Summary
In haemophilia patients, a relationship is usually observed between the clinical expression
of the disease and plasmatic factor VIII/factor IX (FVIII/FIX) activity. However,
it is known from clinical experience, that some haemophilia patients, despite similar
FVIII/FIX plasma levels, could exhibit different bleeding phenotype. After determining
preanalytical test conditions, we evaluated the thrombin generation capacity from
haemophilia plasma samples in various conditions and the potential usefulness of thrombin
generation test (TGT) in haemophilia patients. In a series of 46 haemophilia patients
(34 haemophilia A and 12 haemophilia B patients), we found a significant correlation
between plasmatic FVIII/FIX levels and endogenous thrombin potential (ETP), peak and
time to peak obtained by thrombin generation measurement. In addition, a correlation
was found between severe clinical bleeding phenotype and ETP. Our results suggest
that TGT could be a promising tool to evaluate haemostasis capacity in patients with
haemophilia. Our ex vivo results, obtained 24 hours after FVIII concentrate administration, showed that in
patients presenting similar plasmatic FVIIII levels, thrombin generation capacity
may be significantly different. These results suggest that in patients with haemophilia,
TGT could be useful for individually tailoring prophylactic regimens as well as for
adapting clotting factors infusions in surgical situations, in addition to FVIII/FIX
plasma clotting activities.
Keywords
Factor VIII - factor IX - haemophilia - thrombin generation