Tissue factor pathway inhibitor is associated with risk of venous thromboembolism and all-cause mortality in patients with cancer

Venous thromboembolism (VTE) is a common complication in patients with cancer. Data on the role of natural inhibitors of coagulation for occurrence of cancer-associated VTE are limited, thus, we investigated the association of tissue factor pathway inhibitor (TFPI) with risk of VTE and all-cause mortality in patients with cancer. Total TFPI antigen levels were measured with a commercially available enzyme-linked immunosorbant assay in patients included in the Vienna Cancer and Thrombosis Study, a prospective observational cohort study with the primary outcome VTE. Competing risk analysis and Cox regression analysis were performed to explore the association of TFPI levels with VTE and all-cause mortality. TFPI was analyzed in 898 patients (median age 62 years; interquartile range [IQR], 53-68; 407 (45%) women). Sixty-seven patients developed VTE and 387 died (24-month cumulative risk 7.5% and 42.1%, respectively). Patients had median TFPI levels at study inclusion of 56.4 ng/mL (IQR, 45.7-70.0), with highest levels in tumor types known to have a high risk of VTE (gastroesophageal, pancreatic and brain cancer: 62.0 ng/mL; IQR, 52.0-75.0). In multivariable analysis adjusting for age, sex, cancer type and stage, TFPI levels were associated with VTE risk (subdistribution hazard ratio per doubling =1.63, 95% confidence interval [CI]: 1.03-2.57). When patients with high and intermediate/low VTE risk were analyzed separately, the association remained independently associated in the high risk group only (subdistribution hazard ratio =2.63, 95% CI: 1.40-4.94). TFPI levels were independently associated with all-cause mortality (hazard ratio =2.36, 95% CI: 1.85-3.00). In cancer patients increased TFPI levels are associated with VTE risk, specifically in patients with high-risk tumor types, and with all-cause mortality.

Neutrophil subpopulations and their activation potential in patients with antiphospholipid syndrome and healthy individuals

OBJECTIVES

Patients with APS are at increased risk of thromboembolism. Neutrophils have been shown to play a role in inducing thrombosis. We aimed to investigate differences in neutrophil subpopulations, their potential of activation and neutrophil extracellular trap (NET) formation comparing high and low-density neutrophils (HDNs/LDNs) as well as subpopulations in patients with APS and controls to gain deeper insight into their potential role in thrombotic manifestations in patients with APS.

METHODS

HDNs and LDNs of 20 patients with APS and 20 healthy donors were isolated by density gradient centrifugation and stimulated. Neutrophil subpopulations, their activation and NET release were assessed by flow cytometry.

RESULTS

LDNs of both groups showed higher baseline activation, lower response to stimulation (regulation of activation markers CD11b/CD66b), but higher NET formation compared with HDNs. In patients with APS, the absolute number of LDNs was higher compared with controls. HDNs of APS patients showed higher spontaneous activation [%CD11b high: median (interquartile range): 2.78% (0.58-10.24) vs 0.56% (0.19-1.37)] and response to stimulation with ionomycin compared with HDNs of healthy donors [%CD11b high: 98.20 (61.08-99.13) vs 35.50% (13.50-93.85)], whereas no difference was found in LDNs. NET formation was increased in patients' HDNs upon stimulation.

CONCLUSION

HDNs and LDNs act differently, unstimulated and upon various stimulations in both healthy controls and APS patients. Differences in HDNs and LDNs between patients with APS and healthy controls indicate that neutrophils may enhance the risk of thrombosis in these patients and could thus be a target for prevention of thrombosis in APS.

Altered platelet proteome in lupus anticoagulant (LA)-positive patients-protein disulfide isomerase and NETosis as new players in LA-related thrombosis

Patients with antiphospholipid syndrome (APS) are at high risk of developing venous and arterial thromboembolism (TE). The role of platelets in the pathogenesis of these prothrombotic conditions is not yet fully understood. The aim of this study was to gain mechanistic insights into the role of platelets in APS by comparing the platelet proteome between lupus anticoagulant (LA)-positive patients with (LA+ TE+) and without a history of TE (LA+ TE-) and healthy controls. The platelet proteome of 47 patients with LA, 31 with a history of TE and 16 without thrombotic history, and 47 healthy controls was analyzed by two-dimensional differential in-gel electrophoresis and mass spectrometry to identify disease-related proteins. Afterward, selected LA-related platelet proteins were validated by western blot and ELISA. Alterations of 25 proteins were observed between the study groups. STRING pathway analysis showed that LA-related protein profiles were involved in platelet activation, aggregation, and degranulation. For example, protein disulfide isomerase family members, enzymes that promote thrombosis, were upregulated in platelets and plasma of LA+ TE+ patients. Leukocyte elastase inhibitor (SERPINB1), an antagonist of neutrophil extracellular trap (NET) formation, was decreased in platelets of LA+ TE+ patients compared to healthy controls. Additionally, citrullinated histone H3, a NET-specific marker, was increased in plasma of LA+ TE+ patients. These findings suggest that decreased platelet SERPINB1 levels favor prothrombotic NETosis, especially in LA+ TE+ patients. Our findings reveal protein abundance changes connected to altered platelet function in LA-positive patients, thus suggesting a pathogenic role of platelets in thrombotic complications in APS.

