[Coronary restenosis]. / Koronare Restenose.

Coronary restenosis is the answer of the arterial wall to a mechanical violation through balloon angioplasty, bare-metal (BM) stent implantation or rotational atherectomy through repeated narrowing. It has great clinical and prognostic relevance and occurs in approximately 30% of non-coated stents and in 10% of coated coronary stents. The wound healing process that precedes restenosis includes inflammatory reactions, cellular proliferation and remodeling of the arterial wall, where protein synthesis of the extracellular matrix is initiated. The inflammatory reaction activates platelets, leucocytes and monocytes and stimulates smooth muscle cells. The medications on the drug-eluting stents (rapamycin, paclitaxel, sirolimus, evarolimus and zotarolimus) inhibit cell division, are cytotoxic and only these sustainably influence restenosis. Whether they play a role in neoatherosclerosis needs to be determined. The mechanism of restenosis with implantation of drug-eluting stents is heterogeneous and associated with the deposition of T­lymphocytes and fibrin. Risk factors for the development of restenosis include mechanical factors, such as incorrect apposition and expansion of stents, inflammation, diabetes mellitus, genetic factors, bypass operations, stent length and stent diameter. The restenosis rate is lower with drug-eluting stents and must be considered differently between the drug-eluting stents. Drug-eluting stents of the latest generation and drug-coated balloons (DCB) showed the best clinical and angiographic results for in-stent restenosis in randomized trials. The BM and older first-generation drug-eluting stents should be avoided. Further randomized studies are needed.

Platelet function analyzer (PFA-100) as a useful tool for the prediction of transfusion requirements during aortic valve replacement.

BACKGROUND: Shear stress-induced hemostatic abnormalities, particularly loss of the hemostatically most competent, highest molecular weight von Willebrand factor multimers, are common in patients with aortic valve stenosis. Although controversially discussed, these hemostatic defects might be associated with an increased risk of bleeding during aortic valve replacement. Since the determination of closure times with a platelet function analyzer is sensitive for the detection of defects of primary hemostasis including shear stress-induced von Willebrand factor abnormalities, this study was performed to evaluate a method to predict intraoperative transfusion requirements in this setting. METHODS: Fifty patients (mean age ± SD: 68 ± 9 years, range 40-85 years) admitted for aortic valve replacement were enrolled in the study. Closure times of epinephrine/collagen and ADP/collagen cartridges were determined with a platelet function analyzer in the absence of antiplatelet agents. Results were compared to those obtained in healthy individuals without medication. The probability that a patient would require a transfusion of packed red cells (RBC) and fresh frozen plasma (FFP) was calculated for each obtained closure time using a multiple regression model. RESULTS: Compared to controls, patients undergoing aortic valve replacement had a significantly higher incidence of prolonged closure in the platelet function analyzer. The prolonged closure time of both epinephrine/collagen and ADP/collagen cartridges was significantly correlated with intraoperative transfusion of RBC, but not FFP. CONCLUSIONS: In patients undergoing aortic valve replacement, prolongation of closure times as determined by a platelet function analyzer is frequently observed, indicating the presence of shear stress-induced defects of primary hemostasis. Since the prolongation of closure times is significantly correlated to the probability of intraoperative transfusion, this method might offer a significant contribution to the preoperative risk stratification of patients.

Rotation thromboelastography (ROTEM) parameters are influenced by age, gender, and oral contraception.

Rotation thromboelastography (ROTEM) is a screening method that allows the rapid detection of plasma- and platelet-related haemostatic abnormalities. To use this procedure more efficiently, reference values depending on gender, age, and oral contraception are required. In this study, five cohorts of healthy subjects were examined by ROTEM upon activation of the extrinsic or intrinsic pathway of coagulation, or recalcification alone. The cohorts comprised male subjects below (1) and above (2) 45 years of age, female subjects below 45 years of age with (3) or without (4) oral contraception, and female subjects above 45 years (5) without hormone replacement therapy. A significant influence of gender, age, and oral contraception on parameters determined by ROTEM was observed. Thus, adjustment for age, gender, and oral contraception is required when ROTEM is used to screen for distinct abnormalities of haemostasis.

