Publication Date:
2011-11-18
Description:
Abstract 5265 Background Platelet function is influenced by changes in membrane fluidity (MF) which has an important role in the expression of platelet receptors and in modulating the activity of proteins like phospholipase C or proteinkinase C (Koner et al, Int J Biochem Cell Biol. 1998). It also modifies the aggregation/agglutination of freshly prepared platelets from volunteers (Vlasic et al, Life Sci. 1993). Reactive oxygen species (ROS) are involved in integrin αIIbβ3 activation (Begonja et al, Blood Cells, Mol. and Dis. 2006; Clutton et al, Arterioscler. Thromb. Vasc Biol. 2004). Moreover, bursts of ROS are generated in platelets exposed to thrombin (Wachowicz et al, Platelets. 2002). The MF and ROS have been studied in platelets of patients with Alzheimer disease (Cardoso SM et al, Neurobiol Aging. 2004) or chronic myeloproliferative neoplasms (Popov et al, Blood, ASH abstr.), but to our knowledge, not yet in patients with myelodysplastic syndromes (MDS). Aim Study of platelet MF changes and ROS production in patients with MDS and eventual correlation with altered platelet function as it is reflected in aggregation curves. Material and method The retrospective study included 34 patients with MDS classified according to FAB proposals and 29 healthy volunteers. Platelet MF was quantified by fluorescence anisotropy measurements using the marker 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene p-toluenesulfonate (TMA DPH). ROS production was evaluated by fluorescence measurements using dichlorodihydrofluorescein diacetate(DCFDA-H2). Platelet function was analyzed by optical aggregometry using the agonists: ADP, collagen, ristocetin and epinephrine. Results Platelet MF in patients with MDS was similar to that of healthy volunteers and did not vary according to the category of risk (mean anisotropy: rMDS = 0.155 +/− 0.043 vs. rcontrol= 0.144 +/− 0.040, p = 0.37; r low risk MDS =0.156 +/− 0.050 vs. r high risk MDS= 0.170 +/− 0.051, p = 0.52.) Patients with MDS have increased platelet ROS production compared to control group (mean AUC: MDS=657.66 +/− 51.10 vs control= 575.59 +/− 76.56, p = 0.02.) without statistical correlation with MF. ROS level was proportional to the severity of anemia (R =- 0.587, p = 0.0169). Platelet response to ADP, epinephrine was reduced in patients with MDS comparatively to volunteers. Median amplitude A ADP-MDS=37 (95% CI = 25.21–49.36) vs. A ADP-control=74 (95% CI 62.24–76,5), p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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