[Prevalence of Elevated Lipoprotein (a) Levels in Patients < 60 Years of Age with Retinal Vein Occlusion]. / Prävalenz erhöhter Lipoprotein(a)-Spiegel bei unter 60-jährigen Patienten mit venösen retinalen Gefäßverschlüssen.

BACKGROUND: The potential impact of elevated Lipoprotein (a) [Lp(a)] levels on retinal venous occlusive (RVO) diseases with regard to age and various risk factors has not been studied extensively. PATIENTS AND METHODS: In a retrospective case-control study, thrombophilia data of 106 young patients (< 60 years at the time of the RVO or a previous thromboembolic event) with RVO and 76 healthy subjects were evaluated. RESULTS: Elevated Lp(a) plasma levels were significantly more prevalent among RVO patients (29.2 %) than among controls (9.2 %; p = 0.0009). Lp(a) levels were found to be significantly (p = 0.012) different between patients and controls. Moreover, we found that an unusual personal or family history of thromboembolism was a strong predictor of elevated Lp(a) (p = 0.03). We observed a significant correlation between elevated Lp(a) and other coagulation disorders (p = 0.005). Multivariate analysis showed that elevated lipoprotein(a) levels (OR: 3.5; p = 0.003) were an independent risk factor for the development of RVO. CONCLUSIONS: Elevated plasma levels of Lp(a) are associated with the development of RVO. Selective screening of young patients and subjects with a personal or family history of thromboembolism may be helpful in identifying RVO patients with elevated Lp(a).

[New cross-sectional guidelines of the German Medical Association for hemotherapy with fresh frozen plasma. Evidence-based recommendations for risk-benefit assessment]. / Neue (Querschnitt-)Leitlinien der Bundesärztekammer für die Hämotherapie mit gefrorenem Frischplasma. Evidenzbasierte Empfehlungen für die Risiko-Nutzen-Abwägung.

Some new blood products and plasma derivatives have extended the possibilities in hemotherapy to such an extent that the therapeutic and evidence-based therapy options can only really be managed with the aid of guidelines. Four approved plasma preparations are available in Germany: fresh frozen plasma, lyophilized plasma, solvent-detergent (SD) pool plasma and methylene blue-light-treated plasma. Evidence of the clinical efficacy of plasma is mainly based on uncontrolled observational studies, case reports or expert opinion. Plasma is indicated for complex coagulopathy associated with manifest or imminent bleeding, particularly with massive transfusion, disseminated intravascular coagulation and liver disease. With the exception of emergency situations when clotting assay results are not available in time, a clinically relevant coagulopathy must be verified before plasma is administered. The rapid infusion of at least 10 ml of plasma per kg body weight is required to significantly increase the respective clotting factor or inhibitor levels. Prothrombin complex concentrates (PPSB) should be preferred to plasma for the rapid reversal of oral anticoagulation. Side effects of plasma are rare but have to be considered.

[Prophylaxis of venous thromboembolism and anticoagulation bridging. Strategies in otorhinolaryngology]. / Thromboembolieprophylaxe und überbrückende Antikoagulation. Strategien in der HNO-Heilkunde.

Various interdisciplinary guidelines recommend that in-patients at risk of venous thromboembolism should receive pharmacologic prophylaxis. Among the anticoagulants low-molecular-weight heparins (LMWH) and fondaparinux can be considered the medications of choice because of the favorable pharmacokinetic properties when compared with unfractionated heparin. Treatment with vitamin K antagonists has to be interrupted in patients undergoing major surgery or invasive procedures. Oral anticoagulation has to be temporarily replaced by short-acting anticoagulants such as LMWH in order to prevent thromboembolic complications (anticoagulation bridging). Although LMWHs have not been approved for this clinical setting their efficacy and safety has been demonstrated in several recent studies. Detailed recommendations for prophylaxis of venous thromboembolism in otorhinolaryngology are lacking although numerous surgical procedures are considered to be associated with a significant risk of thromboembolism. A strategy for pharmacologic prophylaxis of venous thromboembolism and anticoagulation bridging in otorhinolaryngology is proposed.

Leukocyte-platelet aggregates in acute and subacute ischemic stroke.

