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Peter Quehenberger

Publications and source records attributed to Peter Quehenberger.

30 records · Page 2Linked to original sources
PubMed2003

Is the determination of anti-beta2 glycoprotein I antibodies useful in patients with venous thromboembolism without the antiphospholipid syndrome?

Anti-beta2-glycoprotein I (beta2GPI) antibodies are frequently found in patients with lupus anticoagulant (LA). To investigate the prevalence of antibeta2GPI antibodies and their clinical impact in patients with a history of venous thromboembolism (VTE) without LA/anticardiolipin antibodies (ACA), we studied 503 patients [128 (36.2%) men, median age 41 years (interquartile range, IQR 28-54 years)] with previous thrombosis. A group of 113 individuals without VTE [43 (38.1%) men, age 46.7 years (IQR 38-52 years)] served as a control group. Among 418 patients without LA/ACA, anti-beta2GPI-IgG levels were elevated in seven (1.7%), -IgM in 15 (3.6%) and -IgA in 14 (3.3%) cases; in 58 patients with ACA, anti-beta2GPI-IgG levels were elevated in two (3.4%), six (10.3%) and three (5.2%), and in 27 with LA, they were elevated in 18 (66.7%), 19 (70.4%) and 10 (37%) respectively. Thus, the prevalence of elevated anti-beta2GPI antibodies was not increased in patients without LA/ACA but was strongly associated with LA. Patients without ACA/LA who had a recurrent event did not have higher prevalence of elevated anti-beta2GPI-IgG, -IgM or -IgA antibodies than those without a recurrent event. Thus, elevated antibeta2GPI antibodies are not likely to be a predictor of recurrent events in patients without LA. We conclude that determination of anti-beta2GPI antibodies does not improve the clinical management of patients with a history of VTE without LA/ACA.

Adult↗
PubMed2003

Superficial thrombophlebitis and risk for recurrent venous thromboembolism.

OBJECTIVE: Superficial thrombophlebitis (ST) is a frequent and potentially serious disease if complicated with venous thromboembolism (VTE). Data on risk factors and incidence rates for ST are scarce. It is also unknown whether ST is a risk factor for recurrence of VTE. METHODS: After discontinuation of secondary thromboprophylaxis for a first spontaneous VTE, we prospectively observed 615 patients on average for 30 +/- 26 months. Patients with natural coagulation inhibitor deficiency, lupus anticoagulant, or cancer, who were pregnant, or were receiving long-term antithrombotic therapy were excluded. The study outcomes were occurrence of symptomatic ST or objectively documented recurrent symptomatic VTE. RESULTS: ST developed in 45 patients (7.3%) with a first VTE. High factor VIII concentration emerged as an independent risk factor for ST (relative risk [RR], 2.0; 95% confidence interval [CI], 1.0-5.2), compared with lower levels after adjustment for age and sex; factor V Leiden and prothrombin G20210A concentration; hyperhomocysteinemia; high body mass index; and duration of oral anticoagulation therapy. VTE recurred in 12 (27%) of 45 patients with ST and in 67 (12%) of 570 patients without ST. In patients with VTE, subsequent ST emerged as an independent risk factor for recurrent VTE. Patients with ST had twofold higher RR (2.1; 95% CI, 1.0-4.2) for recurrence than did patients without ST after adjustment for putative confounding variables. CONCLUSION: Patients with a first spontaneous VTE and subsequent ST are at increased risk for recurrent VTE. High factor VIII concentration is an independent risk factor for ST.

Adult↗
PubMed2003

The role of soluble cell adhesion molecules in patients with suspected deep vein thrombosis.

