Arquivos Brasileiros de Cardiologia (Aug 2003)

Correlation between turbidimetric and nephelometric methods of measuring C-reactive protein in patients with unstable angina or non-ST elevation acute myocardial infarction

  • Luis C. L. Correia,
  • José C. Lima,
  • Gary Gerstenblith,
  • Luis P. Magalhães,
  • Agnaluce Moreira,
  • Octávio Barbosa Jr.,
  • Juliana Dumet,
  • Luiz Carlos S. Passos,
  • Argemiro D'Oliveira Júnior,
  • José Péricles Esteves

DOI
https://doi.org/10.1590/S0066-782X2003001000002
Journal volume & issue
Vol. 81, no. 2
pp. 133 – 136

Abstract

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OBJECTIVE: To evaluate the performance of the turbidimetric method of C-reactive protein (CRP) as a measure of low-grade inflammation in patients admitted with non-ST elevation acute coronary syndromes (ACS). METHODS: Serum samples obtained at hospital arrival from 68 patients (66±11 years, 40 men), admitted with unstable angina or non-ST elevation acute myocardial infarction were used to measure CRP by the methods of nephelometry and turbidimetry. RESULTS: The medians of C-reactive protein by the turbidimetric and nephelometric methods were 0.5 mg/dL and 0.47 mg/dL, respectively. A strong linear association existed between the 2 methods, according to the regression coefficient (b=0.75; 95% C.I.=0.70-0.80) and correlation coefficient (r=0.96; P<0.001). The mean difference between the nephelometric and turbidimetric CRP was 0.02 ± 0.91 mg/dL, and 100% agreement between the methods in the detection of high CRP was observed. CONCLUSION: In patients with non-ST elevation ACS, CRP values obtained by turbidimetry show a strong linear association with the method of nephelometry and perfect agreement in the detection of high CRP.

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