Endogenous t-PA-antigen is an independent predictor of adverse cardiovascular events and all-cause death in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is associated with raised levels of P-selectin and an apparent prothrombotic state. However, levels of tissue plasminogen activator (t-PA)-antigen are increased also. We investigated whether high levels of endogenous t-PA-antigen or soluble P-Selectin (sP-Selectin), independently of CHADS(2-) or CHA(2) DS(2) VASc-scores, predict major adverse cardiovascular events (MACE) in patients with AF when treated according to current guidelines. METHODS: This prospective, longitudinal single-center study included 269 patients with AF. Blood samples were analyzed for sP-Selectin and t-PA-antigen concentration by means of commercially available enzyme-linked immunoassays. RESULTS: Patients were followed for a median duration of 1933 (1517-2277) days, during which 78 MACE and 82 deaths occurred. In multivariable analyses t-PA-antigen above the median of 4.22 ng mL(-1) was associated with MACE and all-cause death (HR 2.55 [1.43-4.57]; P = 0.002) and (HR 2.54 [1.38-4.68]; P = 0.003), respectively. There was no association of sP-Selectin with MACE or all-cause death. Furthermore, t-PA-antigen above the median independently of the CHADS(2-) or CHA(2) DS(2) VASc-scores predicted MACE and all-cause death. In patients with low and intermediate-risk for cardiovascular events according to the CHADS(2)-score the addition of high t-PA-antigen levels (> 4.22 ng mL(-1) ) had a significant impact on the patients' outcome (low-risk group, HR 3.25 [1.13-9.38]; P = 0.029 and intermediate-risk group, HR 2.33 [1.27-4.26]; P = 0.006, respectively). CONCLUSION: High endogenous t-PA-antigen independently predicts MACE and all-cause death in patients with AF. Accordingly, t-PA-antigen as an indicator of a prothrombotic state represents a novel biomarker, which might add to risk stratification in patients with AF.

[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.

Fibrinolytic therapy with rt-PA in a patient with paroxysmal nocturnal hemoglobinuria and Budd-Chiari syndrome.

Paroxysmal nocturnal hemoglobinuria (PNH) is associated with a high risk of thrombosis, particularly in the peripheral, cerebral, and abdominal veins. We report a patient with an occlusion of the hepatic veins and a slit shape narrowing of the cava inferior consistent with the Budd-Chiari syndrome in whom intravenous fibrinolytic therapy with recombinant tissue plasminogen activator (rt-PA) was applied. Systemic rt-PA was given in a dose of 25 mg rt-PA over 3 h and 25 mg rt-PA as constant intravenous infusion over the next 21 h leading to an incomplete recanalization. The same protocol was applied again 2 days later, resulting in a complete recanalization of the hepatic veins and the vena cava inferior. Our case shows that exclusive systemic application of rt-PA can result in full anatomic and clinical restoration.

Is there a possible role for haemostasis in the development of perigraft reaction complicating the modified Blalock Taussig shunt?

The perigraft reaction is an unusual complication found in patients in whom a modified Blalock Taussig shunt has been created using a polytetrafluoroethylene graft. We found that, in two infants, consistent laboratory findings during such a perigraft reaction were hypofibrinogenemia, increased levels of thrombin-antithrombin III complex, prothrombin fragment 1 and 2 and products of degradation of fibrin. Normalization of the levels of fibrinogen produced resolution of the perigraft reaction.

The relation between erythrocyte volume and folate levels is influenced by a common mutation in the methylenetetrahydrofolate reductase (MTHFR) gene (C677T).

