The Thrombodynamics-4D® assay (TD4D) (HemaCore, Moscow, Russia) is an innovative videomicroscopy system allowing analysis of fibrin clot propagation and thrombin generation [ [1] Dashkevich N.M. Ovanesov M.V. Balandina A.N. Karamzin S.S. Shestakov P.I. Soshitova N.P. Tokarev A.A. Panteleev M.A. Ataullakhanov F.I. Thrombin activity propagates in space during blood coagulation as an excitation wave. Biophys. J. 2012; 103: 2233-2240https://doi.org/10.1016/j.bpj.2012.10.011 Abstract Full Text Full Text PDF PubMed Scopus (73) Google Scholar ]. Its novelty mainly consists of the real-time spatial visualization of the clot formation departing from a localized zone where tissue factor (TF) is immobilized, thereby mimicking a damaged vessel in contact with a thin layer of non-stirred thermostatically-controlled (37 °C) plasma. The TD device has been completed by a second innovation, named the TD4D, which offers the parallel measurement of thrombin generation [ [1] Dashkevich N.M. Ovanesov M.V. Balandina A.N. Karamzin S.S. Shestakov P.I. Soshitova N.P. Tokarev A.A. Panteleev M.A. Ataullakhanov F.I. Thrombin activity propagates in space during blood coagulation as an excitation wave. Biophys. J. 2012; 103: 2233-2240https://doi.org/10.1016/j.bpj.2012.10.011 Abstract Full Text Full Text PDF PubMed Scopus (73) Google Scholar ].

Essentials Acetylsalicylic acid (ASA) is prescribed to patients scheduled for carotid endarterectomy (CEA). We measured ASA efficacy during CEA by Multiplate® and searched for influencing factors. Most patients scheduled for CEA and treated by ASA are sensitive to this therapy. Influencing genomic factors are involved in ASA metabolism and in platelet function modulations. SUMMARY:Background Acetylsalicylic acid (ASA) is recommended before, during and after carotid endarterectomy (CEA). The efficacy of ASA is influenced by numerous biological and genotypic factors. Objectives To determine the biological efficacy of ASA by using the Multiplate® method, and to explore the biological parameters and genomic factors influencing this efficacy. Methods This descriptive cross-sectional study included all patients scheduled for CEA between January 2012 and April 2013. Multiplate® tests were performed at day 0 and day 30. A set of 66 single-nucleotide polymorphisms (SNPs) from 38 genes or DNA regions were selected and studied along with phenotypic parameters by the use of hierarchical clustering (HC) for multidimensional data management. Results Fifty-five patients receiving ASA were analyzed. Of the patients, 95% were found to be sensitive to ASA, with values under the threshold of normality (400 AU min-1 ). However, there were notable differences in residual aggregation among subjects over a wide range. HC revealed four subclusters comprising three categories of parameters: (i) routine and functional parameters - in ASA-treated patients, the ASPItest was highly linked to the ADPtest, to platelet count, and, to a lesser extent, to fibrinogen and hematocrit; (ii) polymorphisms in genes involved in ASA absorption and in the arachidonic acid pathway (ABCB1 and COX-1); and (iii) polymorphisms in genes modulating basal platelet function, i.e. TBXA2R, ADRA2A, PEAR1, ITGA2 and ITGB1. Conclusion Most patients treated with ASA before CEA were sensitive to it, according to Multiplate® ASPItest results. Genomic factors influencing this efficacy are SNPs involved in ASA absorption and metabolic pathway, and in modulations in basal platelet function.

