TAFI Antigen Levels (tafi + antigen_level)

Distribution by Scientific Domains


Selected Abstracts


Weak and non-independent association between plasma TAFI antigen levels and the insulin resistance syndrome

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2003
H. Aubert
Summary., Increased plasma thrombin-activatable fibrinolysis inhibitor (TAFI) levels were recently shown to be a part of the insulin resistance syndrome. We investigated the relationship between plasma TAFI antigen levels and insulin resistance markers and compared these results with those obtained for PAI-1 and fibrinogen which are known to be closely related to insulin resistance syndrome and fat mass, respectively. Eighty-nine obese females had 1.3-, 1.2-, and 3-fold higher circulating TAFI, fibrinogen and PAI-1, respectively, compared with 64 lean females. Univariate analysis showed that the significance level for association between TAFI or fibrinogen concentrations and insulin resistance markers was lower than the significance level for association between PAI-1 and insulin resistance markers. Nevertheless, TAFI, fibrinogen, and PAI-1 plasma levels were significantly associated to each other. In linear stepwise ascendant analysis, insulin resistance markers accounted for 50% of the interindividual variability of plasma PAI-1 and only for 10% of plasma TAFI and 13% of fibrinogen variability. The contribution of insulin resistance markers to plasma TAFI antigen levels variability disappeared when PAI-1 or fibrinogen was entered in the statistical model. TAFI mRNA was detected in the liver but not in adipose tissue and endothelial cells. No TAFI mRNA was detected in normal or atherosclerotic vessels either. These results suggest that elevated TAFI antigen levels found in obese subjects are not independently associated with the metabolic markers of the insulin resistance syndrome. Increased plasma TAFI antigen levels in obesity might reflect a specific pathway of regulation at the liver level. [source]


The effect of genetic variants in the thrombin activatable fibrinolysis inhibitor (TAFI) gene on TAFI-antigen levels, clot lysis time and the risk of venous thrombosis

BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2006
C.H. Martini
Summary Thrombin activatable fibrinolysis inhibitor (TAFI) is an important inhibitor of fibrinolysis. High TAFI antigen levels are associated with an increased risk of deep venous thrombosis (DVT). Because TAFI levels are partly determined genetically, we assessed the association between three TAFI gene polymorphisms (,438 G/A, 505 A/G and 1040 C/T), TAFI antigen levels and clot lysis times and the risk of DVT. Carriers of the 505G allele, which is associated with lower TAFI antigen levels than the 505A allele, showed an increased risk of DVT. This indicates that the relationship between TAFI and venous thrombosis is more complex than previously suggested. [source]


Association between thrombin activatable fibrinolysis inhibitor genotype and levels in plasma: comparison of different assays

BRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2004
A. H. C. Guimarães
Summary Thrombin activatable fibrinolysis inhibitor (TAFI) antigen levels exhibit a large interindividual variability in which genetic control seems to play a major role. However, recent reports have questioned the association between TAFI concentration and genotype, suggesting that variable antibody reactivity towards TAFI isoforms, particularly the Thr325Ile polymorphism (1040C/T), may lead to artefacts in TAFI antigen levels. In order to compare assay outcome we determined plasma TAFI levels in 92 healthy individuals, using an enzyme-linked immunosorbent assay (ELISA) (commercial antibodies), an electroimmunoassay (in-house antibodies) and a commercial chromogenic assay (Actichrome® TAFI). Each individual was genotyped for the ,438A/G and 1040C/T polymorphisms in the TAFI gene. TAFI levels were significantly associated with genotype in both antigen and chromogenic assays. All assays displayed significant correlations with each other. Linear regression and Bland,Altman agreement analysis in the genotype subgroups showed that neither the genotype nor the concentration affected the relationship between the Actichrome® TAFI and the electroimmunoassay. In contrast, the ELISA/Actichrome® TAFI and the ELISA/electroimmunoassay relationships were concentration- and genotype-dependent. Our results demonstrate that artefacts may arise when measuring TAFI antigen levels by ELISA. Nevertheless, the electroimmunoassay and the Actichrome® TAFI assay support a genotype-related variation of TAFI concentration. [source]