Thrombin-generating potential, plasma clot formation, and clot lysis are impaired in patients with bleeding of unknown cause

BACKGROUND

In a large proportion of patients with a mild to moderate bleeding tendency no diagnosis can be established (bleeding of unknown cause, BUC).

OBJECTIVES

To investigate possible dysfunctions in thrombin generation and plasma clot formation and lysis in patients with BUC from the Vienna Bleeding Biobank (VIBB).

PATIENTS AND METHODS

Thrombin generation and plasma clot properties of 382 BUC patients were compared to those of 100 healthy controls and 16 patients with factor VIII (FVIII) activity ≤50%.

RESULTS

Thrombin generation was significantly impaired in BUC patients compared to healthy controls, exhibiting a prolonged lag time and time to peak and decreased maximum thrombin generation, velocity index, and area under the curve (AUC). The assessment of clot formation and lysis in BUC patients revealed a lower clot formation rate (Vmax), resulting in a longer TTP, increased absorbance (ΔAbs), and a shorter clot lysis time (CLT) than in healthy controls. Comparing patients with FVIII activity ≤ 50% to those with BUC, parameters of thrombin generation and clot formation and lysis were either stronger or comparably impaired. Bleeding severity did not correlate with parameters of thrombin generation, clot formation, or clot lysis.

CONCLUSION

Patients with BUC have an impaired hemostatic capacity reflected by a lower thrombin-generation potential, a lower clot formation rate, increased clot turbidity, and shorter clot lysis time, which might contribute to their increased bleeding tendency. Assays monitoring these parameters can alert physicians of hemostatic impairment and should be considered in situations where traditional hemostatic lab tests fail to reveal the clinical bleeding tendency.

The role of ADAMTS-13 and von Willebrand factor in cancer patients: Results from the Vienna Cancer and Thrombosis Study

BACKGROUND

Cancer-associated venous thromboembolism (VTE) is an important complication in the course of a malignant disease. Low ADAMTS-13 (a disintegrin-like and metalloproteinase with thrombospondin type 1 motif 13) and increased von Willebrand Factor (VWF) levels in cancer patients have been described numerously.

OBJECTIVES

Investigation of the influence of ADAMTS-13 and VWF on the probability of VTE and survival in malignancy.

PATIENTS/METHODS

In the framework of the ongoing prospective Cancer and Thrombosis Study (CATS) ADAMTS-13 activity and VWF antigen levels were investigated in cancer patients.

RESULTS

In total, 795 patients with various tumor types (364 female/431 male, median age 62 years) were included; of those, 56 developed VTE and 359 patients died during a median follow-up time of 730 days. The hazard ratio (HR) of VTE per doubling of VWF level was 1.56 (95% confidence interval [CI] 1.13-2.16) in multivariable competing risk analysis. ADAMTS-13 levels showed no correlation with the incidence of VTE in univariate competing risk analysis. The HR of mortality per doubling of VWF level was 1.46 (95% CI 1.28-1.66) and per SD increment of ADAMTS-13was 0.90 (95% CI 0.81-1.00) in multivariable Cox regression analysis. Patients with VWF >75th percentile and concomitant low (<25th percentile) or medium (25-75th percentile) ADAMTS-13 values had the highest probability of mortality (HR 4.31 and 4.75, respectively).

CONCLUSIONS

High VWF levels were significantly associated with the risk of developing VTE in cancer patients, whereas ADAMTS-13 was not. Low ADAMTS-13 and increased VWF levels were independently associated with worse overall survival.