Activation of the endothelium, platelets and leukocytes has been shown to play an important role in the aetiology of deep venous thrombosis (DVT) in in-vitro experiments, resulting in the release of soluble cell adhesion molecules (sCAMs). We therefore assessed the value of soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble E-selectin and soluble P-selectin for the diagnostic process in 69 consecutive patients with suspected DVT. Final diagnosis was based on the results of Duplex sonography or ascending venography. Thirty-seven patients (53.6%) finally suffered from DVT. Mean levels of sVCAM-1 were 589 +/- 530 ng/ml for controls and 587 +/- 328 ng/ml for patients. Corresponding levels concerning sICAM-1 were 316 +/- 161 and 342 +/- 186 ng/ml, those concerning soluble E-selectin were 54 +/- 38 and 42 +/- 18 ng/ml, and those concerning soluble P-selectin were 94 +/- 37 and 99 +/- 36 ng/ml (all P > 0.05). There was no significant correlation of the thrombus extension (all P > 0.05) or the duration of symptoms with sCAMs (all P > 0.05). In conclusion, we detected no significant differences concerning the concentration of four major sCAMs between patients with DVT and controls, so their assessment does not add any useful information for the diagnostic process of DVT.

Adult↗
PubMed2003

The effect of beta-receptor blockade on factor VIII levels and thrombin generation in patients with venous thromboembolism.

High factor VIII (FVIII) is a risk factor for venous thromboembolism (VTE). The pathomechanism by which high FVIII leads to an increased risk of VTE is unknown. Physical activity and infusion of adrenalin provoke a rise in FVIII, which can be blocked by a nonselective beta-blockade. We tested the hypothesis that in patients with a VTE beta-blockade decreases FVIII and inhibits coagulation activation. 17 male patients with high FVIII (> 170 IU/dL, n = 7) or low FVIII (<150 IU/dL, n = 10) and a history of VTE received 40 mg of propranolol thrice daily for 14 days. FVIII and vasopressin levels were measured before and during propranolol intake and 28 days thereafter. At the same time points, haemostatic system activation was investigated by measuring prothrombin fragment f1.2 (f1.2) and thrombin antithrombin complexes (TAT) in venous blood and in blood emerging from a skin incision (shed blood). The mean FVIII level before propranolol was 192 IU/dL and 115 IU/dL in patients with high and low FVIII, respectively. During and 28 days after propranolol, no significant change in FVIII was seen in both groups. Changes in f1.2 and TAT were not detectable in either venous blood or in shed blood. beta-receptor blockade did not lower FVIII or inhibit haemostatic system activation in patients with VTE and persistently high FVIII. Administration of propranolol cannot be recommended as secondary thromboprophylaxis in patients with high FVIII.

Adrenergic beta-Antagonists↗
PubMed2002

Endothelial cell activation and blood coagulation in critically ill patients with lung injury.

INTRODUCTION: Adult respiratory distress syndrome is a life-threatening disease that requires respiratory assistance. It is associated with endothelial cell damage, coagulation activation, and intravascular fibrin deposition. This prospective study was conducted to determine whether the plasma levels of specific markers of endothelial cell function and coagulation activation are related to the degree of pulmonary disturbance. PATIENTS AND METHODS: Fourteen patients (8 male, 6 female, median age 69 years), admitted to a medical intensive care unit with various stages of lung injury needing mechanical ventilation, were compared with 16 healthy age- and sex-matched control subjects. RESULTS: Markers of endothelial cell damage and coagulation activation were significantly elevated in patients with lung injury compared with controls: von Willebrand factor (vWF) 4.12 vs. 1.25 U/ml, p < 0.0001; F VIII 4.40 vs. 1.88 U/ml, p = 0.0001; tissue-type plasminogen activator (tPA) 11.6 vs. 8.7 ng/ml, p = 0.02; plasminogen activator inhibitor-1 (PAI) 48.9 vs. 14.6 ng/ml, p < 0.0001; D-dimer 2.9 vs. 0.6 microgram/ml, p < 0.0001; thrombin-antithrombin III complex (TAT) 7.9 vs. 2.2 ng/ml, p < 0.0001 (median values; Mann-Whitney U-test). vWF, tPA, PAI and D-Dimer were significantly correlated with the PaO2/FiO2 ratio (p = 0.0003, 0.003, 0.04, 0.02, respectively; Spearman's rank correlation). CONCLUSION: These findings suggest that the endothelial cell disturbance and the activation of the coagulation system in patients with lung injury are related to the degree of pulmonary dysfunction.

Acute Disease↗
PubMed2002

Point of care measurement of lepirudin and heparin anticoagulation during systemic inflammation.

