Blood BNP concentration can help diagnose malignant mesothelioma

The ratio of pleural fluid to blood B-type natriuretic peptide (BNP), which is secreted from malignant mesothelial cells, can aid in the diagnosis of malignant mesothelioma, suggests a recent study.

The study was divided into three parts. For the first part, the investigators prospectively compared patients with pleural lesions on computed tomography having malignant mesothelioma effusions (MME, n=13) to those with malignant effusions with pleural lesions (MEa, n=14). They also analysed age-matched ME patients without pleural lesions (MEb, n=16) and nonmalignant effusions (NME, n=25).

Retrospectively, the investigators used samples from patients with mesothelioma (n=14), lung cancer (n=8), or heart failure for part II of the study. They then measured BNP in all pleural fluid and blood/plasma. For part III, BNP was examined in the culture supernatants of benign (MeT-5A) and malignant mesothelioma cell lines (M14K-epithelioid, MSTO-biphasic, and ZL34-sarcomatoid; n=10 per cell line in three different biological replicates).

In vitro, significantly higher BNP concentration was observed in the supernatant of all malignant cell lines compared to benign ones (p<0.01), indicating the production of BNP from the former. The pleural fluid to blood BNP ratio in MME was extremely high in parts I and II patients (28.3±12.1 and 25.9±8.6, respectively) compared with part I ME and NME (1.1±0.3 and 0.4±0.1, respectively; p<0.0001) and with part II ME and NME (0.8±0.1 and 0.4±0.1, respectively; p<0.0001).

Additionally, BNP ratio ≥2.11 in part I had a sensitivity of 92 percent and specificity of 94.5 percent for detecting MME (p<0.0001).

“Mesothelial cells and cardiomyocytes have shared embryonic mesodermal origin. Cardiomyocytes release BNP under stretch,” the investigators said.