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

[Coagulation disorders in liver cirrhosis - Diagnostics and management]

Patients with liver cirrhosis often exhibit complex alterations in their hemostatic system that can be associated with both bleeding and thrombotic complications. While prophylactic correction of abnormal coagulation parameters should be avoided, an individualized approach is recommended prior to invasive procedures, whereby specific preventive measures to stabilize hemostasis should be based on the periprocedural bleeding risk. While the haemostatic system of patients with compensated cirrhosis is often in a rebalanced haemostatic state due to a parallel decline in both pro- and anti-haemostatic factors, a decompensation of liver cirrhosis can lead to destabilization of this fragile equilibrium. Since conventional coagulation tests do not adequately capture the complex changes in the hemostatic system in cirrhosis, functional analysis methods such as viscoelastic tests or thrombin generation assays can be used for evaluating the coagulation status. This review describes the underlying pathophysiological changes in the hemostatic system in liver cirrhosis, provides an overview of diagnostic methods and discusses therapeutic measures in case of bleeding and thrombotic complications.

Hydrogen Sulfide Promotes Platelet Autophagy via PDGFR-α/PI3K/Akt Signaling in Cirrhotic Thrombocytopenia

Background and Aims

The role of platelet autophagy in cirrhotic thrombocytopenia (CTP) remains unclear. This study aimed to investigate the impact of platelet autophagy in CTP and elucidate the regulatory mechanism of hydrogen sulfide (H2S) on platelet autophagy.

Methods

Platelets from 56 cirrhotic patients and 56 healthy individuals were isolated for in vitro analyses. Autophagy markers (ATG7, BECN1, LC3, and SQSTM1) were quantified using enzyme-linked immunosorbent assay, while autophagosomes were visualized through electron microscopy. Western blotting was used to assess the autophagy-related proteins and the PDGFR/PI3K/Akt/mTOR pathway following treatment with NaHS (an H2S donor), hydroxocobalamin (an H2S scavenger), or AG 1295 (a selective PDGFR-α inhibitor). A carbon tetrachloride-induced cirrhotic BALB/c mouse model was established. Cirrhotic mice with thrombocytopenia were randomly treated with normal saline, NaHS, or hydroxocobalamin for 15 days. Changes in platelet count and aggregation rate were observed every three days.

Results

Cirrhotic patients with thrombocytopenia exhibited significantly decreased platelet autophagy markers and endogenous H2S levels, alongside increased platelet aggregation, compared to healthy controls. In vitro, NaHS treatment of platelets from severe CTP patients elevated LC3-II levels, reduced SQSTM1 levels, and decreased platelet aggregation in a dose-dependent manner. H2S treatment inhibited PDGFR, PI3K, Akt, and mTOR phosphorylation. In vivo, NaHS significantly increased LC3-II and decreased SQSTM1 expressions in platelets of cirrhotic mice, reducing platelet aggregation without affecting the platelet count.

Conclusions

Diminished platelet autophagy potentially contributes to thrombocytopenia in cirrhotic patients. H2S modulates platelet autophagy and functions possibly via the PDGFR-α/PI3K/Akt/mTOR signaling pathway.

Efficacy and safety of azathioprine plus prednisone versus prednisone alone as first-line treatment for antinuclear antibody-positive immune thrombocytopenia: a retrospective cohort study

OBJECTIVE

Antinuclear antibody (ANA)-positive immune thrombocytopenia (ITP) patients have an unsatisfactory prognosis due to the more severe conditions of these patients and poor response to first-line glucocorticoids (GCs). The current study intended to compare the efficacy and safety of AZA plus prednisone and prednisone alone as first-line treatment in ANA-positive ITP patients.

METHODS

Fifteen ANA-positive ITP patients receiving AZA plus prednisone (AZA + GC group) and eighteen ANA-positive ITP patients receiving prednisone alone (GC group) as first-line treatment were retrospectively enrolled.

RESULTS

The complete response (CR) rate (60.0% versus 22.2%) (P = 0.038) was increased in the AZA + GC group versus the GC group, while the overall response rate (86.7% versus 55.6%) (P = 0.070) only showed an increasing trend that did not achieve statistical significance. In addition, multivariate analysis revealed that AZA + GC (versus GC) (odds ratio = 31.331, P = 0.018) was independently associated with a higher possibility of achieving CR. Additionally, accumulating relapse-free duration was prolonged in the AZA + GC group versus the GC group (median: 7.8 months versus 3.4 months) (P = 0.038). Additionally, the multivariate analysis suggested that AZA + GC (versus GC) (hazard ratio = 0.306, P = 0.007) was independently correlated with longer accumulating relapse-free duration. The incidence of adverse events did not differ between the two groups (all P > 0.05), and the common adverse events in the AZA + GC group were pneumonia (13.3%), anemia (13.3%), cough (13.3%), nausea (6.7%), and granulocytopenia (6.7%), which were all tolerable and manageable.

