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The plasma concentration of activated protein C appears normal in patients with haemophilia

S Schulman1, A Eelde, M Blombäck

  • 1Department of Hematology, Karolinska University Hospital, Stockholm, Sweden. schulms@mcmaster.ca

Haemophilia : the Official Journal of the World Federation of Hemophilia
|January 30, 2009
PubMed

Increased concentration of activated protein C (APC) has been observed in patients with thromboembolic disorders, but whether the level of APC in patients with bleeding disorders is decreased remains unknown. Seventy patients with haemophilia A or B with mild, moderate or severe form were studied. Detailed information on bleeding, arthropathy and factor consumption was collected during a 10-year period. The clinical severity of the disease was expressed as the Hemophilia Severity Score (HSS). Plasma concentration of APC was measured as APC in complex with protein C inhibitor. The median concentration of APC-PCI complex in patients with haemophilia was 0.14 microg L(-1) and it did not differ between the types and forms. In 16 patients with severe haemophilia A and the inversion mutation in intron 22, there was no correlation between clinical severity and the concentration of APC-PCI complex. Patients with haemophilia appear to generate normal concentrations of APC during basal conditions. APC does not seem to be an important modulator of the phenotypic expression of haemophilia.

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