Purpose: To investigate the capacity of the peripheral blood mononuclear cells (PBMC) from patients with systemic sclerosis (SSc) to produce vascular endothelial growth factor (VEGF), and to identify clinical associations of altered production of VEGF by PBMC in SSc. In addition, correlation with another pro-angiogenic cytokine, TNF-related weak inducer of apoptosis (TWEAK), was evaluated.
Methods: PBMC were isolated from 25 patients with SSc and 17 healthy controls (HC). VEGF and TWEAK were measured in the supernatants of cultured PBMC using commercially available ELISA kits.
Results: PBMC from SSc patients spontaneously released significantly greater amounts of VEGF as compared with HC. Production of VEGF was comparable between patients with early SSc and those with longer disease duration, and in both SSc groups higher than in HC. Patients without active digital ulcers produced significantly greater amounts of VEGF as compared with HC, while there was no significant difference in the production of VEGF between SSc patients with active digital ulcers and HC. VEGF/TWEAK ratio was significantly higher in PBMC from SSc patients than in HC indicating that high production of VEGF is not paralleled by increased release of TWEAK in SSc.
Conclusions: PBMC form SSc patients produce increased amounts of VEGF already in the early stage of disease. There is an imbalance in the profile of pro-angiogenic mediators produced by PBMC in SSc which might contribute to the pathogenesis of SSc. Further studies should address clinical significance of our findings.