Effects of increased von Willebrand factor levels on primary hemostasis in thrombocytopenic patients with liver cirrhosis

Portal vein thrombosis in cirrhosis: A literature review

Portal Vein Thrombosis (PVT), a common complication of advanced liver disease, is defined as an obstruction of the portal vein due to thrombus formation that can extend to the superior mesenteric and splenic veins. It was believed that PVT occurred predominantly due to prothrombotic potential. However, recent studies have shown that decreased blood flow related to portal hypertension appears to increase PVT risk as per Virchow's triad. It is well known that there is a higher incidence of PVTs in cirrhosis with a higher MELD and Child Pugh score. The controversy for management of PVTs in cirrhotics lies in the individualized assessment of risks versus benefits of anticoagulation, since these patients have a complex hemostatic profile with both bleeding and procoagulant propensities. In this review, we will systematically compile the etiology, pathophysiology, clinical features, and management of portal vein thrombosis in cirrhosis.

Prognostic value of von-Willebrand factor in patients with liver cirrhosis and its relation to other prognostic indicators

BACKGROUND

Von-Willebrand factor (vWF) disposes certain prognostic value in patients with liver cirrhosis, but its relation to other prognostic indicators has not been fully investigated.

AIM

To analyze the relation between vWF and other prognostic indicators in cirrhotic patients and to evaluate its prognostic value for mortality.

METHODS

This analytic prospective study was carried out in a tertiary center and initially enrolled 71 patients with liver cirrhosis and portal hypertension. It analyzed the relation between vWF and the stage of the disease and several inflammatory and prognostic indicators. The prospective analysis, performed on a sample of 63 patients, evaluated the association between the selected variables [vWF, Model for End-stage Liver Disease (MELD) score, C-reactive protein (CRP), ferritin, vitamin D, activated partial thromboplastin time, thrombin time, D-dimer concentration] and the survival time as well as their predictive value in terms of 3-mo, 6-mo and 1-year mortality.

RESULTS

vWF was significantly higher in patients with higher Child-Turcotte-Pugh class (P = 0.0045), MELD group (P = 0.0057), ferritin group (P = 0.0278), and D-dimer concentration (P = 0.0232). vWF significantly correlated with D-dimer concentration, ferritin, CRP, International Normalized Ratio, and MELD, Child-Turcotte-Pugh, Sequential Organ Failure Assessment, and CLIF-consortium organ failure (CLIF-C OF) scores. vWF, MELD score, and CRP were significantly associated with death and were significant predictors of 3-mo, 6-mo, and 1-year mortality. Each vWF unit significantly increased the probability for 3-mo mortality by 1.005 times (P = 0.008), for 6-mo mortality by 1.006 times (P = 0.005), and for 1-year mortality by 1.007 times (P = 0.002). There was no significant difference between the diagnostic performance of vWF and MELD score and also between vWF and CRP regarding the 3-mo, 6-mo, and 1-year mortality.

CONCLUSION

In patients with liver cirrhosis, vWF is significantly related to other prognostic indicators and is a significant predictor of 3-mo, 6-mo, and 1-year mortality similar to MELD score and CRP.

Antiplatelet drugs and liver fibrosis

Liver fibrosis results from an imbalance between extracellular matrix formation and degradation. The background of liver fibrosis is chronic inflammation and subsequent microcirculation disturbance including microthrombosis. Platelets actively participate in liver fibrosis not only as a part of the clotting system but also by releasing granules containing important mediators. In fact, platelets may play a dual role in the pathophysiology of liver fibrosis as they are able to stimulate regeneration as well as aggravate the destruction of the liver. Recent studies revealed that antiplatelet therapy correlates with inhibition of liver fibrosis. However, liver impairment is associated with extensive coagulation disorders thus the safety of antiplatelet therapy is an area for detailed exploration. In this review, the role of platelets in liver fibrosis and accompanying hemostatic disorders are discussed. Additionally, results of animal and human studies on antiplatelet drugs in liver disorders and their potential therapeutic utility are presented.

The Pathophysiology of Portal Vein Thrombosis in Cirrhosis: Getting Deeper into Virchow's Triad

Portal vein thrombosis (PVT) is a common complication among patients with cirrhosis. However, its pathophysiology is not well established and there are currently very few predictive factors, none of which are actually useful, from a clinical perspective. The contribution of each of the vertices of Virchow’s triad, e.g., blood hypercoagulability, blood flow, and portal vein endothelial damage in the development of PVT is not clear. In this review, we aim to recapitulate the latest studies on the field of PVT development in order to understand its mechanisms and discuss some of the future directions in the study of this important complication of cirrhosis.