Platelet-function analyzer closure times indicate shear stress-induced hemostatic abnormalities in patients with aortic valve stenosis and correlate with perioperative transfusion requirements.

BACKGROUND: Shear stress-induced hemostatic abnormalities are highly prevalent in patients with aortic valve stenosis. In this study, we determined closure times with a platelet-function analyzer (PFA-100, Dade Behring, Marburg, Germany) in patients admitted for aortic valve replacement to assess the correlation with the severity of aortic valve stenosis, blood loss, perioperative transfusion requirements, and need for re-thoracotomy. PATIENTS AND METHODS: Fifty consecutive patients (mean age [+/- SD] 68 +/- 9 years) were enrolled. Closure times of epinephrin/collagen and adenosine diphosphate (ADP)/collagen cartridges were determined at least ten days after discontinuation of antiplatelet medication and compared to those of healthy control subjects without medication. RESULTS: Closure times of epinephrin/collagen (210 +/- 69 sec vs. 140 +/- 50 sec, p < 0.0001) and ADP/collagen (145 +/- 58 sec vs. 108 +/- 45 sec, p < 0.0001) cartridges were prolonged in patients with aortic valve stenosis. Intraoperative transfusion of red blood cell units was associated with the closure times of epinephrin/collagen (r = 0.28, p = 0.04) and ADP/ collagen cartridges (r = 0.28, p = 0.04). Total transfusion of red blood cell units was associated with ADP/ collagen closure times (r = 0.31, p = 0.02), but not epinephrin/collagen closure times (r = 0.26, p = 0.07). No significant association of closure times with intraoperative, postoperative and total transfusion of fresh frozen plasma units was observed. CONCLUSIONS: Prolongation of closure times determined with a platelet-function analyzer is highly prevalent in patients with aortic valve stenosis and appears to reflect shear stress-induced hemostatic abnormalities. Since prolonged closure times are associated with increased perioperative transfusion of red blood cell units, the assay could significantly contribute to the identification of individuals at risk.

[Relevance of a single dose of 270 microg/kg recombinant factor VIIa for the treatment of patients with haemophilia and inhibitors - Recommendations from the GTH experts]. / Stellenwert der Einzelgabe von 270 microg/kg rekombinantem Faktor VIIa in der Behandlung von Hämophilie-Patienten mit Hemmkörpern - Empfehlungen der Experten.

Recombinant factor VIIa (rFVIIa; NovoSeven) is, besides other indications, authorised for the treatment of bleeding episodes in patients with hereditary haemophilia A or B and inhibitors. Based on the results of three clinical studies, marketing authorisation was granted for the single dose of 270 microg/kg body weight rFVIIa for the treatment of mild to moderate bleeding episodes in patients with haemophilia A or B with inhibitors in March 2007. Thereupon, an expert group analysed the relevance of this additional treatment option for clinical routine. Compared with the repeated application of 90 microg/kg body weight rFVIIa, quality of life may be improved if the single dose of 270 microg/kg body weight rFVIIa reduces the number of injections. The single dose has a benefit for those patients who require several rFVIIa applications or who do not respond adequately to low doses. Moreover, patients with poor venous access or patients who fear injections or reject them (especially children) may benefit from the single dose. The prescription of 270 microg/kg body weight rFVIIa as a single dose instead of multiple dosing of 90 microg/kg body weight is basically an individual and indication-related decision.

Rotational thrombelastometry for the bedside monitoring of recombinant hirudin.