CONCLUSION

First-line AZA plus prednisone realizes a better hematological response and relapse-free duration with acceptable adverse events compared to prednisone alone in ANA-positive ITP patients.

Platelet-to-Monocyte Ratio as a Novel Promising Agent for the Prognosis of Hepatitis B Virus-Associated Decompensated Cirrhosis

Aim

The present study aimed at investigating associations of the platelet-to-monocyte ratio (PMR), a novel hematological indicator of inflammatory responses with 30-day outcomes in patients with HBV-associated decompensated cirrhosis (HBV-DeCi).

Methods

We recruited 329 patients with HBV-DeCi for this retrospective study and extracted baseline clinical data and laboratory characteristics from medical records. Univariate and multivariate analyses were performed to determine major factors influencing 30-day mortality. Receiver operating characteristic curve analysis was performed to compare the predictive values of prognostic markers.

Results

During the 30-day follow-up period, 21 (6.4%) patients died. The PMR was significantly different between nonsurvivors and survivors. Lower PMR was found to be associated with an increased risk of 30-day mortality, and PMR (odds ratio: 1.011; 95% CI: 1.003-1.019; P=0.005) was found to be an independent predictor of 30-day mortality in patients with HBV-DeCi with a significant predictive value (AUC = 0.826, 95% CI: 0.781-0.865). The combination of PMR and MELD score could improve prognostic accuracy in these patients (AUC = 0.911, 95% CI: 0.876-0.940).

Conclusions

Our results demonstrate that low PMR may be an independent predictor of 30-day mortality in patients with HBV-DeCi, and combined with the MELD score, it may be useful to complement other conventional measures to enable effective management of these patients.

The use of prothrombin complex concentrate in chronic liver disease: A review of the literature

Patients with chronic liver disease (CLD) and cirrhosis present a rebalanced hemostatic system in the three phases of haemostasis. This balance is however unstable and can easily tip towards bleeding or thrombosis. Management of both spontaneous bleeding and bleeding during invasive procedures remains a challenge in this patient population. Transfusion of blood products can result in circulatory overload and thereby worsen portal hypertension. As an alternative to fresh frozen plasma (FFP), prothrombin complex concentrates (PCC) may have merit in patients with liver disease because of their low volume. The impact of PCC in in-vitro spiking experiments of cirrhotic plasma is promising, but also warrants cautious use in light of thromboembolic risk. The majority of existing studies carried-out in CLD patients are retrospective or do not have an adequate control arm. A prospective study (the PROTON trial) was set up in 2013 to investigate the utility of PCC in patients undergoing liver transplantation. However, the study has never recruited the planned number of patients. Robust data on PCC safety in CLD is also required. The limited existing evidence does not seem to indicate an excessive thromboembolic risk. Currently, the utilisation of PCC in CLD cannot be routinely recommended but can provide an option for carefully selected cases in which other measures were not sufficient to control bleeding and after delicately weighing risks and benefits.

Blood coagulation factors and platelet response to drug-induced hepatitis and hepatosis in rats

BACKGROUND

Knowing the variability of blood coagulation responses to liver damage of different origins can provide a key to curing liver tissues or to mitigating treatment side effects. The aim of the present work was to compare the changes in the main components of hemostasis under experimental drug-induced hepatosis and hepatitis in rats.

METHODS

We modeled diclofenac-induced hepatitis and tetracycline-induced hepatosis. Hemostasis response was gauged by measuring fibrinogen, factor X, protein C (PC), and prothrombin in plasma. The decarboxylated form of prothrombin was detected by measuring prothrombin index and ecamulin index. Platelet reactivity was studied using aggregometry.

RESULTS

Both hepatitis and hepatosis decreased the synthesis of fibrinogen, factor X, and prothrombin. However, protein carboxylation was not disrupted in hepatosis but was much impaired in hepatitis. PC decreased in both models as a consequence of its consumption possibly during inflammatory response. Platelet aggregation rate was lower in hepatosis but higher in hepatitis.

CONCLUSIONS

Our findings imply the need for a thorough monitoring of the hemostasis system in liver diseases to avoid possible thrombotic complications. Its state indicates the disorder's rate and character.