Targeting von Willebrand factor in liver diseases: A novel therapeutic strategy?

Acute and chronic liver disease are associated with substantial alterations in the hemostatic system. Evidence from both experimental and clinical studies suggests that anticoagulants slow the progression of liver disease. Efficacy of those anticoagulant drugs is, in part, attributed to a reduction of microthrombi formation within the liver. Although anticoagulant drugs show promising results, bleeding risk associated with these drugs is an obvious drawback, particularly in patients with a complex coagulopathy driven by decreased liver function. Identifying therapies that reduce intrahepatic thrombosis with minimal bleeding risk would significantly advance the field. Among the hemostatic alterations observed in patients are substantially increased levels of the platelet-adhesive protein von Willebrand factor (VWF). In contrast, levels of A Disintegrin and Metalloproteinase with Thrombospondin motifs, the enzyme that regulates VWF activity, are significantly reduced in patients with liver disease. Highly elevated VWF levels are proposed to accelerate intrahepatic thrombus formation and thus be a driver of disease progression. Strong clinical evidence suggesting a link between liver disease and changes in VWF is now being matched by emerging mechanistic data showing a detrimental role for VWF in the progression of liver disease. This review focuses on clinical and experimental evidence supporting a connection between VWF function and the progression of acute and chronic liver diseases. Furthermore, with the recent anticipated approval of several novel therapies targeting VWF, we discuss potential strategies and benefits of targeting VWF as an innovative therapy for patients with liver disease.

Platelet function in dogs with chronic liver disease

OBJECTIVES

To assess platelet function, buccal mucosal bleeding time and plasma von Willebrand factor concentration in dogs with chronic inflammatory and/or fibrotic liver disease and to compare results with those obtained in healthy dogs.

MATERIALS AND METHODS

Preliminary study including 18 dogs with chronic inflammatory and/or fibrotic liver disease undergoing liver biopsy and 18 healthy age-matched control dogs. Platelet function was assessed by measuring closure time with the PFA-100® analyser using adenosine diphosphate (ADP) as an agonist. Buccal mucosal bleeding time, closure time and plasma von Willebrand factor antigen were measured in dogs in both groups. After undergoing ultrasound-guided needle biopsy, dogs were monitored for haemorrhage to determine if there was an association of any measurement with post-biopsy bleeding.

RESULTS

The closure time was not different between the liver disease group (median 76.3; range 53 to 118.5 seconds) and control group (72.8; 57 to 89.5 seconds). The buccal mucosal bleeding time was longer in the liver disease group (median 138; range 95 to 229 seconds) than the control group (103; 63 to 200 seconds). The plasma von Willebrand factor antigen concentration was not different between the liver disease group (median 203; range 109 to 351%) and control group (165.5; 63 to 246%).

CLINICAL SIGNIFICANCE

In this study, dogs with chronic necroinflammatory and/or fibrotic liver disease did not have overt, clinically relevant derangements in platelet function as assessed by buccal mucosal bleeding time, closure time and von Willebrand factor analysis. In addition, none of the dogs undergoing percutaneous ultrasound-guided biopsy in the study exhibited bleeding complications post-biopsy procedure.

Assessment of hemostatic profile in patients with mild to advanced liver cirrhosis

BACKGROUND

Hemostasis of patients suffering from liver cirrhosis is challenging due to both, pro- and anticoagulatory disorders leading to hemostatic alterations with distinct abnormalities of coagulation. Pathological changes in conventional coagulation analysis and platelet count are common manifestations of decreased liver synthesis of coagulation factors and reduced platelet count in these patients. However, conventional coagulation analysis and platelet count do not reflect in-vivo coagulation status or platelet function. The purpose of this present observational study was therefore to assess the haemostatic profile including plasmatic coagulation using thrombelastometry and impedance aggregometry for platelet function in patients suffering from liver cirrhosis.

AIM

To assess the hemostatic profile of cirrhotic patients according to model for end-stage liver disease (MELD) score.

METHODS

Our study included both in- and outpatients suffering from liver cirrhosis attending the out- and inpatient care of the department of hepatology. Demographic and biochemical data as well as medical history including cause of liver cirrhosis, end stage kidney failure and medication with anticoagulants were recorded. To assess the hemostatic profile, platelet function was analyzed by multiple electrode aggregometry (MEA) using Multiplate^® (ADP-, ASPI- and TRAP-test) and thrombelastometry using ROTEM^® (EXTEM, INTEM, FIBTEM). Data were compared using Mann-Whitney U- or χ²-test. Spearman correlation was performed to analyze the association between MELD Score and results of thrombelastometry and MEA.

