Heparanase procoagulant activity as a predictor of wound necrosis following diabetic foot amputation

Serum heparanase levels and left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

INTRODUCTION

Data regarding the possible role of heparanase (HPA) in the occurrence of left atrial/left atrial appendage (LA/LAA) thrombus in patients with atrial fibrillation (AF) is lacking. The goal of the present study was to assess the association between plasma levels of HPA and LA/LAA thrombus in AF.

METHODS

A total of 687 patients with nonvalvular AF (NVAF) without anticoagulation therapy were included from January 2016 to June 2019. Serum HPA analysis was performed with a commercially available human ELISA kit. Logistic regression models were used to test for association.

RESULTS

Serum HPA levels were significantly higher in patients with LA/LAA thrombus than in those without LA/LAA thrombus (270.8 [193.4 ± 353.2] pg/mL vs 150.3 [125.2 ± 208.4] pg/mL; P < 0.001). In multivariate analysis, serum HPA remained a significantly independent predictor of LA/LAA thrombus (odds ratio 1.674, 95% confidence interval [CI] 1.339-2.289, P < 0.001). In the receiver operating characteristic (ROC) curve analysis, HPA showed a predictive value with an area under the curve (AUC) of 0.757 (95% CI 0.652-0.810, P < 0.001). The optimal cutoff level for HPA predicting LA/LAA thrombus was 210.7 pg/mL, with a sensitivity of 74.3% and a specificity of 64.8%.

CONCLUSION

An elevated HPA level was associated with the presence of LA/LAA thrombus in patients with AF. HPA might portend the risk for the prothrombotic state in AF patients.

Effect of Heparanase and Heparan Sulfate Chains in Hemostasis

Heparanase, the only mammalian enzyme known to degrade heparan sulfate chains, affects the hemostatic system through several mechanisms. Along with the degrading effect, heparanase engenders release of syndecan-1 from the cell surface and directly enhances the activity of the blood coagulation initiator, tissue factor, in the coagulation system. Upregulation of tissue factor and release of tissue factor pathway inhibitor from the cell surface contribute to the prothrombotic effect. Tissue factor pathway inhibitor and the strongest physiological anticoagulant antithrombin are attached to the endothelial cell surface by heparan sulfate. Hence, degradation of heparan sulfate induces further release of these two natural anticoagulants from endothelial cells. Elevated heparanase procoagulant activity and heparan sulfate chain levels in plasma, demonstrated in cancer, pregnancy, oral contraceptive use, and aging, could suggest a potential mechanism for increased risk of thrombosis in these clinical settings. In contrast to the blood circulation, accumulation of heparan sulfate chains in transudate and exudate pleural effusions induces a local anticoagulant milieu. The anticoagulant effect of heparan sulfate chains in other closed spaces such as peritoneal or subdural cavities should be further investigated.

Heparanase and the hallmarks of cancer

Heparanase is the only mammalian enzyme that cleaves heparan sulphate, an important component of the extracellular matrix. This leads to the remodelling of the extracellular matrix, whilst liberating growth factors and cytokines bound to heparan sulphate. This in turn promotes both physiological and pathological processes such as angiogenesis, immune cell migration, inflammation, wound healing and metastasis. Furthermore, heparanase exhibits non-enzymatic actions in cell signalling and in regulating gene expression. Cancer is underpinned by key characteristic features that promote malignant growth and disease progression, collectively termed the 'hallmarks of cancer'. Essentially, all cancers examined to date have been reported to overexpress heparanase, leading to enhanced tumour growth and metastasis with concomitant poor patient survival. With its multiple roles within the tumour microenvironment, heparanase has been demonstrated to regulate each of these hallmark features, in turn highlighting the need for heparanase-targeted therapies. However, recent discoveries which demonstrated that heparanase can also regulate vital anti-tumour mechanisms have cast doubt on this approach. This review will explore the myriad ways by which heparanase functions as a key regulator of the hallmarks of cancer and will highlight its role as a major component within the tumour microenvironment. The dual role of heparanase within the tumour microenvironment, however, emphasises the need for further investigation into defining its precise mechanism of action in different cancer settings.

Heparanase in the Coagulation System

The hemostatic cascade is initiated by the transmembrane coagulation protein - tissue factor (TF) and eventuates in fibrin formation. Heparanase protein was demonstrated to directly enhance TF activity resulting in increased activation of the coagulation system. In addition, heparanase was found to increase hemostatic system activation via two other mechanisms: up-regulating TF expression in endothelial cells and releasing the protein tissue factor pathway inhibitor (TFPI) from the cell surface. Peptides derived from TFPI-2, a protein similar to TFPI, were shown to inhibit the TF/heparanase complex as well as attenuate sepsis and tumor growth. Increased heparanase procoagulant activity was observed in several clinical settings, including women using oral contraceptives, women at delivery, patients following orthopedic surgery and patients with diabetic foot, shift work female nurses, patients with lung cancer, retinal vein thrombosis and prosthetic heart valve thrombosis. Remarkably, the heparanase profile was significantly different across the tested groups. Inhibition of TF / heparanase interaction may represent a new target for attenuating coagulation, cancer and inflammation.

