Serum angiopoietin-like protein 3 concentrations in rheumatic diseases

Angiopoietin-like protein 3 (Angptl3) is one of the angiogenic cytokines that stimulates endothelial cell adhesion, migration, and neovascularization. No link has been established between Angptl3 and rheumatic diseases such as systemic sclerosis or dermatomyositis (DM). In this study, we determined the serum Angptl3 levels in patients with various rheumatic diseases, and tried to evaluate the possibility that serum levels of Angptl3 can be a useful disease marker. Serum samples were collected from 21 SSc patients, 10 systemic lupus erythematosus (SLE) patients, 21 DM patients, 5 polymyositis (PM) patients and 11 patients with clinically amyopathic DM (CADM) as well as 12 healthy volunteers. Levels of serum Angptl3 were measured with a specific ELISA kit. There was a significant increase of serum Angptl3 levels in patients with SSc or DM (p<0.05). Levels of serum Angptl3 were also slightly higher in patients with ADM, PM or SLE compared with healthy controls, but not statistically significant. Myoglobin levels were significantly higher in DM patients with increased serum Angptl3 levels than those with normal levels (p<0.05). In addition, among patients with SSc, the prevalence of cutaneous ulcers was significantly greater in patients with elevated Angptl3 levels than those with normal levels (p<0.05). Serum Angptl3 levels may be associated with the pathogenesis of muscle involvement in DM patients and microangiopathy in SSc patients. Clarifying the role of Angptl3 in each rheumatic disease may lead to further understanding of the pathogenesis and new therapeutic approaches.