To characterise serum concentrations of various cytokines and detection by magnetic resonance imaging (MRI) of synovial hypervascularity in patients with remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome before and after corticosteroid treatment.
Vascular endothelial growth factor(165) (VEGF(165)), tumour necrosis factor alpha (TNFalpha), and interleukin 1beta (IL1beta) were measured by enzyme linked immunosorbent assay (ELISA) in serum samples from three patients with RS3PE syndrome. As controls, serum samples from 26 healthy volunteers, 12 patients with rheumatoid arthritis, 10 patients with systemic lupus erythematosus, 13 patients with polymyositis/dermatomyositis, 13 patients with vasculitis syndrome, and 6 patients with mixed connective tissue disease were also analysed. Synovial hypervascularity of patients with RS3PE syndrome was estimated by rate of enhancement (E-rate) in a dynamic MRI study.
Serum concentrations of VEGF(165) (mean (SD) 2223.3 (156.3) pg/ml) were significantly higher in patients with active RS3PE syndrome than in controls before corticosteroid treatment. TNFalpha and IL1beta levels were similar in patients and controls. Synovial hypervascularity in affected joints and subcutaneous oedema decreased during corticosteroid treatment, in parallel with the fall in serum VEGF(165).
VEGF promotes synovial inflammation and vascular permeability in patients with RS3PE syndrome, suggesting that RS3PE can be classified as a VEGF associated disorder.