BACKGROUND: Recombinant hirudin is used as an alternative anticoagulant, particularly in patients with heparin-induced thrombocytopenia type II. However, bedside monitoring for hirudin is not available. The present study aims to evaluate rotational thrombelastometry regarding its suitability to detect the effects of recombinant hirudin on whole blood coagulation. Hirudin was added to whole blood samples from healthy donors (n=5) and thrombelastometry variables resulting from activation of samples with tissue factor, ellagic acid, and ecarin were determined. METHODS: Hirudin (0.1-10 microg/ml) was added to citrated blood. Thereafter, rotational thrombelastometry was performed by initiating coagulation via recalcification and addition of tissue factor, ellagic acid, and ecarin, respectively, using the commercially available assays. RESULTS: In the absence of hirudin, clotting times (CT) induced by ellagic acid, tissue factor, and ecarin, respectively, were 141.7+/-18.0, 54.0+/-7.6, and 64.5+/-4.1 s. Increasing concentrations of hirudin led to dose-dependent prolongation of the clotting time with the three activators. All assays were capable to detect hirudin concentrations in the range of 0.5-5 microg/ml. At a final hirudin concentration of 1 microg/ml, clotting time increased to 268.0+/-25.1, 84.0+/-9.3, and 107.5+/-9.9 s, respectively, with the above-mentioned activators. The other thrombelastographic variables, including clot formation time, angle alpha, and maximum clot firmness, were not altered by hirudin at concentrations up to 5 microg/ml. CONCLUSIONS: Our study demonstrates the suitability of rotational thrombelastometry to detect anticoagulant effects of recombinant hirudin.

[Thrombophilia in pregnancy: venous thromboembolism, fetal loss, preeclampsia, intrauterine growth restriction]. / Thrombophile Hämostasestörung in der Schwangerschaft: Thrombose, Abort, Präeklampsie, intrauterine Wachstumsretardierung.

Women with acquired and hereditary thrombophilia are at increased risk of developing venous thromboembolism and other associated gestational vascular complications like fetal loss, preeclampsia, intrauterine growth restriction, and placental abruption during pregnancy. These complications are a major cause of maternal and fetal morbidity and mortality. In view of the data showing an association between thrombophilia and these adverse pregnancy outcomes, clinicians are increasingly using antithrombotic therapy in women at risk of these complications. Aside from recurrent pregnancy loss in antiphospholipid syndrome and prevention of venous thromboembolism, there is limited evidence on the benefit of antithrombotic interventions to guide therapy. The data in favour of antithrombotic therapy in women with hereditable thrombophilia and vascular placental complications consist predominantly of small uncontrolled trials or observational studies. Randomized, placebo-controlled trials are lacking as most patients do not accept placebo. Further randomised controlled trials are urgently required to explore this therapeutic option.

Platelet receptor HPA-1 polymorphism of alphaIIbbeta3 and 807 C/T polymorphism of alpha2beta1 and Buerger's disease.

Thromboangiitis obliterans or Buerger's disease is an episodic and segmental inflammatory and thrombotic process of the medium and small arteries of the lower extremities. Even though the disease was described 90 years ago, the etiopathogenesis is still under consideration. Afflicted patients are mostly young male cigarette smokers without signs of atherosclerosis or other risk factors for peripheral arterial occlusive disease. This indicates that hereditary thrombophilic factors could play a role in the etiopathogenesis. Recently, increasing evidence shows that platelet receptor polymorphisms (HPA-1 polymorphism of beta3 subunit of alphaIIbbeta3 and 807 C/T polymorphism alpha2beta1) are associated with early onset of arterial thrombosis (myocardial infarction, stroke). This case-control study was designed to assess whether the 807 C/T polymorphism or the HPA-1 polymorphism is involved in the pathogenesis of Buerger's disease or has any influence on the clinical course of Buerger's disease. Eighteen patients with Buerger's disease and 81 (sex and age matched) healthy control subjects (mean age 44 +/- 10 vs 45 +/- 8 years, respectively) were genotyped for platelet receptor HPA-1 and GPIa 807 C/T polymorphism. The gene frequency of HPA-1 and GPIa 807 C/T polymorphisms was identical in both groups. Prevalence of hetero- and homozygous carriers of the HPA-1b allel (1a1b and 1b1b genotype) as well as the prevalence of the 807 C/T and 807 T/T carriers did not differ significantly between the two groups, p >0.05. The grade of clinical disease manifestation as well as disease progression did not reveal any significant relationship with HPA-1 and 807 C/T polymorphisms. A relationship between the age at onset of the disease and HPA-1 polymorphism was not found. Otherwise analysis of the GPIa 807 C/T platelet receptor polymorphism showed that the average age of patients who are carriers of the T allele at early onset of disease was 32 +/- 6 years (range 27-48 years) compared to 42 +/- 6 years (range 34-53 years) of the C/C carriers (p <0.05). This indicates that the GPIa 807 C/T polymorphism does not represent a risk factor for Buerger's disease itself, but could be associated with premature onset of this disorder in predisposed individuals.