Thrombocytopenia and liver disease: pathophysiology and periprocedural management

Abnormal bleeding in patients with liver disease may result from elevated portal pressure and varix formation, reduced hepatic synthesis of coagulation proteins, qualitative platelet dysfunction, and/or thrombocytopenia. Major mechanisms of thrombocytopenia in liver disease include splenic sequestration and impaired platelet production due to reduced thrombopoietin production. Alcohol and certain viruses may induce marrow suppression. Immune thrombocytopenia (ITP) may co-occur in patients with liver disease, particularly those with autoimmune liver disease or chronic hepatitis C. Drugs used for the treatment of liver disease or its complications, such as interferon, immunosuppressants, and antibiotics, may cause thrombocytopenia. Periprocedural management of thrombocytopenia of liver disease depends on both individual patient characteristics and the bleeding risk of the procedure. Patients with a platelet count higher than or equal to 50 000/µL and those requiring low-risk procedures rarely require platelet-directed therapy. For those with a platelet count below 50 000/µL who require a high-risk procedure, platelet-directed therapy should be considered, especially if the patient has other risk factors for bleeding, such as abnormal bleeding with past hemostatic challenges. We often target a platelet count higher than or equal to 50 000/µL in such patients. If the procedure is elective, we prefer treatment with a thrombopoietin receptor agonist; if it is urgent, we use platelet transfusion. In high-risk patients who have an inadequate response to or are otherwise unable to receive these therapies, other strategies may be considered, such as a trial of empiric ITP therapy, spleen-directed therapy, or transjugular intrahepatic portosystemic shunt placement.

Significance of altered anticoagulant proteins and D-dimer in cirrhotic portal vein thrombosis: relation to the degree of liver dysfunction

Aim of the study

Portal vein thrombosis (PVT) is a well-known consequence of cirrhosis. Its pathophysiology is complex, with possible downstream hepatic decompensation. This study was conducted to describe the changes of protein C (PC), protein S (PS) and D-dimer blood levels associated with PVT formation in cirrhosis and the relation to the degree of liver dysfunction.

Material and methods

This was a case-control study that included 50 cirrhotic patients who presented with acute de novo non-malignant PVT and 50 cirrhotic patients without PVT as a control group. The severity of liver disease was classified as per the Child-Turcotte-Pugh (CTP) score. Doppler ultrasonography identified acute portal vein occlusion, and dynamic contrast-enhanced computed tomography confirmed the extent and nature of PVT. Blood PC, PS and D-dimer levels were measured using enzyme-linked immunosorbent assay.

Results

PC and PS levels were significantly lower, and the D-dimer level was significantly higher, in cirrhotic patients with PVT compared to the control group. PC and PS levels were significantly decreased in patients with higher CTP score of both groups. The D-dimer level did not vary significantly with the degree of liver dysfunction in patients of either group. PC, PS and D-dimer at the cut-off points of ≤ 77 IU/dl, ≤ 63 IU/dl, and > 300 ng/ml, respectively, significantly suggested PVT occurrence.

Conclusions

Alteration of the anticoagulant proteins and D-dimer contributed to PVT formation in cirrhotic patients and could help stratify the degree of liver dysfunction. Blood level of these hemostatic proteins could be incorporated into a probability score for early diagnosis and treatment of PVT in cirrhosis.

Treatment algorithm for thrombocytopenia in patients with chronic liver disease undergoing planned invasive procedures

Thrombocytopenia is highly prevalent in patients with chronic liver disease (CLD) and these patients often require invasive procedures that carry a risk of bleeding. To prevent bleeding, guidelines recommend increasing platelet counts in patients with CLD who have thrombocytopenia and are planned to undergo invasive procedures. There are currently two options to increase platelet counts in patients in this setting: platelet transfusion or thrombopoietin receptor agonists (TPORAs). Several treatment algorithms have been developed in the US to help physicians choose the best course of treatment for each patient; however, to date, no such algorithm has been proposed in other countries, where the choice of treatment has been based on each physician's judgment and experience. Here, we discuss the pathogenesis and treatment of thrombocytopenia in patients with CLD, we review and present current evidence of the efficacy of TPORAs for the treatment of thrombocytopenia in patients with CLD, and we present our expert opinion on a Japanese treatment algorithm for thrombocytopenia in patients with CLD who are planned to undergo invasive procedures. This algorithm aims to provide guidance for optimal decision making in the selection of TPORA therapy or platelet transfusion based on the latest evidence and according to actual clinical practice.

