Use of recombinant activated factor VII to control bleeding in a young child with qualitative platelet disorder: a case report.
Defects of platelet adhesion, aggregation, secretion, or procoagulant activities can lead to bleeding diathesis of variable severity. We used recombinant activated factor VII (rFVIIa) in the treatment of uncontrolled epistaxis in a patient with a qualitative platelet disorder. We aimed to assess the efficacy of a single rFVIIa dose (100 microg/kg) in the control of mild and severe refractory epistaxis, and evaluate the influence of rFVIIa on markers of platelet adhesion and aggregation during a period of hematological stability (i.e. non-bleeding, no medication). The efficacy study showed mild episodes of epistaxis could be successfully managed using a single rFVIIa (100 microg/kg) dose; however, severe bleedings were not well controlled, and platelet transfusion was required to achieve hemostasis. Hematological investigations showed ADP-induced and collagen-induced platelet aggregation increases from 20 to 34% and 16 to 30%, respectively, following rFVIIa administration. There were no differences between pre-dose and post-dose concentrations of membrane glycoproteins. rFVIIa may therefore induce platelet aggregation by activating a glycoprotein-independent aggregation pathway. rFVIIa may have a role in managing mild bleeding episodes not controlled using conventional measures in patients with a qualitative platelet disorder. Further research is needed to determine the mechanism of action, efficacy, and safety of rFVIIa in this population.
Inagaki
Minoru
M
Inagaki Children's Clinic Tokyo, Japan. inagaki.m@mx7.ttcn.ne.jp
Mori
Tetsuya
T
Tsunematsu
Yukiko
Y
Ambo
Hironobu
H
Kawai
Yoko
Y
D002675:Child, Preschool; D015942:Factor VIIa / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000188:drug therapy*; D006490:Hemostatics / Q000008:administration & dosage; D006801:Humans; D007275:Injections, Intravenous; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D011994:Recombinant Proteins / Q000008:administration & dosage; D013915:Thrombasthenia / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome
D006490:Hemostatics; D011994:Recombinant Proteins; D015942:Factor VIIa