BACKGROUND: The enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) plays an important role in folate metabolism and folate-dependent reactions. Homozygosity for a common polymorphism in the MTHFR gene (C677T, Ala to Val) is associated with an increased risk of neural tube defects and hyperhomocysteinemia in individuals with low folate levels. Homozygous carriers of the polymorphism with adequate folate levels, on the other hand, seem to be at lower risk for colorectal cancer. Homozygous carriers of the polymorphism (5-15% of the white population) probably represent a subpopulation with increased folate needs. Hematological sequelae of folate deficiency have been recognized for a long time. However, no data exist concerning the relation between the C677T MTHFR polymorphism, folate levels, and hematological parameters. METHODS: We investigated associations between the C677T MTHFR polymorphism, folate levels, total plasma homocysteine, and hematological parameters in 94 patients with cerebrovascular disease (transient ischemic attack/minor stroke) and in 82 healthy subjects. RESULTS: Homozygous carriers (VV) of the polymorphism with low folate levels showed significantly higher homocysteine levels than mutation-negative (AA) and heterozygous (AV) subjects (P = 0.038). Furthermore, VV subjects in the lowest folate quartile exhibited significantly higher mean erythrocyte volumes (MCV) and a tendency towards higher erythrocyte hemoglobin content (MCH) than AA and AV subjects (P = 0.008 and 0.069, respectively). Although MCV was not influenced by folate levels in AA and AV subjects, in VV subjects a significant inverse correlation with folate levels could be demonstrated (P = 0.544 and 0.020, respectively). CONCLUSION: We demonstrate an association between the C677T polymorphism, folate levels, and hematological parameters. The elevation of MCV in homozygous carriers of the polymorphism with low folate levels indicates impaired DNA synthesis and/or methylation in these subjects. Considering our data and the results of previous studies, the polymorphism may have contrary effects on homocysteine metabolism and DNA synthesis/methylation dependent on a subject's folate supply. Although the polymorphism is disadvantageous in homozygous carriers with low folate levels, its presence may be beneficial in individuals with adequate folate supply.

Evaluation of a highly specific functional test for the detection of factor V Leiden.

In the present study, a new functional test for the detection of increased resistance of coagulation factor V to degradation by activated protein C (factor V Leiden mutation) was evaluated. The STA-STACLOT APC-R Test (Diagnostica Stago, Asnieres, France) is based on the specific activation of factor X by Crotalus viridis helleri snake venom. The results are given as clotting time in seconds of the patient's plasma in the presence of venom and activated protein C. The intra-assay coefficient of variation was 2.17% (n=20) for samples within the normal range, and 1.70% and 1.42% (n=20) for the plasma of a heterozygous or a homozygous carrier of the factor V Leiden mutation, respectively. The inter-assay coefficient of variation (n=10) was 7.75% for the plasma of a healthy donor, 5.05% for the plasma of a heterozygous carrier and 3.38% for the plasma of a homozygous individual. The normal range (5th-95th percentile) of 136.4 s-174.7 s was derived from the clotting time of the plasma of 38 healthy controls. Values below 136 s were found in every sample from patients carrying the factor V Leiden mutation (n=52), whereas no patient with protein C (n=11) or protein S deficiency (n=10) had reduced clotting times. Homozygous carriers of the factor V Leiden mutation had clotting times shorter than 66.0 s and heterozygous carriers had clotting times longer than 80.0 s. Thus, based upon the individual clotting time, patients homozygous for factor V Leiden mutation could easily be distinguished from normals or heterozygous individuals. The influence of coagulation factor X, V, or II deficiency on the STACLOT APC-R Test was evaluated and revealed prolonged clotting times at factor V activities below 50%. In the presence of lupus anticoagulant the specificity of the STA-STACLOT APC-R Test was clearly decreased. In the present study, we clearly show that the STA-STACLOT APC-R Test is able to discriminate carriers of the factor V Leiden mutation from healthy controls or patients with protein C or protein S deficiency.

[Thromboembolism--genetic and acquired risk factors]. / Thromboembolien--genetische und erworbene Risikofaktoren.

