Serum transforming growth factor-β1 levels increase in response to successful anti-inflammatory therapy in ulcerative colitis

Abstract

Objective: To investigate serum levels of transforming growth factor-β1 and interferon-γ in active ulcerative colitis and to assess changes during treatment. Methods: We prospectively evaluated serum from 25 patients with untreated active ulcerative colitis and 19 healthy controls. Disease activity score (DAI), serum transforming growth factor-β1 and interferon-γ levels were measured at baseline and after 7 days of conventional treatment. Disease activity score and transforming growth factor-β1 were also assessed at 42 days. Results: Baseline transforming growth factor-β1 levels were significantly higher in patients than in controls (P < 0.02). On the 7th day, transforming growth factor-β1 levels increased only in patients who responded (P < 0.01); variations in transforming growth factor-β1 levels and disease activity score were inversely correlated (r= -0.72. P < 0.001). At day 42, serum transforming growth factor-β1 decreased significantly compared with the 7th day (P < 0.05). While in controls, interferon-γ was undetectable: untreated patients had higher, widely variable, levels. At day 7, responders had higher interferon-γ values than unresponsive cases. Variations in interferon-γ correlated moderately with changes in transforming growth factor-β1 (r = 0.53. P < 0.05). Cytokine response did not depend upon the type of treatment. Conclusions: Both transforming growth factor-β1 and interferon-γ may play a role in the injury-repair process in active ulcerative colitis. Variations in circulating transforming growth factor-β1 levels in the first week of treatment seem to be related to the therapeutic response.