Transforming growth factor-β1 rise in pleural fluid after tunneled pleural catheter placement: pilot study

Transforming growth factor-β1 (TGF-β1) plays a major role in pleural fibrosis and chemical pleurodesis. Approximately 50% of patients with tunneled pleural catheters (TPCs) for malignant pleural effusions (MPEs) will have autopleurodesis. Pleural TGF-β1 levels have never been measured in the setting of TPC drainage and may predict autopleurodesis.

Pleural fluid was collected prospectively in subjects with MPE and planned TPC insertion. Pleural fluid was collected at time 0 (T0, thoracentecis before TPC placement), time 1 (T1, TPC insertion), and time 2 (T2, 2 wk after TPC insertion). The MPE levels of TGF-β1, vascular endothelial growth factor, and plasminogen activator inhibitor-1 were measured using ELISA. Lactate dehydrogenase levels were also measured at T0. Patients were followed up for autopleurodesis and TPC removal.

Nineteen samples were collected from 9 patients with MPE who underwent TPC placement. Three patients died before the study completion. The median level of TGF-β1 of 1243 pg/mL (range, 620 to 4547 pg/mL) at T1 in 6 patients showed a statistically significant rise to 2857 pg/mL (range, 2120 to 7160 pg/mL) after TPC placement (P=0.004, R=0.898). There was no statistically significant increase in TGF-β1 levels from T0 to T1. There was a linear relationship between TGF-β1 and lactate dehydrogenase at T0 (R=0.635). Plasminogen activator inhibitor-1 levels increased from T1 to T2, but was not statistically significant. There was no significant rise in vascular endothelial growth factor from T1 to T2.

TPC insertion results in an independent increase in TGF-β1 levels in MPE.