P-selectin gene haplotypes modulate soluble P-selectin concentrations and contribute to the risk of venous thromboembolism

The cell adhesion molecule P-selectin mediates the interaction of activated platelets or endothelial cells with leukocytes. In arterial and venous thromboembolism (VTE) increased soluble P-selectin (sP-selectin) concentrations have been found, and associations of P-selectin genotypes with thrombotic disease have been proposed. We assessed the effect of four single nucleotide polymorphisms (SNPs) [one in the promoter region (c.–2123C>G) and three (S290N, c.1087G>A; D562N, c.1902G>A; T715P, c.2363A>C) in the coding region] and the calculated haplotypes in the P-selectin gene (SELP) on sP-selectin concentrations and VTE risk. The analysis was carried out in 116 high-risk patients with a history of objectively confirmed recurrent VTE and 129 age- and sex-matched healthy individuals. Haplotypes were generated using computer-assisted haplotype reconstruction with Phase 2.1. sP-selectin (μg/l) was measured by ELISA. Frequencies of all four individual SNPs were not statistically significantly different between patients and controls. Tenhaplotypes were obtained for the control population, and nine for the patient group. The most frequent haplotype among controls was CGGA (major allele at all positions) (27.8%; frequency in patients 19.0%), which was used as reference for statistical analyses. Among patients GGAA was most frequent (23.3%; frequency in controls 17.5%). Haplotypes were significantly associated with sP-selectin concentrations in patients and in controls (p<0.001 and p=0.011). Compared to CGGA some but not all haplotypes conferred an increased risk for VTE with odds ratios (ORs) between 5.4 (95% CI: 2.5–12.2) for CAGA, 3.3 (1.2–9.2) for CGAC, and 2.4 (1.3–4.7) for GGAA. All ORs remained statistically significant after adjustment for the factor V Leiden mutation, located in close proximity to SELP on chromosome 1, as well as all other established risk factors for VTE. In conclusion, SELP haplotypes modulate plasma concentrations of sP-selectin and affect the risk of recurrent VTE.

Cardiovascular risk factors are major determinants of thrombotic risk in patients with the lupus anticoagulant

BACKGROUND

Patients with the lupus anticoagulant (LA) are at an increased risk of thrombotic events, which in turn increase the risk of death. Understanding the determinants of thrombotic risk in patients with LA may pave the way towards targeted thromboprophylaxis. In the Vienna Lupus Anticoagulant and Thrombosis Study (LATS), we systematically evaluate risk factors for thrombotic events in patients with LA.

METHODS

We followed 150 patients (mean age: 41.3 years, female gender: n = 122 (81.3%), history of thrombosis or pregnancy complications: n = 111 (74.0%)), who tested repeatedly positive for LA until development of thrombosis, death, or censoring. The primary endpoint was a composite of arterial or venous thrombotic events (TEs).

RESULTS

During a median follow-up of 9.5 years (range: 12 days-13.6 years) and 1076 person-years, 32 TEs occurred (arterial: n = 16, venous: n = 16; cumulative 10-year TE incidence: 24.3%). A prolonged lupus-sensitive activated partial thromboplastin time (aPTT-LA) (adjusted subdistribution hazard ratio (SHR) = 2.31, 95% CI: 1.07--5.02), diabetes (adjusted SHR = 4.39, 95% CI: 1.42-13.57), and active smoking (adjusted SHR = 2.31, 95% CI: 1.14-5.02) emerged as independent risk factors of both arterial and venous thrombotic risk. A risk model that includes a prolonged lupus-sensitive aPTT, smoking, and diabetes enabled stratification of LA patients into subgroups with a low, intermediate, and high risk of thrombosis (5-year TE risk of 9.7% (n = 77), 30.9% (n = 51), and 56.8% (n = 22).

CONCLUSIONS

Long-term thrombotic risk in patients with LA is clustered within subjects harboring typical cardiovascular risk factors in addition to a prolonged lupus-sensitive aPTT, whereas patients with none of these risk factors represent a large subgroup with a low risk of thrombosis.

Fibrinolysis in patients with a mild-to-moderate bleeding tendency of unknown cause

