Transforming growth factor beta isoforms and TGF-ßR1 and TGF-ßR2 expression in systemic sclerosis patients.

Systemic sclerosis (SSc) is characterized by chronic inflammation and fibrosis, two processes associated with transforming growth factor ß (TGF-ß) functions. In the present study, we investigated the expression of TGF-ß isoforms in serum and the skin distribution of TGF-ß and two receptors (TGF-ßR1 and TGF-ßR2) and their relationship with some clinical, inflammatory, autoimmune (autoantibodies), and vascular (platelets) biomarkers in SSc patients. A total of 56 SSc patients and 120 control subjects (CS) were included. The serum levels of TGF-ß isoforms were quantified by immunoassay with magnetic microspheres, and the skin biopsies were processed by immunohistochemistry. The soluble levels of the three active TGF-ß isoforms were lower in SSc patients than in CS (p < 0.0001). However, sTGF-ß1 and sTGF-ß3 levels were positively correlated with C-reactive protein levels in SSc patients. Additionally, sTGF-ß2 and sTGF-ß3 levels were positively correlated with the number of platelets in SSc patients. In skin biopsies, TGF-ß1, TGF-ßR1, and TGF-ßR2 expression levels were higher in SSc patients than CS. In conclusion, this is the first study showing a joint decrease of the 3 active TGF-ß isoforms in SSc patients. However, TGF-ß1, TGF-ßR1, and TGF-ßR2 are possibly increased in clinically involved skin. Therefore, it is likely that a distinct role is played by TGF-ß at the local (skin lesions) and systemic levels in SSc patients.