Pentraxin 3 as a biomarker of local inflammatory response to vascular injury in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder with organ injury related to vasculitis. Inflammation of blood vessels results from auto-immunological activation of endothelial cells. The pentraxin 3 (PTX3), might act as an indicator of vasculitides in many diseases. The aim of this study was to determine whether PTX3 might be useful as a marker of vascular injury in SLE. This study was carried out in a group of 56 SLE women, and in the 28 female volunteers control group. All participants’ plasma and serum samples were collected to estimate concentrations (ELISA) of PTX3, soluble thrombomodulin, soluble E-selectin (sE-selectin), soluble P-selectin (sP-selectin), soluble form of vascular cell adhesion molecule 1 (sVCAM-1), soluble inter-cellular adhesion molecule-1 (sICAM-1), soluble platelet endothelial cell adhesion molecule 1, monocyte chemotactic protein-1 (MCP-1) and von Willebrand factor (vWF) activity. Anthropometric, demographic and lifestyle characteristics of SLE patients were also performed. The SLE patients had higher PTX3, vWF, MCP-1, sE-selectin and sVCAM-1 levels than the controls (1.82 ± 1.56 ng/mL, 237 ± 101%, 70.05 ± 18.31 ng/mL, 111.16 ± 49.15 ng/mL and 978.78 ± 462.35 ng/mL vs. 0.86 ± 0.40 ng/mL, 138 ± 43%, 58.56 ± 13.91 ng/mL, 66.04 ± 27.18 ng/mL and 499.07 ± 125.67 ng/mL, respectively). The independent factors affecting PTX3 expression included Systemic Lupus Erythematosus Disease Activity Index, prednisone dose and anemia severity. Moreover, the PTX3 areas under the curve–receiver operating characteristics curves 0.717 ± 0.056 with cut-off level of 1.96 ng/mL was comparable to vWF, MCP-1, sE-selectin, sP-selectin and sICAM-1. PTX3 and sVCAM-1 were the only factors related to SLE activity. Other vascular injury indicators associated with PTX3 were vWF and sVCAM-1. In conclusion, PTX3 concentrations in SLE patients might serve as a indicator of the activation/dysfunction of vascular endothelium.