Capital Medical University. The calibration curves with 4 ERM DA-474/IFCC dilutions were established and used for value transfer for trueness verification materials of two levels. The uncertainty was also assessed during the process. Then, the trueness verification was performed in the EQA at Beijing Center for Clinical Laboratories (BCCL)among 42 clinical laboratories. The samples were distributed according to BCCL standard operating procedure. The Microsoft Excel 2007 and SPSS 17.0 were used to process the results and the function of efficiency (En) was calculated to verify the difference between the value and the overall mean of all participating laboratories.

The values and uncertainties of two trueness verification materials of CRP were (109.9±9.4) mg/L and (27.1±2.4) mg/L respectively. The results of trial application of two level trueness verification materials in the EQA at Beijing Center for Clinical Laboratories (BCCL) were satisfied. There were no significant difference between the transfer values from our study and the values from means of all laboratories in Beijing. The function of efficiency (En) was less than 1.

The valueswhich were established by using multiple detection platforms for CRP trueness verification materialswere accurate and the uncertainties were small. This method is a preferably method for CRP value assignment because there was no suitable reference method for CRP measurement till now. Thematerialswere suitable for the trueness verification program for clinical laboratories in Beijing.(Chin J Lab Med, 2018, 41: 742-748)

C-reactive protein; Reference standards; Reference values; Quality control