BACKGROUND: The number of indications for recombinant human hirudin lepirudin therapy has increased in recent years, and now includes acute coronary syndromes and heparin-induced thrombocytopenia. Hence, point of care monitoring appears desirable for therapy with lepirudin. As CoaguChek Plus (CCP) provides a rapid bedside test to monitor therapy with other anticoagulants, we aimed to determine its suitability for lepirudin therapy. METHODS: Forty-four healthy volunteers received a 2 ng/kg endotoxin infusion (to induce coagulation) together with clinically relevant doses of lepirudin or heparin in a prospective, placebo-controlled, randomised fashion. Measurements of CCP-partial thromboplastin time (aPTT) were compared to laboratory STA-aPTT. RESULTS: As expected, baseline values of CCP-aPTT were shorter than STA-aPTT. Lepirudin increased CCP-aPTT 3-fold, and STA-aPTT 2-fold 1 h after bolus infusion. During lepirudin infusion, the correlation between CCP-aPTT and STA-aPTT was excellent (r=0.86-0.92). Both methods were equally sensitive to over-anticoagulation with heparin. Acute systemic inflammation had little effects on CCP-aPTT. CONCLUSION: CCP-aPTT is suitable for longitudinal point of care monitoring of lepirudin therapy. As baseline values of CCP-aPTT are shorter than STA-aPTT, it is recommended not to indiscriminately change between methods in the follow-up of individual patients.

Adult↗
PubMed2002

Temporary increase in the risk for recurrence during pregnancy in women with a history of venous thromboembolism.

There is strong evidence that the incidence of venous thromboembolism (VTE) is increased during pregnancy. However, it is unknown whether and to which extent pregnancy influences the risk for recurrent VTE in women with previous thrombosis. To investigate whether pregnancy temporarily increases the risk for recurrent thrombosis, we retrospectively evaluated the recurrence rate in 109 women who had at least one pregnancy after an episode of VTE by comparing the time period during pregnancy with the nonpregnant period. Forty-three women had a first recurrence during a total observation time of 1014 years. Eight events (73 observation years) occurred during pregnancy, and 35 events (941 observation years) occurred outside pregnancy. Recurrence rates per 100 patient-years were 10.9% during and 3.7% outside pregnancy. Relative risk during pregnancy was 3.5 (95% confidence interval, 1.6-7.8; P =.002). Our data suggest that pregnancy leads to a temporary increase in the risk for recurrent thrombotic events.

Female↗
PubMed2002

Leptin induces endothelin-1 in endothelial cells in vitro.

Leptin, a protein encoded by the obese gene, is produced by adipocytes and released into the bloodstream. In obese humans, serum leptin levels are increased and correlate with the individual's body mass index and blood pressure. Elevated serum concentrations of endothelin-1 (ET-1), a potent vasoconstrictor and mitogen, were also observed in obese subjects. The pathomechanisms underlying this ET-1 increase in obesity are poorly understood. In the present study, we investigated the influence of the ob gene product leptin on the expression of ET-1 in human umbilical vein endothelial cells (HUVECs). Binding studies using (125)I-radiolabeled leptin revealed high- and low-affinity leptin binding sites on HUVECs (Kd1=13.1+/-3.1 nmol/L and Kd2=1390+/-198 nmol/L, respectively), mediating a time- and dose-dependent increase of ET-1 mRNA expression and protein secretion after incubation of HUVECs with leptin. This leptin-induced ET-1 expression was inhibited by preincubation of HUVECs with 0.75 micromol/L antisense phosphorothioate oligonucleotides directed against the leptin receptor Ob-Rb. Furthermore, after incubation with leptin, increased nuclear staining of c-fos and c-jun, the major components of the transcription factor AP-1, and increased AP-1 DNA binding were observed. Transient transfection studies with ET-1 promoter constructs showed that leptin-induced promoter activity was abolished in the absence of AP-1 binding sites or by cotransfection with a plasmid overexpressing a mutated jun, which is able to bind c-fos but not DNA. Thus, leptin upregulates ET-1 production in HUVECs via a mechanism potentially involving jun binding members of the bZIP family.