[Recombinant factor VIIa in patients with platelet function disorders or thrombocytopenia]. / Rekombinanter Faktor VIIa bei Patienten mit Plättchenfunktionsstörungen oder Thrombozytopenien.

Apart from on-label indications, recombinant factor VIIa (rFVIIa) is increasingly administered for treatment of life threatening bleeding events when appropriate standard therapy fails. Case reports and short treatment series document the efficacy and safety of rFVIIa to achieve haemostasis in patients with platelet function disorders and thrombocytopenias of various origin. An established on-label indication for the use of rFVIIa is given in patients with Glanzmann thrombasthenia with refractoriness to transfusions of platelet concentrates. Bolus applications of rFVIIa at dosages between 80 and 120 microg/kg body weight every 1.5 to 3 h are also administered successfully in patients with Bernard-Soulier syndrome, platelet storage pool defects, and other acquired platelet function disorders. In patients with Glanzmann thrombasthenia, at least three bolus injections are required to achieve effective haemostasis. In approximately half of the patients with thrombocytopenias, a single bolus of rFVIIa has been shown to be sufficient in managing otherwise untreatable bleeding complications. In these patients, haemostasis was achieved even at platelet counts <20,000/microl, although the efficacy of rFVIIa increases at higher platelet concentrations.

[Monitoring of NOAC]. / Monitoring von NOAK.

BACKGROUND: Monitoring non-vitamin K antagonist oral anticoagulants (NOAC) is usually not necessary; however, in some patients it may prove beneficial. OBJECTIVES: Patient subgroups who may profit from monitoring were identified, and methods of monitoring (including assessment of which coagulation parameters are affected by NOAC) are described. MATERIALS AND METHODS: We searched the PubMed database for each of the search terms, "NOAC", "DOAC", "rivaroxaban", "dabigatran", and "apixaban", in combination with one of the terms, "monitoring", "measurement", "measuring", or "assessment". The results were compiled and reviewed. RESULTS: Monitoring is most advantageous in emergency cases with severe bleeding where drug activity needs to be assessed. It can also help in deciding for or against lysis therapy after acute stroke in patients taking NOAC. Furthermore, it can also identify compliance problems and help in planning periprocedural management. There are quantitative measurement methods which measure plasma concentrations exactly and qualitative methods which only allow for a rough estimate or a general confirmation of drug activity. Recommended quantitative measurement methods are diluted thrombin time for dabigatran, and anti-factor Xa activity (calibrated) for rivaroxaban and apixaban. CONCLUSIONS: Several patient subgroups may profit from monitoring of NOAC plasma concentration. One should, however, take several issues into consideration before measurements, such as the objective of each individual measurement, possible consequences (e. g., dose adjustment), and which measurement method to pick.

Safe therapeutics of murine melanoma model using a novel antineoplasic, the partially methylated mannogalactan from Pleurotus eryngii.

