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


CONCLUSIONS
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.
D000368:Aged; D000789:Angina, Unstable / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D008297:Male; D009203:Myocardial Infarction / Q000097:blood*; D009391:Nephelometry and Turbidimetry
D015415:Biomarkers; D002097:C-Reactive Protein