Coagulation activator levels higher in patients with antiphospholipid syndrome

A coagulation activator implicated in deep vein thrombosis was seen in higher serum concentrations in patients with antiphospholipid syndrome patients compared with a healthy population, according to research presented at the American College of Rheumatology conference in Boston.

Researchers studied sera and plasma from 50 patients with antiphospholipid syndrome (APS) diagnosed by the revised Sapporo classification criteria and compared the levels of neutrophil extracellular trap (NET) release with that of healthy control participants. Neutrophils from APS patients were scored for their ability to release NETs and in healthy participants, neutrophils were stimulated with APS patient sera, purified immunoglobulin G (IgG) or antiphospholipid (aPL) monoclonal antibodies and measured. Additionally, the expression of known aPL receptors, beta-2-glycoprotein and annexin A2, was measured on the neutrophil surface, and the generation of reactive oxygen species was determined.

Patients with APS showed 2.7-fold higher levels of NETs and were also predisposed to spontaneous NET release compared with healthy volunteers, according to the researchers. APS-patient sera and IgG purified from patients with aPL stimulated NET release in neutrophils from healthy volunteers.

Neutrophils from both patients with APS and healthy volunteers displayed beta-2 glycoprotein I on their surface, which can enhance NET release, according to the researchers.

Circulating NET levels were higher in patients with APS during and in between thrombotic events. Further investigation into the role of neutrophils as a potential target for therapy are warranted, the researchers concluded. – by Shirley Pulawski

Reference:

Yalavarthi S, et al. Paper #2867. Presented at: American College of Rheumatology Annual Meeting. Nov. 14-19, 2014; Boston.

Disclosure: The authors had no relevant financial disclosures.