Background: The diagnostic accuracy of a new Point of Care, rapid and quantitative D-dimer assay (Stratus (R) CS DDMR from Dade Behring) was evaluated.Methods: Vidas (R) test from bioMerieux was used as reference method in 279 patients recruited from a management study in progress in our institution.Results: Both assays show comparable reproducibility (2.9% with the Stratus (R) CS DDMR and 4.4% with the D-dimer Vidas (R) in the cut-off range) and good correlation (R-2=0.9057). The overall test performance as assessed by the area under the curve of the ROC curves is 0.801 for the Stratus (R) CS DDMR assay and 0.798 for the D-dimer Vidas (R) assay. By using assay regression curves, likelihood ratios or test agreement approaches, a 440-450 ng/ml value is evidenced as the threshold value for the Stratus (R) CS DDMR, which nears at best the performances of the D-dimer Vidas (R) 500 or 550 ng/ml threshold value. This proposed exclusion value ensures a 95% sensitivity and a 45% specificity. The few false negative results using the two assays only evidenced sub-popliteal thromboses, that would not have been considered as having thrombosis if an above-the-knee test had been performed. In these conditions, sensitivity would have been 100%.Conclusions: A new quantitative D-dimer assay, the Stratus (R), CS DDMR, demonstrated performances comparable with those of the DD Vidas (R) test. (c) 2004 Elsevier B.V. All rights reserved.

This paper presents a critical assessment of protein C (PC) and protein S (PS) functional and immunological approaches with regard to DNA sequencing in a large hospital recruitment for thrombosis exploration in more than 1700 consecutive patients. After examination of clinical status and PC and PS phenotype, a genotypic study was implemented for 17 PC-deficient and 28 PS-deficient patients (activity < 70%). Sixty-five percent of the genotyped PC-deficient patients were found to have heterozygous mutations. Among the < 70% values, decreases in PC activity without gene mutation were always slight (mean value 64 +/- 7%) while patients presenting a PC gene mutation had a mean 50 +/- 17% activity (P < 0.05). Among the eight PC mutations found, only one has previously been described. A novel mutation in the promoter region (-1522), located in the HNF-1 site and associated with the Y226H heterozygous mutation, was found in a 9-month-old girl with 4% PC activity. Determination of PS functional activity was considerably improved by contemporaneous measurement of calibration and samples in a single step. Only 50% of the genotyped PS-deficient patients demonstrated heterozygous alterations of the gene. The benefit of sequencing to identify putative causal mutations was only 39% in PS-deficient women, while it was 90% in men. Among the nine PS mutations found, six have not yet been published. In the present paper, we explain our methodological choices and diagnostic strategy.

Surgery induces immediate hypercoagulability by direct alteration of the vascular bed, release of procoagulant substances from the extravascular spaces and blood flow decrease, and delayed hypercoagulation in response to tissue damage which triggers inflammatory responses. Thus, the postoperative period represents a high-risk time for thrombosis. Recognition of high-risk individuals would make it possible to improve thromboembolism prevention. We studied in women undergoing laparoscopic surgery a series of markers known to be related to the thrombotic risk and confronted their results with those of a global test, the thrombin generation test (TGT) described by Hemker’s group. Our results show that two groups of patients can be distinguished according to usual risk markers (PAI-1, TAT, body mass index): the higher risk group demonstrates higher initial TGT values, but also a postoperative decrease of the TGT values whose mechanisms remain to be defined.

The clinical diagnosis of deep-vein thrombosis (DVT) and pulmonary embolism (PE) is known to be unreli able. Until now, no biological marker has been found to con firm thrombosis, but help can be gained from a biological marker ruling out the diagnosis of DVT or PE, i.e., the sensitive measurement of D-dimer (DD) species. This article summa rizes our experience in introducing a rapid D-dimer test (ELISA VIDAS D-dimères test, bioMérieux) in a collaborative strategy for thrombosis diagnosis during 9 consecutive months involving 1,131 measurements. The efficacy of the DD test was very different according the type of patient, and departments where the DD test provides a real diagnostic benefit were iden tified. High clinical probability for thrombosis was encountered in 32 patients and radiology was carried out, although D-dimer was negative: none of these patients was found to have a throm bosis after radiologic examination. However, extensive prog ress must be made in test prescription to reduce the excessive rate of positive D-dimer tests (78%) and positive measurements that are not followed up by radiology (42%).