Within the last few years, the knowledge of hereditary and acquired risk factors for venous thromboembolism has increased. Antithrombin-, protein C- and protein S-deficiency have been known since a long time as hereditary risk factors. Since 1993, three hitherto unknown risk factors have been described, the APC (activated protein C) resistance, hyperhomocysteinemia and a polymorphism in the 3-UT region of the prothrombin gene. These risk factors are relatively common in the normal population (in total 10-15%) and are found in 30-50% of patients with venous thromboembolism. The most important acquired risk factor for thromboembolism is the antiphospholipid antibody syndrome (APLS). The APLS is found in around 3% of patients with thromboembolism, patients with these abnormalities have a high risk for recurrency. The upper mentioned risk factors for thromboembolism do not only increase the risk for spontaneous thrombosis, but also the risk for thrombosis during typical high risk situations, such as surgery, trauma of the lower extremities, pregnancy and delivery. APC resistance and antithrombin deficiency increase the risk for development of thrombosis during oral contraceptive intake. Patients, in whom one of the upper mentioned risk factors have been diagnosed, should receive thrombosis prophylaxis during high risk situations. Not all patients with one thromboembolic event and a known risk factor are candidates for long-term oral anticoagulant treatment. Long-term oral anticoagulant treatment should be introduced after exclusion of major contraindications in patients with recurrent events, patients with a combination of risk factors and a life threatening event.

[Monitoring blood coagulation]. / Gerinnungskontrollen.

Standard heparin in therapeutic doses has to be monitored by the activated partial thromboplastin time. There is no need for monitoring of treatment or prophylaxis with low molecular weight heparins. Only specific clinical situations, like renal insufficiency, long-term treatment, pregnancy, high risk of bleeding or thrombosis, small children and an extremely low or high body weight demand determination of anti-factor Xa activities. Monitoring of oral anticoagulant treatment should be done by determination of prothrombin time, values should be given in International Normalized Ratio (INR). It has been shown that monitoring by specialized centers and most probably self monitoring at home by the patient himself are able to optimize treatment.

C677T MTHFR mutation and factor V Leiden mutation in patients with TIA/minor stroke: a case-control study.

A common C677T mutation in the gene for the enzyme 5,10-methylenetetrahydrofolate reductase (5,10-MTHFR) has been linked to elevated levels of homocysteine and was therefore suspected to be a candidate genetic risk factor for arterial occlusive disease. Another mutation, factor V Leiden, has been established as a common hereditary risk factor for venous thrombosis, but its role in arterial disease remains controversial. We investigated the prevalence of both the C677T MTHFR mutation and the factor V Leiden mutation in 81 patients with transient ischemic attack (TIA) or minor stroke (MS) and in 81 age- and sex-matched control subjects free from clinically manifest vascular disease. We further compared clinical and laboratory data as well as clinical course of patients carrying the factor V Leiden mutation alone or in combination with the C677T MTHFR mutation and mutation-free patients. The prevalence of the MTHFR mutation did not differ between patients and control subjects with 11.1% homozygous carriers in both groups (OR for homozygous carriers 1.0; 95% CI 0.38-2.66). However, there was a trend towards a higher prevalence of carriers of factor V Leiden in patients (12.3%) than in control subjects (4.9%) (OR 2.75; 95% CI 0.83-9.17;p=0.09). Furthermore, we found some evidence that the combined occurrence of the C677T MTHFR mutation and factor V Leiden might unfavorably affect the clinical course of the disease, but the number of respective patients was small. Larger studies with a greater number of carriers of both the C677T MTHFR mutation and factor V Leiden seem therefore warranted.

677C to T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and plasma homocyst(e)ine levels in patients with TIA or minor stroke.

