Relationship between hypercoagulable state and erythrocyte phosphatidylserine exposure in splenectomized haemoglobin E/beta-thalassaemic patients

Br J Haematol. 2002 Sep;118(3):893-8. doi: 10.1046/j.1365-2141.2002.03711.x.


Small pulmonary arterial thromboses can occur following splenectomy of patients with haemoglobin E/beta-thalassaemia (Hb E/beta-thal). We compared plasma markers of coagulation activation in vivo and red blood cell (RBC) markers of procoagulant activity in 15 Hb E/beta-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 x 3% (P = 0 x 174) and 6.3% (P = 0 x 675) of the variation in plasma TAT levels. Our findings indicated that, when compared with NC, splenectomized patients with Hb E/beta-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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antithrombin III
  • Chronic Disease
  • Erythrocytes / metabolism
  • Female
  • Hemoglobin E / analysis*
  • Humans
  • Male
  • Peptide Fragments / blood
  • Peptide Hydrolases / blood
  • Phosphatidylserines / blood*
  • Prothrombin
  • Splenectomy / adverse effects*
  • Thrombophilia / blood
  • Thrombophilia / etiology*
  • beta-Thalassemia / blood
  • beta-Thalassemia / surgery*


  • Peptide Fragments
  • Phosphatidylserines
  • antithrombin III-protease complex
  • prothrombin fragment 1.2
  • Antithrombin III
  • Prothrombin
  • Hemoglobin E
  • Peptide Hydrolases