Reassessing the Role of the Active TGF- β 1 as a Biomarker in Systemic Sclerosis: Association of Serum Levels with Clinical Manifestations

Objective . To determine active TGF- β 1 (aTGF- β 1) levels in serum, skin, and peripheral blood mononuclear cell (PBMC) culture supernatants and to understand their associations with clinical parameters in systemic sclerosis (SSc) patients. Methods . We evaluated serum samples from 56 SSc patients and 24 healthy controls (HC). In 20 SSc patients, we quantified spontaneous or anti-CD3/CD28 stimulated production of aTGF- β 1 by PBMC. The aTGF- β 1 levels were measured by ELISA. Skin biopsies were obtained from 13 SSc patients and six HC, and TGFB1 expression was analyzed by RT-PCR. Results . TGF- β 1 serum levels were significantly higher in SSc patients than in HC ( p < 0.0001). Patients with increased TGF- β 1 serum levels were more likely to have diffuse subset ( p = 0.02), digital ulcers ( p = 0.02), lung fibrosis ( p < 0.0001), positive antitopoisomerase I ( p = 0.03), and higher modified Rodnan score ( p = 0.046). Most of our culture supernatant samples had undetectable levels of TGF- β 1. No significant difference in TGFB1 expression was observed in the SSc skin compared with HC skin. Conclusion . Raised active TGF- β 1 serum levels and their association with clinical manifestations in scleroderma patients suggest that this cytokine could be a marker of fibrotic and vascular involvement in SSc.