In more than 50% of patients with a mild-to-moderate bleeding tendency, no underlying cause can be identified (bleeding of unknown cause, BUC). Data on parameters of fibrinolysis in BUC are scarce in the literature and reveal discrepant results. It was the aim of this study to investigate increased fibrinolysis as a possible mechanism of BUC. We included 270 patients (227 females, median age 44 years, 25–75^th percentile 32–58) with BUC and 98 healthy controls (65 females, median age 47 years, 25–75^thpercentile 39–55). Tissue plasminogen activator (tPA-) antigen and activity, plasminogen activator inhibitor type-1 (PAI-1), tPA-PAI-1 complexes, thrombin activatable fibrinolysis inhibitor (TAFI), α2-antiplasmin, and D-dimer were determined. While PAI-1 deficiency was equally frequent in patients with BUC and controls (91/270, 34%, and 33/98, 34%, p = 0.996), tPA activity levels were more often above the detection limit in patients than in controls (103/213, 48%, and 23/98, 23%, p < 0.0001). We found lower levels of tPA-PAI-1 complexes (6.86 (3.99–10.00) and 9.11 (7.17–13.12), p < 0.001) and higher activity of TAFI (18.61 (15.80–22.58) and 17.03 (14.02–20.02), p < 0.001) and α2-antiplasmin (102 (94–109) and 98 (90–106], p = 0.003) in patients compared to controls. Detectable tPA activity (OR 3.02, 95%CI 1.75–5.23, p < 0.0001), higher levels of TAFI (OR 2.57, 95%CI 1.48–4.46, p = 0.0008) and α2-antiplasmin (OR 1.03, 95%CI 1.01–1.05, p = 0.011), and lower levels of tPA-PAI-1 complexes (OR 0.90, 95%CI 0.86–0.95, p < 0.0001) were independently associated with BUC in sex-adjusted logistic regression analyses. We conclude that the fibrinolytic system can play an etiological role for bleeding in patients with BUC.

PO-63 - Exhausted platelets in cancer patients with high risk of venous thromboembolism and poor prognosis

INTRODUCTION

Platelets play a crucial role in cancer development, progression and metastatic spread of malignancy. In vitro data show that cancer cells have the ability to activate platelets, and clinical studies found increased levels of platelet activation markers in cancer patients. Moreover, platelets are thought to be involved in the development of venous thromboembolism (VTE) in cancer patients, a frequent complication of malignant disease associated with high morbidity and mortality.

AIM

In this study, we aimed to examine the activation status of platelets in cancer patients and investigate the association with risk of future venous thromboembolism (VTE) and mortality.

MATERIALS AND METHODS

In a prospective observational cohort study of cancer patients we measured pre-chemotherapy platelet P-selectin and glycoprotein (GP) IIb/IIIa expression and monocyte-platelet aggregates (MPA) in vivo and in response to ex vivo stimulation of the platelet activation receptors protease-activated receptor (PAR) -1, -4, and GPVI by whole blood flow cytometry. Primary and secondary endpoints of the study were occurrence of objectively confirmed VTE and death during 2-year follow-up, respectively.

RESULTS

Out of 62 patients (median age [interquartile range, IQR]: 63 [54-70] years, 48% female) with cancers of the pancreas (n=19), lung (n=18), brain (n=14), colon (n=8) and stomach (n=3), 9 (14.5%) developed VTE and 32 (51.6%) died. P-selectin, activated GPIIb/IIIa expression and MPA formation did not significantly differ between tumor sites (Kruskal Wallis test). Reduced platelet responsiveness to PAR-1 and GPVI stimulation was associated with a higher risk of VTE (hazard ratio [HR] per decile increase in %P-selectin positive platelets: 0.73 [95% confidence interval: 0.56-0.92, p=0.007] and 0.77 [0.59-0.98, p=0.034], respectively; Table 1). Further, lower platelet P-selectin and activated GPIIb/IIIa expression in vivo and in response to PAR-1, -4 and GPVI stimulation, but not MPA formation, were associated with a higher risk of death (Table 1).

CONCLUSIONS

Cancer patients with a poor prognosis had degranulated platelets, presumably as a consequence of previous activation. Our data suggest that platelets' continuous activation and thus exhaustion is involved in cancer-associated VTE and cancer mortality.

Alterations of blood coagulation in controlled human malaria infection

Background

Alterations of blood coagulation are thought to be involved in malaria pathogenesis. This study had the aim to investigate changes of blood coagulation under the standardized conditions of controlled human malaria infection.

Methods

In a clinical trial aseptic, purified, cryopreserved Plasmodium falciparum sporozoites were intravenously (n = 24) or intradermally (n = 6) injected into 30 healthy volunteers. Twenty-two participants developed parasitaemia. Serial blood samples before and during prepatent period and at parasitaemia, diagnosed by microscopic assessment of thick blood smear, were obtained. Biomarkers of blood coagulation (thrombin generation potential, D-dimer, prothrombin fragment 1 + 2, von Willebrand factor, ADAMTS13 activity and soluble P-selectin) were determined.

Results

At first detection of P. falciparum parasitaemia, 72.7 % of volunteers had peak thrombin generation 10 % above their baseline. Overall, peak thrombin generation was 17.7 % higher at parasitaemia compared to baseline [median (25th–75th percentile): 225.4 nM (168.1–295.6) vs. 191.5 nM (138.2–231.9); p = 0.026]. There were no significant changes of other coagulation parameters.

