scholarly journals Resistance to activated protein C caused by the R506Q mutation in the gene for factor V is a common risk factor for venous thrombosis

1997 ◽  
Vol 242 ◽  
pp. 1-8 ◽  
Author(s):  
B. DAHLBÄCK
Blood ◽  
2014 ◽  
Vol 124 (9) ◽  
pp. 1531-1538 ◽  
Author(s):  
Farida Omarova ◽  
Shirley Uitte de Willige ◽  
Paolo Simioni ◽  
Robert A. S. Ariëns ◽  
Rogier M. Bertina ◽  
...  

Key Points Fibrinogen, and particularly fibrinogen γ′, counteracts plasma APC resistance, the most common risk factor for venous thrombosis. The C-terminal peptide of the fibrinogen γ′ chain inhibits protein C activation, but still improves the response of plasma to APC.


2011 ◽  
Vol 154 (2) ◽  
pp. 241-247 ◽  
Author(s):  
Astrid Bergrem ◽  
Anders Erik Astrup Dahm ◽  
Anne Flem Jacobsen ◽  
Marie-Christine Mowinckel ◽  
Leiv Sandvik ◽  
...  

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1271-1276 ◽  
Author(s):  
Marieke C.H. de Visser ◽  
Frits R. Rosendaal ◽  
Rogier M. Bertina

Abstract Activated protein C (APC) resistance caused by the factor V Leiden mutation is associated with an increased risk of venous thrombosis. We investigated whether a reduced response to APC, not due to the factor V point mutation, is also a risk factor for venous thrombosis. For this analysis, we used the Leiden Thrombophilia Study (LETS), a case-control study for venous thrombosis including 474 patients with a first deep-vein thrombosis and 474 age- and sex-matched controls. All carriers of the factor V Leiden mutation were excluded. A dose-response relationship was observed between the sensitivity for APC and the risk of thrombosis: the lower the normalized APC sensitivity ratio, the higher the associated risk. The risk for the lowest quartile of normalized APC-SR (<0.92), which included 16.5% of the healthy controls, compared with the highest quartile (normalized APC-SR > 1.05) was greater than fourfold increased (OR = 4.4; 95% confidence interval, 2.9 to 6.6). We adjusted for VIII:C levels, which appeared to affect our APC resistance test. The adjusted (age, sex, FVIII:C) odds ratio for the lowest quartile was 2.5 (95% confidence interval, 1.5 to 4.2). So, after adjustment for factor VIII levels, a reduced response to APC remained a risk factor. Our results show that a reduced sensitivity for APC, not caused by the factor V Leiden mutation, is a risk factor for venous thrombosis.


1997 ◽  
Vol 78 (03) ◽  
pp. 0993-0996 ◽  
Author(s):  
P J Svensson ◽  
G Benoni ◽  
H Fredin ◽  
O Bjӧrgell ◽  
P Nilsson ◽  
...  

SummaryResistance to activated protein C (APC) caused by the R506Q mutation in factor V is the most common inherited risk factor for venous thrombosis. To elucidate whether APC-resistance is a risk factor for venous thrombosis after elective total hip replacement, the association between APC-resistance (presence of FV:Q506 allele) and postoperative thrombosis was investigated in patients (n = 198) randomised to received short (during hospitalisation, n = 100) or prolonged prophylaxis (three weeks after hospitalisation, n = 98) with low molecular weight heparin (LMWH). Among APC-resistant individuals receiving short prophylaxis, 7/10 developed thrombosis as compared to 2/12 receiving long prophylaxis (p <0.0179). Odds ratio for association between APC-resistance and thrombosis in the short prophylaxis group was 4.2 (CI 95% 1.02-17.5) (p <0.0465). Among those receiving prolonged, prophylaxis, there was no increased incidence of thrombosis associated with APC-resistance. Two unexpected observations were made. One was that APC-resistance was much more common in women (19/109) than in men (3/89) (p <0.001). The other was that even women without APC-resistance were much more thrombosis-prone than men. Thus, 24/48 of women with normal FV genotype and short prophylaxis developed thrombosis vs 8/42 among men, p = 0.002. The increased risk of thrombosis associated with female gender and APC-resistance was neutralised by the prolonged treatment. In conclusion, among patients receiving short prophylaxis, female gender was found to be a strong risk factor for venous thrombosis. Even though APC-resistance appeared to be a risk factor for postoperative thrombosis, the uneven distribution of APC-resistance between men and women, taken together with the increased risk of thrombosis among women, precluded valid conclusions to be drawn about the association between APC-resistance and an increased risk of thrombosis. Our results suggest that prolonged prophylaxis with LMWH after hip surgery is more important for women than for men.


Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1271-1276 ◽  
Author(s):  
Marieke C.H. de Visser ◽  
Frits R. Rosendaal ◽  
Rogier M. Bertina

Activated protein C (APC) resistance caused by the factor V Leiden mutation is associated with an increased risk of venous thrombosis. We investigated whether a reduced response to APC, not due to the factor V point mutation, is also a risk factor for venous thrombosis. For this analysis, we used the Leiden Thrombophilia Study (LETS), a case-control study for venous thrombosis including 474 patients with a first deep-vein thrombosis and 474 age- and sex-matched controls. All carriers of the factor V Leiden mutation were excluded. A dose-response relationship was observed between the sensitivity for APC and the risk of thrombosis: the lower the normalized APC sensitivity ratio, the higher the associated risk. The risk for the lowest quartile of normalized APC-SR (<0.92), which included 16.5% of the healthy controls, compared with the highest quartile (normalized APC-SR > 1.05) was greater than fourfold increased (OR = 4.4; 95% confidence interval, 2.9 to 6.6). We adjusted for VIII:C levels, which appeared to affect our APC resistance test. The adjusted (age, sex, FVIII:C) odds ratio for the lowest quartile was 2.5 (95% confidence interval, 1.5 to 4.2). So, after adjustment for factor VIII levels, a reduced response to APC remained a risk factor. Our results show that a reduced sensitivity for APC, not caused by the factor V Leiden mutation, is a risk factor for venous thrombosis.


1995 ◽  
Vol 74 (01) ◽  
pp. 449-453 ◽  
Author(s):  
Rogier M Bertina ◽  
Pieter H Reitsma ◽  
Frits R Rosendaal ◽  
Jan P Vandenbroucke

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