D-dimer levels in pleural effusions.
BACKGROUND
D-dimer is a degradation product of cross-linked fibrin. We hypothesized that hemorrhagic pleural effusions would have greater D-dimer levels than non-hemorrhagic pleural effusions, and that persistently bloody effusions would be distinguishable from thoracentesis-induced bloody effusions by the D-dimer level.


METHODS
Forty pleural effusions were studied. D-dimer levels (measured by ELISA), red blood cell (RBC) count, white blood cell (WBC) count, lactate dehydrogenase (LDH), and protein level was measured for each effusion. Ten effusions, five non-bloody, and five bloody were studied for each of the following disease states: parapneumonic effusion, congestive heart failure, post-coronary artery bypass grafting, and lung cancer.


RESULTS
No significant difference of the D-dimer level was noted between bloody and non-bloody effusions of different disease states (P=0.286). There was no significant difference in the median D-dimer levels between all the bloody and all the non-bloody effusions (P=0.88). There was no significant difference (P=0.51) in D-dimer levels between five diseases groups when the bloody and non-bloody fluids were combined. The D-dimer levels did not correlate with the RBC count (r=0.11, P=0.48), WBC count (r=0.13, P=0.53), LDH (r=0.01, P=0.93), or protein levels (r=-0.01, P=0.93) in any of the groups.


CONCLUSIONS
Measurement of pleural fluid D-dimer levels does not distinguish persistently bloody effusions from non-bloody effusions, and does not aid in narrowing the differential diagnosis of an effusion.
Dikensoy
O
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Saint Thomas Hospital, 4220 Harding Road, and Vanderbilt University, Nashville, TN 37232, USA.
Stathopoulos
G T
GT
Zhu
Z
Z
Light
R W
RW
D001026:Coronary Artery Bypass; D003937:Diagnosis, Differential; D004906:Erythrocyte Count; D005122:Exudates and Transudates / Q000737:chemistry; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006333:Heart Failure / Q000378:metabolism; D006470:Hemorrhage; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D007958:Leukocyte Count; D008175:Lung Neoplasms / Q000378:metabolism; D010996:Pleural Effusion / Q000097:blood / Q000737:chemistry* / Q000175:diagnosis
D005338:Fibrin Fibrinogen Degradation Products; D007770:L-Lactate Dehydrogenase