Monocyte tissue factor (TF) quantitation evaluates the involvement of coagulation processes in many diseases. However, technical difficulties, such as blood sampling of cells representative of the whole intravascular pool, cell isolation, protein quantitation or activity assessment, hinder reliable evaluation of TF expression by activated monocytes. Early determination of such activation can be achieved through TF mRNA quantitation by RT-PCR and sensitive product detection, such as automated electrophoresis of fluorescently labeled products. Although it is very sensitive, this method has its limitations. It needs to be standardized using other mRNA that display two main characteristics: the absence of upregulation during inflammation and similar levels of expression when compared with the target mRNA. Widely used standardization housekeeping genes such as HLA or GAPDH genes only meet the former requirement. We demonstrate here that CD11b gene expression meets both conditions. Moreover, because of its specific expression in myelomonocytic cells, it is possible to avoid further monocyte purification from a regular mononuclear cell preparation. A rapid, sensitive, specific and accurate way to evaluate monocyte TF expression is described in this paper.

Since the cross talk between inflammation and coagulation was described by Esmon et al. in 1991 [1], many vascular pathologies have appeared as complex disorders of the "vascular ecosystem," which encompasses a fine-tuning of cellular events involving cells (parietal or circulating) and complex networks of soluble mediators. Leukocyte alterations are a cornerstone in the development of inflammatory conditions: They lead to activation of coagulation, microvascular plugging, and/or toxic attack of the vascular and perivascular environment, which are involved to different degrees in vascular pathologies [2]. Leukocytes are easily withdrawn from circulating blood and are thus easier to study in clinical situations than parietal endothelial cells, although the functions of the latter are also important in regulation processes. A plethora of regulating soluble mediators (cytokines, chemokines, hormones, bioactive lipids, and serine proteases acting in an autocrine or paracrine manner) constitute a compact network of redundant regulating pathways. Most have been demonstrated in isolated in vitro systems, but their relative importance remains to be established in vivo.

Neuropeptide FF (NPFF, FLFQPQRFamide) is an FMRFamide-like octapeptide exhibiting antiopiate activity. The presence of both NPFF-immunoreactivity (NPFF-IR) and NPFF-specific receptors has been described in the mammalian central nervous system (CNS). The peripheral effects of NPFF indicate that NPFF-IR material is present outside the CNS. Biochemical and immunohistochemical methods enabled us to determine the presence and distribution of NPFF-IR in the rat adrenal gland. The amount of NPFF-IR material in whole gland was estimated by radioimmunoassay to be 19.00 +/- 4.00 fmol/gland. High performance liquid chromatography analysis of adrenal extracts revealed a single molecular form which coeluted with authentic NPFF. Demedullation decreased adrenal NPFF-IR content, indicating that NPFF-IR was present in both cortex and medulla. Light microscopy revealed NPFF-IR in beaded fibers confined in the outer part of the cortex and in medullary cells. Double-labeling with antityrosine-hydroxylase and anti-NPFF antibodies showed NPFF-IR in cortical catecholaminergic postganglionic fibers restricted to the subcapsular and glomerulosa zonae. NPFF-IR was also located in medullary chromaffin cells and in rays and islets of chromaffin cells dispersed throughout the cortex. Insulin-induced hypoglycemia did not alter NPFF-IR content. Denervation lowered adrenal NPFF-IR content. These data indicate that this peptide is present in nerve fibers of extrinsic origin. In vitro approaches using adrenal slices have shown that NPFF inhibited aldosterone release in a dose-dependent manner. Taken together, these data suggest that NPFF may participate in the control of aldosterone production and adrenal blood supply.

