Hypercoagulability in splenectomized thalassemic patients detected by whole-blood thromboelastometry, but not by thrombin generation in platelet-poor plasma.
BACKGROUND
The mechanisms responsible for the increased thrombotic risk associated with thalassemia are still unclear. They might be related to the effects of red blood cell or endothelial cell derangements, increased numbers of platelets as well as abnormal plasma coagulation.


METHODS
To evaluate the relative role played by cells and plasma we investigated 169 patients with thalassemia by means of thromboelastometry and thrombin generation tests. Thromboelastometry measures indices of the viscoelastic properties of whole blood after activation of coagulation and is characterized by the clotting time, which may be considered as a conventional coagulation time, clot formation time, defined as the time needed for the clot to reach a fixed firmness, and the maximum clot firmness, defined as the maximal amplitude of the tracing.


RESULTS
All the thromboelastometry parameters determined in whole blood (including shortened clotting time and clot formation time, and increased maximum clot firmness), were consistent with hypercoagulability, especially in splenectomized patients. Conversely, thrombin generation as determined in platelet-poor plasma was not.


CONCLUSIONS
These findings point to blood cells and/or platelets rather than to plasma abnormalities as the most important determinants of the thrombotic risk observed in thalassemic patients who had been splenectomized. These results might have important diagnostic and therapeutic implications.
Tripodi
Armando
A
Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, University and IRCCS Maggiore Hospital, Mangiagalli and Regina Elena Foundation, Milan, Italy.
Cappellini
Maria Domenica
MD
Chantarangkul
Veena
V
Padovan
Lidia
L
Fasulo
Maria Rosaria
MR
Marcon
Alessia
A
Mannucci
Pier Mannuccio
PM
D000328:Adult; D000368:Aged; D001773:Blood Cells / Q000473:pathology; D001792:Blood Platelets / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D013156:Splenectomy; D013789:Thalassemia / Q000097:blood* / Q000150:complications; D013916:Thrombelastography / Q000379:methods*; D013917:Thrombin / Q000096:biosynthesis; D019851:Thrombophilia / Q000175:diagnosis / Q000209:etiology*; D013927:Thrombosis / Q000209:etiology; D055815:Young Adult
D013917:Thrombin