Conclusions

The thrombin generation potential, an in vitro blood coagulation test, which reflects an individual´s global coagulation status, was increased by 17.7 % at very early stages of P. falciparum malaria, suggesting a hypercoagulable state may be induced, even when parasite density is low.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-015-1079-3) contains supplementary material, which is available to authorized users.

Soluble Vascular Endothelial Growth Factor (sVEGF) and the Risk of Venous Thromboembolism in Patients with Cancer: Results from the Vienna Cancer and Thrombosis Study (CATS)

PURPOSE

Cancer patients are at an increased risk of venous thromboembolism (VTE). VEGF promotes the growth of highly thrombogenic tumor vessels. Here, we explored the utility of soluble plasma VEGF-A (sVEGF) as a biomarker for the prediction of VTE in patients with cancer.

EXPERIMENTAL DESIGN

Eight hundred four patients with newly diagnosed cancer or progression after remission were prospectively followed for 2 years until the occurrence of VTE or death [tumor sites: brain (n = 87), breast (n = 137), lung (n = 120), gastrointestinal (n = 143), pancreas (n = 53), prostate (n = 95), kidney (n = 22), myeloma and lymphoma (n = 99), and others (n = 48)]. Primary endpoint was symptomatic or fatal VTE. sVEGF was measured by immunoassay in baseline plasma.

RESULTS

Fifty-five patients developed VTE (6.8%) and 364 patients (45.3%) died. Five-hundred and forty-two (68.3%) participants had sVEGF levels above the detection limit of 0.5 pg/mL. The median sVEGF level (25th-75th percentile) was 8.1 pg/mL (0-17.7). The cumulative 2-year incidence of VTE was 10.2% [95% confidence interval (CI), 6.4-14.9] in patients with sVEGF greater than the 75th percentile of the sVEGF distribution (Q3, cutoff: 17.7 pg/mL), and 5.9% (95% CI, 4.2-7.9) in patients with lower levels (P = 0.03). The corresponding 2-year risk of death was 52.8% (95% CI, 46.0-60.0) and 43.9% (95% CI, 40.0-48.0), respectively (P = 0.02). In univariable time-to-VTE regression, elevated sVEGF was associated with VTE [subhazard ratio (SHR) per 10 pg/mL increase, 1.04; 95% CI,1.00-1.09; P = 0.04)]. The association between sVEGF and risk of VTE prevailed after multivariable adjustment for high-risk tumor sites, age, gender, factor VIII, thrombin generation potential, and soluble P-Selectin (adjusted SHR, 1.04; 95% CI, 1.00-1.09, P = 0.05).

CONCLUSIONS

Elevated sVEGF is associated with an increased risk of VTE in patients with cancer.

Association of platelet activation markers with cancer-associated venous thromboembolism

Venous thromboembolism (VTE) is a frequent complication in cancer patients. Platelet activation is thought to be involved in cancer-associated VTE. Here, we determined the association between evolving markers of platelet activation (soluble P-selectin [sP-selectin], soluble CD40 ligand [sCD40L], thrombospondin-1 [TSP-1] and platelet factor-4 [PF-4]) and the development of cancer-associated VTE. A nested matched case-control study was applied within a cohort of 1779 patients with different types of cancer that had been included in the Vienna Cancer and Thrombosis Study (CATS), a prospective, observational study on patients with newly diagnosed or progressive cancer after remission. Primary endpoint is symptomatic VTE during a maximum follow-up of 2 years. Cases (patients who developed VTE during follow-up) were matched in a 1:2 ratio to controls without VTE during follow-up with respect to tumor type, stage and time of observation in the study. In total, 131 VTE cases were compared to 262 controls. In logistic regression analysis, only sP-selectin was associated with risk of VTE. The odds ratios (OR) per double increase of sP-selectin, sCD40L, TSP-1 and PF-4 were 1.66 (95% confidence interval: 1.17-2.35, p = 0.005), 1.04 (0.89-1.21, p = 0.635), 1.09 (0.90-1.32, p = 0.360) and 1.03 (0.87-1.21, p = 0.737), respectively. In conclusion, sP-selectin, but not sCD40L, TSP-1 or PF-4 were associated with risk of VTE in cancer patients in this nested case-control study.