It was the aim of this study to determine the associations of clinical and laboratory data with plasma homocyst(e)ine levels in patients with transient ischemic attack (TIA) or minor stroke (MS), with special reference to their 677C to T mutation status in the 5,10-methylenetetrahydrofolate reductase (5,10-MTHFR) gene. Seventy-six patients with TIA or MS were investigated at least 3 months after their (last) clinical event. By means of univariate analysis, significant correlations of homocyst(e)ine levels with male gender (P<0.02), age (P<0.0005), creatinine levels (P<0.0002), folate levels (inversely, P<0.05), and alcohol use (P<0.02) were found, but not with vitamin B12 levels. Multivariate regression analysis, including age, creatinine levels, and folate levels as independent variables, revealed age (P<0.01) and creatinine levels (P<0.02) to be significantly correlated with homocyst(e)ine levels. After adjustment for age, creatinine levels and homocyst(e)ine levels remained significantly correlated to each other (P<0.005), whereas the relation between folate levels and homocyst(e)ine levels was no longer significant (P=0.10). Mutation-positive patients exhibited moderately and statistically non-significantly higher homocyst(e)ine levels than mutation-negative patients, particularly those who were homozygous positive. Homocyst(e)ine levels were closely correlated with creatinine levels (P<0.0002) and with folate levels (inversely, P<0.05), but only in mutation-positive and not in mutation-negative patients. Homozygous positive, heterozygous positive, and mutation-negative patients did not differ with respect to clinical and laboratory data concerning 'risk factors for stroke' or co-existing vascular disease. In conclusion, the associations of creatinine levels and, inversely, of folate levels with plasma homocyst(e)ine levels in patients with TIA or MS are dependent on the 5,10-MTHFR mutation status. Significant correlations between these variables were found only in mutation-positive but not in mutation-negative patients.

Evaluation of a new screening assay ProC Global for identification of defects in the protein C/protein S anticoagulant pathway.

In the present study a new assay, ProC Global, globally estimating the activity of the main plasma components of anticoagulant protein C/protein S pathway, was evaluated with respect to test characteristics and its sensitivity in the detection of deficiency states of protein C and protein S and of increased aPCR. In the ProC Global assay procedure protein C is activated in patient's plasma by an activator reagent (venom from agkistrodon contortrix). The extent of the prolongation of a sample's aPTT, caused by the activation of protein C, is taken as a measure for its anticoagulant capacity. Ninety-eight patients with one of the above mentioned defects were investigated. Decreased plasma protein C activity and increased aPCR were detected with a sensitivity of 1.0, while only 11 of 14 patients with decreased levels of free protein S antigen showed abnormal results in the ProC Global assay (sensitivity = 0.79). The test can be used in heparinized samples up to 1.0 anti Xa U/ml heparin (UFH and LMWH). When samples from patients on oral anticoagulant treatment are prediluted with factor V deficient plasma the test is sensitive for increased aPCR.

Improved characteristics of aPC-resistance assay: Coatest aPC resistance by predilution of samples with factor V deficient plasma.

Screening for a resistance against activated protein C (aPCR), which is in most cases caused by FV:Q506 mutation, is performed by functional tests measuring the effect of aPC on activated partial thromboplastin time (aPTT). Because of an insufficient discrimination between FV:Q506 mutation negative and positive individuals with the first generation of the functional test Coatest aPC Resistance (Chromogenix AB, Mölndal, Sweden), the definition of an arbitrary cut-off level was only possible using the results of DNA analysis. The use of an arbitrary cut-off level still resulted in unsatisfactory low sensitivity and specificity for the functional test. Thus, time- and cost-consuming DNA analyses had to be performed frequently to establish the diagnosis. The objective of this study was to evaluate an improved version of this assay that uses predilution of samples with factor V deficient plasma containing a heparin neutralizer. Using the data from 32 FV:Q506 mutation positive and 55 mutation negative individuals, the authors calculated a cut-off value resulting in an enhanced sensitivity (0.91 versus 1.0) and specificity (0.77 versus 1.0) compared to the old one. Imprecision was lowered from 5.36% (first generation) to 2.43%, in particular in samples with longer clotting times. In patients with prolonged aPTT, either caused by therapy with oral anticoagulants or heparin, correct results were obtained with the second generation assay, in contrast to the first generation assay. With this second generation assay the number of DNA analyses can be substantially reduced.

Six novel and three recurrent mutations in nine Austrian patients with hemophilia B.