DD are now recognized as a valuable tool to screen patients suspected of deep venous thrombosis or pulmonary embolism before carrying out a gold standard radiologic examination. The newest methods available claim to be able to ascertain the absence of thrombosis, but they have yet to prove their efficiency. We compared the performances of 3 reference ELISA methods (D-DI Asserachrom Stago, D-dimer Enzygnost Behring and Dimertest GOLD EIA Agen), 5 recent rapid methods (VIDAS D-Dimer bioMérieux, Instant IA Stago, Simplired Agen, Nycocard D-dimer Nycomed and Accuclot D-Dimer Sigma Diagnostics) and two routine latex methods (Dimertest American Diagnostica and FDP-Slidex bioMérieux) in 100 patients. One of the rapid quantitative methods was demonstrated to have a level of efficiency comparable to that of ELISA methods. Finally, the cost and efficiency of different strategies were evaluated, the association of a routine latex method with the VIDAS D-Dimer bioMérieux being proven to be the most efficient.

Acquired alterations in hemostatic parameters can be the result of both thrombotic events and aging. Indeed, aging is associated with an increased risk of deep venous thrombosis (DVT) and ischemic stroke (IS), which may be due to physiological alterations of the hemostatic system or the vessel wall. Moreover, the incidence of predisposing conditions (hypertension, immobility, malignancies, surgery) increases with age. Table 1 summarizes several studies reporting influence of aging or of thrombotic events on hemostasis parameters, but no study has considered both aging and thrombotic events together in a large assay of variables assessing inflammation, activation of coagulation, anticoagulation, and fibrinolysis. Aging-related alterations have been studied in healthy subjects [ 1 Hamilton P.J. Allardyce M. Ogstn D. Dawson A.A. Douglas A.S. The effect of age upon the coagulation system. J Clin Pathol. 1974; 27: 980-982 Crossref PubMed Scopus (49) Google Scholar , 2 Balleisen L. Bailey J. Epping P.H. Schutle H. Van de Loo J. Epidemiological study on factor VII, factor VIII, and fibrinogen in an industrial population, I Baseline data on the relation to age, gender, body-weight, smoking, alcohol, pill using, and menopause. Thromb Haemost. 1985; 54: 475-479 PubMed Google Scholar , 3 Aillaud M.F. Pignol F. Alessi M.C. Harle J.R. Escande M. Mongin M. Juhan-Vague I. Increase in plasma concentration of plasminogen activator inhibitor, fibrinogen, von Willebrand factor, factor VIIIc and erythrocyte sedimentation rate with age. Thromb Haemost. 1986; 55: 330-332 PubMed Google Scholar , 4 Bauer K.A. Weiss L.M. Sparrow D. Vokonas P.S. Rosenberg R.D. Aging-associated changes in indices of thrombin generation and protein C activation in humans. Normative aging study. J Clin Invest. 1987; 80: 1527-1534 Crossref PubMed Scopus (209) Google Scholar , 5 Folsom A. Wu K. Davis C. Conlan M. Sorlie P. Szklo M. Population correlates of plasma fibrinogen and factor VII, putative cardiovascular risk factors. Atherosclerosis. 1991; 91: 191-205 Abstract Full Text PDF PubMed Scopus (341) Google Scholar , 6 Tracy R.P. Bovill E.G. Thrombosis and cardiovascular risk in the elderly. Arch Pathol Lab Med. 1992; 116: 1307-1312 PubMed Google Scholar , 7 Tracy R.P. Bovill E.G. Fried L.P. Heiss G. Lee M.H. Polak J.F. Psaty B.M. Savage P.J. The distribution of coagulation factors VII, VIII, and fibrinogen in adults over the age of 65 years Results from the Cardiovascular Health Study. Ann Epidemiol. 1992; 2: 509-519 Abstract Full Text PDF PubMed Scopus (73) Google Scholar , 8 Lowe G.D. Rumley A. Woodward M. Morrisson C.E. Philippou H. Lane D.A. Tunstall-Pedoe H. Epidemiology of coagulation factors, inhibitors and activation markers The Third Glasgow MONICA survey. I. Illustrative references ranges by age, sex and hormone use. Br J Haematol. 