Pentraxin-3 levels are associated with vasculitis and disease activity in childhood-onset systemic lupus erythematosus.

Objectives Childhood-onset systemic lupus erythematosus (cSLE) is a multisystemic autoimmune disease characterized by inflammatory organ damage by means of vasculitis. Pentraxin-3 (PTX3) is expressed locally at the sites of inflammatory processes, predominantly from endothelial cells. In adult studies, PTX3 has shown to be an indicator of active vasculitis both in large-vessel and small-vessel vasculitides, as well as in SLE. Moreover, in SLE it has found to be correlated with disease activity, and with some of the clinical manifestations and laboratory parameters. We aimed to ascertain if PTX3 might be a significant mediator in cSLE and if it might indicate active vasculitis during the course of the disease. Methods Serum PTX3 levels were measured in 76 patients with cSLE and 41 healthy subjects. We have investigated its relation with disease activity, damage, clinical features, laboratory parameters and medications. Results Serum levels of PTX3 were found to be increased in cSLE compared to healthy controls (mean ± SD; 10.6 ± 8.2 ng/mL vs 2.7 ± 1.3 ng/mL, p < 0.001). PTX3 concentrations were also in correlation with SLEDAI-2K ( r = 0.57, p < 0.001). When viewed from the clinical perspective, serum PTX3 levels were significantly higher only in patients with active vasculitis ( p < 0.001), Raynaud phenomenon ( p = 0.006) and mucocutaneous manifestations ( p < 0.001). However, an association between PTX3 and age, age at disease onset, disease duration, complement levels, PedSDI score (pediatric version of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index), ESR, CRP, procalcitonin levels, anti-ds DNA antibody, anticardiolipin antibodies was not detected. Conclusions Patients with cSLE have increased levels of serum PTX3 compared to healthy controls. Thus, serum PTX-3 level might be a significant mediator in cSLE. Apart from these, the results support that PTX3 reflects active cutaneous vasculitis in cSLE and correlates with disease activity.