Adjusting for Bias in C-Reactive Protein Levels When Using a Vitros Slide Method in Infants

Mohamad Elabiad, Kristopher L. Arheart, Sheldon B. Korones, Massroor Pourcyrous

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

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 (R2=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.

Original languageEnglish (US)
Pages (from-to)851-854
Number of pages4
JournalAmerican Journal of Perinatology
Volume31
Issue number10
DOIs
StatePublished - Nov 1 2014

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C-Reactive Protein
Nephelometry and Turbidimetry
Blood Proteins
Reference Values
Regression Analysis
Confidence Intervals
Serum

All Science Journal Classification (ASJC) codes

  • Pediatrics, Perinatology, and Child Health
  • Obstetrics and Gynecology

Cite this

Adjusting for Bias in C-Reactive Protein Levels When Using a Vitros Slide Method in Infants. / Elabiad, Mohamad; Arheart, Kristopher L.; Korones, Sheldon B.; Pourcyrous, Massroor.

In: American Journal of Perinatology, Vol. 31, No. 10, 01.11.2014, p. 851-854.

Research output: Contribution to journalArticle

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