Evaluation of atrial natriuretic peptide in differentiating benign and malignant pleural effusion

Objective: To discuss the value of atrial natriuretic peptide (ANP) in differentiating benign and malignant pleural effusion.

Methods: Direct radioimmunoassay was used to detect ANP of pleural effusion and serum in 30 tuberculous and 26 cancerous pleural effusion patients.

Results: The ANP in tuberculous and cancerous pleural effusion were (75 +/- 9) ng/L, (157 +/- 45) ng/L respectively, and significant difference was found (P < 0.001). The ANP of tuberculous pleural effusion was apparently lower [(75 +/- 9) ng/L] than serum [(170 +/- 37) ng/L], and significant difference was also found (P < 0.001). The ratio of ANP of pleural effusion to that of serum were 0.47 +/- 0.17, 0.99 +/- 0.46 respectively in tuberculous and cancerous pleural effusion patients. The sensitivity of ANP was 81% and specificity 100% in diagnosing malignant pleural effusion.

Conclusions: Detecting ANP of pleural effusion is one of important methods for differentiating benign and malignant pleural effusion.