1997; 4: 775-784 Crossref Scopus (259) Google Scholar ] while alterations related to thrombotic events have mostly been studied in young patients (less than 45 [ 8 Lowe G.D. Rumley A. Woodward M. Morrisson C.E. Philippou H. Lane D.A. Tunstall-Pedoe H. Epidemiology of coagulation factors, inhibitors and activation markers The Third Glasgow MONICA survey. I. Illustrative references ranges by age, sex and hormone use. Br J Haematol. 1997; 4: 775-784 Crossref Scopus (259) Google Scholar ] or 60 years old [ 10 Meade T.W. Mellows S. Brozovic M. Miller G.J. Chakrabarti R.R. North W.R. Haines A.P. Stirling Y. Imeson I.D. Thompson S.G. Hemostatic function and ischaemic heart disease Principal results of the Northwick Park Heart Study. Lancet. 1986; 9: 533-537 Abstract Scopus (1962) Google Scholar ]), except for fibrinogen and VIIIc in the Framingham Study [ 11 Kannel W.B. Wolf P.A. Castelli W.P. d’Agostino R.B. Fibrinogen and risk of cardiovascular disease; the Framingham Study. JAMA. 1987; 258: 1183-1186 Crossref PubMed Scopus (1494) Google Scholar ], which includes patients aged from 35 to 94 years. Generally, these studies only concern arterial diseases [ 9 Hamsten A. Blombäck M. Wiman B. Svensson J. Szamosi A. de Faire U. Mettinger L. Hemostatic function in myocardial infarction. Br Heart J. 1986; 55: 58-66 Crossref PubMed Scopus (163) Google Scholar , 10 Meade T.W. Mellows S. Brozovic M. Miller G.J. Chakrabarti R.R. North W.R. Haines A.P. Stirling Y. Imeson I.D. Thompson S.G. Hemostatic function and ischaemic heart disease Principal results of the Northwick Park Heart Study. Lancet. 1986; 9: 533-537 Abstract Scopus (1962) Google Scholar , 11 Kannel W.B. Wolf P.A. Castelli W.P. d’Agostino R.B. Fibrinogen and risk of cardiovascular disease; the Framingham Study. JAMA. 1987; 258: 1183-1186 Crossref PubMed Scopus (1494) Google Scholar , 12 Hamsten A. de Faire U. Walldius G. Dahlen G. Szamosi A. Landou C. Blombäck M. Wiman B. Plasminogen activator inhibitor in plasma Risk factor for recurrent myocardial infarction. Lancet. 1987; 2: 3-9 Abstract PubMed Scopus (1450) Google Scholar ]. Moreover, studies of venous thrombosis risk generally focus on alterations in physiological anticoagulants. Fibrinogen, vWF and plasminogen activator inhibitor-1 (PAI-1) have been more studied with regard to arterial risk than with regard to venous thrombosis, although they may also be involved in the latter. One explanation is that arterial pathologies are treated in specific medical care units whereas venous pathologies are usually diagnosed in many different types of unit. Studying the incidence of age and thrombotic events on hemostatic alterations, either venously or arterially localized, may thus throw light both on base-line values and thrombosis-related alterations. Indeed, recognizing thrombosis-associated changes in hemostasis in elderly subjects implies that “physiological changes” have been previously identified to constitute a base-line pattern in elderly subjects, thereby enabling additional alterations to be determined. The present study was thus undertaken to establish the relative weight of aging itself and thrombotic events in the hemostatic changes observed, by selecting different groups of patients of varying age (elderly vs. young) and clinical history (thrombosis or not). Table 1Studies from the literature on effects of aging and thrombotic events on hemostasis parameters legend DVT, deep venous thrombosis; PE, pulmonary embolism. Population characteristics Author, year, reference number Influenced factors and main ideas Health status Number (men/women) Range of age (years) Hamilton et al., 1974 1 Hamilton P.J. Allardyce M. Ogstn D. Dawson A.A. Douglas A.S. The effect of age upon the coagulation system. J Clin Pathol. 