Background
Immune cell-derived microparticles (MPs) are present at increased amounts in synovial fluid of rheumatoid arthritis (RA) patients [1] and can activate disease-relevant signalling pathways in RA synovial fibroblasts (SF) [2, 3]. Increased resistance to apoptosis is one of the main characteristics of aggressive phenotype of RASF [4, 5] and MPs have been shown to mediate both pro- and anti- apoptotic effects in different target cells [6, 7]. The aim of the present study was to investigate the functional role of immune cell-derived MPs in modulating the apoptosis of SF in RA.