Inhibitory anti-factor V antibodies bind to the factor V C2 domain and are associated with hemorrhagic manifestations.
Blood
; 91(11): 4188-96, 1998 Jun 01.
Article
en En
| MEDLINE
| ID: mdl-9596666
ABSTRACT
Factor V inhibitors may develop as spontaneous autoantibodies, as alloantibodies after exposure to bovine thrombin preparations, or in factor V-deficient patients after plasma therapy. Clinical manifestations range from asymptomatic laboratory abnormalities to life-threatening hemorrhage. We have characterized the anti-factor V antibodies from 12 patients diagnosed with factor V inhibitors. In 8 patients, hemorrhagic complications (5 autoantibodies and 3 bovine thrombin-induced alloantibodies) developed, and 4 were asymptomatic (2 autoantibodies and 2 alloantibodies). The IgG fractions from all 12 patients immunoprecipitated the factor Va light chain, but only the 8 IgG fractions associated with hemorrhage inhibited factor V activity in a prothrombinase assay. Nine IgG fractions, including the 8 patients with hemorrhage, immunoprecipitated the isolated second C-type domain (C2). The 8 IgG fractions from the symptomatic patients also immunoprecipitated recombinant chimeras containing only the N-terminal third of the factor V C2 domain, and isolated recombinant C2 domain abrogated the inhibitory effect of the antibodies. Five of the inhibitory IgG fractions blocked binding of factor V to phosphatidylserine. These results suggest that inhibitory anti-factor V antibodies are associated with hemorrhagic manifestations and frequently bind to a common region within the C2 domain, whether originating spontaneously or after exposure to bovine thrombin.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Autoanticuerpos
/
Factor V
/
Trastornos Hemorrágicos
Tipo de estudio:
Risk_factors_studies
Límite:
Adolescent
/
Aged
/
Aged80
/
Animals
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Blood
Año:
1998
Tipo del documento:
Article
País de afiliación:
Estados Unidos