Microparticle-associated tissue factor activity in patients with metastatic pancreatic cancer and its effect on fibrin clot formation

Highly elevated microparticle (MP)-associated tissue factor (TF) activity was found in patients with pancreatic cancer, one of the most prothrombotic malignancies. It remains to be elucidated whether MP-TF activity reflects the prothrombotic state in these patients. MP-TF activity levels and the TF-dependent and -independent effect of MPs on fibrin clot formation were determined in patients with metastatic pancreatic cancer (n = 27), in healthy individuals (n = 10) and in plasma samples from lipopolysaccharide (LPS)-stimulated blood (LPS-plasma), which is rich in monocyte-derived TF-bearing MPs. The median MP-TF activity was 1.06 pg/mL (range, from 0.19 to 10.34 pg/mL) in patients with pancreatic cancer, 0.61 pg/mL (range, from 0.36 to 0.79 pg/mL) in LPS-plasma, and 0.18 pg/mL (range, from 0.04 to 0.39 pg/mL) in healthy individuals. MPs derived from LPS-plasma had the strongest impact on fibrin clot formation time (median, 157.6 seconds; range, from 149.5 to 170.4 seconds). Fibrin clot formation occurred significantly later in MPs derived from patients with pancreatic cancer (median, 273.4 seconds; range, from 146.6 to 354.4 seconds; P < 0.001) and in healthy individuals (median, 299.0 seconds; range, from 261.1 to 417.9 seconds; P < 0.001). Only in MPs derived from LPS-plasma the fibrin clot formation time dependent strongly on TF (median prolongation after TF blockade: 68% in LPS-plasma, 10% in patients with pancreatic cancer, and 4% in healthy individuals). In conclusion, highly elevated MP-TF activity was found in patients with metastatic pancreatic cancer, but TF-bearing MPs had a small effect on fibrin clot formation. TF-bearing MPs might not be the main mediators of the prothrombotic state associated with pancreatic cancer. However, the small but significant increase in coagulation potential by TF-bearing MPs might contribute to the multifactorial pathogenesis of venous thromboembolism in pancreatic cancer.

Thrombin generation in type 2 diabetes with albuminuria and macrovascular disease

BACKGROUND

Albuminuria is an indicator of cardiovascular morbidity and mortality in patients with type 2 diabetic mellitus (T2DM).

MATERIALS AND METHODS

In our cross-sectional study, we measured thrombin generation (TG), a key process in haemostasis and a tool to detect an individual's coagulation potential, in normo-, micro- and macroalbuminuria in T2DM with and without macrovascular disease (MVD). The TG-assay was performed, and the TG-curve [including the lag phase, peak thrombin and area under the curve (AUC)] was analysed.

RESULTS

A total of 160 patients (62 women; mean age ± SD: 67 ± 11 years) with T2DM and normo-, micro- or macroalbuminuria were investigated. Of those, 90 (56%) patients had normoalbuminuria, 40 (25%) microalbuminuria and 30 (19%) macroalbuminuria. The AUC between the groups of patients with normo-, micro- and macroalbuminuria was statistically significantly different [3297 (2785; 3764) vs. 3222 (2381; 3678) vs. 3726 (3153; 4235) nM Thrombin; P = 0AE019]. T2DM patients with MVD (n = 121) had a significantly shorter lag phase [12 (9; 16) vs. 20 (15; 25) min; P < 0AE001], a significantly higher peak thrombin [233 (130; 339) vs. 133 (82; 187) nM; P < 0AE001] and a significantly higher AUC [3464 (2969; 3868) vs. 3091 (2384; 3619) nM Thrombin; P = 0AE01] than T2DM patients without MVD (n = 39), indicating an earlier and higher thrombin generation.

CONCLUSION

Our results support the hypothesis that TG may be involved in the pathogenesis of MVD in diabetic nephropathy as for the first time, we could show that patients with T2DM in different stages of diabetic nephropathy had disturbances in thrombin generation.

Association of elevated soluble P-selectin levels with fetal loss in women with a history of venous thromboembolism

INTRODUCTION

An association between pregnancy complications such as fetal loss with inherited and acquired thrombophilic defects has frequently been reported. Recently, the cell adhesion molecule P-selectin has been identified to be a strong risk factor for venous thromboembolism (VTE).

PATIENTS AND METHODS

The aim of our study was to investigate whether soluble P-selectin (sP-selectin) is also associated with fetal loss (e.g. miscarriage or stillbirth) in 304 women (median age [25th-75th percentile]: 45 [37-54] years) with a history of VTE, in whom data on pregnancy-associated complications had been evaluated. At the time of sP-selectin measurement none of the women was pregnant or had an acute VTE.

RESULTS

The prevalence of miscarriage was 21.4% and that of stillbirth was 4.6%. The median sP-selectin level of the total study population was 38.0 [31.7-44.4] ng/mL. In subjects with elevated sP-selectin levels (defined as sP-selectin ≥44.4ng/mL, representing the 75th percentile of levels in the study population) the prevalence of stillbirth was significantly higher compared to those with lower levels (10.5% vs. 2.6%, p=0.008), whereas no statistically significant difference in the prevalence of miscarriage was observed between women with and without elevated sP-selectin (17.1% vs. 22.9%, p=0.303). The odds ratio [95% CI] of elevated sP-selectin was 4.2 [1.5-12.7] for stillbirth and 0.7 [0.4-1.3] for miscarriage.

