PURPOSE: Pleural effusions can occur as complications of many different diseases. A serum-effusion albumin gradient is recognized as a useful tool that can distinguish transudate from exudate in the pleural effusions. But the role of albumin in diagnosis of detailed exudative effusions is not widely well studied. The purpose of this study was to evaluate efficiency of albumin-related parameters for diagnosis of exudative pleural effusions, especially tuberculous or malignant pleural effusions.
METHODS: The study was performed in 3 educational tertiary referral hospitals from January 2009 to July 2009 prospectively. Concentrations of albumin including basic pleural fluid laboratory data, cytology, and acid fast bacilli stain/culture in the fluids were determined. The diagnostic values of albumin-related parameters were compared using sensitivity, specificity, and misclassification rate.
RESULTS: Exudative pleural effusions from 78 patients were classified on the basis of definitive diagnosis as tuberculosis (n=29), or neoplastic (n=49). Young patients (p=0.009) with high serum protein concentration (p=0.016) predominated in the tuberculosis group. With threshold value of 1.6g/dL, pleural protein-albumin gradient (pleural protein-pleural albumin) had a sensitivity of 69% and specificity of 63.3%. The other parameters such as pleural albumin and pleural albumin/serum albumin were not superior to pleural protein-albumin gradient in sensitivity and specificity. The misclassification rate of pleural protein-albumin gradient was significantly greater than that of ADA (37.2% vs. 1.4%, p<0.001).
CONCLUSION: The albumin-related pleural parameters are not superior to the conventional parameter such as pleural ADA level in diagnosis of exudative pleural effusions, especially tuberculous or malignant pleural effusions.
CLINICAL IMPLICATIONS: Pleural fluid albumin can be used for additional supportive data for differential diagnosis of pleural effusions, especially exudative pleural effusions.
DISCLOSURE: Seok-Chul Yang, No Financial Disclosure Information; No Product/Research Disclosure Information