Age, gender and disease-related platelet and neutrophil activation ex vivo in whole blood samples from patients with Behcet's disease

Objectives. Behcet's disease (BD) is more severe among young males and disease severity decreases with age. Therefore, the effect of disease activity, gender and age on platelet and neutrophil activation in whole blood taken from patients with BD was investigated. Methods. Using an anti-coagulant Tripotassium ethylenediaminetetra acetic acid (K(3)EDTA) plus citrate-theophylline-adenosine-dipyridamole (CTAD) (K(3)EDTA/CTAD) that preserves the degree of platelet activation that exists in vivo, we assessed neutrophil and platelet activation, microparticles, and monocyte and neutrophil-platelet aggregate formation in 43 BD patients using flow cytometry. This is the first description of platelet activation and microparticles in BD patients using this methodology. Results. Inactive [2.78 (0.56)%, P = 0.0009; 3.11 (0.78)%, P < 0.0001] and active [2.28 (0.84)%, P < 0.0001; 3.071 (0.67)%, P = 0.0031] BD patients had significantly higher percentages of CD62P-expressing platelets and CD62P(+) platelet microparticles as compared with healthy controls (HCs) [0.84 (0.1)% and 1.23 (0.14)%], respectively. The percentages of CD62P(+) platelets and CD62P(+) platelet microparticles in female and male BD patients were also significantly higher than those expressed by female and male HCs. The percentages of CD62P(+) microparticles were significantly increased in the 20-30-(P = 0.0301) and 31-50-(P < 0.0162) year age ranges, but not in the > 50-year age group of BD patients. Conclusion. BD is a rare, chronic multi-systemic vasculitis and interaction of activated platelets with leucocytes has been linked to pathological disorders associated with vascular inflammation. Importantly, this study demonstrates that platelet microparticle activation is increased in BD. Also, this is the first report in which changes in platelet activation in BD are concordant with the observations that BD disease activity diminishes with age.