In this report we describe the molecular basis of the factor IX (FIX) deficiency in nine patients with severe (n = 6), moderate (n = 1) or mild (n = 2) hemophilia B. The following genetic defects were identified by enzymatic amplification with the polymerase chain reaction (PCR) and subsequent direct sequencing of all exons and exon-intron-junctions: patient B.B. (FIX "Vienna I"): deletion of nucleotides 6343 to 6362; patient M.H. and W.J. (FIX "Vienna II"): nucleotide 17704 (C to G), Gln 97 to Glu; patient L.K. (FIX "Vienna III"): nucleotide 17761 (C to T), Arg 116 to stop; patient U.A. (FIX "Vienna IV"): nucleotide 10415 (C to G), Pro 55 to Ala; patient H.G. (FIX "Vienna V"): nucleotide 6488 (C to T), Thr 38 to Ile; patient H.M. (FIX "Vienna VI"): nucleotide 31276 (G to C), Trp 385 to Cys; patient L.C. (FIX "Vienna VII"): deletion of nucleotide 6700; patient S.F. (FIX "Vienna VIII"): nucleotide 10392 (A to T), Asp 47 to Val. The causative mutation was detected in the FIX gene in each of the nine patients with hemophilia B. There was one small deletion, one point deletion and seven point mutations. The latter include six missense mutations and one nonsense mutation. The mutations in Vienna III, IV and V have already been described in previous studies. The two deletions, Vienna I and Vienna VII have not been reported previously. The genetic defects observed in Vienna II, VI and VIII are novel missense mutations which result in amino acid changes at residues 97, 47 and 385, respectively.

Symptomatic hereditary type-II protein C deficiency caused by a missense mutation in exon IX of the protein C gene (Gly381 to Ser).

We report the characterization of the genetic defect in a family with hereditary type-II protein C (PC) deficiency. The propositus is a 28-year-old woman with a history of thrombosis. Her PC activity level (58%) and PC antigen level (115%) are compatible with the diagnosis of type-II PC deficiency. Her asymptomatic sister is also PC deficient. Analysis of the PC gene of the propositus revealed a point mutation (G to A) at nucleotide 8856, which results in the replacement of Gly381 by Ser in the heavy chain of PC. The amino acid change occurs close to the active-site serine at a residue which is highly conserved among the serine proteases. The mutation is also present in the PC gene of the propositus' sister. Her brother, who is asymptomatic, has a normal genotype with respect to the mutation at nucleotide 8856.

Randomized double-blind, placebo-controlled trial of twice-daily zidovudine in asymptomatic haemophiliacs infected with the human immunodeficiency virus type 1. European-Australian Haemophilia Collaborative Study Group.

In this double-blind, placebo-controlled trial of HIV-infected asymptomatic haemophiliacs, the efficacy of 2-year zidovudine therapy (1000 mg daily in two divided doses) in preventing progress of HIV infection was prospectively evaluated. Drug tolerance was also studied. 143 haemophiliacs from five European countries and Australia with p24 antigenaemia and/or CD4 cell counts of 0.1-0.4 x 10(9)/l were enrolled. The main measures of outcome were progression to AIDS, CDC group IV disease, symptomatic HIV-related disease, and a decrease in CD4+ T-lymphocyte count to fewer than 0.2 x 10(9)/l. There were no significant treatment differences in the proportion of patients progressing to AIDS, CDC group IV or symptomatic disease. Analysis of time to CD4+ counts less than 0.2 x 10(9)/l showed a non-significant trend in favour of zidovudine. Haemoglobin concentrations were less than 8 g/dl in 4% of zidovudine recipients; neutropenia was less than 0.75 x 10(9) cells/l in 5% of zidovudine recipients; alanine aminotransferase levels were greater than 10 times the upper normal limit in 3% of zidovudine recipients, but also in 4% of placebo recipients. Hence there was a very low prevalence of side-effects in haemophiliacs, despite the use of a higher zidovudine dosage than is currently widely used.

Twelve novel and two recurrent mutations in 14 Austrian families with hereditary protein C deficiency.