BACKGROUND: Leukocyte-platelet aggregates appear to be a stable and sensitive marker of platelet activation as suggested by studies in coronary heart disease. We tested the hypothesis that leukocyte-platelet aggregates are increased after ischemic stroke and investigated the contribution of different leukocyte subtypes to such increase. METHODS: We serially determined granulocyte-, lymphocyte- and monocyte-platelet aggregates, using flow cytometry at days 1, 2, 3, 5, 7, 10, and 90 in patients with ischemic stroke (n = 45) and in age- and sex-matched healthy control subjects (n = 30). RESULTS: Granulocyte-platelet aggregates (granulocytes with > or =1 platelet/microl) were more common in patients than control subjects from day 1 through day 10 (p < 0.04, respectively), but not on day 90 after stroke. The percentage of granulocytes forming aggregates was increased on days 1-3 after stroke but not at other time points. Lymphocyte-platelet aggregates were not more common at any time point after stroke. Total numbers and percentages of monocytes forming platelet aggregates were significantly increased on day 2 (p = 0.003), but not at other time points after stroke. CONCLUSION: The 3 leukocyte subtypes showed different kinetics regarding aggregate formation with platelets after ischemic stroke. Increase of monocyte-platelet aggregates is short-lived and may reflect an acute reaction to cerebral ischemia, whereas granulocyte-platelet aggregate formation persists into the subacute phase, suggesting that they are a particularly sensitive parameter reflecting both prothrombotic and inflammatory processes after stroke.

[Haemostatic testing prior to elective surgery? Yes!]. / Laboranalytischer Ausschluss einer hämorrhagischen Diathese vor elektiven Eingriffen? Ja!

Haemorrhagic disorders must be excluded prior to any operation or other invasive procedure that has the potential to involve serious bleeding. When assessing the individual risk of bleeding, screening tests of hemostasis must be combined with the patient's clinical history and symptoms, and any history of bleeding must be explored under direct medical supervision using a standardized questionnaire. However, this bleeding history is neither very specific, nor is it particularly sensitive. Screening tests that have been found to be useful include platelet count, activated partial thrombo plastin time (aPTT), prothrombin time (PT) and clottable fibrinogen. No reliable, sensitive and specific screening test is however available today to screen for platelet dysfunction or von Willebrand disease. A specialized coagulation laboratory should be involved when the bleeding history or laboratory screening indicate a potential haemorrhagic disorder.

Preservation of in vitro function of platelets stored in the presence of a synthetic dual inhibitor of factor Xa and thrombin.

BACKGROUND: The use of citrate anticoagulant limits the clinical significance of platelet function tests. Thrombin inhibitors cannot prevent thrombin-induced platelet activation completely. We examined the influence of benzylsulfonyl-d-Arg-Pro-4-amidinobenzylamide (BAPA), a dual inhibitor of Factor Xa (FXa) and thrombin, on platelet responsiveness to agonists when measured between 2 and 24 h after venipuncture. METHODS: Blood samples from 36 individuals were anticoagulated with citrate and BAPA, respectively. Turbidimetric platelet aggregometry (TPA) and impedance platelet aggregometry (IPA), a whole blood platelet counting assay for measuring platelet aggregation (PCA), and Platelet Function Anlayzer-100 (PFA-100 closure times (CTs) were determined after whole blood storage between 2 and 24 h after venipuncture. Native whole blood was studied over 48 h to determine the inhibition of thrombin generation by BAPA, hirudin and melagatran. RESULTS: BAPA inhibited thrombin generation completely for 48 h, while hirudin and melagatran did not. The use of citrate resulted in significantly reduced TPA induced by arachidonic acid (AA) or adenosine 5'-diphosphate (ADP), and significantly reduced IPA regardless of agonist when measured 10 and 24 h after blood collection. PCA ratios in citrated blood also dropped significantly 10 and 24 h after venipuncture. The length of storage of BAPA-anticoagulated blood samples over 24 h had no significant influence on any platelet response. The reproducibility of platelet function assay results obtained from BAPA-anticoagulated samples was significantly better than corresponding data from citrated blood. CONCLUSION: TPA, IPA, PCA or PFA-100 CTs remain stable for 24 h when whole blood is anticoagulated with a dual inhibitor of FXa and thrombin. This would greatly simplify the shipment of samples for platelet function testing.

