Transforming growth factor beta‐1 level in pleural effusion

Objective:  Transforming growth factor‐β1 is an important immunomodulator. The diagnostic role of TGF‐β1 has not been systematically investigated in pleural effusion.Methodology:  A prospective clinical study of 45 patients (23 men, 22 women; mean age 49 ± 21 years) with pleural effusion was performed. Of these patients, 19 had malignant pleural effusion, 14 had tuberculous pleural effusion, seven had empyema/parapneumonic pleural effusion, and five had transudative pleural effusion due to congestive heart failure. The concentrations of TGF‐β1 were measured by ELISA in all pleural fluid samples and in serum samples only from patients with malignant and tuberculous pleural effusions.Results:  The median TGF‐β1 levels of malignant, tuberculous and empyema/parapneumonic pleural effusions were 7.25 ng/mL, 7.81 ng/mL, and 9.75 ng/mL, respectively. There was no significant difference between them. The median TGF‐β1 level was 5.62 ng/mL in the transudate pleural effusion group and it was significantly lower than that in the empyema/parapneumonic group (P < 0.05). The pleural fluid TGF‐β1 levels did not correlate with cell profiles of the pleural fluid. The median serum TGF‐β1 levels in malignant and tuberculous pleural effusion groups were 7.38 ng/mL and 7.38 ng/mL, respectively. There was no significant difference between the levels of TGF‐β1 in paired samples of serum and pleural fluid.Conclusions:  This study shows that TGF‐β1 concentrations in exudative pleural effusions are higher than those in transudative effusions secondary to congestive heart failure but TGF‐β1 concentrations do not assist in differentiating exudative effusions.