The hypercoagulable status in common Mediterranean β-thalassaemia mutations trait

The coagulation activation in β-thalassaemia is multifactorial and most likely a consequence of the exposure of phosphatidylserine (PS) on RBCs surface. The degree of PS exposure and procoagulant activity of RBCs in β-thalassaemia trait (BTT) subjects carrying common Mediterranean mutations were assessed.

Eighty BTT subjects carrying common Mediterranean mutations (β+, n = 53 and β0 , n = 27) and sixty healthy subjects served as controls were studied. Plasma prothrombin fragment 1+2 (F1+2), percentage of PS expression on RBCs membrane, clotting times of modified thromboplastin generation test (MTGT) and modified partial thromboplastin with kaolin (MPTTK) were estimated.

The percentage of annexin V positive RBCs and plasma F1+2 had a significant increase and MTGT had a significant decrease in BTT subjects versus controls and in β0 group versus β+ group. MPTTK was significantly shorter in BTT subjects than controls, but no significant deference between BTT subjects. The percentage of annexin V positive RBCs showed a significant negative correlation with haemoglobin level, MTGT and MPTTK, and a significant positive correlation with plasma F1+2.

BTT subjects may have a risk of hypercoagulable state particularly in β0 genotype. Measurement of PS exposure on RBCs and the plasma F1+2 is useful to evaluate hypercoagulability state.