The molecular basis of hereditary type I and type II protein C deficiency was studied in a panel of 14 unrelated Austrian families. By direct sequencing of the nine exons and their splice junctions sequence alterations were found in one of the protein C alleles in all but one subject. In twelve subjects a single alteration was found whereas in one subject one of the protein C alleles carried two sequence abnormalities. Whenever DNA from family members was available (11 of the 14 cases) cosegregation of the protein C deficiency with the mutation was observed. In contrast to what has been found previously in a panel of Dutch patients with hereditary protein C deficiency, none of the 14 mutations occurred in more than one family. Only two of the genetic defects (157Arg-->Stop and 178Arg-->Gln) have been found previously in other geographic locations. These data confirm the large genetic heterogeneity of protein C deficiency.

Disseminated intravascular coagulation and decrease in fibrinogen levels induced by vincristine/prednisolone therapy of lymphoid blast crisis of chronic myeloid leukemia.

Therapy with vincristine (2 mg i.v. weekly) and prednisolone (100 mg p.o. daily) caused a decrease in fibrinogen levels in nine patients treated for lymphoid blast crisis LBC) of chronic myeloid leukemia (CML). During the first days of treatment disseminated intravascular coagulation (DIC), evidence by a positive ethanol gelation test, markedly increased thrombin-antithrombin III complex and fibrin-split product D-dimer levels, and a rapid fall in fibrinogen levels was observed in two patients. The induction of DIC in these two patients caused profuse bleeding in one and necessitated substitution therapy with fibrinogen and platelet concentrates. The remaining seven patients revealed no signs of DIC; nevertheless, four of them showed a moderate increase in D-dimer levels after initiation of therapy. In these patients a well-known side effect of long-term steroid therapy, namely a decrease of fibrinogen levels, was observed within the first week of treatment. Fibrinogen levels did not fall below 150 mg/dl and increased after dose reduction from 100 mg/day to 50 mg/day. We conclude from our results that two types of disturbances in fibrinogen metabolism can be observed during vincristine/prednisolone therapy of LBC of CML: (a) a decrease of fibrinogen levels due to a steroid-mediated impairment of liver synthesis, and (b) a rapid fall in fibrinogen levels in the course of DIC, most likely induced by the release of procoagulants from deteriorating blast cells, leading to severe bleeding in selected cases.

[Warfarin embryopathy in maternal coumarin therapy for protein S deficiency]. / Warfarin-Embryopathie bei mütterlicher Coumarin-Therapie wegen Protein-S-Mangels.

A case of Warfarin embryopathia is shown. The newborn, whose mother had been treated with Marcoumar (Phenprocoumon 3 mg/day) during the whole pregnancy because of a hereditary protein-S-deficiency showed the typical symptom of nasal hypoplasia. Coumarol derivates pass the placental membrane and are known as teratogenic. Recent retrospective and prospective studies show that the risk of fetal or embryonal teratogenic injury is about 25-30% if Coumarol derivates are given through the 6th to the 9th week of pregnancy. It is possible to nearly avoid those injuries when Heparin is used for anticoagulant therapy in this period and Coumarol itself is used in the lowest possible therapeutic dose.

Anticardiolipin antibodies in patients with venous thrombosis.

The levels of anticardiolipin antibodies (ACA) and lupus anticoagulant (LAC) were measured in 266 consecutive unselected patients with a history of venous thrombosis. 19 (7.1%) had elevated levels of IgG- or IgM-ACA. The prevalence of LAC was 1 of 266 (0.4%) in the whole patient group and 1 of 19 (5.3%) in the ACA-positive group. Patients with elevated ACA levels did not differ from those with normal ACA with regard to age at the first thrombosis, risk of recurrence, presence of arterial thrombosis, and other clinical features. 8 out of 19 (42.1%) patients with elevated ACA levels also had elevated levels of antinuclear antibodies, but only 1 fulfilled the criteria of systemic lupus erythematosus. These data indicate that in some patients with elevated ACA, autoimmune processes may be present. The clinical significance of elevated ACA levels is uncertain.