[Multiple thrombophilic risk markers in patients ≺65 years of age with retinal vein occlusion]. / Multiple thrombophile Risikomarker bei Patienten ≺65 Jahre mit venösen retinalen Gefäßverschlüssen.

BACKGROUND: The potential impact of multiple thrombophilic defects on retinal venous occlusive (RVO) diseases with regard to age and various risk factors has not been studied extensively. MATERIALS AND METHODS: In a retrospective, multicenter study, thrombophilia data of 128 patients <65 years of age with RVO and 110 healthy subjects were evaluated. The main measure outcome was the prevalence of multiple thrombophilic disorders. RESULTS: Multiple thrombophilic defects were significantly more prevalent among RVO patients (18.0%) than among controls (1.8%; P < 0.0001). We identified factor VIII elevation, elevated lipoprotein(a) plasma levels and resistance to activated protein C as the most prevalent combined disorders. Factor XII deficiency and prothrombin mutation G20210A were found to be isolated thrombophilic risk factors. Multiple thrombophilic defects were significantly associated with RVO recurrence (P = 0.008). CONCLUSION: Multiple thrombophilic disorders are associated with the development of RVO among patients younger than 65 years of age. Moreover, our results suggest that patients with RVO associated with underlying combined thrombophilic defects are at increased risk for RVO recurrence. Further studies are required to analyze whether the diagnosis of combined thrombophilic defects among RVO patients could be a predictor for RVO recurrence.

Prevalence of antibodies to HTLV-III in AIDS risk groups in West Germany.

The prevalence of antibodies to human T-lymphotropic virus III was determined in acquired immunodeficiency syndrome (AIDS) risk groups by an enzyme linked immunosorbent assay and confirmatory tests in four different areas in West Germany. Twenty-four of 28 homosexual AIDS patients (86%), 24 of 33 homosexual patients with lymphadenopathy syndrome or AIDS related complex (73%), and 44 of 113 asymptomatic homosexuals at risk for AIDS (39%) were seropositive. In three groups of hemophiliacs, 8 of 35 in 1983 (23%), 25 of 65 in early 1984 (39%), and 19 of 23 in late 1984 (83%) showed positive results. Two sera from 36 polytransfused patients were also positive, whereas 36 selected blood donors, and 32 healthy laboratory and clinical personnel were all negative. Also no human T-lymphotropic virus III antibodies were detected in sera of 187 prostitutes in the Munich area.

Comparative study of intranasal, subcutaneous and intravenous administration of desamino-D-arginine vasopressin (DDAVP).

This study was performed to evaluate the influence of different routes of administration on the efficacy of DDAVP treatment. Ten healthy volunteers received DDAVP intranasally (i.n.), subcutaneously (s.c.) and intravenously (i.v.) in a randomized cross-over trial. Factor XII and high molecular weight (HMW)-kininogen levels increased only slightly after DDAVP administration. The mean increase of factor VIII: C was 3.1 (i.v.), 2.3 (s.c.), and 1.3 (i.n.) - fold over baseline. Ristocetin cofactor (von Willebrand factor antigen) increased 3.1 (2.5), 2.0 (2.3) and 1.2 (1.2) - fold over baseline mean values after i.v., s.c. and i.n. DDAVP, respectively. The half-disappearance time of factor VIII and von Willebrand factor (vWF) after DDAVP ranged from five (factor VIII:C) to eight hours (vWF). The mean increase of fibrinolytic activity was more pronounced after i.v. DDAVP. The antidiuretic effect was moderate with no apparent differences between the routes of application. This study provides further evidence that both i.v. and s.c. DDAVP administration result in an appropriate and reliable stimulation of haemostasis. An additional advantage of s.c. administration is its suitability for home treatment.

Thrombin-induced platelet malondialdehyde (MDA) formation in normal subjects and in women taking oral contraceptives.

Thrombin-induced platelet malondialdehyde (MDA) production and platelet count were studied in 82 male and 74 female healthy blood donors. 37 women on oral contraceptives (OC) had significantly lower values of MDA production than women who were not using the pill. There were no statistically significant differences of MDA production in women on a low dose estrogen, a medium dose, and a relatively high dose. Males had significantly higher values than females. In 15 further subjects (5 males, 5 OC-users, 5 OC-nonusers) the kinetics of MDA formation was determined by using increasing doses of thrombin. No significant differences could be found. Platelet count in women on OCs was lightly increased, but the difference was not significant.

