Increased procoagulant cell-derived microparticles (C-MP) in splenectomized patients with ITP

• Published in: Thrombosis research Vol. 122; no. 5; pp. 599 - 603
• Main Authors: Fontana, V, Jy, W, Ahn, E.R, Dudkiewicz, P, Horstman, L.L, Duncan, R, Ahn, Y.S
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 2008; Elsevier Science
• Subjects: Biological and medical sciences; Blood and lymphatic vessels; Blood Coagulation Factors - metabolism; Blood vessels and receptors; Cardiology. Vascular system; Cardiovascular disease; Cardiovascular Diseases - etiology; Case-Control Studies; Cell-Derived Microparticles - pathology; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Erythrocytes - pathology; Female; Fundamental and applied biological sciences. Psychology; Hematology, Oncology and Palliative Medicine; Humans; ITP; Male; Medical sciences; Microparticles; Middle Aged; Purpura, Thrombocytopenic, Idiopathic - blood; Purpura, Thrombocytopenic, Idiopathic - complications; Purpura, Thrombocytopenic, Idiopathic - surgery; Red cell microparticles; Risk Factors; Splenectomy; Splenectomy - adverse effects; Thrombosis - etiology; Vertebrates: cardiovascular system; Splenectomy; Cardiovascular disease; Red cell microparticles; ITP; Microparticles; Vascular disease; Human; Blood cell; Risk factor; Red blood cell; Thrombosis
• ISSN: 0049-3848; 1879-2472
• DOI: 10.1016/j.thromres.2007.12.022

Abstract Background : Splenectomy is frequently employed for therapeutic and diagnostic purposes in various clinical disorders. However its long-term safety is not well elucidated. Although risk of infection by encapsulated organisms is widely recognized, less well-known are risks of thrombosis and cardiovascular disease. Methods : We investigated levels of cell-derived microparticles (C-MP) in 23 splenectomized ITP (ITP-S) and 53 unsplenectomized ITP patients (ITP-nS). Assay of C-MP derived from platelets (PMP), leukocytes (LMP), red cells (RMP) and endothelial cells (EMP) were performed by flow cytometry. Coagulation parameters included PT, aPTT and activities of FVIII, IX and XI. Results of all measures were compared between the two groups, ITP-S vs ITP-nS. Results : Levels of all C-MP were higher in ITP-S than ITP-nS but only RMP and LMP reached statistical significance ( p = 0.0035 and p < 0.0001, respectively). The aPTT was significantly shorter in ITP-S ( p = 0.029). Interestingly, correlation analysis revealed that RMP, but not other C-MP, were associated with shortening of aPTT ( p = 0.024) as well as with increased activities of factors VIII ( p = 0.023), IX ( p = 0.021) and XI ( p = 0.0089). Conclusions : RMP and LMP were significantly elevated in splenectomized compared to non-splenectomized ITP patients. This suggests that the spleen functions to clear procoagulant C-MP, and that elevation of C-MP might contribute to increased risk of thrombosis, progression of atherosclerosis and cardiovascular disease following splenectomy.