A heteropolysaccharide was isolated by cold aqueous extraction from edible mushroom Pleurotus eryngii ("King Oyster") basidiocarps and its biological properties were evaluated. Structural assignments were carried out using mono- and bidimensional NMR spectroscopy, monosaccharide composition, and methylation analyses. A mannogalactan having a main chain of (1→6)-linked α-d-galactopyranosyl and 3-O-methyl-α-d-galactopyranosyl residues, both partially substituted at OH-2 by ß-d-Manp (MG-Pe) single-unit was found. Biological effects of mannogalactan from P. eryngii (MG-Pe) were tested against murine melanoma cells. MG-Pe was non-cytotoxic, but reduced in vitro melanoma cells invasion. Also, 50mg/kg MG-Pe administration to melanoma-bearing C57BL/6 mice up to 10days decreased in 60% the tumor volume compared to control. Additionally, no changes were observed when biochemical profile, complete blood cells count (CBC), organs, and body weight were analyzed. Mg-Pe was shown to be a promising anti-melanoma molecule capable of switching melanoma cells to a non-invasive phenotype with no toxicity to melanoma-bearing mice.

[Pregnancy-associated venous thromboembolic disease: prediction, prevention, and therapy]. / Venöse Thrombose in der Schwangerschaft. Prädiktion, Prävention und Therapie.

Thromboembolic disease remains a leading cause of maternal mortality during pregnancy and the puerperium. Rational and risk-adapted administration of heparin prophylaxis depends on 1. the identification of those women who have an increased risk of thrombosis and 2. the accurate quantification of this risk. In women without prior thrombosis, the presence of a heterozygous factor V Leiden or heterozygous G20210A mutation in the prothrombin gene is associated with a pregnancy-associated thrombotic risk of approximately 1 in 400. Thus, in pregnant carriers of either one of these mutations the risk of venous thromboembolism is low. Therefore, no heparin prophylaxis is recommended. A combination of the two genetic risk factors can increase the risk to a modest level of 1 in 25. In women with a single episode of prior thrombosis associated with a transient risk factor, e.g. surgery or trauma, and no additional genetic risk factor, the probability of a pregnancy-associated thrombosis appears also to be low. However, data are sparse and conflicting. In contrast, in women with a prior idiopathic venous thrombosis who carry an additional hereditary risk factor or who have a positive family history of thrombosis, a high risk (>10%) can be expected supporting the indication for active antepartum and postpartum heparin prophylaxis. Despite the remarkable progress in risk stratification, the absolute magnitude of risk and the optimal management in many cases is an issue of ongoing debate.

Associations between thrombophilic risk factors and determinants of atherosclerosis and inflammation in patients with non-arteritic anterior ischaemic optic neuropathy.

UNLABELLED: Non-arteritic anterior ischaemic optic neuropathy (NAION) is caused by ischaemia of the optic nerve head. The pathophysiology of NAION is unclear, and no proven effective treatment exists. PATIENTS, METHODS: We analyzed thrombophilic risk factors and determinants of atherosclerosis and inflammation in 109 consecutive patients and 109 age- and sex-matched volunteers using a case-control design. RESULTS: High levels of fibrinogen (>384 mg/dl; OR 3.2, p = 0.003), factors VIII:C (>183%; OR 2.6, p = 0.02), IX (>153%; OR 2.6, p = 0.026), XI (>142%; OR 3.4, p = 0.006), von Willebrand factor (activity >205%; OR 3.1, p = 0.005; antigen >194%; OR 3.5, p = 0.002), and triglycerides (>228 mg/dl; OR 2.8, p = 0.026), higher platelet counts (>294,000/µl; OR 2.5, p = 0.04), low levels of HDL cholesterol (<40 mg/dl; OR 2.7, p = 0.032), and an accelerated erythrocyte sedimentation rate (>20 mm/h; OR 4.4, p = 0.003) were associated with NAION. CONCLUSION: Our findings support the contention of a complex pathogenesis of NAION resulting from the coincidence of proatherogenic, prothrombotic and proinflammatory processes. The alterations described could be causative, side effects, or just coincidental findings.