Determination of factor XIII activity and of factor XIII inhibitors using an ammonium-sensitive electrode.

An assay for rapid factor XIII activity measurement has been developed based on the determination of the ammonium released during fibrin stabilization. Factor XIII was activated by thrombin and calcium. Ammonium was measured by an ammonium-sensitive electrode. It was demonstrated that the assay procedure yields accurate and precise results and that factor XIII-catalyzed fibrin stabilization can be measured kinetically. The amount of ammonium released during the first 90 min of fibrin stabilization was found to be 7.8 +/- 0.5 moles per mole fibrinogen, which is in agreement with the findings of other authors. In 15 normal subjects and in 15 patients suffering from diseases with suspected factor XIII deficiency there was a satisfactory correlation between the results obtained by the "ammonium-release-method', Bohn's method, and the immunological assay (r1 = 0.65; r2 = 0.70; p less than 0.01). In 3 of 5 patients with paraproteinemias the values of factor XIII activity determined by the ammonium-release-method were markedly lower than those estimated by the other methods. It could be shown that inhibitor mechanisms were responsible for these discrepancies.

Thromboembolic complications associated with the use of prothrombin complex and factor IX concentrates.

In 1994, shortly after a heat-treated prothrombin complex concentrate (PCC) had been withdrawn from the German market due to transmission of hepatitis B, the license of another brand was withdrawn, due to 3 acute fatalities associated with the use of this product. We report on the clinical data of altogether 5 patients, who died during a 3 month period in Germany after having received this brand of PCC. All patients had surgery, acquired deficiencies of coagulation factors, and underlying diseases predisposing for thrombosis or disseminated intravascular coagulation. PCC was administered for the prevention of bleeding. In three patients, a drug interaction of PCC with aprotinin may also have played a role. Several points, however, are suspicious of a major causative effect of the respective product, (a) the close temporal correlation between administration of the drug and the subsequent clinical as well as laboratory deterioration, (b) the accumulation of these adverse events in a short period of time, when the use and market share of this brand increased due to the shortage of other products, and (c) laboratory abnormalities of this brand which have been consistently observed in several in vitro studies.

Dose response relationships of anticoagulant activities after subcutaneous administration of two low molecular weight heparins in healthy individuals.

This study was performed to estimate appropriate dosages of two low molecular weight heparins (LMWH) for clinical trials on subcutaneous perioperative thrombosis prophylaxis. Anticoagulatory activities and platelet function were investigated after single doses of two LMWH and of unfractionated sodium heparin (UFH) in 24 healthy individuals. Twelve subjects received subcutaneous injections of 1000, 1500, and 2500 i.u. (aPTT) of LMHW 1, and the other 12 received LMWH 2 at same dosages. The following parameters were determined before 30 min, 1 h, 90 min, 2 h, 3 h, 4 h, 6 h, 8 h, and 10 h after either LMWH or 5000 i.u. (aPTT) UFH: aPTT, thrombin time, anti-Xa activity (S 2222, Coatest heparin), and anti-IIa activity (Chromozym TH). Bleeding time, platelet count, and adrenalin-, collagen-, and ADP-induced platelet aggregation were assessed before and 3 h after administration. After application of 1500 i.u. LMWH 1 and LMWH 2, the anti-Xa and anti-IIa levels were already significantly higher than after 5000 i.u. UFH. 2500 i.u. LMWH 1 and LMWH 2 evoked significantly greater prolongations of aPTT and thrombin time values than did 5000 i.u. UFH. This was not the case after 1000 and 1500 i.u. LMWH. The half-lives of anticoagulatory effects after LMWH were markedly longer than after UFH. Platelet function was not altered by any of the heparins tested. Our results indicate that LMWH cause anticoagulatory effects in vivo that cannot be predicted by in vitro studies and that the appropriate single dosages of LMWH in subcutaneous perioperative thrombosis prophylaxis have to be estimated by dosage determinations in healthy subjects.

Factor VIII: C (FVIII: C) recovery and half-life after infusion of steam-treated high purity factor VIII concentrate in severe hemophilia A--comparison of one-stage assay, two-stage assay and a chromogenic substrate assay.

