Pseudo-homozygous activated protein C resistance due to coinheritance of heterozygous factor V Leiden mutation and type I factor V deficiency. Variable expression when analyzed by different activated protein C resistance functional assays.
Blood Coagul Fibrinolysis
; 8(8): 503-9, 1997 Nov.
Article
em En
| MEDLINE
| ID: mdl-9491268
ABSTRACT
The laboratory diagnosis of activated protein C (APC) resistance is based on a weak anticoagulant response to APC using a chronometric procedure confirmed in almost all cases by molecular diagnosis of the FV Leiden mutation. A recently-developed Xa-based assay (Accelerimat, Biomerieux) was compared with two different activated partial thromboplastin time (APTT)-based procedures (Coatest APC resistance and Modified Coatest, Chromogenix) in 115 patients with a personal or familial history of thrombotic disease, or both, being studied for the FV Leiden mutation. Our results confirmed the improvement in specificity for the FV Leiden mutation when the APTT-based assay was performed after dilution of samples in FV-deficient plasma (Modified Coatest). However, five patients who were heterozygous for the FV Leiden mutation appeared to be homozygous when tested by both APTT-based assays. These patients, belonging to three different families, had a FV type I deficiency with FV plasma levels between 43 and 64%. In contrast, the Xa-based method was not influenced by the decrease in plasma FV levels. Thus, this procedure is more specific than APTT-based assays to predict the genotype status of the FV Leiden mutation.
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Base de dados:
MEDLINE
Assunto principal:
Fator V
/
Proteína C
/
Mutação Puntual
/
Deficiência do Fator V
/
Heterozigoto
/
Homozigoto
Tipo de estudo:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Child
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Blood Coagul Fibrinolysis
Assunto da revista:
ANGIOLOGIA
/
HEMATOLOGIA
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
França