Cells, Cultured↗
PubMed2002

C-reactive protein in the diagnosis of deep vein thrombosis.

The role of C-reactive protein (CRP) in the diagnosis of suspected deep vein thrombosis (DVT) and a possible advantage of its additional evaluation with D-dimer has not been clearly evaluated. We therefore studied plasma CRP and D-dimer levels in 233 consecutive patients with suspected DVT; the final diagnosis was based on the results of colour duplex ultrasound or venography. DVT was diagnosed in 31.3%. CRP and D-dimer correlated significantly (r = 0.64, P < 0.01); both were increased significantly in patients suffering from DVT (P < 0.001). Multivariate analysis revealed a significant influence of the presence of DVT (P < 0.001), the presence of malignancy (P < 0.001) and the presence of inflammatory diseases (P = 0.009) on plasma CRP, while there was no significant influence of the duration of symptoms (P = 0.30). The sensitivity (75% vs 93%) to specificity (69% vs 55%) relationship showed inferior results for CRP compared with D-dimer; its additional evaluation did not improve the diagnostic value of D-dimer. We conclude that CRP can provide additional information neither for the diagnostic process in patients with suspected DVT nor for the differential diagnosis of DVT and inflammatory diseases.

Acute-Phase Reaction↗
PubMed2002

Frequent development of lupus anticoagulants in critically ill patients treated under intensive care conditions.

OBJECTIVE: To investigate how often a prolongation of the activated partial thromboplastin time in critically ill patients is caused by lupus anticoagulants and to identify possible triggering events. DESIGN: Prospective study. SETTING: Internal medicine intensive care unit (University Hospital of Vienna, Vienna, Austria). PATIENTS: Fifty-one critically ill patients without severe coagulopathy, hepatopathy, or anticoagulant treatment (35 male, 16 female, median age 60 yrs, range: 22-85 yrs). INTERVENTIONS: All patients were screened daily for lupus anticoagulants with the activated partial thromboplastin time STA assay. MEASUREMENTS AND MAIN RESULTS: Diluted Russell's viper venom time, plasma mixing studies, and confirmation assays were used to identify lupus anticoagulants at the time of an unexplained prolongation of the activated partial thromboplastin time. The influence of heparin was excluded by determination of thrombin clotting time and anti-Xa activity. In 27 of 51 patients (52.9 %) lupus anticoagulants were found after a median stay of 13 days. None of the patients had concomitant immune thrombocytopenia, hypoprothrombinemia, bleeding, or thromboembolic complications. Sepsis (p =.006) and/or catecholamine treatment (p =.002) were significantly associated with the development of lupus anticoagulants. Extracorporeal circulation, transfusion of blood products, or surgery did not increase this risk. Lupus anticoagulants resolved spontaneously in 63% of the patients after a median stay of 17 days. CONCLUSIONS: Lupus anticoagulants are frequent in critically ill patients and associated with sepsis syndrome and/or catecholamine treatment. The prolonged activated partial thromboplastin time does not warrant the administration of coagulation factors or the cessation of anticoagulant therapy or prophylaxis, inasmuch as this phenomenon is not associated with bleeding or thromboembolic complications.

Adult↗
PubMed2002

Unilateral chronic thromboembolic pulmonary disease associated with combined inherited thrombophilia.

Chronic thromboembolic pulmonary hypertension (CTEPH) is considered to be an extreme variant of pulmonary thromboembolism. The underlying mechanisms for the failure of thrombus resolution are still unclear. In looking for inherited thrombophilia, an association with a lupus anticoagulant has been described repeatedly, and single cases of anticoagulant deficiencies (ie, antithrombin [AT], protein C, and protein S) have been reported. We describe a young patient with type I AT deficiency, the heterozygous prothrombin G20210A mutation, and unilateral chronic thromboembolic pulmonary disease presenting after a single thrombotic event. Pulmonary vascular patency was restored successfully by surgical pulmonary thromboendarterectomy. This case is unique because unilateral CTEPH is extremely uncommon, and it illustrates the severe clinical sequelae of the cosegregation of inherited thrombophilic defects.

Adult↗