Circulating angiogenesis inhibitor endostatin and positive endothelial growth regulators in patients with systemic lupus erythematosus

Serum concentrations of three angiogenic cytokines: vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), interleukin-18 (IL-18) and antiangiogenic factor endostatin in the serum of 52 patients with systemic lupus erythematosus (SLE) and 20 healthy subjects were investigated. The possible association between serum levels of these proteins and SLE activity as well as correlation between the concentrations of angiogenic cytokines and the level of endostatin was also analyzed. VEGF and IL-18 were detectable in all SLE patients and healthy control group. bFGF was measurable in 71.2% of patients with SLE and 65% of healthy persons. Endostatin was detectable in 94.2% of SLE patients and 95% of normal subjects. The serum levels of endostatin and bFGF were not significantly different in SLE and healthy control (P > 0.05). The median concentration of VEGF was higher in active SLE (238.4pg/ml) than in inactive disease (118.1pg/ml, P < 0.05) or in control group (133.5pg/ml, P < 0.04). The median serum level of IL-18 was higher in the SLE patients (595.2pg/ml) than in the control group (252.7pg/ml) (P < 0.001). The correlations between the levels of angiogenic cytokines and endostatin with clinical features, laboratory abnormalities and also with the type of treatment were analysed. We found a positive correlation between VEGF serum concentration and SLE activity according to SLAM score (r=0.275, P < 0.05). The significant positive correlation was also found between IL-18 and endostatin (r=0.289, P < 0.04). In contrast, the correlation between bFGF and endostatin was significantly negative (r=7 0.299, P < 0.04). In conclusion, serum levels of the angiogenic and antiangiogenic factors may play an important role in SLE pathogenesis.