Factor VIII:C recovery and half-life was measured in 16 hemophilia A patients under comprehensively standardized conditions. Each patient received the same lot of a steam-treated high purity FVIII concentrate at a dose of 19-33 U/kg body weight. A comparison was made between the one-stage assay, the two-stage assay and a chromogenic substrate test for FVIII:C determination using a FXa-sensitive chromogenic substrate. Factor VIII:C potency of the administered FVIII concentrate was measured using calibration curves derived from a concentrate standard and FVIII:C plasma levels were read from calibration curves derived from a plasma standard. The chromogenic assay showed a good reproducibility at FVIII:C levels between 0.015 and 0.50 U/ml. The FVIII:C recoveries calculated from the results of the one-stage assay, the two-stage assay and the chromogenic substrate test were 109 +/- 20, 92 +/- 14 and 81 +/- 11% (mean +/- SD), respectively. The elimination half-lives of FVIII:C were calculated by non-linear least square analysis using a modified computerized Gauss-Newton algorithm. The half-lives calculated from the FVIII:C plasma levels measured by the one-stage assay, the two-stage assay and the chromogenic test were 23.8 +/- 6.4, 22.2 +/- 5.7 and 17.1 +/- 4.8 h (mean +/- SD), respectively. No previous study has reported such long half-life values. Our findings indicate that measurements of recoveries and half-lives by the chromogenic FVIII:C assay and by computerized non-linear least square analysis allow the possibility of individualized FVIII replacement therapy.

Rationale and design of the LURIC study--a resource for functional genomics, pharmacogenomics and long-term prognosis of cardiovascular disease.

BACKGROUND AND AIM: Coronary artery disease (CAD), arterial hypertension and Type 2 diabetes mellitus are common polygenetic disorders which have a major impact on public health. Disease prevalence and progression to cardiovascular complications, such as myocardial infarction (MI), stroke or heart failure, are the product of environment and gene interaction. The LUdwigshafen RIsk and Cardiovascular Health (LURIC) study aims to provide a well-defined resource for the study of environmental and genetic risk factors, and their interactions, and the study of functional relationships between gene variation and biochemical phenotype (functional genomics) or response to medication (pharmacogenomics). Long-term follow-up on clinical events will allow us to study the prognostic importance of common genetic variants (polymorphisms) and plasma biomarkers. SETTING: Cardiology unit in tertiary care medical centre in south-west Germany. STUDY DESIGN: Prospective cohort study of individuals with and without cardiovascular disease at baseline. PATIENTS AND METHODS: LURIC is an ongoing prospective study of currently > 3300 individuals in whom the cardiovascular and metabolic phenotypes CAD, MI, dyslipidaemia, hypertension, metabolic syndrome and diabetes mellitus have been defined or ruled out using standardised methodologies in all study participants. Inclusion criteria for LURIC were: German ancestry (limitation of genetic heterogeneity) clinical stability (except for acute coronary syndromes [ACSs]) availability of a coronary angiogram (this inclusion criterium was waived for family members provided that they met all other inclusion and exclusion criteria) Exclusion criteria were: any acute illness other than ACSs any chronic disease where non-cardiac disease predominated a history of malignancy within the past five years. Exclusion criteria were pre-specified in order to minimise the impact of concomitant non-cardiovascular disease on intermediate biochemical phenotypes or on clinical prognosis (limitation of clinical heterogeneity). A standardised personal and family history questionnaire and an extensive laboratory work-up (including glucose tolerance testing in non-diabetics and objective assessment of smoking exposure by determination of cotinine plasma levels) was obtained from all individuals after informed consent. A total of 115 ml of fasting venous blood was sampled for the determination of a pre-specified wide range of intermediate biochemical phenotypes in serum, plasma or whole blood, for leukocyte DNA extraction and immortalisation of B-lymphocytes. Biochemical phenotypes measured included markers of endothelial dysfunction, inflammation, oxidative status, coagulation, lipid metabolism and flow cytometric surface receptor expression of lympho-, mono- and thrombocytes. In addition, multiple aliquots of blood samples were stored for future analyses. RESULTS: A total of 3500 LURIC baseline measurements were performed in 3316 individuals between July 1997 and January 2000. The baseline examination was repeated within a median of 35 days in 5% of study participants (n = 166, including a third examination in 18 after a median of 69 days) for pharmacogenomic assessment of lipid-lowering therapy and for quality control purposes. A five-year follow-up on major clinical events (death, any cardiovascular event including MI, stroke and revascularisation, malignancy and any hospitalisation) is ongoing. The clinical phenotypes prevalent at baseline in the cohort of 2309 men (70%) with a mean age of 62 +/- 11 years and 1007 women (30%), mean age 65 +/- 10 years, were angiographically-documented CAD in 2567 (79%), MI in 1368 (41%), dyslipidaemia in 2050 (62%) with hypercholesterolaemia > or = 240 mg/dl (27%), hypertriglyceridaemia > or = 150 mg/dl (44%) and HDL-cholesterol < or = 35 mg/dl (38%) in individuals not treated with lipid-lowering agents, systemic hypertension in 1921 (58%), metabolic syndrome in 1591 (48%), Type 2 diabetes in 1063 (32%) and obesity defined by body mass index > or = 30 kg/m2 in 770 (23%). Control patients in whom CAD had been ruled out angiographically were five years younger than those with CAD (59 +/- 12 and 64 +/- 10 years, respectively; p < 0.001), twice as often females (48% compared to 25% females in the CAD group, p < 0.001) and had significantly less cardiovascular risk factors than individuals with CAD. The prevalence of specific cardiovascular risk subsets in LURIC, such as the elderly (> or = 75 years), was 375 (11%), while 213 (6%) were young adults (< 45 years) and 904 (27%) were postmenopausal women (90% of all females). A low risk status (< or = 1 out of the four traditional risk factors: dyslipidaemia, smoking, hypertension and diabetes mellitus) was identified in 314 (9%) individuals of the entire cohort (5% in CAD and 26% in controls, p < 0.001) and 97 (3%) carried none of the four risk factors (1% in CAD and 9% in controls, p < 0.001). (ABSTRACT TRUNCATED)