1974; 27: 980-982 Crossref PubMed Scopus (49) Google Scholar X, VII, V: increased with age Healthy 10/10 20–40 Balleisen et al., 1985 2 Balleisen L. Bailey J. Epping P.H. Schutle H. Van de Loo J. Epidemiological study on factor VII, factor VIII, and fibrinogen in an industrial population, I Baseline data on the relation to age, gender, body-weight, smoking, alcohol, pill using, and menopause. Thromb Haemost. 1985; 54: 475-479 PubMed Google Scholar VII, VIIIc, Fg: increased with age Healthy 2880/1306 All ranges of age Aillaud et al., 1986 3 Aillaud M.F. Pignol F. Alessi M.C. Harle J.R. Escande M. Mongin M. Juhan-Vague I. Increase in plasma concentration of plasminogen activator inhibitor, fibrinogen, von Willebrand factor, factor VIIIc and erythrocyte sedimentation rate with age. Thromb Haemost. 1986; 55: 330-332 PubMed Google Scholar PAI-1, Fg, vWF, VIIIc: increased with age Healthy 10/10 10/10 20–28 70–97 Bauer et al., 1987 4 Bauer K.A. Weiss L.M. Sparrow D. Vokonas P.S. Rosenberg R.D. Aging-associated changes in indices of thrombin generation and protein C activation in humans. Normative aging study. J Clin Invest. 1987; 80: 1527-1534 Crossref PubMed Scopus (209) Google Scholar F1+2: increased with age ATIII, PC: no variation Healthy 199 42–80 Folsom et al., 1991 5 Folsom A. Wu K. Davis C. Conlan M. Sorlie P. Szklo M. Population correlates of plasma fibrinogen and factor VII, putative cardiovascular risk factors. Atherosclerosis. 1991; 91: 191-205 Abstract Full Text PDF PubMed Scopus (341) Google Scholar Fg, VII: increased with age Healthy 12000/12000 45–64 Tracy et al., 1992 6 Tracy R.P. Bovill E.G. Thrombosis and cardiovascular risk in the elderly. Arch Pathol Lab Med. 1992; 116: 1307-1312 PubMed Google Scholar , 7 Tracy R.P. Bovill E.G. Fried L.P. Heiss G. Lee M.H. Polak J.F. Psaty B.M. Savage P.J. The distribution of coagulation factors VII, VIII, and fibrinogen in adults over the age of 65 years Results from the Cardiovascular Health Study. Ann Epidemiol. 1992; 2: 509-519 Abstract Full Text PDF PubMed Scopus (73) Google Scholar Fg, VII and PAI-1: increased with age Healthy 2106/2724 65–100 Lowe et al., 1997 8 Lowe G.D. Rumley A. Woodward M. Morrisson C.E. Philippou H. Lane D.A. Tunstall-Pedoe H. Epidemiology of coagulation factors, inhibitors and activation markers The Third Glasgow MONICA survey. I. Illustrative references ranges by age, sex and hormone use. Br J Haematol. 1997; 4: 775-784 Crossref Scopus (259) Google Scholar Increases in coagulation factors (Fg, VII, VIIIc, IX) with age greater than increases of coagulation inhibitors (ATIII, PC, PS) Healthy 747/817 25–74 Hamsten et al., 1986 9 Hamsten A. Blombäck M. Wiman B. Svensson J. Szamosi A. de Faire U. Mettinger L. Hemostatic function in myocardial infarction. Br Heart J. 1986; 55: 58-66 Crossref PubMed Scopus (163) Google Scholar Fg and PAI1: elevated in male pa- tients VIIIc, vWF, PAI: elevated in female patients Myocardial infarction Healthy 116/32 136/136 <45 <45 Meade et al., 1986 10 Meade T.W. Mellows S. Brozovic M. Miller G.J. Chakrabarti R.R. North W.R. Haines A.P. Stirling Y. Imeson I.D. Thompson S.G. Hemostatic function and ischaemic heart disease Principal results of the Northwick Park Heart Study. Lancet. 1986; 9: 533-537 Abstract Scopus (1962) Google Scholar Increased Fg level associated with increased risk of ischemic heart disease Ischemic heart disease 109 45–60 Kannel et al., 1987 11 Kannel W.B. Wolf P.A. Castelli W.P. d’Agostino R.B. Fibrinogen and risk of cardiovascular disease; the Framingham Study. JAMA. 1987; 258: 1183-1186 Crossref PubMed Scopus (1494) Google Scholar Increased Fg level significantly associated with incidence of cardiovascular disease Cardiovascular diseases 165/147 35–94 Hamsten et al., 1987 12 Hamsten A. de Faire U. Walldius G. Dahlen G. Szamosi A. Landou C. Blombäck M. Wiman B. Plasminogen activator inhibitor in plasma Risk factor for recurrent myocardial infarction. Lancet. 