Hemostasis testing in patients with liver dysfunction: Advantages and caveats

Due to concomitant changes in pro- and anti-coagulant mechanisms, patients with liver dysfunction have a “rebalanced hemostasis”, which can easily be tipped toward either a hypo- or a hypercoagulable phenotype. Clinicians are often faced with the question whether patients with chronic liver disease undergoing invasive procedures or surgery and those having active bleeding require correction of the hemostasis abnormalities. Conventional coagulation screening tests, such as the prothrombin time/international normalized ratio and the activated partial thromboplastin time have been demonstrated to have numerous limitations in these patients and do not predict the risk of bleeding prior to high-risk procedures. The introduction of global coagulation assays, such as viscoelastic testing (VET), has been an important step forward in the assessment of the overall hemostasis profile. A growing body of evidence now suggests that the use of VET might be of significant clinical utility to prevent unnecessary infusion of blood products and to improve outcomes in numerous settings. The present review discusses the advantages and caveats of both conventional and global coagulation assays to assess the risk of bleeding in patients with chronic liver disease as well as the current role of transfusion and hemostatic agents to prevent or manage bleeding.

The contact system in liver injury

Coagulation is controlled by a delicate balance of prothrombotic and antithrombotic mechanisms, to prevent both excessive blood loss from injured vessels and pathologic thrombosis. The liver plays a pivotal role in hemostasis through the synthesis of plasma coagulation factors and their inhibitors that, in addition to thrombosis and hemostasis, orchestrates an array of inflammatory responses. As a result, impaired liver function has been linked with both hypercoagulability and bleeding disorders due to a pathologic balance of pro- and anticoagulant plasma factors. At sites of vascular injury, thrombus propagation that finally may occlude the blood vessel depends on negatively charged biopolymers, such as polyphosphates and extracellular DNA, that provide a physiological surface for contact activation of coagulation factor XII (FXII). FXII initiates the contact system that drives both the intrinsic pathway of coagulation, and formation of the inflammatory mediator bradykinin by the kallikrein–kinin system. Moreover, FXII facilitates receptor-mediated signalling, thereby promoting mitogenic activities, angiogenesis, and neutrophil stimulation with implications for liver diseases. Here, we summarize current knowledge on the FXII-driven contact system in liver diseases and review therapeutic approaches to target its activities during impaired liver function.

Assessing the periprocedural magnitude of platelet count change in response to lusutrombopag

BACKGROUND & AIMS

Despite limitations, platelet transfusion has been used to minimise bleeding risk in patients with thrombocytopaenia. Lusutrombopag is an oral, thrombopoietin receptor agonist approved for treatment of thrombocytopaenia associated with chronic liver disease in patients undergoing planned invasive procedures. This post-hoc analysis assessed the magnitude of platelet count change based on the integrated per-protocol population from 2 similar phase III multicentre, randomised, double-blind, placebo-controlled trials.

METHODS

Adults with chronic liver disease-induced thrombocytopaenia and platelet count <50 (× 109/L) received lusutrombopag 3 mg or placebo ≤7 days before invasive procedure scheduled 9-14 days after randomisation. Platelet transfusion was required per protocol if the platelet count remained <50 no more than 2 days before the planned invasive procedure. Post-hoc analysis included: proportion of patients with platelet count ≥50, ≥1.5-fold increase, and a doubling of platelet count; maximum and maximum change in platelet count; and platelet count time course.

RESULTS

Platelet count ≥50, a platelet count increase ≥1.5-fold, and at least a doubling in platelet count were achieved in 88.3%, 86.9%, and 52.6% of patients in the lusutrombopag group (n = 137) vs. 58.6%, 32.3%, and 6.0% of patients in the placebo group (n = 133), respectively. In the lusutrombopag group, median maximum platelet count across baseline platelet counts of <30, ≥30 to <40, and ≥40 was 46, 76, and 87, respectively. Median maximum change in platelet count by baseline platelet count was +24, +42, and +40, respectively. Patients who received lusutrombopag without platelet transfusion achieved a median platelet count ≥50 for 3 weeks.

CONCLUSIONS

Patients treated with lusutrombopag experienced a clinically relevant response in platelet count for a substantial duration of time.

LAY SUMMARY

Patients with low platelet counts caused by chronic liver disease may not receive planned invasive procedures or surgeries because of an increased risk of bleeding. Lusutrombopag has previously demonstrated efficacy in raising platelet counts and is approved to treat chronic liver disease patients with low platelet counts in advance of a planned surgery. Physicians need to understand more clearly what to expect in terms of platelet count change when using lusutrombopag; this integrated analysis provides data to help guide its clinical application.