TY - JOUR JF - Blood-Journal JO - Sci J Iran Blood Transfus Organ VL - 4 IS - 3 PY - 2007 Y1 - 2007/9/01 TI - Natural anticoagulant system in children with beta-thalassemia major TT - سطح فعالیت پروتئین‌های ضد انعقادی طبیعی پلاسما در کودکان مبتلا به تالاسمی ماژور N2 -   Abstract  Background and Objectives Thrombotic events are among the most important complications in patients with beta-thalassemia major. Alterations in natural anticoagulation system have a major contribution to the occurrence of thrombotic events in these patients. This study was performed to evaluate the protein C, protein S and Antithrombin III activity in patients with beta-thalassemia major having referred to Mofid Children Hospital in 1382.   Materials and Methods Thalassemic children older than 2 years of age, with the interval of more than 25 days since last transfusion, and without any evidence of symptomatic liver or heart disease were enrolled in the study. Plasma activity of protein C and protein S was assessed by PTT based tests and the activity of antithrombin III was determined by chromogenic method. The correlation between decreased levels of anticoagulants and other parameters such as splenectomy, liver transaminases and serum ferritin level was analyzed by spss software.T-test and Mann whitney U-test were used to compare the mean values of variables.   Results 20.3% of patients showed a decrease in protein C and 15.3% in protein S. 12 patients had been splenectomized. Mean protein C activity in splenectomized and non-splenectomized patients were 63.4 ± 17.9% and 74.5± 15.1% , respectively (p SP - 181 EP - 187 AU - Alavi, S. AU - Arzanian, M.T. AU - Ahmadinejad, M. AU - Meshkat Razavi, G. AU - Valaee, N. AU - Tabatabaee, M.R. AU - Karbasizadeh, M. AD - KW - Thalassemia major KW - Thrombosis KW - Anticoagulant KW - Splenectomy UR - http://bloodjournal.ir/article-1-172-en.html ER -