CONCLUSIONS

Elevated sP-selectin plasma levels were associated with a 4.2-fold risk for stillbirth in women with a history of VTE. Our data support a possible role of P-selectin in late pregnancy loss.

Prediction of Venous Thromboembolism in Patients With Cancer by Measuring Thrombin Generation: Results From the Vienna Cancer and Thrombosis Study

Purpose

Patients with cancer are at increased risk of venous thromboembolism (VTE). Laboratory tests measuring the overall thrombophilic tendency might be useful to assess VTE risk. The aim of this study was to investigate thrombin generation, a key process in hemostasis, as predictor of cancer-associated VTE.

Patients and Methods

The Vienna Cancer and Thrombosis Study (CATS) is a prospective observational cohort study of patients with newly diagnosed cancer or progression of disease after remission. The study end point is occurrence of objectively confirmed symptomatic or fatal VTE within a follow-up period of 2 years. Thrombin generation was measured with a commercially available assay.

Results

One thousand thirty-three patients with malignancies of the breast (n = 151), lung (n = 148), upper (n = 44) and lower gastrointestinal tract (n = 125), pancreas (n = 67), kidney (n = 34), prostate (n = 122), and brain (n = 134) or lymphoma (n = 126), multiple myeloma (n = 26), and other tumor types (n = 56) were observed for a median observation period of 517 days. VTE occurred in 77 patients (7.5%). Patients with elevated peak thrombin (defined as values ≥ 611 nM thrombin, representing the 75th percentile of the total study population) had an increased risk of VTE with a hazard ratio of 2.1 (95% CI, 1.3 to 3.3, P = .002) in multivariable analysis including age, sex, surgery, chemotherapy, and radiotherapy. The cumulative probability of developing VTE after 6 months was significantly higher in patients with elevated peak thrombin than in those with lower peak thrombin (11% v 4%; log-rank test: P = .002).

Conclusion

Measurement of thrombin generation may help identify patients with cancer at high risk of VTE.

High concentrations of soluble P-selectin are associated with risk of venous thromboembolism and the P-selectin Thr715 variant

BACKGROUND

The cell adhesion molecule P-selectin has an important role in the pathophysiology of thrombosis. The effect on venous thromboembolism (VTE) of increased circulating concentrations of soluble P-selectin (sP-selectin) and their association with the P-selectin variant Thr715Pro is still uncertain.

METHODS

This study was a case-control study of 116 patients with confirmed recurrent VTE and at least 1 event of unprovoked deep venous thrombosis or pulmonary embolism, and 129 age- and sex-matched healthy individuals. We measured sP-selectin by ELISA and P-selectin gene (SELP) variation by genotyping and sampled blood after a mean interval of 2.55 years after the most recent VTE event.

RESULTS

The mean (SD) sP-selectin concentration was higher in patients than in controls: 47.3 (15.0) microg/L vs 36.8 (11.0) microg/L, P <0.001. The unadjusted odds ratio (OR) for sP-selectin >55.1 microg/L, representing the 95th percentile for controls, was 8.5 (95% CI, 3.7-23.3; P <0.001) and increased after adjustment for factor V Leiden, the prothrombin G20210A variant, increased factor VIII, and hyperhomocysteinemia (OR, 10.6; 95% CI, 4.1-31.2; P <0.001). Pro715 carriers were more prevalent among controls than patients (21.7% vs 14.7%). sP-selectin concentrations were lower in this subgroup than in noncarriers: 31.3 (7.9) microg/L vs 44.1 (14.1) microg/L; P <0.001).

CONCLUSIONS

Increased sP-selectin concentrations are associated with VTE and genotype status. sP-selectin concentrations are lower in individuals carrying the P-selectin Pro715 variant than in those without this variant.

The clinical significance of anti-prothrombin antibodies for risk assessment of thromboembolism in patients with lupus anticoagulant

INTRODUCTION

Thromboembolism is a common manifestation of lupus anticoagulant (LA), however only a subgroup of LA-patients is affected by thrombosis. Study objective was to investigate whether anti-prothrombin antibodies can identify LA-patients at increased risk for thrombosis.

MATERIALS AND METHODS

In total 79 patients, 50 with (42 men/8 women) and 29 without thrombosis (21 men/8 women), were investigated for their presence of anti-prothrombin IgG and IgM antibodies using assays from two different manufacturers (Aeskulisa=assay I, CoaChrom=assay II).