Heparanase is a predictive marker for high thrombus burden in patients with ST-segment elevation myocardial infarction

Objective: Heparanase (HPA) is an endo-β-D-glucuronidase capable of degrading heparin sulphate (HS) and heparin side chains. HPA plays a role in tumour growth, angiogenesis, cell invasion and in activation of the coagulation system. We aimed to investigate the relationship between HPA and thrombus burden (TB) in patients with ST-Segment Elevation Myocardial Infarction (STEMI). Methods: This prospective study enrolled 187 patients with STEMI who were treated with primary percutaneous coronary intervention (pPCI). Blood samples were taken to determine serum HPA levels prior to coronary angiography and heparin administration. Serum HPA analysis was performed with a commercially available Human Elisa kit. Results: Patients were divided into two groups: high TB (n:58) and low TB (n:129) group. Serum HPA levels were significantly higher in patients with high TB than low TB [250.1 (188.5-338.1) vs. 173.6 (134.3-219.8) pg/mL] (p < 0.001). Serum HPA levels were higher in patients with no-reflow phenomenon compared with others [(409.3 (375.6-512.5) pg/mL vs. 186.2 (144.2-247.4) pg/mL, p < 0.001]. In multiple logistic regression analysis HPA was a predictor of high TB. Conclusion: Elevated HPA level in patients with STEMI is related to high TB. Furthermore, increased HPA level may be associated with thrombotic complications such as no-reflow phenomenon in patients with STEMI.

The relationship between heparanase levels, thrombus burden and thromboembolism in patients receiving unfractionated heparin treatment for prosthetic valve thrombosis

INTRODUCTION

Procoagulant activity of heparanase has been recently described in several arterial and venous thrombotic disorders. In this study, we aimed to investigate the role of heparanase with regard to thrombus burden, thromboembolism, and treatment success with unfractionated heparin (UFH) in patients with prosthetic valve thrombosis (PVT).

METHODS

This study enrolled 79 PVT patients who received UFH for PVT and 82 controls. Plasma samples which were collected from patients both at baseline and after the UFH treatment and from controls at baseline only, were tested for heparanase levels by heparanase enzyme-linked immunosorbent assay.

RESULTS

The PVT group included 18 obstructive and 61 non-obstructive PVT patients who received UFH infusions for a median duration of 15 (7-20) days. The UFH treatment was successful in 37 (46.8%) patients. Baseline heparanase levels were significantly higher in the patient group than in the controls [0.29 (0.21-0.71) vs. 0.25 (0.17-0.33) ng/mL; p = 0.002]. Baseline heparanase levels were significantly higher in obstructive PVT patients. There was a significant increase in heparanase levels after UFH treatment. Post-UFH heparanase levels were higher in patients who experienced treatment failure compared to successfully treated group. Baseline and post-UFH heparanase levels were significantly higher in patients with a thrombus area ≥1 cm² and with a recent history of thromboembolism.

CONCLUSIONS

Increased heparanase levels may be one of the esoteric causes for PVT. UFH treatment may trigger an increase in heparanase levels which may affect the treatment success. Increased heparanase levels may be associated with high risk of thromboembolism and increased thrombus burden in PVT patients.

Heparanase level and procoagulant activity are reduced in severe sepsis

BACKGROUND

During severe sepsis, levels and activity of all coagulation proteins are reduced. Heparanase is implicated in angiogenesis and tumor progression. We previously demonstrated that heparanase also affected the hemostatic system. It forms a complex and increases the activity of the blood coagulation initiator tissue factor.

AIM

To evaluate heparanase levels and procoagulant activity as predictors of sepsis severity.

MATERIALS AND METHODS

Twenty-one patients with non-trauma, non-surgical sepsis admitted to the intensive care unit and 35 controls were recruited. Plasma samples were drawn from the study participants on days 1 and 7 following admission.

RESULTS

Heparanase levels and procoagulant activity on day 1 were significantly reduced in patients compared to controls (P < .0001, P < .0001, respectively). Day 1 heparanase procoagulant activity ≥350 ng/mL yielded a negative predictive value for severe sepsis of 89%. Additionally, heparanase procoagulant activity on day 7 correlated with the change in the APACHE score between days 1 and 7 (r = .66, P = .007).

CONCLUSIONS

Heparanase procoagulant activity decreases during sepsis and returns to normal levels as soon as the patient recovers. Hence, it can be potentially used to predict the risk of severe sepsis. These findings need to be further explored in large-scale studies.