Transforming growth factor β‐1 as a predictor of fibrosis in tuberculous pleurisy

Background and objective: To clarify the influence of transforming growth factor β‐1 (TGF‐β 1 ) in the development of pleural thickening in tuberculosis (TB), the levels of TGF‐β 1 in pleural fluid and in serum of patients with pleural TB and transudative effusions were determined. Methods: TGF‐β 1 was quantified in 58 pleural fluid and serum samples of patients with TB ( n = 50) or transudative effusions ( n = 8). Pleural thickening evaluated by high‐resolution CT was scored as 0 (<3 mm); 1 (≥3 and <10 mm) or 2 (≥10 mm). Results: The highest pleural fluid TGF‐β 1 levels before treatment for TB were observed in patients with a pleural thickness score of 2. Of the 14 patients with score 1, five regressed to 0, five progressed to 2, and four maintained 1. All 17 patients with score 2 maintained this evaluation. Patients who presented score 1 and progressed to 2 had higher TGF‐β 1 levels than those who maintained the same score or regressed (score 1 or 0). Patients with score 2 (before or after treatment) had higher TGF‐β 1 levels than those with score 0 or 1. Conclusion: Pleural fluid and serum TGF‐β 1 levels were higher in patients with TB, with a correlation between pleural fluid TGF‐β 1 levels before treatment and the degree of pleural thickening. This finding suggests that TGF‐β 1 might be considered as a predictor of pleural thickening in pleural tuberculosis.