RESULTS

A total of 68 patients attending the out- and inpatient care suffering from liver cirrhosis were screened. Of these, 50 patients were included and assigned to groups according to MELD score 6 to 11 (n = 25) or ≥ 17 (n = 25). Baseline patient characteristics revealed significant differences for MELD score (8 vs 22, P < 0.0001) and underlying laboratory parameters (international normalized ratio, bilirubine, creatinine) as well as fibrinogen level (275 mg/dL vs 209 mg/dL, P = 0.006) and aPTT (30 s vs 35 s, P = 0.047). MEA showed a moderately impaired platelet function (medians: AUC_ADP = 43U, AUC_ASPI = 71U, AUC_TRAP = 92U) but no significant differences between both groups. Thrombelastometry using ROTEM^® (EXTEM, INTEM, FIBTEM) revealed values within normal range in both groups. No significant correlation was observed between MELD score and results of MEA/thrombelastometry.

CONCLUSION

Our data demonstrate a partially impaired hemostatic profile in liver cirrhosis patients unrelated to MELD score. An individual assessment of a potential coagulopathy should therefore be considered.

Primary Hemostasis in Chronic Liver Disease and Cirrhosis: What Did We Learn over the Past Decade?

Changes in primary hemostasis have been described in patients with chronic liver disease (CLD) and cirrhosis and are still subject to ongoing debate. Thrombocytopenia is common and multifactorial. Numerous studies also reported platelet dysfunction. In spite of these changes, primary hemostasis seems to be balanced. Patients with CLD and cirrhosis can suffer from both hemorrhagic and thrombotic complications. Variceal bleeding is the major hemorrhagic complication and is mainly determined by high portal pressure. Non portal hypertension-related bleeding due to hemostatic failure is uncommon. Thrombocytopenia can complicate management of invasive procedures in CLD patients. Recently, oral thrombopoietin agonists have been approved to raise platelets before invasive procedures. In this review we aim to bundle literature, published over the past decade, discussing primary hemostasis in CLD and cirrhosis including (1) platelet count and the role of thrombopoietin (TPO) agonists, (2) platelet function tests and markers of platelet activation, (3) von Willebrand factor and (4) global hemostasis tests.

A Review on Clinical, Pathophysiological, and Diagnostic Hematological Features in Children With Liver Cirrhosis

Appropriate diagnostic and therapeutic measures for liver cirrhosis is critical, particularly in children. In the present review, a comprehensive approach was provided toward hematological parameters in pediatric liver cirrhosis. The literature search included MeSH terms "liver cirrhosis" and "hepatic cirrhosis" and databases such as PubMed, Web of Science, Scopus, and Google Scholar were searched up until December 2017. Hematologic changes in the liver cirrhosis mainly encompassed anemia and coagulopathies. In addition, bleeding diathesis was considered as the most clinical complication in these patients. In addition to reduced coagulation factors, hyperfibrinolysis is a common feature in childhood cirrhosis and may be an important contributor to the risk of bleeding. Based on the results, children with liver cirrhosis also demonstrated a procoagulant state at laboratory and clinical levels. This may be partly due to a reduction in coagulation inhibitors such as anti-thrombin, C1 inhibitor, and α1-antitrypsin in children with cirrhosis. The portal vein thrombosis and portal hypertension are considered as the most clinical presentations of the hypercoagulable state. Further, children with liver cirrhosis complicated with portal hypertension usually show leukopenia, anemia, and thrombocytopenia due to hypersplenism. Although the etiology of childhood and adult cirrhosis may be different, their hematological compilations and clinicopathological features are somehow similar.

Acquired platelet function disorders

The possibility of an acquired platelet function disorder should be considered in patients who present with recent onset muco-cutaneous bleeding. Despite the availability of newer and faster platelet function assays, light transmission aggregometry (LTA) remains the preferred diagnostic test. This review examines and discusses the causes of acquired platelet dysfunction; most commonly drugs, dietary factors, medical disorders and procedures. In addition to well-known antiplatelet therapies, clinicians should be alert for newer drugs which can affect platelets, such as ibrutinib. There is little clinical trial evidence to guide the management of acquired platelet function defects, but we summarise commonly employed strategies, which include addressing the underlying cause, antifibrinolytic agents, desmopressin infusions, and in selected patients, platelet transfusions.

Elevated D-dimer is associated with increased 28-day mortality in acute-on-chronic liver failure in China: a retrospective study

Background

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by profound disrupted coagulation and fibrinolysis. Fibrinolytic marker D-dimer is increased in critically ill patients with cirrhosis which is associated with poorer prognosis. We aim to determine the potential association of D-dimer with the 28-day mortality in ACLF patients.

Methods

In a single center retrospective study performed in China, we collected data of 115 patients with ACLF from October 1, 2012 to December 31, 2016. We investigated correlations between D-dimer and other laboratory tests and prognostic scores. The relationship between D-dimer and 28-day mortality was explored by smoothing plot with an adjustment for potential confounders. Logistic regression analyses with crude and adjusted models were performed to explore the association of D-dimer with 28-day mortality in ACLF patients.

Results

In ACLF patients, D-dimer at admission was correlated with all prognostic scores (MELD-Na: r = 0.385, P < 0.001; CLIF-C ADs: r = 0.443, P < 0.001; CLIF-C ACLFs: r = 0.375, P < 0.001). A nonlinear relation between D-dimer and 28-day mortality was found with a turning point at 6.5 mg/L FEU. D-dimer level was independently associated with 28-day mortality with an adjusted odds ratio of [1.4 (1.0–1.9), P = 0.030] as continuous variable and [10.3 (1.3, 81.5), P = 0.028] as a classified variable with the cut-off of 6.5 mg/L FEU. An elevated D-dimer within the following 10 days also tended to be associated with higher risk of 28-day mortality [OR: 27.5 (0.9, 814.9), P = 0.055].

Conclusions

Elevated D-dimer levels was associated with increased risk of 28-day mortality in patients with ACLF in China.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-0941-0) contains supplementary material, which is available to authorized users.

Major Changes of von Willebrand Factor Multimer Distribution in Cirrhotic Patients with Stable Disease or Acute Decompensation

Background  There is an unstable balance between pro- and anti-haemostatic processes in patients with cirrhosis. We hypothesized, that in patients with acute decompensation (AD) the major alterations of von Willebrand factor (VWF) could contribute to the pro-thrombotic situation as compared to patients with stable (ST) cirrhosis.

Patients and Methods  We analysed different parameters of VWF, including detailed multimer distribution by densitometry and platelet adhesion, together with ad isintegrin-like a nd m etalloproteinase with t hrombo s pondin type-1 motifs 13 (ADAMTS13) activity and antigen and C-reactive protein (CRP) levels in patients with ST cirrhosis ( n  = 99), with AD ( n  = 54) and controls ( n  = 92).

Results  VWF antigen, ristocetin co-factor as well as collagen-binding activities were elevated in both cirrhotic groups in a stepwise manner. There was a decrease in high and an increase in low molecular weight multimer ratios in the majority of ST cirrhosis. However, in 24 out of 54 AD patients, ultra-large VWF multimers (ultra-large molecular weight multimers [ULMWM]) were found. ADAMTS13 activity in ST and AD patients without ULMWM was similar to controls (median [interquartile range; IQR]%: 98 [67–132] and 91 [60–110] vs. 106 [88–117], respectively). The presence of ULMWM in AD patients was associated with low ADAMTS13 activity [33 (24–49)%] and high CRP level [23 (7.1–83.6) mg/L]. Adhesion of normal platelets showed a stepwise increase in the presence of cirrhotic plasmas, reaching the highest level in AD patients with ULMWM.

Conclusion  Characteristic changes of VWF parameters are seen in ST cirrhosis. In AD patients, highly increased VWF and reduced ADAMTS13 activity could be found, along with the presence of ULMWM, which are possible markers and contributors of the disease progression.

Whole Blood Platelet Aggregometry

Light transmittance aggregometry is the historical reference method for platelet function testing and continues to be used extensively. Whole blood impedance lumiaggregometry represents an updated methodology that provides for simplified specimen management, an assay milieu that replicates in vivo platelet activation conditions, improved reproducibility, and near-patient testing. While the impedance-based whole blood aggregometer with luminescence channel is becoming the standard for platelet function testing using this methodology, at least three near-patient whole blood instruments are available, each employing its unique technology. We provide descriptions of whole blood lumiaggregometry and three near-patient systems. We include the principle of operation, materials, and stepwise example protocols and speculate on the importance of concordance among the platforms.

von Willebrand factor and procoagulant imbalance predict outcome in patients with cirrhosis and thrombocytopenia

BACKGROUND & AIMS

Several lines of evidence suggest that the hemostatic disorders of cirrhosis may have a significant clinical impact. We investigated the independent predictive value of components of the hemostatic system on the occurrence of ascites, variceal bleeding (VB), and survival.

