Pleural fluid amino-terminal brain natriuretic peptide in patients with pleural effusions.
BACKGROUND
Definite diagnosis of transudative or exudative pleural fluids often presents a diagnostic dilemma. The aim of this study was to evaluate whether amino-terminal brain natriuretic peptide (NT-proBNP) levels in pleural fluid has a diagnostic value for discriminating heart-failure-related pleural effusions from non-heart-failure effusions.


METHODS
Sixty-six subjects (40 male, mean age 61 ± 18 y) with pleural effusions were included. Samples of pleural fluid and serum were obtained simultaneously from each subject. Biochemical analysis, bacterial and fungal culture, acid-fast bacilli smear and culture, and cytology were performed on the pleural fluid.


RESULTS
Subjects with heart-failure-related pleural effusion had significantly higher pleural NT-proBNP levels than other subjects (P < .001). Pleural and serum NT-proBNP measures were closely correlated (r = 0.90, P < .001). An NT-proBNP cutoff value of ≥ 2,300 pg/mL in pleural fluid had a sensitivity of 70.8%, a specificity of 97.6%, and positive and negative predictive values of 94.4% and 85.4%, respectively, for discriminating transudates caused by heart failure from exudates. Eight heart-failure subjects were misclassified as exudates by Light's criteria, 5 of whom received diuretics before thoracentesis. All misclassified subjects had pleural NT-proBNP levels higher than 1,165 pg/mL, which predicted heart-failure-associated transudates with 95.8% sensitivity and 85.7% specificity.


CONCLUSIONS
Pleural fluid NT-proBNP measurement in the routine diagnostic panel may be useful in differentiation of heart-failure-related pleural effusions and exudative pleural fluids with reasonable accuracy, especially in heart-failure patients treated with diuretics.
Department of Cardiology, Bayburt Government Hospital, Bayburt, Turkey.
Altug
A
Cincin
Yasin
Y
Abul
Beste
B
Ozben
Azra
A
Tanrikulu
Nurhayat
N
Topaloglu
Gulsevil
G
Ozgul
Sait
S
Karakurt
Ahmet
A
Oktay
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D003937:Diagnosis, Differential; D004232:Diuretics / Q000627:therapeutic use; D004653:Empyema / Q000097:blood / Q000150:complications / Q000175:diagnosis; D005122:Exudates and Transudates / Q000737:chemistry*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000032:analysis* / Q000097:blood; D010446:Peptide Fragments / Q000032:analysis* / Q000097:blood; D010996:Pleural Effusion / Q000209:etiology*; D016066:Pleural Effusion, Malignant / Q000737:chemistry / Q000175:diagnosis / Q000209:etiology; D011237:Predictive Value of Tests; D012372:ROC Curve; D014376:Tuberculosis / Q000097:blood / Q000150:complications / Q000175:diagnosis
D015415:Biomarkers; D004232:Diuretics; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain