摘要:

The development of inhibitor antibodies is one of the more important complications in the management of haemophilia patients. In a previous study, the prevalence of inhibitor varies between 5 and 52%, seems to be different for different types of concentrates, and is less frequent in multitransfused patients. In our prospective study we followed for 3 years 62 multitransfused haemophilia patients without inhibitor or past history of inhibitor. Thirty-seven haemophilia patients were treated with intermediate purity factor VIII concentrates, whereas 25 were given high purity concentrates (from the eighth month of the study five of these patients were treated with recombinant products). Factor VIII inhibitor antibody developed in seven of 25 haemophilia patients treated with high purity concentrates or recombinant products, whereas none of the haemophilia patients treated with intermediate purity concentrates had inhibitors. The difference was statistically significant (P< 0.001; OR = 0.06, 95% CI 0.001–0.3). In all patients, the titre of the inhibitor was low and no problem occurred in their management. Since inhibitors appeared in multitransfused patients when transfused with high purity concentrates and/or when the patients were switched to recombinant FVIII product, the development of inhibitor seems to be due to the administration of a new concentrate. Therefore this potential complication must be considered every time a new concentrate is administered.

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Analyses of D-dimers in plasma are frequently used as diagnostic tools for deep venous thrombosis (DVT). Enzyme-linked immunosorbent assays (ELISAs) are considered to be the method of choice for quantitative assays, but are time consuming. Therefore, we have assessed plasma levels of D-dimers in patients with clinically suspected DVT using quantitative (Asserachrom D-Di ELISA and TintEIize), semiquantitative (Minutex latex, D-Di latex, NycoCard D-Dimer) and qualitative (INSTANT.I.A) assays. Phlebography was used as the gold standard to verify or exclude the suspected diagnosis. We conclude that the fast assays, INSTANT.I.A and Minutex, have essentially the same negative predictive value [91% and 89%, respectively, using a cut-off value < 0.5 mg/1 fibrinogen equivalent units (FEU)] for excluding DVT as the Asserachrom D-Di ELISA and TintElize tests (92%). The D-Di Latex assay had a negative predictive value of 82% (cut-off < 0.5 mg/1 FEU) and turned out to be less useful in our material. The NycoCard D-dimer assay had a negative predictive value of 100% when using the cut-off value < 0.5 mg/1 FEU, but this was substantially lower when the cut-off was changed to ≤ 0.5 mg/1. Thus, we conclude that several fast tests offer a simpler and more rapid way of determining plasma levels of D-dimer than conventional ELISA methods without loss of clinical usefulness in excluding DVT.

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Published reports do not agree about whether protein C activity is non-significantly changed or decreased in a hypercoagulable state induced by pre-eclampsia without hemoloysis-elevated liver enzyme/low platelet (HELLP) syndrome. In order to assess the relationship between this anticoagulant and enhanced hemostasis, levels of protein C activity, thrombin-antithrombin complexes, soluble fibrin, fibrin D-dimers and antithrombin were determined in 30 pre-eclampsia patients without the HELLP syndrome, in 22 normal pregnant women in gestational weeks 30–35, and in 13 non-pregnant controls. Levels of thrombin-antithrombin complexes, soluble fibrin and D-dimers increased (P< 0.05) whereas antithrombin decreased (P< 0.05) in patients with preeclampsia, compared with normal pregnant women. Levels of protein C did not differ significantly between patients with preeclampsia, normal pregnant women and controls (P> 0.05). The 5th and 95th percentiles of protein C levels in normal pregnant women were 0.53 and 1.30 U/ml, respectively; levels between these two values could be considered physiological. When the preeclampsia patients were subdivided according to these percentiles, none belonged to the subgroup with protein C ≤ 5th percentile; 23% (seven of 30) fell into the subgroup with protein C ≥ 95th percentile. Elevated levels of hypercoagulation markers were shown in the groups whose protein C fell within 5th-95th or ≥ 95th percentiles (P < 0.05), compared with normal pregnant women. Concentrations of protein C and thrombin-antithrombin complex were significantly correlated (r= 0.69,P> 0.05) in patients with pre-eclampsia. In summary, in subjects with pre-eclampsia without the HELLP syndrome, protein C activity may be similar to that in normal pregnant women. However, such a ‘physiological’ anticoagulant level in association with the enhanced thrombin generation and fibrin formation does not necessarily reflect a physiological capability of coagulation. Thus, assays of protein C activity might not always assist in monitoring the hemostatic function during pre-eclamptic pregnancy.

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Lipid-lowering statin treatment reduces cardiovascular morbidity and mortality and improves endothelial function in patients with hypercholesterolemia. The aim of the present study was to evaluate plasma levels of fibrinogen, factor VII, and the macrophage-derived inflammatory mediator neopterin during lipid lowering. In addition, the endothelial production of platelet antiaggregatory and vasodilatory factors such as nitric oxide and prostacyclin, and vasoconstrictive factors such as endothelin-1, was assessed. Plasma fibrinogen, factor VII, endothelin-1, and the neopterin and intraplatelet nitric oxide and prostacyclin mediators cyclic 3′-5′guanosine monophosphate (cGMP) and cyclic 3′-5′adenosine monophosphate (cAMP) were measured before and 6 months after the institution of treatment with fluvastatin in 17 patients (eight men and nine women, median age 60 years) with vascular disease and previously untreated hypercholesterolemia. After 6 months, a decrease of 1.62 mmol/1 [1.26–2.18 (19%);P< 0.01] was noted in levels of total cholesterol, and a decrease of 1.70 mmol/1 [1.52–2.30 (28%);P< 0.01] in levels of low-density lipoprotein cholesterol. Plasma levels of fibrinogen had increased [from 4.81 g/1 (4.26–5.27) to 5.17 g/1 (4.81–5.67);P< 0.05], whereas no significant changes had occurred in intraplatelet levels of cGMP [decrease by 0.05 pmol/109platelets (-0.17 to 0.24); NS], cAMP [decrease by 0.13 pmol/109platelets (-0.37 to 0.86); NS], plasma endothelin-1 [decrease by 0.05 pg/ml (-0.60 to 0.70); NS], plasma factor VII [from 1.14 IE/ml (0.58–1.38) to 1.22 IE/ml (0.96–1.46); NS], or plasma neopterin [from 8.6 nmol/1 (7.1–11.5) to 8.7 nmol/1 (7.9–11.3); NS]. In conclusion, during cholesterol-lowering treatment with fluvastatin, plasma levels of fibrinogen increased whereas intraplatelet cyclic nucleotide levels and plasma endothelin-1, factor VII and neopterin levels were unchanged.

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Thromboembolism represents the most serious complication in patients with prosthetic heart valves, and causes significant mortality and morbidity. Many risk factors for the condition have been identified. However, many patients who have a therapeutic level of anticoagulation and no obvious risk factors develop thromboembolism. Factor V Leiden, found in 3–7% of the normal population, is the most common inherited factor associated with thrombosis. Whether or not this factor is associated with thromboembolism in this setting has not been explored. This study compares the prevalence of factor V Leiden in patients with prosthetic heart valves, with and without thromboembolic complications. A total of 148 patients were studied. Thirty had documented thromboembolic complications and none exhibited the factor V mutation. Of the 118 patients without thromboembolic complications, seven (5.9%) were heterozygous for factor V Leiden (P= 0.345, by Fisher's two-tailed exact test; odds ratio 0, 95% confidence interval 0.0–4.34). We conclude that until future data shows otherwise, routine testing for factor V Leiden in patients with prosthetic heart valves is not warranted, except as part of ongoing research.

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Glucocorticoids are known to increase plasma concentrations of factor VIII (FVIII) and von Willebrand factor (vWF), and their administration is associated with an increased incidence of thrombotic complications. Because Cushing's syndrome is characterized by an endogenous increase in glucocorticoids, we studied levels of FVIII and vWF in 20 patients with Cushing's syndrome. Plasma levels of FVIII and vWF were found to be markedly increased. Moreover, the molecular organization of plasma vWF appeared to have been altered by the presence of unusually large multimers, normally present only in the cellular compartments. Spontaneous platelet aggregation and hyperresponsiveness to ristocetin were also observed. All patients underwent therapeutic surgery. Within 1 month of the intervention, regardless of its efficacy as evaluated by the assay of plasma and urinary Cortisol, an additional significant increase in levels of FVIII and vWF was observed, with a concomitant more pronounced representation of abnormally large vWF multimers in circulation. In the cured patients, a progressive decrease in the levels of FVIII and vWF was observed, beginning in the third month after surgery, with complete normalization of the pattern within 12 months of surgery; a concomitant improvement in the plasma vWF multimer pattern was also observed. In contrast, no significant changes in FVIII or vWF were found in patients with persistent Cushing's syndrome. Our findings emphasize that vWF abnormalities are also part of the prothrombotic state of Cushing's syndrome. Moreover, this study also identified a period of additional thrombotic risk immediately after surgery, as a result of the worsening of the hemostatic pattern.

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0957-5235    

出版商:OVID    

年代:1999

数据来源: OVID