Comparison of High Sensitivity C-Reactive Protein Assay with a Wide Assay Range.
- Author:
So Young KANG
1
;
Jin Tae SUH
;
Jeong Hun KIM
;
Woo In LEE
;
Hee Joo LEE
Author Information
1. Department of Laboratory Medicine, KyungHee University College of Medicine, Seoul, Korea. suhjt@hitel.net
- Publication Type:Original Article
- Keywords:
High sensitivity-C reactive protein;
Turbidoimmunometric assay;
Immunonephelometric assay
- MeSH:
C-Reactive Protein*;
Cardiovascular Diseases;
Humans;
Inflammation;
Limit of Detection
- From:The Korean Journal of Laboratory Medicine
2005;25(4):227-233
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: C-reactive protein (CRP) concentrations are measured by two different assays depending on the clinical concern: the conventional CRP assay for estimating the extent of inflammation and the high sensitivity-CRP (hs-CRP) assay for assessing the risk of cardiovascular diseases. To integrate the conventional CRP test detecting acute phase response and the hs-CRP assay with a lower detection limit, we evaluated the performance characteristics of hs-CRP assay methods with a wide range of concentrations. METHODS: Immunonephelometric assay (BNII) and two turbidoimmunometric assays (TIA), the Hitachi 7600 with Daiichi reagent (Daiichi-Hitachi) and the Roche Cobas Integra 700 (Integra), were evaluated for the precision with 8 levels of pooled sera ranging from 0.3 to 120 mg/L and the agreement of TIA with the BNII assay using regression analysis and Bland-Altman analysis with 89 patient samples. RESULTS: The within-day coefficients of variation (CVs) of BNII were less than 10% in all levels of pooled sera. The CVs of Daiichi-Hitachi and Integra exceeded 10% in pooled sera below 1.0 mg/L and 0.5 mg/L, respectively. Both Daiichi-Hitachi and Integra appeared to be linear over the entire range of CRP concentrations used and were comparable with the results of BNII (Daiichi-Hitachi: y=0.98x+0.13, r=0.97, Integra; y=1.02x+0.22, r=0.99). However, at the concentrations over 100 mg/L TIA and BNII showed discrepant results. CONCLUSIONS: Both Daiichi-Hitachi and Integra showed a good precision over a wide range of CRP. However, the discrepant results found at very high concentrations require standardization among different assay methods or instruments.