Characterization of the functional border zone around regionally ischemic myocardium using circumferential flow-function maps.

Previous studies have suggested that there exists a functional border zone in myocardium at the lateral margins of an ischemic area. The functional border zone is normally perfused but is characterized by abnormal contractile function. To define the spatial characteristics of this border zone, circumferential maps of left ventricular function by two-dimensional echocardiography and of coronary flow using radioactive microspheres were generated in 18 dogs at baseline and after circumflex coronary occlusion. Circumferential left ventricular wall thickening was measured in all dogs at 22.5 degrees intervals over 360 degrees. In seven dogs, the pathologic slice corresponding to the two-dimensional echocardiographic image was circumferentially dissected into 16 segments corresponding to 22.5 degrees intervals and a subendocardial myocardial blood flow map was derived. In the other 11 dogs, autoradiography was performed of the pathologic slice corresponding to the two-dimensional echocardiographic image, and the hypoperfusion zone was directly measured. There was no difference between the circumferential extent of hypoperfusion zones by either perfusion measurement technique in the five dogs that had both techniques performed (140 +/- 12 versus 124 +/- 7 degrees, p = NS). The hypofunctional zone by two-dimensional echocardiography was significantly larger than the hypoperfusion zone (174 +/- 4 versus 125 +/- 26 degrees, p less than 0.0005), indicating that a zone of normally perfused but abnormally contracting muscle surrounds the ischemic area. However, this border zone in our model was small, measuring 49 +/- 34 degrees (approximately 8 to 9 mm on either lateral border). This suggests that the functional border zone lateral to ischemic myocardium exists, but is relatively discrete.

Immediate rebound followed by deterioration of regional left ventricular function with coronary reperfusion.

The immediate and early effects of coronary artery reperfusion initiated 1 and 3 hours after coronary artery occlusion were evaluated by two-dimensional echocardiographic measurements of overall and regional left ventricular function. A total of 29 anesthetized open chest dogs underwent one of the following: 1 hour occlusion followed by reperfusion (Group I, n = 9), 3 hour occlusion followed by reperfusion (Group II, n = 12) or 5 hour occlusion without reperfusion (Group III, n = 8). Serial two-dimensional echocardiography was performed at baseline; at 1, 3 and 5 hours of coronary occlusion; within 5 minutes of reperfusion; and at 2 hours of reperfusion. After occlusion, all groups manifested significant (p less than 0.01) increases in left ventricular diastolic and systolic area and decreases in left ventricular area ejection fraction. With coronary reperfusion, there was no improvement in these global variables in Groups I and II. However, immediately after reperfusion, there was improvement in the regional extent of dysfunction (Group I, 138 +/- 35 to 66 +/- 62 degrees, p less than 0.05; Group II, 156 +/- 51 to 85 +/- 77 degrees, p less than 0.05) as well as improvement in the regional degree of dyskinesia (p less than 0.05). These regional improvements were transient and resolved by 2 hours of coronary reperfusion. This immediate rebound of function was not associated with the duration of coronary occlusion, hemodynamic variables or ultimate infarct size. Thus, in the anesthetized open chest dog model, coronary artery reperfusion at 1 or 3 hours produces an immediate but transient improvement in regional systolic myocardial function.

Association of polymorphisms of platelet membrane integrins alpha IIb(beta)3 (HPA-1b/Pl) and alpha2(beta)1 (alpha807TT) with premature myocardial infarction.

