Evaluation of fluorescence hs-CRP immunoassay for point-of-care testing

Background: C-reactive protein (CRP) is one of acute phase respondents that has been used to monitor infection and inflammation episodes. Recent studies have shown that high-sensitivity C-reactive protein (hs-CRP) is a potential risk predictor for future atherosclerosis and cardiovascular diseases (CVD). Methods: We previously developed a fluorescence-based immunochromatographic method for measuring hs-CRP concentrations (i-CHROMA™ hs-CRP assay) in blood. Whole blood was mixed with detector buffer, and then loaded onto a test cartridge. After 10 min of incubation, the test cartridge was inserted and scanned for acquisition of fluorescence intensity in a laser fluorescence reader (i-CHROMA™ reader). The fluorescence intensity was microprocessed and converted into the concentration of CRP in blood. The test result of 150 samples by the i-CHROMA™ hs-CRP assay method was compared and evaluated with those by TBA 200FR turbidimetry and BN II nephelometry method. The Deming regression and the Bland-Altman difference plot analysis were used for comparison of hs-CRP test result. Results: The i-CHROMA™ hs-CRP assay system exhibited a good linearity with in the whole measuring range (R = 0.997). The imprecision of intra- and the inter-assay CVs (coefficient of variation) of assay system were CVs< 3% and < 5% in the range of 0.5-20 mg/l, respectively. The i-CHROMA™ hs-CRP assay method correlated well with TBA 200FR turbidimetry and BN II nephelometry assay method (R = 0.988, N = 143 and R = 0.989, N = 143). Conclusion: The i-CHROMA™ hs-CRP assay system is comparable to those of other well-known fully automated hs-CRP assay and is suitable for point-of-care testing (POCT) in detection and quantification of hs-CRP.