Adjusting for bias in C-reactive protein levels when using a vitros slide method in infants
| Autor: | Sheldon B. Korones, Massroor Pourcyrous, Kristopher L. Arheart, Mohamad T. Elabiad |
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| Rok vydání: | 2014 |
| Předmět: |
medicine.medical_specialty
Gastroenterology Low total serum protein Nephelometry and Turbidimetry Predictive Value of Tests Reference Values Internal medicine Reference level Medicine Cutoff Humans Prospective Studies biology business.industry C-reactive protein Infant Newborn Obstetrics and Gynecology Infant Predictive value Confidence interval C-Reactive Protein Pediatrics Perinatology and Child Health Immunology biology.protein Positive bias business Nephelometry Blood Chemical Analysis |
| Zdroj: | American journal of perinatology. 31(10) |
| ISSN: | 1098-8785 |
| Popis: | OBJECTIVE Low total serum protein levels may cause a positive bias on C-reactive protein (CRP) detected by the Vitros 250 Chemistry System (Ortho-Clinical Diagnostics, Inc., Johnson & Johnson Co., Raritan, NJ). Low total serum protein levels are observed in some infants. Our objective was to define a cutoff value for normal levels of CRP measured on the Vitros System that is comparable to the cutoff value of 1.0 mg/dL measured by rate nephelometry on a Beckman Array System (Beckman Instruments Inc., Fullerton, CA). STUDY DESIGN CRP was prospectively measured on the same serum sample on Vitros and Beckman systems. Using a result of ≥1.0 as the "gold standard" definition of an abnormal CRP, measures of association were calculated. RESULTS CRP was measured in 981 blood samples that were collected from 361 infants. A cutoff CRP level using the Vitros system at 1.5 mg/dL had the highest sensitivity and negative predictive value comparable to 1.0 mg/dL measured by nephelometry. By regression analysis, each increase by 1 mg/dL by nephelometry caused an increase by 1.5 mg/dL on the Vitros system (R(2) = 0.94; p < 0.001; slope = 0.66; 95% confidence intervals, 0.65, 0.67). CONCLUSION In infants, when measuring CRP levels by Vitros CRP slide system, a normal reference level of 1.5 mg/dL instead of 1 mg/dL should be used. |
| Databáze: | OpenAIRE |
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