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- Sampram, Ellis, et al.
(author)
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Activated protein C resistance in patients with peripheral vascular disease
- 1998
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In: Journal of Vascular Surgery. - 1097-6809. ; 28:4, s. 624-629
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Journal article (peer-reviewed)abstract
- PURPOSE: The frequency of activated protein C (APC) resistance, caused by factor V R506Q gene mutation and abnormal APC ratio, in patients with peripheral vascular diseases was analyzed. METHODS: All patients electively admitted to the vascular ward unit of our tertiary care academic medical center from January 1995 through October 1996 (n = 679) were prospectively analyzed using an APC-resistance screening test to determine the frequency of abnormal APC ratio (< or =2.6). Baseline activated partial thromboplastin time (APTT) and its prolongation after the addition of a standard amount of APC were determined. The factor V R506Q gene mutation (Leiden) was analyzed in patients with an APC ratio less than 3.0. Statistical comparisons were made to an age-matched control population (n = 278). RESULTS: The factor V Leiden gene mutation or abnormal APC ratio was detected in 154 of the patients (22.7%), compared with 34 of 278 the control subjects (12.2%; t = 13.65; P < .001). The factor V Leiden gene mutation was found in 102 patients (15.2%), compared with 29 control subjects (10.4%; t = 4.64; P < .05); an abnormal APC ratio was found in 132 patients (19.8%), compared with 26 (9.8%) of controls (t = 14.56; P < .001). The frequency of the factor V Leiden gene mutation was significantly increased in patients with femoro-popliteal occlusive disease (n = 126), to 21.6% (t = 16.94; P< .001), and venous disease (n = 50), to 36.0% (t = 20.93; P< .001). Overall, 63% of the patients with abnormal APC ratios tested positive for the factor V Leiden gene mutation. A significantly increased frequency of APC resistance was demonstrated in patients undergoing aorto-iliac (n = 37) or femoro-crural graft reconstructions (n = 72); it was found in 41% and 35%, respectively (P < .001). In addition, a significantly increased frequency of APC resistance was found in patients who suffered from occlusion after reconstruction; 13 of 41 (32%) had the factor V Leiden gene mutation (P < .001), and 19 of 39 (49%) had an abnormal APC ratio (P < .001). CONCLUSION: The factor V Leiden gene mutation and abnormal APC ratios are significantly increased in patients with lower extremity peripheral vascular disease and failed reconstructions. An abnormal APC ratio was seen without factor V Leiden gene mutation in 37% of patients with peripheral vascular diseases, suggesting additional causes of an abnormal APC ratio, exclusive of gene mutation.
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- Sampram, Ellis, et al.
(author)
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APC resistance due to Factor V Leiden is not related to baseline inflammatory mediators or survival up to 10 years in patients with critical limb ischemia.
- 2013
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In: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 1573-742X .- 0929-5305. ; 36:3, s. 288-292
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Journal article (peer-reviewed)abstract
- To prospectively evaluate the potential influence of resistance to activated protein C (APC-resistance) on the initial inflammatory response, amputation rate and survival during 10 years of follow-up in patients with critical limb ischemia (CLI). Two hundred and fifty-six consecutive CLI patients were analyzed for APC-ratio, the Factor V Leiden mutation and inflammatory mediators and then prospectively followed for 10 years. Inflammatory mediators, amputation rate, morbidity and mortality were compared between patients with and without APC resistance. Of the 256 CLI patients, 35 (14 %) were heterozygotes and 2 (1 %) homozygotes for the Factor V gene mutation, whereas 219 (86 %) patients were non-APC resistant. No significant differences were found between APC resistant and non-APC resistant patients regarding inflammatory mediators. Non-APC resistant patients more often had infrainguinal atherosclerosis (172 [79 %] vs 22 [59 %]; p = 0.017). Amputation rate at 1 year did not differ. Furthermore, there were no significant differences between groups regarding 1-, 3-, 5-, or 10-year survival. APC resistance in patients with CLI was not related to inflammatory activity, and had no impact on limb salvage or rate of amputation or long-term mortality. APC-resistant CLI-patients less frequently had infrainguinal arteriosclerosis, however.
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- Sampram, Ellis
(author)
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Arterial Thrombosis in Factor V Leiden or Activated Protein C Resistance. Clinical and Experimental Studies.
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Abstract The last two decades has seen an avalanche of studies establishing Activated protein C (APC) resistance due to Factor V Leiden mutation as the most prevalent genetic risk factor, yet known, for venous thromboembolism. This has been documented in 20-60% of patients with deep vein thrombosis (DVT). Whether such propensity also exists in arterial circulation is still controversial. The general aim of the present thesis is to clearify some of the controversies that cloud the impact of APC resistance or Factor V leiden mutation on arterial thrombosis. Paper I showed a significantly high prevalence of APC resistance or factor V Leiden mutation in peripheral vascular patients compared to the control group (22.7% vs 12.2%). In Paper II, association between early occlusions of vascular reconstructions and Factor V Leiden mutation was shown. At one month, there was a two-fold risk of occlusion of vascular reconstructions compared to non-carriers (14% vs 7%, p=0.02). At one year, the same tendency was noted although not significant (22% vs 12%). Paper III, an experimental arterial thrombosis study with factor V Leiden mice, revealed increased thrombogenicity in mice with Factor V Leiden mutation and arterial injury. There was a significant relationship between time to occlusion (TTO) and genotype (p=0.002). TTO was highest in the wild type mice (TTO: homozygote
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