Production and composition of prothrombin complex concentrates: correlation between composition and therapeutic efficiency.

Four-factor PCCs are most frequently used for replacement of vitamin K-dependent clotting factors and inhibitors proteins C and S in patients bleeding after phenprocoumon or warfarin overdose, in vitamin K-deficient patients presenting life-threatening bleeding, and liver disease. Since many of these patients are prone to thromboembolic complications including DIC, all conceivable measures should be taken against the thrombogenic potential of PCC preparations. This thrombogenic potential of PCCs is obviously dependent on several factors including activated clotting factors, lack of inhibitors of blood coagulation, and coagulation factor overload, as well as predisposing factors referred to recipients and drug interactions. The composition of PCC should meet the following criteria: Antithrombin in addition to heparin for the neutralization of FIXa and FXa should be present in the preparations; no overloading with FII and FX; substantially lower FVII than FIX potencies in order to minimize contamination with or generation of FVIIa; and substantial protein C as well as protein S activities. Quality control should include determinations as recommended by the European Pharmacopoeia. Specific assays for quantification of FIXa and FXa are urgently required, and validity of these assays must be proven in surveys. All lots should also be tested for their FVIIa content. Furthermore, the safety of PCCs must be proven by suitable animal models. Whenever possible, patients receiving PCCs should be under low-dose heparin prophylaxis; simultaneous administration of heparin-neutralizing drugs or antifibrinolytic agents must be avoided.

Measurement of factor VII and of activated factor VII in healthy individuals and in prothrombin complex concentrates.

We established reference ranges for factor VII clotting activity (FVII:C), factor VII amidolytic activity (FVII:AM), and activated factor VII (FVIIa) in 102 healthy individuals. The reference ranges were 65-160 U/100 ml, 70-165 U/100 ml, and 30-170 mU/ml, respectively (2.5 and 97.5 percentiles). Freezing and thawing of the plasma samples had no influence on the assay results. Due to the small sample size, the results were not influenced by gender, age, smoking habits, and oral contraceptive use. The plasma levels of FVII:C, FVII:AM, and FVIIa were significantly correlated with each other. The significant correlation between FVIIa and FVII:AM indicates that FVIIa is not completely independent of circulating FVII mass. There was also a significant, though weak, correlation between FVIIa and FVII:C/FVII:AM ratios. Sixteen batches of prothrombin complex concentrates (PCC) from 3 manufacturers were also analysed. FVIIa could be detected in all preparations, with considerable variations from batch to batch. In contrast to the results obtained in plasma from normal individuals, there was a close correlation between FVIIa and FVII:C/FVII:AM ratios. The preparations could be characterized by their FVII and FVIIa potencies and by their FVII:C/FVII:AM ratios. In PCC, FVII:C was very strongly correlated with FVIIa, whereas no significant correlation was observed between FVII:AM and FVII:C and between FVII:AM and FVIIa, respectively. These results demonstrate that the FVII:C assay used is sensitive for detecting FVIIa. Thus, we cannot confirm that FVIIa sensitivity of one-stage clotting assays for FVII:C is low when a rabbit thromboplastin and a non-adsorbed FVII-deficient plasma is used.

