Comparison of pleural fluid N-terminal pro-brain natriuretic peptide and brain natriuretic-32 peptide levels.
BACKGROUND
Current evidence indicates that measurement of pleural fluid N-terminal pro-brain natriuretic peptide (NT-proBNP) levels can aid in distinguishing pleural effusions of cardiac origin from those of noncardiac origin. To date, only one study, to our knowledge, has described simultaneous measurement of pleural fluid brain natriuretic-32 peptide (BNP) and NT-proBNP. The purpose of the present study was to determine pleural fluid BNP and NT-proBNP levels and analyze the relationship between these two measurements. We hypothesized that there would be a positive correlation between pleural fluid NT-proBNP and BNP, whereas NT-proBNP levels would be higher than BNP levels.


METHODS
Levels of pleural fluid NT-proBNP and BNP were measured by enzyme immunoassay in a total of 80 patients: 20 with congestive heart failure, 20 status post-coronary artery bypass graft, 20 with carcinoma, and 20 with pneumonia.


RESULTS
Comparison of NT-proBNP and BNP concentrations using the Spearman method of statistical analysis revealed a correlation coefficient of 0.572, P < .001. Evaluation of the diagnostic accuracy of BNP and NT-proBNP in patients with pleural effusions of cardiac origin demonstrated an area under the receiver operating characteristic curve of 0.700 (95% CI, 0.569-0.831) and 0.835 (95% CI, 0.721-0.949), respectively.


CONCLUSIONS
Although levels of pleural fluid BNP have a statistically significant correlation with those of NT-proBNP, this relationship only explains 32% of the variance in NT-proBNP levels. Furthermore, when compared with BNP, NT-proBNP is a more accurate diagnostic aid in the evaluation of pleural effusions of cardiac origin.
Long
Ann C
AC
Department of Internal Medicine, Louisiana State University, Earl K. Long Medical Center, 5825 Airline Hwy, Baton Rouge, LA, 70805, USA. along2@lsuhsc.edu
O'Neal
Hollis R
HR
Peng
Suiwei
S
Lane
Kirk B
KB
Light
Richard W
RW
D015415:Biomarkers / Q000032:analysis*; D001026:Coronary Artery Bypass; D005122:Exudates and Transudates / Q000737:chemistry* / Q000378:metabolism; D006333:Heart Failure / Q000175:diagnosis / Q000378:metabolism*; D006801:Humans; D020097:Natriuretic Peptide, Brain / Q000032:analysis*; D009369:Neoplasms / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis*; D010996:Pleural Effusion / Q000175:diagnosis / Q000378:metabolism*; D016066:Pleural Effusion, Malignant / Q000175:diagnosis; D011014:Pneumonia / Q000378:metabolism; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain