Abstract:

Objective To evaluate the performances of 5 common systems for C-reactive protein（CRP） determination. Methods The imprecision [coefficient of variation（CV）],accuracy,linearity and anti-interference ability of 5 systems for CRP determination were evaluated. The 5 systems included Uppergold U2 gold spot method system,NEPHSTAR specific protein analyzer,ABX Micros CRP200 automatic blood analyzer,i-CHROMA Reader immune fluorescence analyzer and QuikRead 101 detecting system. Their original reagents were used. The 5 systems were labelled as A,B,C,D and E in turn. The reference range was validated. The results were compared with those of Dade Behring BN ProSpec automatic system （DADE）. Results The within-run and between-run precisions of the 5 systems were 1.01%-16.91%,which met the requirements from manufacturers,but they were lower than those of DADE. Passing-Bablok regression analysis showed that the regression equation slopes between DADE and the 5 systems were 0.88-1.73. The correlations were good between DADE and A,B,C systems,but the correlations were poor between DADE and D,E systems. For 50 mg/L CRP as cut-off value,the consistency of the 5 systems for CRP determination with DADE was 92.4%-100%. The linear range of 4 systems was 5-160 mg/L,and the linear range of 1 system was 5-100 mg/L. The interference rates of 1 500 FTU chyle,0.2 mg/L free bilirubin（FBil）,0.2 mg/L conjugated bilirubin（CBil）and 5 g/L hemoglobin（Hb） were <10%. The reference value met the requirements from manufacturers. Conclusions The performances of the 5 systems are good. However,there is a bias between the 5 systems and DADE system,which should be considered in clinic.

Key words: C-reactive protein, Rapid determination method, Immunoturbidimetric assay, Immunonephelometric assay