Markers of activated hemostasis and fibrinolysis in patients with pulmonary malignancies: comparison of plasma levels in central venous and pulmonary venous blood.

Malignancy frequently is accompanied by activated coagulation and fibrinolysis indicating a hypercoagulable state. The purpose of our study was to estimate the contribution of local tumor-induced mechanisms to the activation of hemostasis and fibrinolysis. In a prospective study, we compared the plasma levels of thrombin-antithrombin complexes, prothrombin fragment 1+2, and D-dimers in blood samples that simultaneously were drawn from the superior vena cava and the pulmonary vein of a tumor-bearing pulmonary lobe. Samples from the superior vena cava were drawn before operation and served as controls. After thoracotomy, a second group of samples was simultaneously taken from the pulmonary veins of the tumor-bearing lobe and the superior vena cava. Forty-five patients with pulmonary malignancies were included (25 adenocarcinomas and 20 squamous cell carcinomas). There were no significant differences of thrombin-antithrombin complexes, prothrombin fragment 1+2, and D-dimers levels in patients suffering from adenocarcinoma and from squamous cell carcinoma. Intraoperatively, prothrombin fragment 1+2 and D-dimers levels were markedly increased when compared with the preoperative values (p<0.0001). There was no increase of thrombin-antithrombin complexes levels due to the operative traumatization. Prothrombin fragment 1+2, thrombin-antithrombin complexes, and D-dimers plasma levels were significantly higher in the pulmonary venous blood than in the blood simultaneously drawn from the superior vena cava (p<0.0001). Our findings indicate that malignant lung tumors directly contribute to the activation of hemostasis and fibrinolysis in these clinical settings.

Manufacturing of a prothrombin complex concentrate aiming at low thrombogenicity.

The paper describes the production of a prothrombin complex concentrate (PCC) with high virus safety and a well-balanced content of vitamin K-dependent clotting factors and inhibitors. Solid-phase extraction is followed in a second step by optimized anion exchange chromatography using a radial column. A step for virus removal by nanofiltration is introduced in addition to the solvent/detergent step. By speeding up the chromatographic step, the period of time required for production is reduced considerably. The activities of the four vitamin K-dependent clotting factors II, VII, IX and X are in ratios of about 1:1:1:1. Protein C, Protein S, and Protein Z are also present in therapeutically effective concentrations. The product shows no thrombogenicity, in either in vivo nor in vitro models. Clinical investigations show that the PCC is a safe and efficient preparation for the substitutive treatment of FIX or FVII in patients suffering from the respective deficiencies. All bleeding episodes have been efficiently controlled with relatively low doses of the concentrate. The surgical procedures have been conducted without any problems in severely FIX and FVIII deficient patients.

Clinical experience with the viral safety of immunoglobulins.

Preparations of intramuscular immunoglobulins (IMIGs) have not been reported to transmit viral disease since the inclusion of third-generation tests screening donor blood for hepatitis B virus. IMIGs and intravenous immunoglobulins (IVIGs) have never been a source of transmission of human immunodeficiency viruses. One episode of hepatitis B transmission by IVIGs caused by the addition of contaminated material during the manufacturing process, has been reported. Between 1983 and 1994 there were at least 17 reports of transmission of non-A, non-B hepatitis or [transaminitis' connected with the application of six IVIG preparations. These preparations were produced without including a validated virus-inactivation method in the manufacturing process. Careful analysis of these accidents demonstrates that minimization of virus contamination of source plasma, guarantee of good manufacturing practice, as well as application of an accepted virus-inactivation procedure are essential requirements for the production of safe immunoglobulin preparations.