AB0629 CIRCULATING ENDOTHELIAL CELLS MAY BE A MARKER FOR VASCULAR INVOLVEMENT IN BEHCET DISEASE

Background: Circulating endothelial cells (CEC) are defined in conditions which vascular damage is seen in course of disease such as systemic vasculitis, coronary artery disease and chronic renal failure. CEC is thought to be an indicator of vascular damage (1). Behcet disease (BD) is a systemic vasculitis mostly known with recurrent oral and genital ulceration, uveitis and mucocutaneus lesions. On the other hand vascular involvement such as deep venous thrombosis, cerebral sinus thrombosis and pulmonary artery aneurysm, is an important clinical finding of disease which may cause mortality (2). Objectives: Our aim in this study was to analyse CEC levels in patients with Behcet disease, to compare them between patients with vascular (Group 1) and mucocutaneous (Group 2) involvement. Also we have compared the results of Behcet patients with patients with thrombosis due to other causes (Group 3) and healthy controls (Group 4). Each group involved 20 participant. Methods: Blood samples of the patients and healthy controls are drawn into tubes containing etylene-diamine-tetra-acetic acid (EDTA). A panel of monoclonal antibodies, including anti-CD45 to exclude hematopoietic cells, anti-CD31, -CD34, -CD36, -CD105, -CD106, -CD133,and –CD 146 and appropriate analysis gates were used to enumerate resting and activated CECs and circulating and endothelial progenitor cells (CEP). A hundred microlitre complete blood was added and incubated for 20 minutes at room temperature in the dark. After incubation for 10 minutes with erythrocyte lysing solution at room temperature, centrifugation at 1,800 rpm for 5 minutes was performed. Supernatant was removed and washed with phosphate buffer saline (PBS) for two times. Pellet was resuspended with PBS and 300.000–400.000 cells were counted with FACSCalibur flow cytometry device. Results: Mean age, sex distribution and duration of disease were similar in all groups (Table 1).Table 1 Demographic features of the study population Group p Group 1 Group 2 Group 3 Group 4 mean ± standart deviation Age 43.55 ± 8.31 46.85 ± 9.43 42.50 ± 15.22 41.65 ± 6.54 0.323** Duration of disease 14.90 ± 8.69 11.30 ± 8.80 - - 0.109* n (%) Sex Female 9 (% 45.0) 12 (% 60.0) 11 (% 55.0) 14 (% 70.0) 0.447*** Male 11 (% 55.0) 8 (% 40.0) 9 (% 45.0) 6 (% 30.0) * Mann Whitney U Test ** Kruskal Wallis H Test **** Pearson Chi Square Test * Mann Whitney U Test ** Kruskal Wallis H Test **** Pearson Chi Square Test CEC levels did not show a statistically significant difference between all groups. CEPs, activated CECs (aCEC) and resting CECs (rCEC) were also compared between groups. CEPs were higher in Behcet patients with thrombosis similar to patients with thrombosis due to other causes (p:0.042). Activated CECs levels did not show a difference between groups (p>0.05). Resting CECs are higher in Groups 1 and 3 than Groups 2 and 4. The detailed analysis of CEC, CEP, activated and resting CECs between groups is listed in Table 2.Abstract aB0629 Table 2 Comparision of CEC, CEP, aCEC and rCECs between groups Group p Multi analysis Group 1 Group 2 Group 3 Group 4 mean ± standart deviation CEC 5.09 ± 4.7 2.52 ± 2.55 4.89 ± 3.83 4.09 ± 4.9 0.077** - CEP 13.49 ± 9.38 7.62 ± 4.02 15.6 ± 11.21 13.71 ± 10.1 0.042** 1-2: 0.0152-3: 0.009 aCEC 4.39 ± 5.78 2.24 ± 2.14 8.17 ± 13.26 8.78 ± 13.21 0.054** - rCEC 6.44 ± 5.4 5.43 ± 3.49 9.03 ± 7.79 3.52 ± 2.34 0.007** 1-4: 0.0343-4: <0.001 Conclusion: Increased levels of aCECs may be an indicator of active vascular involvement in BD. But in the current study aCEC levels did not show a difference between groups but none of the patients had active vascular involvement which may cause of this sameness. CEP and resting CEC levels were elevated in both groups of patients with thrombosis. So CEC may be a marker for vascular damage but it is not specific for BD. References [1] Woywodt a Circulating endothelial cells in vasculitis and transplantation. Pathophysiol Haemost Thromb. 2003;33:500-2 [2] Kutlay S, Calayoglu R, Boyvat a, Turkcapar N, Sengul S, Keven K, Nergizoglu G. Circulating endothelial cells: a disease activity marker in Behçet’s vasculitis. Rheumatol int2008;29:159-162 Disclosure of interests: None declared