BSG and rheumatoid arthritis: Flow cytometry showed the percentage of cells that stained positive for CD147, PAC-1 and P-selectin (CD62P); the percentages of stained active (mean ± SD 47.63 ± 3.1, 41.73 ± 2.89 and 10.18 ± 1.15%, respectively) platelets and platelets from patients with inactive RA (28.69 ± 1.42, 17.41 ± 1.63 and 3.99 ± 0.46%, respectively) were significantly higher than those of healthy platelets (12.26 ± 0.83, 3.8 ± 0.44 and 0.39 ± 0.07%, respectively; P <0.05), especially in active RA patients.