Relationship between hypercoagulable state and erythrocyte phosphatidylserine exposure in splenectomized haemoglobin E/β‐thalassaemic patients*

• DOI: 10.1046/j.1365-2141.2002.03711.x
• Publication Date: 2003-03-11T06:47:01Z
• Authors: Vichai Atichartakarn; Pantep Angchaisuk...; Katcharin Aryurachai; Supornchai Onpun; Suporn Chuncharunee; Ammarin Thakkinstian; Kanlayanee Atamas...
• Keywords: Adult; Male; Erythrocytes; Hemoglobin E; Antithrombin III; beta-Thalassemia; Phosphatidylserines; Peptide Fragments; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Chronic Disease; Splenectomy; Humans; Thrombophilia; Female; Prothrombin; Peptide Hydrolases

Summary. Small pulmonary arterial thromboses can occur following splenectomy of patients with haemoglobin E/β‐thalassaemia (Hb E/β‐thal). We compared plasma markers of coagulation activation in vivo and red blood cell (RBC) markers of procoagulant activity in 15 Hb E/β‐thal patients who were not splenectomized (NS), 15 who had been splenectomized (S), and 15 normal controls (NC). Levels of plasma thrombin–antithrombin III complex (TAT) were significantly higher in the S group than in either the NS or the NC groups, and levels of prothrombin fragment 1.2 (F 1.2) were significantly higher in the S than in the NC group. Diluted Russell's viper venom clotting times were significantly shorter when RBCs from group S patients were added to the assay compared with RBCs from the NC group. Phosphatidylserine (PS) expression (% of annexin V‐positive RBCs) on the outer leaflet of RBC membrane of both ‘larger’‐ and ‘smaller’‐sized RBCs was significantly higher for the S than the NC group. The RBC PS expression of the S and the NS groups, respectively, accounted for 25·3% (P = 0·174) and 6·3% (P = 0·675) of the variation in plasma TAT levels. Our findings indicated that, when compared with NC, splenectomized patients with Hb E/β‐thal were in a chronic low‐grade hypercoagulable state associated with increased numbers of circulating PS exposed RBCs. This condition may have a role in the risk of these patients for pulmonary arterial thromboses.