METHODS

One hundred and two patients with thrombocytopenia (Child-Pugh class A/B/C: 34/34/34) were enrolled. Platelet counts, factors (F) II, V, VII, and VIII, antithrombin, protein C (PC), FVIII-to-PC ratio as an index of procoagulant imbalance, von Willebrand factor antigen (vWF-Ag), and model for end-stage liver disease (MELD) were evaluated. Two multivariate analyses were performed: one excluding (model 1) and one including MELD (model 2).

RESULTS

Higher vWF-Ag levels and FVIII-to-PC ratios were the most prominent hemostatic disorders in patients with cirrhosis. Increased levels of vWF-Ag and FVIII, and higher FVIII-to-PC ratios independently predicted the presence of ascites and varices at baseline. Independent predictors of ascites and VB during follow-up were vWF-Ag (model 1/2: p=0.001/p=0.009 and p=0.008/p=0.01, respectively) and FVIII-to-PC ratio (model 1/2: p=0.003/p=0.02 and p=0.01/p=0.03, respectively). vWF-Ag (model 1/2: p=0.007/p=0.002), FVIII-to-PC ratio (model 1/2: p=0.001/p=0.01), and MELD (p=0.02) independently predicted mortality. Patient groups with significantly higher probability of new-onset ascites, VB, and mortality were identified by certain cut-offs of vWF-Ag (213%, 466%, and 321%, respectively) and FVIII-to-PC ratio (1.99, 3.29, and 2.36, respectively). vWF-Ag and FVIII-to-PC ratio equaled MELD in mortality prediction.

CONCLUSIONS

Advanced cirrhosis is characterized by increased thrombotic potential. vWF-Ag and FVIII-to-PC ratio independently predict new-onset ascites, VB, and mortality. Targeting hypercoagulability could improve the outcome of patients with cirrhosis.

LAY SUMMARY

Higher von Willebrand factor antigen (vWF-Ag) levels and factor VIII-to-protein C (FVIII-to-PC) ratio are the prominent hemostatic disorders in patients with cirrhosis. vWF-Ag and FVIII-to-PC ratio independently predict new-onset ascites, variceal bleeding, and mortality in these patients.

Von Willebrand factor and alkaline phosphatase predict re-transplantation-free survival after the first liver transplantation

BACKGROUND

After liver transplantation (LT), there are liver-related, infectious and cardiovascular complications that contribute to reduced graft survival. These conditions are associated with an increase in the Von Willebrand factor antigen (VWF-Ag), which was previously correlated with survival in cirrhotic patients.

OBJECTIVE

Evaluate VWF-Ag as a predictive marker of re-transplantation-free survival in patients after LT.

METHODS

We measured VWF-Ag in patients after first LT and then followed them prospectively with regard to the primary endpoint, namely re-transplantation-free survival.

RESULTS

There were 6 out of 80 patients who died or received re-LT during follow-up. In these patients, the median VWF-Ag was 510.6%, which was significantly higher (p = 0.001) than in the patients who were alive at the end of follow-up (with a median VWF-Ag = 186.8%). At a cut-off of 286.8%, VWF-Ag was significantly correlated with re-transplantation-free survival (p < 0.001). VWF-Ag was independently associated with re-transplantation-free survival in a multivariate analysis; as was alkaline phosphatase (ALP), but not the model of end-stage liver disease (MELD) score, donor age, nor cold ischemia time. A score combining VWF-Ag and ALP showed an impressive capability in the receiver operating characteristic (ROC) analysis (with area under the curve (AUC) = 0.958) to distinguish between patients with regard to the primary endpoint.

CONCLUSIONS

VWF-Ag is a non-invasive marker that can predict outcome in patients after LT. Its diagnostic performance increased when combined with ALP in a newly developed scoring system.

Hemostatic balance in patients with liver cirrhosis: Report of a consensus conference

Patients with cirrhosis present with hemostatic alterations secondary to reduced availability of pro-coagulant and anti-coagulant factors. The net effect of these changes is a rebalanced hemostatic system. The Italian Association of the Study of the Liver (AISF) and the Italian Society of Internal Medicine (SIMI) promoted a consensus conference on the hemostatic balance in patients with cirrhosis. The consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Rome in December 2014. The statements were graded according to quality of evidence and strength of recommendations, and approved by an independent jury. The statements presented here highlight strengths and weaknesses of current laboratory tests to assess bleeding and thrombotic risk in cirrhotic patients, the pathophysiology of hemostatic perturbations in this condition, and outline the optimal management of bleeding and thrombosis in patients with liver cirrhosis.