Conflicting results of an association of the human platelet antigen 1b (HPA-1b/PlA2), localized on the beta-subunit of the integrin alpha(IIb)beta3, and the alpha(2)807TT genotype of the integrin alpha2beta1 with coronary atherosclerosis and myocardial infarction have been reported. Both platelet receptor polymorphisms were genotyped in 3261 patients who had undergone coronary angiography, including 1175 survivors of a myocardial infarction, 1211 individuals with coronary artery disease but no history of myocardial infarction, and 571 control patients without angiographic coronary artery disease, and in 793 blood donors. In a case-control design, the prevalence of HPA-1b and alpha(2)807TT genotypes did not differ significantly between the patient groups with coronary artery disease or myocardial infarction and patient controls or blood donors. By contrast, using a multivariate case-only design, it was found that the median age of onset of myocardial infarction was 5.2 years earlier (P = 0.006) in carriers of the HPA-1b allele and 6.3 years earlier (P = 0.006) in carriers of the alpha(2)807TT genotype in the 264 survivors of myocardial infarction of recent onset with one- or two-vessel coronary artery disease. A significant interaction with the conventional risk factors hypercholesterolemia, smoking, diabetes, hypertension, and hyperfibrinogenemia was excluded. Human platelet antigen 1b and alpha(2)807TT are associated with premature myocardial infarction but not with coronary artery disease, suggesting a role of distinct integrin genotypes for increased platelet thrombogenicity. This association requires confirmation in follow-up studies.

The G20210A prothrombin-gene mutation and the plasminogen activator inhibitor (PAI-1) 5G/5G genotype are associated with early onset of severe preeclampsia.

Hereditary risk determinants of venous thrombosis have been reported to be associated with severe preeclampsia. So far there are no data to support whether these risk determinants are related to the time of onset of severe preeclampsia. We used a case-control design, studying 97 women with severe preeclampsia in previous pregnancies and 277 normal women, to assess hereditary risk factors of venous thrombosis as risk determinants for severe preeclampsia. A case-only design comprising solely the 97 women with a history of preeclampsia was used to evaluate these risk factors as risk determinants for early onset of severe preeclampsia. Using the case-control design, there was no significant risk association of the hereditary risk factors with severe preeclampsia [factor V Leiden, odds ratio (OR) 0.9, 95% confidence interval (CI) 0.4, 2.2; prothrombin mutation, OR 1.9, 95% CI 0.5, 7.0; methylentetrahydrofolate reductase 677TT genotype, OR 0.8, 95% CI 0.4, 1.8; plasminogen activator inhibitor (PAI-1) 4G/4G genotype, OR 1.2, 95% CI 0.7, 2.1; PAI-1 5G/5G genotype, OR 1.0, 95% CI 0.5, 1.8]. However, the onset of severe preeclampsia was significantly earlier in women with the G20210A prothrombin gene mutation (24.5 weeks vs. 30.1 weeks, P = 0.046) and in women with the PAI-1 5G/5G genotype (25.7 weeks vs. 30.8 weeks, P = 0.024). Hereditary risk factors for venous thrombosis do not predispose for severe preeclampsia. However, women who are carriers of the G20210A prothrombin gene mutation and the PAI-1 5G/5G genotype are at risk for early onset of severe preeclampsia. It appears that these risk factors do not induce the pathomechanism but accelerate the course of preeclampsia.

Spontaneous echo contrast caused by platelet and leukocyte aggregates?

BACKGROUND AND PURPOSE: Spontaneous echocardiographic contrast (SEC) is correlated to clinical thromboembolic events. We sought to determine the origin of SEC by utilizing direct analysis of left atrial blood. METHODS: We examined the blood of 13 patients with and 19 without SEC. Blood samples were taken from the femoral vein and artery and from the right and left atria after transseptal puncture. Samples were incubated with fluorescence-labeled antibodies directed against the platelet (CD41a-PE, CD42b-PE, and CD62p-FITC) and leukocyte membrane epitopes (CD45-APC and CD14-FITC). The expressed epitopes were analyzed by dual laser flow cytometry immediately after blood withdrawal. RESULTS: In the peripheral blood of both groups, more activation and aggregation were found in the venous blood than in the arterial blood (CD41a, P=0.007; CD14neutro, P=0.017; and leukocyte-platelet aggregates [LTAg], P=0.002). In patients without SEC, the degree of activation and aggregation of the cardiac samples closely resembled the results of the peripheral samples. The degree of activation and aggregation was significantly higher in the right atrium than in the left atrium (LTAg, P<0.01; leukocyte activation, P<0.01; CD41a, P<0.01; CD62p, P<0.02). In contrast, in patients with SEC the parameters of platelet and leukocyte activation as well as LTAg was significantly higher in the left atrium than in the right atrium of the same patient (all P<0.01). A correlation between the amount of SEC and platelet-monocyte aggregates could be found (r=0.92, P<0.0001). CONCLUSIONS: The hypothesis that platelet aggregates are involved in the pathogenesis of SEC is supported by the fact that platelets in the left atrium of patients with SEC showed more activation.

