Use of pleural fluid ceruloplasmin in the differentiation of exudative and transudative pleural effusion.

Background: Differentiating into transudate or exudate is the first step in the evaluation of effusions. Light's criteria is the standard but a significant number of transudates may not be differentiated based on these criteria. Acute phase proteins (APP) are present in plasma, which increase or decrease by about 25% during an acute inflammatory response.