Figure 1

Microparticle (MP) assessment in synovial fluids from arthritic patients and cell supernatants. (a) Concentrations of MPs in synovial fluids from patients with rheumatoid arthritis (RA) (n = 7), osteoarthritis (OA) (n = 5), microcristalline arthritis (MC) (n = 3), and reactive arthritis (AR) (n = 5) were determined by a solid-phase capture assay on immobilized annexin V by use of a prothrombinase assay (nM PhtdSer Eq). (b) Concentrations of MPs isolated from THP-1 cells stimulated with lipopolysaccharide (LPS) (15 μg/mL) for 18 hours were determined by a solid-phase capture assay on immobilized annexin V or on immobilized CD14 antibody by use of a prothrombinase assay (nM PhtdSer Eq). The control (C) corresponded to untreated cells. Data are expressed as the mean of triplicate samples ± standard deviation and are representative of three independent experiments. *P < 0.05. PhtdSer Eq, phosphatidylserine equivalents.