CD40LG and rheumatoid arthritis: Increased expression of P-selectin (21.6±0.5 % vs 24.4±0.6 %; P<0.001) (Fig. 1a), increased P-selectin mean fluorescence intensity (MFI) (119.5±1.5 vs 130.5±2.0; P<0.0001) (Fig. 1b), more platelet aggregation (3.3±0.1 vs. 3.9±0.2; P<0.01) (Fig. 1d) and enhanced production of sCD40L (0.99±0.0.14 ng/ml vs 1.5±0.18 ng/ml; P<0.05) (Fig. 1f) were detected after incubation of platelets of healthy subjects in the presence of plasma from patients with RA.