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;
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
Subjects: 91 healthy controls and 126
Measurements: Patients and controls were
genotyped for the factor V Leiden (VaQ506) mutation. The
anticoagulant response of the patient's plasma to APC was
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