Référence 3

P Hainaut, MA Azerad, F Lehmann, AF Schlit, F Zech, M Heusterspreute, M Philippe, C Col, E Lavenne, M Moriau.

Prevalence of activated protein C resistance and analysis of clinical profile in thromboembolic patients. A Belgian prospective study.

J Intern Med 1997; 241: 427-33


Objectives : To assess the prevalence of activated protein C resistance (APC-R) among healthy subjects and thromboembolic patients and to determine the clinical characteristics associated with APC resistance.

Design: A prospective study.

Setting: One academic medical centre.

Subjects: 91 healthy controls and 126 thromboembolic patients.

Measurements: Patients and controls were genotyped for the factor V Leiden (VaQ506) mutation. The anticoagulant response of the patient's plasma to APC was also determined.

Results: The frequency of APC-R was 3,3 % among healthy control subjects and 22 % among thrombotic patients including 18 % heterozygous and 4% homozygous. The mean age at the first thrombotic event and the severity of thrombotic disease including the proportion of proximal DVT and the frequency of lung embolism were identical among APC-R positive and negative patients. A family history of thromboembolic disease was elicited more frequently in APC-R positive than in negative patients (57% vs 22%, p<0,001). The recurrence rate was higher for APCR-R positive patients (57% vs 34% , p<0,05). The percentage of cases with a factor predisposing to thrombosis was very similar in APC-R positive (57%) and negative (68%) patients.

Conclusions: a familial history of thromboembolic disease and recurrences are significantly more frequent among APC-R positive than APC-R negative patients.