Value of an extended monoethylglycinexylidide formation test and other dynamic liver function tests in liver transplant donors.

Measuring monoethylglycinexylidide (MEGX) formation after intravenous administration of lidocaine in potential organ donors (MEGX test) has been advocated as a useful test to select donor livers for transplantation, but some groups have demonstrated a low test efficacy. We, therefore, investigated the value of an extended MEGX formation test and the value of other dynamic liver function tests, in selecting suitable human donor livers. In 51 human multi-organ donors, we measured elimination of galactose, indocyanine green, and lidocaine, as well as formation of MEGX, at 15, 30, and 60 min after administration of the test substances. In the early postoperative period, the function of the transplanted liver was then classified as good or poor, as defined by a prothrombin time above or below 65% by day 4 and fibrinogen concentration above or below 300 mg/dl by day 7. Donor characteristics and preservation modalities were very similar between the two groups. Galactose, indocyanine green, and lidocaine metabolism failed to predict good or poor graft function in the early postoperative period. MEGX serum concentrations, however, were significantly higher in the group of donors whose organs functioned well in the recipients, as compared with donors whose organs functioned poorly in the recipients. This was true for MEGX concentrations at 15 min (117+/-9 vs. 90+/-9 ng/ml; P=0.03), 30 min (108+/-8 vs. 86+/-8 ng/ml; P=0.04), and 60 min (100+/-6 vs. 73+/-5 ng/ml; P=0.006). Extending the MEGX formation test from 15 to 60 min improved test efficacy. Maximal MEGX concentration in 9 or up to 12 consecutive blood samples, drawn between 3 and 120 min after lidocaine infusion, was also significantly higher in donors whose organs functioned well, than in donors whose organs functioned poorly (129+/-10 vs. 101+/-10 ng/ml; P=0.03). Although the groups with good and poor organ function differed significantly with respect to their MEGX serum concentrations, and although efficacy of the MEGX test was improved by extending the test from 15 to 60 min, the overlap in individual MEGX serum concentrations was still so wide that it is virtually impossible to predict early graft function only on the basis of the MEGX test in the donor. Therefore, the MEGX test, although of potential scientific interest, does not predict early graft function with an accuracy necessary for clinical use.

Mutation in the gene coding for coagulation factor V and resistance to activated protein C: detection of the genetic mutation by oligonucleotide ligation assay using a semi-automated system.

Resistance of coagulation factor Va to inactivation by activated protein C (APCR) is associated with a point mutation in which adenine is substituted for guanine at nucleotide 1691 in the gene coding for factor V (FV Leiden). To date, this mutation of factor V is the most frequent genetic risk factor for venous thrombophilia. In this report, we describe the adaptation of an automatable oligonucleotide ligation assay (OLA) to detect the mutation in polymerase chain reaction-amplified DNA samples from 40 normal, 20 affected heterozygous, and 3 affected homozygous individuals. The genotypes determined by conventional allele-specific restriction enzyme site analysis were in complete concordance with the results obtained by ELISA-based oligonucleotide-ligation assay. The automated oligonucleotide ligation assay provides a rapid, reliable, nonisotopic method to detect the mutation responsible for APCR that can rapidly be applied to large population screening.