Annals of Hematology

, Volume 93, Issue 4, pp 683–692

An in-vitro assessment of tranexamic acid as an adjunct to rFVIII or rFVIIa treatment in haemophilia A

  • Catherine J. Rea
  • Jonathan H. Foley
  • David H. Bevan
  • Benny Sørensen
Original Article

DOI: 10.1007/s00277-013-1921-z

Cite this article as:
Rea, C.J., Foley, J.H., Bevan, D.H. et al. Ann Hematol (2014) 93: 683. doi:10.1007/s00277-013-1921-z

Abstract

Haemophilia is characterised by defective thrombin generation, reduced clot stability and spontaneous bleeding. Treatment with factor VIII (FVIII) concentrate or bypassing agents (e.g. recombinant factor VIIa (rFVIIa)) is generally effective. Occasionally, haemostasis is not achieved, which may reflect a failure of factor concentrate to normalise clot stability. Tranexamic acid (TXA) is often used to aid haemostasis in surgery (e.g. joint replacements and dental procedures). Used routinely as an adjunct, it may enhance clot stability and allow effective, reliable, and cost-effective treatment at lower doses of factor concentrate. This study hypothesised that clot stabilising adjunct TXA is required in addition to factor substitution to normalise clot stability in whole blood from patients with severe haemophilia A. The in vitro effect of varying concentrations of recombinant FVIII or recombinant FVIIa and adjunct TXA on whole blood clot stability was measured by thromboelastometry. Coagulation was triggered by tissue factor and clots were challenged with tissue plasminogen activator. The area under the elasticity curve was the primary endpoint. High concentrations of FVIII and rFVIIa increased clot stability to levels that were not significantly different from controls (Mean ± SD: control 112,694 ± 84,115; FVIII 78,662 ± 74,126; rFVIIa 95,918 ± 88,492). However, the response was highly variable between individuals and demonstrates why some patients show clinical resistance to treatment. Addition of TXA resulted in normalised clot stability in all individuals, even when combined with the lowest doses of factor concentrate. The results support the concept that a more efficient, reliable and cost effective treatment may be obtained if TXA is combined with factor concentrates to treat individuals with haemophilia.

Keywords

Tranexamic acidHaemophilia AClot stabilityAdjunctrFVIIIrFVIIa

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Catherine J. Rea
    • 1
    • 2
  • Jonathan H. Foley
    • 4
  • David H. Bevan
    • 1
  • Benny Sørensen
    • 3
  1. 1.Centre for Haemophilia and ThrombosisGuy’s and St Thomas’ NHS Foundation TrustLondonUK
  2. 2.School of MedicineKing’s College LondonLondonUK
  3. 3.Centre for Haemophilia and ThrombosisAarhus University HospitalSkejbyDenmark
  4. 4.Centre for Blood ResearchUniversity of British ColumbiaVancouverCanada