1987; 2: 3-9 Abstract PubMed Scopus (1450) Google Scholar Decrease in fibrinolytic capacity due to increased plasma levels of PAI predisposes to reinfarction Myocardial infarction 109 <45 Ridker et al., 1995 23 Ridker P.M. Hennekens C.H. Lindpaintner K. Stampfer M.J. Eisenberg P.R. Miletich J.P. Mutation in the gene coding for coagulation factor V and the risk of myocardial infarction, stroke, and venous thrombosis in apparently healthy men. N Engl J Med. 1995; 332: 912-917 Crossref PubMed Scopus (1052) Google Scholar Leiden mutation (25.8%) DVT and PE Healthy 31 355 >60 >60 legend DVT, deep venous thrombosis; PE, pulmonary embolism. Open table in a new tab

SummaryDD are now recognized as a valuable tool to screen patients suspected of deep venous thrombosis or pulmonary embolism before carrying out a gold standard radiologic examination. The newest methods available claim to be able to ascertain the absence of thrombosis, but they have yet to prove their efficiency. We compared the performances of 3 reference ELISA methods (D-DI Asserachrom™ Stago, D-dimer Enzygnost™ Behring and Dimertest GOLD EIA™ Agen), 5 recent rapid methods (VIDAS D-Dimer™ bioMérieux, Instant IA™ Stago, Simplired™ Agen, Nycocard D-dimer™ Nycomed and Accuclot D-Dimer™ Sigma Diagnostics) and two routine latex methods (Dimertest™ American Diagnostica and FDP-Slidex™ bioMérieux) in 100 patients. One of the rapid quantitative methods was demonstrated to have a level of efficiency comparable to that of ELISA methods. Finally, the cost and efficiency of different strategies were evaluated, the association of a routine latex method with the VIDAS D-Dimer™ bioMérieux being proven to be the most efficient.

The aim of the present study was to evaluate the relative performance of five screening methods for APC resistance caused by the factor V:Q506 mutation: the original method Coatest APC Resistance Chromogenix, a modified method using the same reagents but a predilution 1+4 of the plasma in a factor V deficient plasma from Stago (Stago deficient V) or from Chromogenix (V-DEF Plasma), the Coatest APC Resistance V (Chromogenix), and Accélérimat from bioMérieux. Normalization was done against a pool of normal plasmas for the methods from Chromogenix. The study included 350 subjects, 219 were genotyped (174 FV:R506R, 42 FV:Q506R, 3 FV:Q506Q) and most of them were assessed by more than one method. Uncertainty in predicting the FV genotype was evaluated by statistical analysis, which provided a way to quantitate the performance of the different diagnostic approaches. Performance of each test was evaluated by its sensitivity, specificity, R.O.C. curves, positive and negative likelihood ratios (LR), and the overall performance was determined by two parameters derived from the LR curves : the maximum LR value obtained at the crossover of the two curves, and the distance between the two curves for LR = 10. Coatest APC Resistance V and Accélérimat were proven to be the methods most able to discriminate for factor V:Q506, while normalization was not shown to improve the screening performance. The original method from Chromogenix was confirmed to undergo many influences (factor XII, PAI-1, thrombin-antithrombin complexes, antithrombin III, hematocrit). Although a very good improvement was provided by the newest methods, they were shown to be influenced by protein S and/or factor V levels in the sample plasma.