RESULTS

The prevalence of elevated levels of anti-prothrombin IgG, IgM as well as IgG and/or IgM antibodies was 66% [assayI] (36% [assayII]), 38% (24%) and 72% (50%) in patients with thrombosis and 55% (24%), 28% (28%) and 66% (41%) in patients without thrombosis, respectively. Neither anti-prothrombin IgG or IgM nor IgG and/or IgM antibodies were found to indicate an increased risk for thrombosis. In the subgroup of patients with arterial or venous thrombosis there was also no association between anti-prothrombin antibodies and thrombosis. The comparison of median levels of IgG and IgM anti-prothrombin antibodies between patients with and without thrombosis yielded a borderline statistically significant difference only for anti-prothrombin IgG antibodies by using assay II (p=0.033), all other comparisons were not statistically significant.

CONCLUSIONS

In conclusion, presence of anti-prothrombin antibodies was not associated with thromboembolism in LA-patients.

Impact of environmental and hereditary risk factors on the clinical manifestation of thrombophilia in homozygous carriers of factor V:G1691A

BACKGROUND

Limited data exist on the clinical manifestations of homozygous factor (F)V:G1691A mutation (FV Leiden) and the impact of environmental and genetic risk factors.

OBJECTIVES

To assess the contribution of these factors on the thrombophilic phenotype.

PATIENTS AND METHODS

In a retrospective multicenter cohort study 165 individuals with homozygous FV:G1691A mutation, of whom 129 had previous venous thromboembolism (VTE), were included. To study the role of environmental risk factors, patients were compared by the use of a standardized questionnaire to 165 sex- and age-matched individuals (reference group A); of these, two had previous VTE. To assess the role of genetic risk factors, factor (F)II:G20210A and MTHFR:C677T were determined in individuals homozygous for FV:G1691A and in 177 healthy individuals without previous VTE (reference group B).

RESULTS

The first VTE occurred significantly earlier in women (median age 25 years) than men (35.5 years). In 81% of women and 29% of men an environmental risk factor was present before first VTE. Oral contraceptives increased the risk of thrombosis 4-fold [odds ratio (OR) 4.0, 95% confidence interval (CI) 1.7, 10.4] in women with homozygous FV:G1691A. Postoperative and post-traumatic VTE as first manifestation occurred in 13% and 15% of surgical/traumatic events in patients and in 0.7% and 1.8% in reference group A, respectively (OR 19.7, 95% CI 2.5, 154 and OR 9.2, 95% CI 1.1, 79.4). Heterozygous FII:G20210A was more prevalent in symptomatic patients (11.7%) compared with reference group B (2.8%, OR 4.6, 95% CI 1.6, 13.2). The prevalence of homozygous MTHFR:C677T genotype was similar in patients and reference group B.

CONCLUSIONS

Our study supports the concept of thrombophilia as a multifactorial disorder. The knowledge of coexisting factors predisposing to VTE is useful for medical advice for primary and secondary prophylaxis in these patients.

Pregnancy-associated risk for venous thromboembolism and pregnancy outcome in women homozygous for factor V Leiden

INTRODUCTION

To evaluate the pregnancy-associated risk of venous thromboembolism and the risk of stillbirth and miscarriage a multicenter, retrospective and controlled study was conducted in women carrying the homozygous factor V Leiden mutation and in an agematched control group of women from the normal population.

PATIENTS AND METHODS

In 64 homozygous (median age 44 years, range 21-75 years) and in 52 control women from five different centers data on venous thromboembolism and pregnancy outcome were obtained.

RESULTS

The 64 homozygous women had in total 212 pregnancies, the 52 control women had 118 pregnancies. In homozygous women 65% of pregnancies ended with delivery of a viable infant, 15% with fetal loss (3.3% stillbirth, 12% miscarriage) and 20% by pregnancy termination. In the control women 75% of pregnancies ended with delivery of a viable infant, 12% with fetal loss (1.7% stillbirth, 10% miscarriage) and 13% by pregnancy termination. The differences were statistically not significant. Venous thromboembolism occurred significantly more often in the homozygous women, in 4.2% (9/212) during pregnancy and in 4.7% (10/212) after delivery or pregnancy termination. None of the control women had a thromboembolic episode.

CONCLUSION

Our data indicate that women with homozygous factor V Leiden have a high probability for a favorable pregnancy outcome. The increased risk for venous thromboembolism during pregnancy and after delivery would favor heparin prophylaxis during and after pregnancy in women homozygous for factor V Leiden.